Изследване на ферментационни системи за получаване на етанол (Investigation of fermentation systems for ethanol production)

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СНС по Хранително –Вкусови Технологии
Университет по Хранителни Технологии – Пловдив
маг. инж. Георги Атанасов Костов
ИЗСЛЕДВАНЕ НА ФЕРМЕНТАЦИОННИ СИСТЕМИ ЗА
ПОЛУЧАВАНЕ НА ЕТАНОЛ
АВТОРЕФЕРАТ
НА
ДИСЕРТАЦИЯ
 



-  

-
-


- 2 -
Използвани означения
dp  m
u  m/s
ut  , , m/s
umf  m/s
Q  m3/s
S- m2
 
d  
  kg/m3
S  kg/m3
  Pa.s/m
 
H, L  m
P  
P/L  /m
 ()
S  
n- 
k  
C1, C2,   Grbavcic
C3, C4 - 
CD  
CDt  
G- N
 N
V  m3

p
ud
Re
- 

pt
t
du
Re
- 
 
g
d
Ar SP
2
3




- 
 
g
d
Ga Sp
2
3




- 

- 3 -
ax
D
uH
Pe


- 
Dax  m2/s
g  m/s2
f()  
G(t)  t
G(0)  
=t/  
  s
Ut  m/s
Ht  m
Ua  
  m
, t  s
D- h-1
  h-1
  g/dm3.h
X  g/dm3
P  g/dm3
S  g/dm3
S, P  
Sin, Pin  g/dm3
Индекси
0  
f  
^ - 
- 

- 4 -
І. Въведение


 

         
   
          

       
          

           

         
           


          


             


          
         
           

ІІ.ЛИТЕРАТУРЕН ОБЗОР
          
  - .     


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           
          

         

Изводи от литературния обзор
1.      
      
 - 
-


           

2.         
          
       
            
        

3.            
          
 

4.           -
 
         

5.           
    
            
.
6.        
 


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ІІІ. ЦЕЛ И ЗАДАЧИ
      -   

        




Целта на дисертационната работа е експериментално и аналитично изследване на
ферментационни процеси и синтезиране на оптимална система за получаване на етанол.

1. 
2. 
3.         
         

4.          
           

5.          
 

ІV. МАТЕРИАЛИ И МЕТОДИ
4.1. Продуценти на етанол
   Saccharomyces cerevisiae  -  
         
        -   
    Saccharomyces cerevisiae 46 EVD,    Martin
Vialatte OEnologie France         
-60
4.2. Хранителни среди
4.2.1. За сравняване на етаноловата продуктивност на различните щамове

- 7 -
   g/dm3  - 5, NH4Cl - 0,2, MgSO4x7H2O  0,05,
KH2PO4  0,3, Na2HPO4  - 0,15.
3- 150, NH4Cl - 4, MgSO4x7H2O 
0,5, KH2PO4 - - 1.
4.2.2 За подготовка на инокулата за имобилизация
34SO4 5, MgSO4x7H2O 0.5, KH2PO4 1

    3  - 50, (NH4)2SO4- 12,5,
MgSO4x7H2O - 1,25, KH2PO4 - 2- 2,5
4.2.3 Хранителни среди за оптимизация на състава на хранителната среда за
получаване на етанол с имобилизирани клетки
    3)   - 100; (NH4)2SO4  4; KH2PO4  2,5;
MgSO4x7H2O   1.
- 2SO4).
  118,40; (NH4)2SO4
 2; KH2PO4  2,72; MgSO42  1
    min 0

4.3 Опитни процедури

 
 
 
            
        - 
Ламбрев, 1994].
  
 
          

4.5 Биореактори и условия на култивиране
4.5.1 Биореактор „Ф1” –       
  1,7 dm3,
-
4.5.2 Биореактор с флуидизиран слой биокатализатор „Ф2”
           


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4.6 Определяне на хидродинамичните характеристики на реактора с флуидизиран
слой.
4.6.1. Моделна твърда фаза

3. 
, [Willaert, 2004].
4.6.2 Течна фаза (моделна течност)
3.
4.6.3 Определяне на граничната скорост на утаяване на частиците и коефициента на
съпротивление при утаяване на единична частица –  [Chhabra, 1999 [Kelessidis, 2003].
4.6.4 Загуби на налягане в слоя. Минимална флуидизационна скорост. Коефициент на
съпротивление при движение на частиците в слоя.
а) загуби на налягане -         -
-   [Felice, 1995].
б) определяне на минималната флуидизационна скорост - по [Miura and Kawase, 1998].
в) определяне на коефициента на съпротивление на единична частица в плътен слой -
 [Felice, 1995]:
4.6.5 Експанзионни характеристики на кипящия слой -  [Buffiere and Moletta, 1998
Grbavcic [Grbavcic et. al., 1991].
4.6.6 Преходни характеристики на кипящите слоеве
а) методика на работа – [Poncelet, 1990].
4.6.7 Разпределение на времето на престой на течността в реактора
a) Единично стъпално въздействи [Levenspiel and Bishof, 1963].
в) импулсно въздействие [Levenspiel and Bishof, 1963].
4.7. Математично моделиране на ферментационните процеси.
4.7.1 Математично моделиране на периодична алкохолна ферментация със свободни и
имобилизирани клетки - по [Ангелов, 1986]  [Wang et al., 2006]:
4.7.2. Математично моделиране на непрекъсната алкохолна ферментация с
имобилизирани клетки – по [Ангелов, 1986 [Wang et al., 2006].
Изследване на реологичните характеристики на имобилизираните препарати -
        Dynamic Mechanical
AnalyzerDMAQ800, USA [www.tainstruments.com],  - Stress
relaxationCreep
4.9 Анализи
4.9.1 Определяне на концентрацията на етанол и редуциращи захари в културалната
среда -  Anton Paar DMA 4500Austria [www.anton-paar.com].

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4.9.2. Определяне на концентрацията на биомаса в културалната среда -
Spekol , Germany nm.
4.9.3. Определяне на концентрацията на биомаса в имобилизираните препарати - 
[Zhou et. al., 1998].
4.10 Математическа и статистическа обработка на опитните резултати

7.0, TableCurve 2D, TableCurve 3D.
V.РЕЗУЛТАТИ И ДИСКУСИЯ
5.1 Избор на продуцент на етанол и носител за имобилизация.
5.1.1 Избор на щам-продуцент за алкохолна ферментация
         
 
Saccharomyces cerevisiae 46 EVD, 
  -       
.
5.1.2. Избор на носител за имобилизация на дрождевите клетки
  Ca-        
Ca-
         
        
       -   

-
Таблица 5.1
Сравнение на алкохолсинтезиращите свойства на изследваните дрождеви щамове
Щам-продуцент
Етанол, kg/m3
Добив в % от теоретичния
Saccharomyces cerevisiae K32
60,43
81
Saccharomyces cerevisiae П2
59,19
79
Saccharomyces cerevisiae Y_C
60,32
80
Saccharomyces cerevisiae СП
54,64
73
Saccharomyces cerevisiae SSOS
55,13
74
Saccharomyces cerevisiae C11
58,44
78
Saccharomyces cerevisiae 46 EVD
60, 40
81

- 10 -
5.1.3 Някои реологични характеристики на перли от Са-алгинат
         Stress
RelaxationCreep
-

  Creep      
        
              
             
        -    
 
).

 
   
         
  w/v       
         
          
    
            
            Creep 
         
             

0
10
20
30
40
50
60
70
Алгинат 1% Алгинат 2% Алгинат 3% Алгинат 4%
Вид на гела
Релаксация на деформациите, %
0,1 MPa 0,2 MPa 0,3 MPa
0
0,005
0,01
0,015
0,02
0,025
0,03
Алгинат 2% Алгинат 3% Алигинат 4%
Вид на гела
Остатъчни напрежения, МРа
5% 10% 20% 30%
Фиг. 5.3 Релаксация на деформациите при
различни видове гелове
Фиг.5.5 Остатъчни напрежения в
имобилизирани препарати

- 11 -
Таблица 5.4
Сравнение на релаксацията на деформациите при чисти и имобилизирани гелови
препарати
Вид на гела
Релаксация на
деформации при чисти
гелове
Релаксация на
деформации при
имобилизирани
препарати
-
%
%
Алгинат 2%
59,98
25,15
39,8
12,06
23,57
5,806
Алгинат 3%
54,53
44,84
32,85
20,09
18,79
17,78
Алгинат 4%
48,41
44,12
35,08
34,62
20,57
20,85
            

     
             
  

5.2 Оптимизация на състава на хранителната среда за получаване на
етанол с имобилизирани клетки.
5.2.1. Избор на управляващи параметри (компонентите на хранителната среда).
           
           4)2SO4,
KH2PO44x7H2O.
-
       6).    
           
          

5.2.2 Моделиране на състава на хранителната среда.
-
606,1

6).
            


- 12 -
2
4
2
11 83.1451.361.454.84 XXX 

(5.3)
Таблица 5.6
Граници на вариране на отделните компоненти
Компонент, g/dm3


Долно ниво
Основно ниво
Горно ниво


Глюкоза
19,7
50
100
150
180,3
(NH4)2SO4
0,79
2
4
6
7,21
KH2PO4
1,7
2
2,5
3
3,3
Дрождев екстракт
0,2
0,5
1
1,5
1,80
MgSO4x7H2O
0,5
pH начално
5
Fisher    
 1=- dm34dm3).
         

 
 
 
12 

Fisher 
2
4
2
3
2
1311 54.724.193.269.019.1538.47 XXXXXXQ 
(5.4)
       
 2PO4      
1   180,15 g/dm3 2=-1 ((NH4)2SO4  2 g/dm3  3=+0,45 (KH2PO4  2,72
g/dm34- 1 g/dm3).
           
  3
             
           
 



- 13 -
Фиг.5.6 Крива на отклик за добива на етанол,
в % от теоретичния
фиг.5.7 Крива на отклик за концентрация на
етанол в културалната среда
         

   -       

            
            

5.2.3 Моделиране на параметрите на ферментационния процес
   
 (g/dm3): Глюкоза – 180,15, (NH4)2SO4 – 2, KH2PO4 – 2,72 дрождев
екстракт - 1.
     

 
350,1

.
        

2
2
2
13221321 64,120,249,121,267,300,2525,759,54 XXXXXXXXX 

(5.7)
         

           
         
  
     

- 14 -
1   2=- 118,4 g/dm3); X3=1,32
 1.108 
             


2
23221321 56,605,293,373,313,219,774,50 XXXXXXXXQ 
(5.8)
         
           
             
dm3.
Таблица 5.9
Граници на вариране на управляващите параметри при оптимизация на условията на
култивиране
Параметър


Долно ниво
Основно ниво
Горно ниво


Време, h
44
48
60
72
76
Глюкоза, g/dm3
19,7
50
100
150
180,3
Количество на
посевния материал,
КоЕ/cm3
1.104
1.105
8.106
2,3.106
1.108
pH
5
      
[Яровенко, 2002]:
2
51,0 ZQ


(5.9)
2           
Z2=118,4 g/dm3 
3
2g/dm 36,549,0*4,118*51,051,0  ZQ

(5.10)
          

 

 Хранителна среда, g/dm3: Глюкоза – 118,40; (NH4)2SO4 – 2; KH2PO4 – 2,72; Дрождев
екстракт – 1; MgSO4x7H2O – 0,5;
 Време на ферментация – 73,8 h;
 Количество на посевния материал – 1.108 KOE/cm3

- 15 -
0
20
40
60
80
100
Д оби в , %
В ре ме , h
Гл ю коз а, g/d m3
250
180
110
215
145
60
72
66
48
54
48 54 60 66 72
180
145
110
50
50
50
50
60
60
60
60
70
70
70
70
80
80
80
80 90
90
90
90 100
40
40
40
30
30
Вр ем е н а ф ер ме нта ци я, h
Гл юк оз а, g /dm 3
250
215
фиг.5.9 Крива на отклика и линии на равен изход за добива на етанол като функция на
времето за ферментация и концентрацията на глюкозата при X3=1,32
5.3 Параметри на периодична алкохолна ферментация в оптимална
хранителна среда в биореактор с механично разбъркване
5.3.1. Параметри на периодична алкохолна ферментация със свободни клетки
Saccharomyces cervisiae 46 EVD.

             
      
          
           

          
             
h.
5.3.2. Определяне на кинетичните параметри на периодична алкохолна ферментация
със свободни клетки.
          
 
        
Saccharomyces cervisiae 46 EVD        
[Перт, 1978; Гапонов, 1980; Бирюков, 2004]:
 
X
d
dX
d
dS
d
dX
KXq
d
dP
XX
d
dX
p
m










0
(5.11)

- 16 -
         -
 - 
      ,      
       
         
R2=82,82% 
R2=99      - R2=     

 
   











































385,0
385,0
385,0
385,0
385,0
1
77,5
29,3
1ln
385,0
77,5
178,01
1
77,5
29,3
1
29,3.26,35118
1
29,3
77,5
1ln
385,0
77,5
.386,0
48,229,3
98,18
e
e
e
S
eP
e
X
(5.14)
          

    
             
           
[Перт, 1978]. 
[Яровенко, 2002]     -   
γ 

5.3.3 Изследване и оптимизация на алкохолна ферментация с имобилизирани
клетки.

    0 
      Saccharomyces cerevisiae 46 EVD
[www.martinvialatte.com].
 5.1          
        (pH  
           

 

- 17 -
рН
3, 5 4, 0 4, 5 5, 0 5, 5
Ко нц ен тра ция н а е тан ол , g/ dm 3
0
10
20
30
40
50
pH
3, 5 4, 0 4, 5 5 ,0 5 ,5
Д об ив на ет ано л, % от тео ре тич ни я
0
20
40
60
80
Фиг.5.15 Концентрация на етанол и добив на етанол на 12 h от началото на процеса при различни
стойности на рН на процеса
Фиг.5.13 Основни параметри на периодична алкохолна ферментация със Saccharomyces cervisiae
46 EVD с контролирано рН
Фиг.5.16 Основни параметри на периодична алкохолна ферментация с имобилизирани клетки
Saccharomyces cervisiae 46 EVD

- 18 -
 
Saccharomyces cerevisiae 46 EVD.
          
  h     (45,04 g/dm3)  
- 
          
 [Nedovic and Wiliert, 2004].           
          
             


 
   











































378,0
378,0
378,0
378,0
378,0
1
18,1
719,0
1ln
378,0
18,1
365,61
1
18,1
719,0
1
719,0.40,64108
1
78,3
18,1
1ln
378,0
18,1
.052,2
461,0719,0
848,0
e
e
e
S
eP
e
X
(5.15)
  1         
Saccharomyces cerevisiae 46 EVD.
Таблица 5.11
Кинетични параметри на периодичен процес на алкохолна ферментация със
свободни и имобилизирани клетки
Параметър
Свободни клетки
μm, h-1
β,
m3/(kg.h)
qpo,
g/(g.h)
K, g/(g.h)
δ
γ
0,385
0,066
0,386
0
0,178
35,26
Имобилизирани
клетки
0,378
0,320
2,052
0
6,365
64,40
        
         


- 19 -

          
         
981,0385,0378,0  СК
m
ИК
mi

     
            
        -   
     
 
         

, 
3.       qP0 
 -            
       

          
K=0)
-
             
     
    -     

5.3.4 Някои реологични характеристики на перли от Са-алгинат по време на
ферментационния процес.

-  
  


  
Фиг.5.20 Снимки на разрушаване на перлите
А-перла след имобилизация; Б-налачо на формиране на пукнатина; В- разрушена перла

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           - 
Saccharomyces cerevisiae 46 EVD 
  
             
- 2.
            
d.
5.4. Разработване на колонен биореактор с кипящ слой биокатализатор.
Хидродинамика на кипящия слой.
          
         
          
.
        
       mm     
        
  -        
           
              
                 
           „PR-
205-Evrolec„    

         
         
          mm     
   -          
cm3.
           

 

     
             
            

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

Фиг. 5.21 Принципна схема на колонен биореактор с кипящ слой при определяне на
хидродинамичните му характеристики
1-        -
               
           
             
- 
5.4.1. Характеристики на твърдата фаза. Гранична скорост на утаяване на
носителите. Коефициент на съпротивление при утаяване.
           


- 22 -


91,0
Re
56,150
t
dt
C
(5.17)
(R2=0,9203) 
2
Таблица 5.12
Основни размери, гранична скорост на утаяване и коефициент на съпротивление на
използваните моделни частици и сравнение на скоростта на утаяване с някои модели


d
ut
Ret
Cdt
ut
Stokes
Dallavale

-
kg/m3
mm
m/s
-
-
m/s
Алгинат
1055
2,590,23
0,0218
56,46
3,791
0,0336
0,0340
0,0222
Алгинат 2,5П
1125
2,0250,132
0,0365
73,73
2,222
0,0485
0,0483
0,0333
Алгинат 5П
1175
2,490,189
0,0469
116,78
2,117
0,0746
0,0703
0,0540
Полимерни
1600
2,020,20
0,185
373,70
0,463
0,173
0,143
0,153
Полимерни
1600
7,780,20
0,454
3532,12
0,269
0,373
0,348
0,838
5.4.2. Загуби на налягане в плътен и флуидизиран слой. Минимална
флуидизационна скорост на частиците.
5.4.2.1 Минимална флуидизационна скорост на частиците
 () 

826,1472,0
0
7
10.39,4Re Ar
mf



(5.18)
        

 180-250 Pa/m- -3500 Pa/m.
5.4.2.2 Загуби на налягане в слоя. Коефициент на съпротивление при движение на
частиците в слоя.
 30          
    -      
 
            

- 23 -
 
 Felice, 1995]   

Таблица 5.14
Минимална флуидизационна скорост на частиците
Вид на
частиците
Критерий
на Архимед,
Ar
Начална
порьозност
на слоя, ε0
Минимална
флуидизационна
скорост, m/s
Remf
Remf
От модела
Алгинат
9374,13
0,245
0,00203
5,26
4,044798
Алгинат 2,5П
10107,25
0,268
0,00407
8,22
4,841768
Алгинат 5П
26503,61
0,404
0,00542
13,50
34,16894
Полимерни
48514,81
0,301
0,0402
81,20
89,69215
 3         
     -      
    -       


 3         
ReP 
Foscolo. 
            
           
     -   


        
    
           
               






 
8,1
3336,0
Re
4

c
d
c
C
(5.19)

- 24 -
Cd
     -         
Cd 
5.19 

0,000 0,005 0,010 0,015 0,020
0
100
200
300
400
Опитни резултати
Модел на Ergun
Модел на Foscolo
Чрез използване на
коефициента на съпротивление
получен с уравнение (5.19)
P/L, Pa/m
Скорост на водата, m/s
010 20 30 40 50
0
10
20
30
40
50
60
70 Опитни резултати
Модел на Ergun
Модел на Foscolo
Уравнение (5.19)
Cd
Rep
в) Алгинатни перли с плътност 1175 kg/m3
Фиг. 5.30 Специфични загуби на налягане в слоя и коефициент на съпротивление
5.15


(5.19) 3-
     

5.4.3 Експанзионни характеристики на системата „течност-твърдо тяло”
   
 
         hardson-Zaki  
5.17.
         
                -

     
-()
       
           t 

- 25 -
           

Таблица 5.15
Константити в регресионното уравнение, описващо коефициента на съпротивление



-
C3
C4
-
Алгинат
88,71
-1
0,3421
Алгинат 2,5П
34,94
-5,19
0,1672
Алгинат 5П
60,95
-1,51
0,0981
Полимерни
-
-
-
 
0,00 0,02 0,04 0,06 0,08 0,10 0,12
0,2
0,3
0,4
0,5
0,6
0,7
0,8
Съдържание на твърда фаза, s
Скорост на водата, m/s
Алгинат
Алгинат 2,5П
Алгинат 5П
Полимерни частици
0,3 0,4 0,5 0,6 0,7 0,8 0,9 1
1E-3
0,01
0,1
log(u)
log()
Алгинат
Алгинат 2,5П
Алгинат 5П
Полимерни частици
Регресионно уравнeние
Фиг. 5.31 Съдържание на твърда фаза в
слоя като функция на скоростта на потока
Фиг.5.32 Линейната скорост на потока, като
функция на порьозността на слоя
    
           
Grbavic et. al.,1991
           
           
         


             
5.18.

- 26 -
 
 
d
mfd
mfmf
mf C
C
uu ,
3
3
1
1





(4.25)

 
 
2
12
,1
1
1
1









 CC
C
C
mf
mf
mfd
d



(4.26)
3          
-
          
- 5.18).
Таблица 5.17
Стойности на константите в уравнение (4.15) и коефициент на експанзия, изчислен според
някои литературни модели

 
15:
-
K
n
Richardson-
Zaki
Rowe
Al-
Doubini
Khan-
Richardson
Алгинат

1,7
2,94
2,86
3,20
2,67
Алгинат 2,5П


2,86
2,78
3,11
2,66
Алгинат 5П


2,73
2,67
2,99
2,56
Полимерни


2,43
2,49
2,81
2,51
           

Таблица 5.18
Константи в модела на Grbavcic за изчисляване на порьозността на кипящия слой

mf
umf
ut
C1
C2

AVD
Алгинат
0,245
0,00203
0,0218
0,861408
-1,43684
-0,35349
0,025
Алгинат 2,5П
0,268
0,00407
0,0365
0,839995
-1,82446
-0,2974
0,059
Алгинат 5П
0,476
0,00542
0,0469
0,99242
-0,14133
-0,86953
0,0913
Полимерни
0,441
0,0402
0,185
0,876014
-1,22492
-0,39373
0,235

- 27 -
Фиг.5.33 Скорост на потока течност като функция на порьозността на слоя
5.4.4 Разпределение на времето на престой (RTD) на течността в кипящия слой

   Levenspiel and Bishof, 1963; Ангелов, 1986   
   
-50 cm3-
   
   

[Levenspiel and Bishof, 1963; Zessen, 2003].
() RTD  
   g       

          

 
 
 
       
            

            

Levenspiel and Bishof, 1963].

- 28 -
 3          
-


RTD 
   -  Levenspiel and Bishof, 1963   

 


















2
2/1 1
4
exp
2
1
)( PePe
E
(4.36)

            
Ре

            


        
 

      
            
           

A

Фигура 5.34.  (a)         
             kg/m3 
m/s

- 29 -
Фигура 5.35 Сравнение на опитните резултати с осово дисперсионния модел
           
         Remf,     
.
         

452,1
369,06
Re
Re
10.642,0 








mf
ax ArD
(5.20)
R2=0,795.
Биореакторът работи като апарат с изтласкване и обратно смесване в
изследвания диапазон на скорости на потока течност, което се дължи на кипящия слой.
5.4.5. Изследване на разпределението на времето на престой на течността в
реактора с рециркулация на течността.
           

      , m/s: 0,00203; 0,00338;
0,00474; 0,00677, -
 
     0,5 h-1; 0,83 h-1; 1 h-1; 1,25 h-1; 1,5 h-1 [Ангелов и
Костов, Непубликувани данни, 2006];

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        осъществяването на
рециркулация на течността в апарата води до нова структура на потоците в него, която се
описва с модел на апарат с идеално разбъркване.      
[Godia and Sola, 1995; Levenspiel and Bishof, 1963].

            
  -         
           

5.4.6. Преходни характеристики на кипящия слой от алгинатни частици
 
Poncelet et. al., 1990].
5.4.6.3 Количествени характеристики на преходния процес.
    Ht  
            
  
Ut    

           
             
     -    Poncelet et. al., 1990],
  
             
  Ht0,        
5.21).
         
             
[Poncelet et. al., 1990]       
            
 
     Ha   t.     
      (R2    


- 31 -
Таблица 5.21
Скорост на изменение на общата височина при стъпално изменение на скоростта потока
течност

u0
uf
Ht0

Ht0

Ut

Ut

R2
kg/m3
m/s
m/s
m
m
m/s
m/s
-

1055
0,00339
0,00677
0,364

0,00278

0,950
1055
0,00135
0,00339
0,258

0,00204

0,927
1055
0,00203
0,00744
0,292

0,00541

0,970
1125
0,00339
0,0102
0,258

0,00681

0,892
1125
0,00339
0,0135
0,255

0,0101

0,894
1125
0,00339
0,0169
0,255

0,01351

0,900
1175
0,00339
0,0102
0,310

0,00681

0,884
1175
0,00673
0,0169
0,363

0,01017

0,968
1175
0,00339
0,0169
0,310

0,01351

0,966

1055
0,00812
0,00135
0,683
0,652,013
-0,00677
-0,,00032
0,983
1055
0,00677
0,00339
0,533
0,
-0,00338
-
0,973
1125
0,0136
0,00677
0,563

-0,00683
-
0,971
1125
0,0169
0,00677
0,752

-0,01013
-0
0,992
1125
0,0169
0,00339
0,752

-0,01351
-
0,997
Таблица 5.22
Скорост на изменение на височината на преходната зона при стъпална промяна на
скоростта
5.5. Непрекъснато получаване на етанол в биореактор с кипящ
слой имобилизиран биокатализатор. Изследване на кинетиката на
непрекъснатия процес.
5.5.1 Система за непрекъснато получаване на етанол с имобилизирани клетки
      ()  
  mm   
    
mm
2 


u0
uf
Hao

Ua

Ua

R2
kg/m3
m/s
m/s
m
m/s
m/s
-

1055
0,00812
0,00135


0,00358
0,994
1055
0,00677
0,00339


0,00502
0,993
1125
0,0136
0,00677


0,00964
0,922
1125
0,0169
0,00677


0,00735
0,964
1125
0,0169
0,00339


0,00664
0,912

- 32 -
    -  Aplikon, Holland  
           
 
Хранителна
среда
20% KOH
10% H2SO4
Охлаждаща вода
Към канализация
Културална
среда
Фиг.5.42 Схема на лабораторен биореактор с кипящ слой
1-                
    
               
   Pt 100; 17 
        Applikon; 19,20 
- 
        
            

           

- 33 -

             
h.
     

           
 2  


5.5.2 Моделиране на непрекъсната алкохолна ферментация с имобилизирани
клетки
        

          

     

 
            
 

Малек и Фенцль, 1968].
           
 

[Перт, 1979; Ангелов, 1986 г.]:
m
SXS
S
mYm
SK
S
/




(5.23)
 
        
     mS=3,48 g/(dm3.h);μm=1,49 h-1;
KS=9,113 g/dm3;YmX/S=0,382; qP=2,047 g/(g.h); YmP/S=0,298 g/g.  mS 
-           

           
         R2=91,68.  

- 34 -
          
  qP=2,047 g/(g.h        R2=84,4%. 
           
D

          

          

DY
Xq
SS m
SP
p
/
0
~
~
(5.25)

   YmP/S=0,298 g/g         
R2=74,5%.

        
Saccharomyces cerevisiae 46 EVD 








































DD
DQ
DD
S
DD
P
DD
DX
49,1
113,9
48,3
4,118
.782,0
~
49,1
113,9
48,3
4,118
.322,24,118
~
49,1
113,9
48,3
4,118
.782,0
~
49,1
113,9
48,3
4,118
..382,0
~
(5.26)
   

 D=0,75 h-1
R2=91,67%.
          
, 
          

Таблица 5.23
Оптимални стойности на процесните параметри за провеждане на непрекъсната алкохолна
ферментация с имобилизирани клетки Saccharomyces cerevisiae 46 EVD
Dm, h-1
m
X
~
, g/dm3
P
~
, g/dm3
S
~
, g/dm3
m
Q
~
, g/(dm3.h)
0,725
4,52
12,76
80,72
9,265

- 35 -
          
      -    
        g/dm3 
             

    
-
 
    
           
Bodalo et. al., 1995]:
 
 
Pff
Sff
PPAu
d
dP
V
SSAu
d
dS
V








0
0
.
.
(5.27)
fS
p
in
PP
fS
p
in
SS
V
d
PPk
V
d
SSk


6
)(
6
)(


(5.28)
фиг.5.43 Непрекъсната алкохолна ферментация с имобилизирани клетки Saccharomyces
cerevisiae 46 EVD

- 36 -
   
  
          
Bodalo et. al., 1995]:
 
in
P
S
in
S
p
in
SS
k
k
PP
d
dS
k
d
SS




6
(5.29)
(5.29) (5.28) 
 
fP V
d
dS



 1
(5.30)
 (5.30 
          
 
(5.27) (5.30) (5.22) 
















F
f
SP
PV
Au
DP
DY
X
qDSDS



/
0
1
(5.31)
(5.31) e 
        
  

[Bodalo et. al., 1995; Godia and Sola, 1994].
     (5.31)      
       

1. Образуването на продукта и консумацията на субстрата от средата са свързани
със следната зависимост [Яровенко, 2002]:
 
SSYP SP  0/
(5.32)
2. Добивният коефициент на продукт от единица субстрат има максимална
стойност YP/S=0,51 g/g.
3. За описание на хидродинамичните условия, в уравнение (5.31) е използвано
уравнение (4.24), което в явен вид в съответствие с табл. 5.17 приема вида:
76,1
0266,0

u
(5.33)

- 37 -
        =0,82,
 - 











00127,0.
00246,0..0266,0
725,0459,0
1
82,0
459,0.725,0
52,4.047,2
4,118 76,1




S
(5.34)
 (5.34)          
          
       
(5.34)          ε=0,778  

S
~
=9,26 g/dm3. 
u=0,0171 m/s
        kg/m3     
Н=52 cm  MS=0,320 kg.
         
        
    Saccharomyces cerevisiae 46 EVD.   
  
Таблица 5.24
Стойности на процесните параметри на непрекъсната алкохолна ферментация с
имобилизирани клетки Saccharomyces cerevisiae 46 EVD в оптимални условия
Dm, h-1
m
X
~
, g/dm3
P
~
, g/dm3
S
~
, g/dm3
m
Q
~
, g/(dm3.h)
0,725
6,24
38,62
10,13
28,00
           
         
 Saccharomyces cerevisiae 46 EVD,  
     -  
     -        -
 .
ИЗВОДИ
1. Чрез експериментални проучвания са избрани подходящ продуцент на етанол,
метод и носител за неговата имобилизация:

- 38 -
1.1. Saccharomyces cervisiae 46 EVD -
      
         -  

1.2          
- 
            

1.3.   
      2     
   Na -- 

2. Извършена е експериментална оптимизация на състава на хранителната среда за
алкохолна ферментация чрез централен-композиционен план (метод на Box-Wilson).
Разработени са конкретни математични модели, описващи целевите функции: добива на
продукт и концентрацията му в културалната среда в зависимост от състава на
хранителната среда и някои параметри на ферментационния процес.
3. Извършена е параметрична оптимизация на периодична алкохолна ферментация
със свободни и имобилизирани клетки в биореактор с механично разбъркване.
Експериментално са определени рН и температурния оптимум на двата процеса. Създадени
са математични модели за описание на кинетиката на процесите и е установено:
           
         


      -  

3.3. 
-
4. Разработен е лабораторен колонен биореактор с кипящ слой имобилизиран
биокатализатор със системи за измерване и управление на параметрите на
ферментационния процес и архивиране на данните. Определени са основните
хидродинамични параметри на процеса на псевдокипене и са разработени модели за
тяхното описание.
4.1 



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5. Описана е кинетиката на непрекъсната алкохолна ферментация с имобилизирани
клетки Saccharomyces cerevisiae 46EVD в колонен биореактор с кипящ слой:
5.1            


5.2 
           

5.3        

        
    Saccharomyces cerevisiae 46 EVD 
-      -   

НАУЧНО-ПРИЛОЖНИ И ПРИЛОЖНИ ПРИНОСИ
1.  
           

      2        
           
-
         
-
2. 
          
          
         

Saccharomyces cerevisiae
46 EVD 
ПУБЛИКАЦИИ СВЪРЗАНИ С ДИСЕРТАЦИОННИЯ ТРУД
1.   Г.Костов     
           
       LI,
-295

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2. Костов, Г        
  
LII-168
3. Костов, Г        
        
LII-173
4. Костов, Г., D.Poncelet,         

5. Костов, Г.,       
