Biomass Conversion - Science topic

I don't think there is one standard protocol for this question. It will be dependent on the strain of S. cerevisiae that you are using and on the nature of the hydrolysate. Is your strain tolerant to inhibitors in the hydrolysate or is it a 'lab' yeast? Are you wanting papers that describe how to prepare the hydrolysate or just papers growing yeast in hydrolysates. Are you just looking for growth or will you have a product other than biomass? If a product, which? Growth conditions will be dependent on requirements for the product - e.g. to produce ethanol you want low oxygen or anaerobic, but to produce something like xylitol you want an aerobic culture. It is often a good idea to do a small-scale preliminary experiment to assess whether the hydrolysate is toxic and if so how toxic. (e.g. a set of low volume flasks with a series of dilutioins of they hydrolysate such as 100, 75, 50, 25% hydrolysate with a constant amount of added sugar, inoculate and assess whether all sugar is consumed in all concentrations). From this you can then define a proper experiment with replicates. If the hydrolysate is very toxic, you may also need to make a 'synthetic' medium in which you add each potential inhibitor in a separate flask so you can assess which ones are most toxic. And of course start with a good analysis of the hydrolysate itself, to know what it contains.

There are numerous reviews on hydrolysates which should provide links to the literature describing how to produce the hydrolysate. There are also reviews on further pre-treatments if they seem necessary. And abundant literature on growing S. cerevisiae in various hydrolysates. I recommend looking not at a single paper, but at several so you have an idea of the range of problems you may encounter. If the strain you are using has been published about before, focus on publications which have used it. If the material that is being hydrolysed is something that has been used before, than focus also on those publications.

Adarsh Shetty

PFA the file for reference, 0.5-2.0% H2O2 works for these types of biomass.

I understand your question as that you're wondering why the H2 concentration is low at very high S/B ratios. You're not taking about H2 yield, are you.

I'm not an expert for gasification, but I think, you find the answer when considering the steam reforming reaction.

CH4 + H2O = CO + 3H2

Biomass is not exactly CH4, but it reacts in a similar fashion. C is oxidized by water which releases H2. High S/B ratio means, you have only few C. As soon as all C is oxidized, you cannot get more H2, regardless of how much more steam, i. e. water you add.

However, I expect that the H2 yield is better at high S/B ratios.

Yes, it is necessary to have inert bed material in bubbling fluidized bed reactors. The inert bed material helps to ensure that the fuel particles are evenly distributed throughout the reactor and that they do not settle and accumulate in one area. Additionally, the inert bed material helps to reduce the risk of the fuel particles burning too quickly and creating hot spots within the reactor, which can lead to explosions. The inert bed material also acts as a heat sink, helping to dissipate heat generated by the fuel particles and maintaining a more even temperature throughout the reactor. Finally, the inert bed material helps to reduce the risk of the fuel particles sticking to the reactor walls.

Sudeep Mudhulu thank you for the clarification.

Dear Abdelrahman,

I assume you want to feed exponentially. Use the following formula to calculate the feed rate at any time in the feeding phase:

F(t) = (µ_set / Y_xs + m) * ((V_0 * X_0 * exp(µ_set(t-t_0))/S_0)

with

F(t) - time-dependent feed rate [mL/h]

µ_set - targeted specific growth rate [1/h]

Y_xs - biomass yield [g dry cell weigth / g substrate]

(m - optional maintenance term [g substrate / g dry cell weight / h]

V_0 - reactor volume at the beginning of the feed phase [mL]

X_0 - biomass concentration at the beginning of the feed phase [g/L]

t-t_0 - time span between feed start and current process time [h]

S_0 - Substrate concentration in the feed medium [g/L]

If you want to calculate the time it takes to reach a certain biomass level just rearrange and solve for t-t_0.

See e.g.

Good luck

Michael

Lalit R Kumar and Sandile Fakudze Thank you for the insightful responses

Cheers!

Dear J.Lorenzo,

I have the same concern. Have you managed to get an answer?

Thank you

Regards,

Suaad

Hi Katerine,

It depends on the definition of energy efficiency. You can assume a boundary for the process and determine inlet and outlet energy streams.

Inlet energy streams could be biomass (m [kg/h] * LHV [kH/kg]), heats added to the system through steam or other sources, pumps power, etc.

The outlet energy streams are the produced energy in the form of syngas or hydrogen and work produced through a turbine.

Another indicator of the process performance is the Levelized costs of hydrogen (LCOH), which indicates the costs of 1 kg of hydrogen production.

Please see this paper for more information:

Regards,

Abdollah

Snehalatha V 5c/min upto 800c. N2 atm.

Thank you for the reply

For such organic residues insoluble in organic solvents, the only solution to remove them is aggressive oxidation. You can try a mixture of potassium dichromate and sulfuric acid or a mixture of nitric acid and hydrochloric acid (aqua regia).

Hello Pali,

I have previously simulated a hydrotreating process in Aspen Plus by using an R-Yield block ruled by a calculator block. I assumed a desired output based on the carbon yields for hydrocarbon species present in the hydrotreating product (see ) and calculated the required amount of fresh H₂. The exported variables in the calculator would be the mass yields for each component in the hydrotreated bio-oil and the calculated H₂ input.

Another feasible approach would be to assume a specific H₂/bio-oil mass ratio (I've mostly seen on the literature a value of 0.04 with a 10x excess) and using an RGibbs block in which you would pre-define the feasible output compounds. In such case, you'd need to check the predicted output matches experimental or literature composition.

In the simulations reported by NREL and PNNL, they utilize an RStoich reactor in which they define a specific set of reactions, but in case you'd like to use that approach, you would need to exactly have your bio-oil defined with the same set of compounds they utilize. You can download the NREL biomass pyrolysis simulations in https://www.nrel.gov/extranet/biorefinery/aspen-models/ , which include the upgrading section for the bio-oil.

Hope you find this helpful.

Regards

Try to vary the time as well to determine the optimum time.

All of these are effective, but the problem is that in any region of the world, one may take precedence over the other.

Please Ref to

Dear Arushdeep

You can estimate the contents of cellulose, hemicellulose and lignin from any agricultural residue using detergent system method (Goering and Van Soest 1970). Full reference is-

Goering, H.K., and P.J. Van Soest. 1970. Forage fibre analysis

(apparatus, reagents, procedures and some applications). USDA

Agricultural handbook no. 379.

Thanks

Biomass Gasification and Pyrolysis- Practical design and Theory by Prabir Basu - Elsevier ISBN 978-0-12-374988-8

The lower heating value for pure methane is 35.8 MJ/m3. Note that it is per normal cubic metre (1 m3 at 0 C and 1 atm.).

The lower heating value of 100 ml CH4 at 0 C and 1 atmosphere equals 3.58 kJ.

If the temperature and pressure differ you can use the ideal gas law PV=nRT to calculate which volume it corresponds to at 0 C and 1 atm.

There is no accurate method to measure temperature in MW field .You can use thermocouple..or use closed reactor system ..IR camera can help but ,it measure the surface temperature .

From a more generalized viewpoint, the promising kinds of feedstock for renewable fuels should:

Dear Ramesh ,

I am agree with Paulo Fernando Trugilho, mineral content is more important that the % of ash in biomass.

I suggest you the article "Effect of citric acid leaching on the demineralization

and thermal degradation behavior of sugarcane trash and bagasse. Biomass and Bioenergy, 108, 371-380.

Kind regards,

Lizet

Hi! I have the same problem. I have check every detail (acid concentration, temperature, time, etc)... however, none of the expected monosaccharides appear in the HPLC chromatrograms.

I will to try highing the first hydrolysis step (72%) temperature.

A challenge and an opportunity is to take advantage of the synergies between anaerobic digestion, gasification and Power-to-gas. Heat integration seems to be a first step especially if you need to heat the digester, dry the digestate and/or regenerate the scrubber liquid in case of amine based biogas upgrading. Separated CO2 from AD/upgrading and gasification/methanation as input for Power-to-gas. Use the microbial consortia in the digester to convert nitrogen free syngas from gasification to methane. Lower the specific investment cost in upgrading and downstream processes by combining AD, gasification and Power-to-gas.

Because the value of BOD/COD ranges between 1,50,000 mg/l to 3,45,000 mg/l in food waste. The value of COD varies for different food wastes.so there is high O2 demand. The food waste having carbohydrates, proteins, and oil so the COD value is high. But especially the simple carbohydrate: glucose is one of the major contributors to COD that demands oxygen

Dear Sajib Aninda Dhar ,

as mentioned by Tamjid Us Sakib we can use FTIR to study the change (increase) in aromaticity. For example, you can plot the ratio of integrated areas at 3000–2800 cm^-1 (aliphatic CH_x stretching vibration) to 1650–1500 cm^-1 (aromatic C=C ring stretching vibration) vs temperature to demonstrate the relative contents of aliphatic and aromatic functional groups of charcoal ( ). The ratios of integrated areas at 900–700 cm^-1 (aromatic CH out-of-plane deformation) to 1650–1500 cm^-1 you can be used as a measure of the degree of condensation of aromatic rings.

Raman spectroscopy (

) and ¹³C NMR ( ) are also very useful analytical tools to study the aromaticity of biochars.

Pankaj Kumar Yes. your topic is interesting and you can submit. The APC is 1200 USD in 2019 and will be 1400 USD in 2020.

in my opinion, we first need to define the "sustainable utilization" of biomass sources in developing countries. In case that sustainable utilization entails the supplementary energy production, then the biomass characteristics (HHV, moisture content), the climatic conditions (solar radiation, water precipitation), agrarian conditions (soil type, irrigation management), and competitive land uses/landscape management for nutrition and livestock feeding vs energy crops (the so named "food vs fuel" debate), are critical aspects. Besides, the proximity of energy production sites to the (nearby, or remote) residential areas, the transportation modes of fossil-fueled machinery, the cost effectiveness and the scaling-up perspectives, are also influential parameters of biomass "sustainable utilization". In a societal viewpoint, the local workforce strengthening and the social cohesion in favour of (or social opposition against) biofuel production units cannot be undermined.

you can try using the Colorado State/USDA farm-ranch carbon calculator

Carbon sequestration is the process of capturing and storing atmospheric carbon.

Carbon stock is the amount of carbon stored in a reservoir whether it may be in the form of vegetative biomass or

in earth or sea.

Carbon emission is the amount of carbon emitted in atmosphere by naturally or human activities.

Thank you for your wonderful contribution, Bemgba B. Nyakuma.

It will be my delight to have the recommended book. My email address is:

samuel.david@fupre.edu.ng.

Thanks.

Thank you Dr

Also check out https://www.agrifutures.com.au/wp-content/uploads/publications/08-117.pdf . A bit old but issues discussed are still relevant.

There is need to consider trade-offs. Issues of sustainable biomass production and transport costs related to feedstock economics are relevant. It could be value-adding for biomass suppliers, but "costly" for bioenergy/biofuel producers.

There's a lot of challenges in implementing the distributed model, some include: 1) How to incentivise farmers to give up their wastes (financial?), 2) Seasonal variations in production, 3) Transportation issues associated with the remoteness of many sights, 4) Market viability of the products (biochar, bio-oil, etc.), 5) Low HHV of biomass often means long ROI for plants that are built for energy production. All of these challenges can be overcome, I should add, but there will not be a single correct model for every country/waste.

The only way to have a considerable increase in bio oil production is to move from slow pyrolisis to fast pyrolisis.

Biomass production has three main human uses: for food and fodder production; for energy, such as liquid bio-fuels; for production of materials, not only for construction and paper, but also for wool, cotton etc. Net primary production of biomass has to support Earth's ecosystems as well as the human uses listed above. Ethically, providing food for Earth's people must be given precedence over the other uses, but not necessarily providing high animal products diets. Also, using timber as a construction material to replace (some) energy-intensive steel and concrete will reduce global GHG emissions more than using bio-energy to replace fossil fuel combustion. Overall, bioenergy can only be a minor contributor to future energy--we will have to rely more on other renewable energy sources, and on energy reductions.

Hey Ohad, not aware of any universal method but you may have given the answer in your question " %cover to biomass conversion tables would be an awesome way to go"... In the case you did not find it elsewhere, you may collect samples to build up your own relationship (at a given quadrat size obviously)... Cheers, JC

Dear Sir. Concerning your issue about the elemental and proximate analysis, wet and dry basis . In the proximate analysis, moisture, ash and volatile matter are determined. There are standard tests to determine proximate analysis. Moisture is determined by drying 1gm of sample at 105o C for 1hr. Weight loss is expressed in % of initial weight of sample. The main chemical elements in coal (apart from associated mineral matter) are C, O, H, N and S. The chemical analysis is very important to calculate material balance accurately and calorific value of coal. I think the following below links may help you in your analysis:

http://nptel.ac.in/courses/113104058/mme_pdf/Lecture2.pdf

https://mycourses.aalto.fi/pluginfile.php/137671/mod_resource/content/1/CGT%202015%20HW1%20-%20model%20answer%20v03.pdf

http://www.polarpelagic.com/wp-content/uploads/2016/05/Donnelly-et-al.-1993.pdf

Thanks

Dear sir, have a look at this important manual for your queries.

Dear sir, have a look at this important manual for your queries.

The issues is the same everywhere, the low energy density of biomass. The problem looks smaller in developed countries due to the highly developed road, railway, and sea shipping systems.

Decentralization and improving energy density could help to reach out these valuable sustainable resources.

Please find one of my paper enclosed (optimization of torrefaction from economic, social and environmental perspectives):

Chemical analysis is difficult...you can use acid hydrolysis for removal lignin residue. for bleaching you can use peroxide hydrogen...for hard wood you should using higher percent of NaOH.

Dear Ahmad,

I have analyzed the LA and EL with GC-FID. I think you should keep your GC-column program between 313 to 473 K. Please see the details about the GC column specifications in my article.

Hi Raj,

If you have access to a software HYSYS or AspenPlus, you can simply enter the chemical composition that you specified and the simulation software to calculate the enthalpy of the biochar. You can download at a no cost a trial version of HYSYS or AspenPlus from Aspen technologies at:

Best,

Prof. Khalil

Thanks for your answer Yurii

In most  cases, a mathematician can find a solution that fits the data points amongst a large panel of different kinetic models or even model-free approaches. The chemist’s role is not only to identify the most plausible solution but also to define suitable analytical technologies for the determination of the components of interest. The performance of the analytical determination is crucial in the development of kinetic models but could result in important workload that limits the number of determinations. Also, the required number of data points is directly linked to the acceptable limits of the uncertainty of the solution and here skills in stats are also needed. For this reason, I would be very interested to find publications where kinetic studies were conducted with limited amount of data points.

Thank you very much Malek, much appreciated your information.

The HHV of biocrude (and biomass) depends largely on (a) the moisture content, and (b) the oxygen content. Therefore, biocrude HHV increases as the process that generates it minimizes these two things. The first is minimized by using dry feedstock and the first and second by optimizing (usually minimizing) the oxygen exposed to the biomass during conversion to biocrude. 

Hi André,

Thanks again for your time in replying my question.

To answer your question, yes - the overall extracted solute is the average of easily accessible and not easily accessible solute. However, the mass transfer model is divided into three parts (where all 3 are distinct from each other) - easily extracted part, not easily extracted part, and in-between part in simple terms.

Combining all this 3 parts will give the predicted extraction yield.

And here is the paper you requested.

It gave me a better explanation compared to other recent papers for me.

Regards,

The densities of of the pyrolysis gas (pyrogas) and tar vary depending on many parameters including:

1) Feedstock.

2) Inert gas (N2 or CO2)

3) Temperature of the pyrolysis.

In any case, the pyrogas density is about 1E-3 g/cc and the tar density is about 1.2 g/cc.

Hope this helps answer your question.

Professor Yehia Khalil, Yale University, USA

Fellow of the University of Oxford, UK

The statement may be misleading. Exothermic or endothermic is a process, which is either negative or positive. Calorific value, on the other hand, is not a process but rather energy content.

Hi

this link can help you

 0371 6809 7667‎

thank you sir

Keep in mind that the volatile matter (VM) from the prolysis process has two components:

1) Non-condensible VM such as CH4, H2, etc

2) Condensible VM. These are essentially Tar oil which is used as a fuel and has high calorific value.

Hence, the insights from your data are correct.

Hope this helps answer your question.

Professor Yehia Khalil, Yale University, USA

Fellow of the University of Oxford, UK

Dear Bello,

Your operating parameters as you listed are what you need to vary and obtain optimum combination that will help you with a desired output. Mind you that biochar derived from sawdust could have varied usage so it depends on your end product. Sometimes all you need is to reduce the volatile matter and unbounded moisture in your biomass, such need warrant just mild pyrolysis (Torrefaction process---200-300degrees) in an inert environment with lower gas flow rate say 50ml/min and your reactiion time may be 30-60minutes. However, when you need to use the biochar in an enevironment where volatile matter is not desired, you need to go to higher pyrolysis temperature environment (400-600 degreees). so the choice is yours but i will advice you to do a DOE for your parameters using Response surface methodology or Tauguchi method. It will help you to know which of those parameters are important and can affect your desired output more based on your end use.

I hope it helps.

Dear Abdul,

From my observation of recent in dealing with biomass of different types apart from literature . Generally, the temperature range given in your question might not be observable as we have unbounded moisture loss and evaporation taking place below 150 degrees C. Moisture loss and light volatile matter content often occur at the reactive drying stage where biomass will be unable to return to its original stage (150-220 degrees C thereabout). After which hemicellulose will begin to decompose at 220 degrees and above with partial degradation of lignin. So biochar produced at this point will still be with low energy density, high C-O and H-O  bonds and the grindability will be low. However, going to 300- 600 degrees C, you might have had complete decomposition of your biomass polymers even lignin where in the formation of condensable gases becomes prominent. For biochar with high energy density and low volatiles, you can obtain that with this stage but with lower mass and energy yield.

Dear Hassen

Please look in attach file, you found research in Arabic 

thank you Sir abdul majeed and Hassan  usually in analytical  fast pyrolysis of Lignocellulosic biomass,  LG is more than 20% but in my experiment it is not more than 5%. while linear aldehydes are more in comparison with other study

Most probably, it will be based on experimental findings at different conditions.

Regards.

DR. KHAN

Thanks, Is it possible for you to send me the pictures (internal and external view) of your oven.

Regards.

DR. KHAN

 http://ageconsearch.tind.io//bitstream/57785/2/DrKG-Kshirsagar.pdf

Thanks Dear David for the protocol is very interesting

Dear Pervaiz there is also the APHA protocol available on the internet

Demineralization could be an option to consider. Read 10.3389/fenrg.2015.00006.

The condensed water is not usually wasted, but put to some use. Condenser can be air cooled or water cooled. If your fuel cell can run at higher temperature the efficiency can be increased by using the condenser to warm up the incoming air, especially in cold weather.

Several potential methods could be used. The following list includes them and some of their distinguishing characteristics.

1. Biodiesel - in this method, the moss is harvested for its organic/vegetable oil (triglyceride) content and these are catalytically processed with methanol via transesterification to form biodiesel and glycerol. However, moss has little triglyceride content and the processing steps are complex.

2. Ethanol - in this method, the sugars in biomass convert to ethanol via fermentation and the ethanol is distilled. However, moss contains little sugar.

3. Gasification - in this method the biomass thermally decomposes, ideally at high pressure, to form H2 and CO (and H2O and CO2). The H2 and CO are further treated in a Fischer-Tropsch process to form biodiesel (or in any number of similar catalyzed processes to form methanol, dimethyl ether, or other compounds). This is probably the most efficient way to convert moss to a liquid fuel and the most technologically matture process.

4. Combustion - in this method, the biomass is used as fuel to produce heat for direct use of for use in a heat engine. This is by far the most efficient and easiest of these processes, but it does not produce a fuel per se, just heat that can sustitute for a fuel. 

Larry

Slegers, P.M., Lösing, M.B., Wijffels, R.H., van Straten, G., van Boxtel, A.J.B., 2013. Scenario evaluation of open pond microalgae production. Algal Res. 2, 358–368.

this paper evaluates a model-based framework  used to study the effect of   available radiation and the water temperature effect on algal biomass yield.

 For instance if thermal rate of your bio-reactor is 20 kw. Convert it  MJ/hr = 20×3600÷1000 = 61.2, Measure NCV of your biomass producer gas and the quantity i.e. volume / unite time, i.e.NCV of  bio gas = 10 MJ/ cubic ft.     Now  divide thermal output of 61.2 by NCV. you will get  biogas feed rate to the bio gas power plant i.e 10.12 cubic ft/hr. Now multiply this plant efficiency. if plant efficiency is 40%  then power generated will be 4.048 kw.

You can calculate the higher heating value of your product taking into account its elemental composition ,

HHV (kJ/kg)=3,55*C2-232*C+2230*H+51,2*C*H+131N+20600

The C, H, N content is presented in % on Dry matter of corn

The HMF extraction will happens anyways, with or without salt. By saturating the aqueous layer with salt you decrease the HMF solubility in the aqueous layer and improve the extraction coefficient. Adding non inorganic compounds to saturate the aqueous layer might be a problem, since it can also be extracted by the organic layer.

Keep in mind that you can always modify the organic solvent (or increase its volume, as already mentioned) in order to improve the extraction

Greetings,

If you have values of proximate analysis in wet basis, just divide each value by (1-%moisture). Then you can convert each value from wet to dry basis.

However, if  You have not any value, you should realize experimental tests with specific protocols as it is well mentioned in literature to determine, the moisture content, the volatile matter, the fixed cabon, the HHV/LHV and the ash content.

(CH2O)(6n) --> 6n H2O + n( C6 )

Easily done with heat of any source.

Dear Mr. Rezania,

Photo, dark and combined photo/dark fermentation are processes used for bio-hydrogen production. However, the anaerobic digestion process produces a biogas consisting of mainly methane and carbon-dioxide. While some hydrogen is produced in the initial phases of the anaerobic digestion process, these are consumed by methanogens to produce methane (hydrogenotrophic methanogenesis). As such, I would not include anaerobic digestion as a method to produce hydrogen.

Besides, the dark fermentation/anaerobic digestion processes are now being coupled whereby hydrogen is initially produced in the dark fermentation process and the resulting "broth" (consisting of soluble metabolites such as acetic acid) from the dark fermentation process is then subjected to the anaerobic digestion process for methane production. The biogas from both processes is often referred as hythane (hydrogen+methane).

You may compare H2 yield from the photo vs. dark fermentation process individually. You may also do a combined dark/photo fermentation process and compare the total H2 yield with the sum of the H2 yields from the single dark and photo fermentation processes.

Kind regards,

Bundhoo M.A. Zumar

Thanks everyone for your tips.

Thank you very much.

Dear Anneke,

The lost of biomass strongly depends on earthworm species, adult/juvenile stage as well as the method of conservation (formol versus alcohol). I think the previous paper could help you, I add those of G. Cuendet (1985).

Regards,

Claire

Assume 1kg of biomass can be converted to 2m3

of syn-gas (“Modeling Gasifier Mass,” 2010).

2. Standard HHV (Waldheim & Nilsson, 2001) for: H2 = 12.76MJ/m3

; CO = 12.63MJ/m3

; CH4 = 39.76MJ/m3.

3. Syn-gas composition: H2, O2, N2, CH4, CO, CO2. The total percentage of all these gases is 100%.

4. HHV of biomass fuels.

Since only H2, CO and CH4 are combustible, the HHV of syn-gas is the calorific value of these three gases:

ΔH (2m3syn-gas) = (12.76MJ/m3× 2m3× H2%) + (12.63MJ/m3× 2m3× CO%) + (39.76MJ/m3×2m3×CH4%) = 2(12.76 × H2% + 12.63 × CO% + 39.76 × CH4%)MJ/m

reference:http://castle.eiu.edu/~energy/hhv_of_syn_gas.pdf

Since you're working on nanocataysts, I would recommend the following technology for fuel production from CO2.

The technology is called "Photocatalytic reduction of CO2" into hydrocarbon fuels. It is also called photosynthesis. It is inspired by the natural photosynthesis in plants  whereby oxygen (in the air) and carbohydrates are produced from H2O and CO2 using sunlight UV radiation as an energy source. The useful product in this case would be the liquid fuel produced from this photosynthesis process.

Hope this helps answer your question.

Professor Yehia Khalil

Yale University

USA

The methodology for assessing “volatile solids” is easy, fast and cheap compared to options such as COD (chemical oxygen demand) and BOD (biological…). Therefore, it is a very convenient approach to assess organics in a sample.  If this organics comes from the “feed” or “influent” you will assume that it refers to “substrate”. However, if you sample comes from inside of the reactor, you will assume that the SV values will reflect “microbial density”.

Is it true? Nope, but it is a very good reactor operating tool.

If you really want to asses susbrate and microorganisms you would need more specific methodology, which, apart from being very expensive, they have longer delay for producing the needed result…