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Prediction of product distribution in fine biomass pyrolysis in fluidized beds based on proximate analysis

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... With the selection of the T py = 500°C, un upper part of BC stability area can be reached (Cross and Sohi, 2013). Other properties of the BC are achieved by optimization of the reactor residence times of BC/BM in the range from 15 to 20 min and rather short times for gases in the range of seconds (Kim, 2015;Crombie and Mašek, 2014). Selected T py is an average temperature of gases leave pyrolysis reactor; it is lower than highest treatment temperature (HTT), used in pyrolysis processes as characteristic temperature. ...
... Almost all process models are based on DSC, TGA and small lab pyrolysis reactor measurements like Chen et al. (2014), Crombie and Mašek (2014), Yang et al. (2013) and Gómez et al. (2014) and others. More plant stream definition approach as we propose can be found in Rogers and Brammer (2012), Gómez et al. (2014), Uslu et al. (2008), Kim (2015) and Daugaard and Brown (2003) (Fig. 4). ...
... Primary sources of water in flue gases after burning are free water from biomass and hydrogen from BM (average content of 6-7% H 2 ) which reacts and form water. About 30% of dry (MF) BM converts to water according to laboratory tests results Crombie and Mašek, 2014;Kim, 2015;Kan et al., 2016). Heat needed for water evaporation -ðq bmWe Þ and heating to ðT py Þ is taken from ðQ volatiles Þ Eq. (3), but normally cannot be utilized in output while remaining in flue gases uncondensed. ...
... A number of studies on lignocellulosic biomass pyrolysis in fluidized beds have been reported in the literature. However, many works focused on biomass conversion in certain operating conditions in fluidized bed reactors, and essential information to evaluate fluidization quality such as the details of the bed material were not fully included in the report [21]. Data from a set of investigations with detailed information, including 19 different biomass samples and specific information about the operating conditions of fluidized bed reactor, were collected as shown in Tables 1 and 2. The collected data are limited to biomass smaller in size than 2 mm to minimize the effect of internal heat transfer inside feed particles on the product distribution and quality from pyrolysis [14,21]. ...
... However, many works focused on biomass conversion in certain operating conditions in fluidized bed reactors, and essential information to evaluate fluidization quality such as the details of the bed material were not fully included in the report [21]. Data from a set of investigations with detailed information, including 19 different biomass samples and specific information about the operating conditions of fluidized bed reactor, were collected as shown in Tables 1 and 2. The collected data are limited to biomass smaller in size than 2 mm to minimize the effect of internal heat transfer inside feed particles on the product distribution and quality from pyrolysis [14,21]. The experimental data on the elemental analyses of feedstock and pyrolytic bio-oil were analyzed and correlated with the information concerning the experimental rigs and operating parameters based on previous findings in the literature. ...
... Biomass pyrolysis in fluidized bed is induced by the heat transported from the surrounding gas and bed material to the fuel particle, causing it to decompose thermally into a huge number of products. During transient heating of the particle, temperature increases locally, leading first to the evaporation of moisture in drying stage and then to the progressive release of pyrolytic volatiles in primary pyrolysis stage [24,21], where feedstocks undergo hydration and decarbonylation reactions to make intermediate oxygenates with removal of oxygen in the form of CO, CO 2 and H 2 O. In the primary pyrolysis stage, the volatiles have no significant change in elemental composition compared to original feedstock [24]. ...
Article
tA predictive correlation of effective hydrogen to carbon ratio ((H/C)eff) of bio-oils was satisfactorily devel-oped to describe the general trends of bio-oil quality in fluidized beds of lignocellulosic biomass pyrolysisfor production of bio-oils compatible with petroleum refinery. The correlation was based on an empiricalrelationship with operating parameters including fluidization hydrodynamics in fluidized bed pyrolyzers,which was derived from the data of this study and literature. The increment of (H/C)efffrom feedstock tobio-oil during pyrolysis was a strong function of fluidization variables related with hydrodynamics andbed mixing such as fluidization number, bubble fraction and entrainment flux of bed materials. The pre-dicted (H/C)effof bio-oil based on the correlation well accorded to the experimental data. The predictionresults indicate that the correlation can predict an optimum operating condition for balancing qualityagainst bio-oil yield.
... On this basis, the introduction of time reflects the different time periods and different teaching levels of each teacher. rough internal improvement and title improvement, the teaching effect is enhanced; the age of introduced teachers can reflect which age group of teachers has better teaching effect [9]. We put forward the idea of multistrategy design, combined with data mining technology and statistical analysis, based on the classification of the K-nearest neighbor algorithm mining method, analyze the student scores in the library data, and generate the K-nearest neighbor algorithm. ...
... e results provide a reference for the design of teaching plans and information to improve the quality of students' learning [26]. Use the K-nearest neighbor algorithm classification method to construct the student performance analysis system and use this system for course grade analysis, so as to promote the education quality promotion [9]. Previous studies have the following shortcomings: first, the decision tree classifier is not perfect enough, and the data preprocessing needs to be completed manually by other database tools; second, the pruning operation of the decision tree is not controlled automatically by the program. ...
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This paper presents the concept and algorithm of data mining and focuses on the linear regression algorithm. Based on the multiple linear regression algorithm, many factors affecting CET4 are analyzed. Ideas based on data mining, collecting history data and appropriate to transform, using statistical analysis techniques to the many factors influencing the CET-4 test were analyzed, and we have obtained the CET-4 test result and its influencing factors. It was found that the linear regression relationship between the degrees of fit was relatively high. We further improve the algorithm and establish a partition-weighted K-nearest neighbor algorithm. The K-weighted K nearest neighbor algorithm and the partition algorithm are used in the CET-4 test score classification prediction, and the statistical method is used to study the relevant factors that affect the CET-4 test score, and screen classification is performed to predict when the comparison verification will pass. The weight K of the input feature and the adjacent feature are weighted, although the allocation algorithm of the adjacent classification effect has not been significantly improved, but the stability classification is better than K-nearest neighbor algorithm, its classification efficiency is greatly improved, classification time is greatly reduced, and classification efficiency is increased by 119%. In order to detect potential risk graduating students earlier, this paper proposes an appropriate and timely early warning and preschool K-nearest neighbor algorithm classification model. Taking test scores or make-up exams and re-learning as input features, the classification model can effectively predict ordinary students who have not graduated.
... However, they are similar in content. They contain basically cellulose, hemicellulose and lignin in various percentages (Kim, 2015). Figure 1 summarizes and opens route to construct a new conceptual framework for the application of artificial neural network (ANN) on scientific research, which would have ended a possible new natural law in consideration with aforementioned discussion. ...
... Generally, there are three types of prediction models: mechanistic physical models, statistical models, and neural network models. The physical and statistical models have been used to define the vigorous thermolysis reaction medium in kinetics and thermodynamics perspectives to obtain ultimate functions of the system (Aydinli and Caglar, 2013;Kim, 2015;Lopez-Urionabarrenechea et al., 2012). The kinetics of thermo-gravimetric behaviour of polymeric materials and the content of atmospheric gas oils sequentially has been predicted (Conesa et al., 2004). ...
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The potentiality determination of renewable energy resources is very important. The biomass is one of the alternative energy and material resources. There is great effort in their conversion to precious material but yet there is no generalized rule. Therefore, the prediction of the energy and material potentials of these resources has gained great importance. Also, the solution to environmental problems in real time can be found easily by predicting models. Here, the basic products of pyrolysis process, char, tar and gas were also predicted by artificial neural network modelling. The half of data obtained from real experimental process along with some content and proximate analysis were fed into artificial neural network modelling. After the training of the model with this data, the remaining half of the data were introduced into this artificial neural network model. And the model predicted the pyrolysis process products (char, tar and gaseous material). The predicted data and the real experimental data were compared. In addition, another aim of this study is to reduce the labour in identification and characterization of the pyrolysis products. For this purpose, a theoretical framework has also been sketched. The necessity of a generalized rule for generation of energy and matter production from biomass pyrolysis has been punctuated. As a result, the ANN modelling is found to be applicable in the prediction of pyrolysis process. Also, the extensive reduction in labour and saving in economy is possible.
... Pyrolysis can convert straws to solid char, liquid oil, and fuel gas, all of which have higher value than the original straw (Aysu and Kucuk, 2014;Biswas et al., 2014;Sarkar et al., 2015;Shi and Wang, 2014;Tinwala et al., 2015;Yang et al., 2014b). A straw conversion factory with usable products is therefore an economically attractive option (Gomez-Monedero et al., 2015;Kim, 2015;Sarker et al., 2015). One promising conversion technology, polygeneration of solid char, liquid oil, and biogas from straws, has been investigated by recent studies (Chen et al., 2012(Chen et al., , 2014bXin et al., 2013). ...
... 一些学者采用了传统的经验拟合方法来研究 这种非线性关系 [6][7] ,但是结果显示,采用传统拟 合方法发展的经验拟合表达式不能很好地表达这 种关系 [5] . 随着人工智能方法的提出和发展,发现 神经网络 [8] 、随机森林 [9] 等算法被能够较好地处理 非线性问题. ...
Article
The random forest (RF) model was developed to accurately predict the kinetic parameters of biomass devolatilization based on its chemical compositions and heating condition. Two biomass devolatilization databases, including the training and validation databases, were constructed from diverse available experiments in literature. The kinetic parameters were fitted under the framework of order-based biomass devolatilization model. The training and validation results show that the RF model can well predict the kinetic parameters of different biomass types under different heating rates with the determination coefficient more than 0.92, resulting an accurate prediction of the biomass devolatilization process (R2>0.93). The variable importance measurement (VIM) result shows that the fraction of cellulose(CL) has a significant effect on the reaction order and activation energy, the fraction of lignin (LIG) has the maximum effect on the reaction order. The effect of heating rate is negligible for activation energy, but considerable for the frequency factor and reaction order.
... Moreover, it is important to note that the products and conversion yields depend mainly on the nature of the lignin, its composition and its functional groups, although processing conditions such as heating rate and temperature also have a strong influence (Shen et al., 2010;Ferdous et al., 2002). Lignins, in general, possess fewer volatiles and higher fixed carbon content than biomass (Shen et al., 2010;Won Kim, 2015). On the other hand, lignin also has a potential for use as a raw material in the polymer industry. ...
... Moreover, it is important to note that the products and conversion yields depend mainly on the nature of the lignin, its composition and its functional groups, although processing conditions such as heating rate and temperature also have a strong influence (Shen et al., 2010;Ferdous et al., 2002). Lignins, in general, possess fewer volatiles and higher fixed carbon content than biomass (Shen et al., 2010;Won Kim, 2015). On the other hand, lignin also has a potential for use as a raw material in the polymer industry. ...
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The potential of organosolv and kraft eucalyptus and spruce lignin as feedstock for polymeric materialsand biofuel applications was assessed. Proximate analysis was used to predict the heating values andchar formation. Chemical modification, based on the esterification reaction with methacryloyl chloride,was applied to introduce vinyl groups into the lignin macromolecules for enhanced reactivity. Krafteucalyptus and spruce lignins had a more condensed structure than organosolv lignins, which resultedin greater thermal stability for these lignins. For different species within the same process, the thermalparameters showed a correlation with certain structural and compositional parameters (ash and sugarscontent, molecular weight and degree of condensation). Organosolv spruce lignin produced the highestheating value of 24 MJ/Kg, which is suitable for biofuel applications. The content of phenolic OH groupswas higher for kraft lignins and especially higher for softwood lignins, both organosolv and kraft. Thedegree of methacrylation, estimated from the content of vinyl groups per C9 lignin unit, was significantlygreater for organosolv lignins than for kraft lignins despite the higher OH-groups content in the latter.
... In literature, there are some attempts in modelling the thermochemical reactions via mechanistic physical models, statistical models, and neural networks. Previously, physical and statistical models have been used to define the vigorous thermolysis reaction medium in kinetics and thermodynamics perspectives to obtain ultimate functions of the system [22,23]. But, now, artificial neural networks (ANNs) take the attention to predicting various values of thermal process in several dimensions. ...
Article
The main aim of this study is subject of thermochemical conversion process data into computational modelling. Especially, prediction of hydrogen gas from the pyrolysis of waste materials regarded as environmentally pollutants were accomplished by Artificial Neural Network (ANN) in context of sustainability. The data obtained from pyrolysis of biomass wastes; cotton cocoon shell (cotton–S), tea waste (tea–W) and olive husk (olive–H) were categorized and hydrogen rich gas (H–rG) portion was introduced to the NFTOOL of MATLAB program for ANN. The variables in the pyrolysis process were catalyst type, amount, temperature and biomass diversity. The H–rG production was rendered by catalysts; ZnCl2, NaCO3 and K2CO3. The combination of following condition; ZnCl2–10%, Olive–H and 973 K yield the best ANN models. This helped us save comprehensive amount of labour and time during experimentations, which also result in sharpness data in energy and environmental issues and were very ambiguous. The results were discussed by using new concepts related with energy resources, hydrogen gas, modelling and sustainability. The presented perspective here can be a useful tool for researchers and users as well as planners.
... This is important because it accounts for loss of potentially condensable hydrocarbon oils (tar) when the initially released vapors are retained for too long a period at high temperature in the reactor. Based on extensive reviews of experimental results both Kim (2015) and Brown (2015) note that vapor phase tar reactions can significantly affect overall yields of bio-oil, although the details of these reactions are still poorly understood. The effect of these reactions appears to be similar to reactions noted in earlier studies with coal pyrolysis, which also led to losses in liquid yield [Kathelakis et al (1990)]. ...
... The complex and nonlinear correlations between the kinetic parameters and the heating conditions/ biomass chemical compositions are still unclear and need to be explored [18]. Several studies have attempted to quantify the nonlinear correlations with traditional methods, such as the empirical correlations (EC) [19,20]. However, the proposed empirical correlations were found to be insufficient to represent the complex nonlinear correlations [18], and more advanced approaches are desirable. ...
Article
The single-step model has been widely used for devolatilization in the computational fluid dynamics (CFD) of biomass gasification and combustion due to its low computational cost. The kinetic parameters of the single-step model are just obtained from previous studies and kept constant without regarding to the effects of biomass types and heating conditions, resulting in an obvious deviation on the treatment of biomass devolatilization. Here, several models, including the empirical correlations (EC), artificial neural networks (ANN) and random forest (RF) models, are developed to predict the kinetic parameters of the single-step model for CFD applications based on the biomass chemical compositions and heating conditions, and their performances are compared to highlight the optimal model. Two biomass devolatilization databases, used for training and validation respectively, are constructed from available experiments in the literature. The kinetic parameters are then fit from the database. The training and validation results show the EC model provides a poor performance with the lowest determination coefficients (R²≤0.80), while the ANN and RF models show an obviously better performance, with the ANN giving the middle performance (R²≥0.84) and the RF model giving the best performance (R²≥0.92). The variable importance measurement (VIM) results are also presented and discussed.
... 17 The humidity content of the CW was found 6.77% less than reported biomass feedstock such as Japanese larch (8.8%), Quercus acutissima (8.3%) and Corn stover (8.5%). 20 Importantly, such humidity contents are acceptable for thermochemical conversion as high humidity contents influences pyrolysis behavior and affects the physical properties of pyrolysis products especially quality of the bio-oil. 21 Eventually, these characteristics demonstrate appropriateness of CW for applying it for thermochemical conversion. ...
Article
This study sheds light upon how the decomposition of cabbage waste (CW) is brought to make it capable of providing bioenergy along with bio-chemicals. The CW is evaporated through three steps, and at the same time, non-condensable products (NH 3 , CO 2 , CH 4 , CO, SO 2 and NO) and condensable products like (H 2 O, CH 3 CH 2 OH, CH 3 COOH, C C, C 6 H 5 OH and HCOOH) are yielded. The products that have gone through the pyrolysis process comprise 45% condensable products. Thermogravimetry-Fourier transform infrared (TG-FTIR) analysis shows that lower temperature can be more effective for con-densable products formation from CW as compared to higher temperature. Pyrolysis gas chromatography (Py/GC-MS) confirms presence of the high energy and value-added chemical compounds such as toluene, benzene and phenols among pyrolytic products. According to initial reports, liquid pyrolytic products produce more than 70% energy. All these results demonstrate that CW could be promising source of bioenergy and valuable bio-chemicals production via pyrolysis. K E Y W O R D S bio-chemicals, bioenergy, cabbage waste, thermochemical conversion
... The result revealed that moisture, ash, and fixed carbon in lignin are 4.43,0.78 and 13.66%, respectively which is similar to other lignin's (Kim, 2015;Shen et al., 2010b). Fig. 1 shows thermogravimetric curve (TGA) along with its first derivative (DTG) for lignin sample. ...
Article
Catalytic fast pyrolysis of soda lignin was examined at different temperatures (500,600,700,800 and 900 °C) in the presence of three zeolites with different Si/Al ratio using the Py-GC/MS in order to investigate best catalytic system. The three zeolites are y-zeolite (8-9), mordenite (15-17), ZSM-5 (30-40), which have static pore sizes 0.74, 0.65, and 0.59 nm respectively. The shape and acidity of zeolites, as well as pyrolysis temperature, have a significant effect on product distribution in catalytic fast pyrolysis. Y-zeolite was the most effective catalytic system among all catalysts for deomethoxylation and dehydroxylation of small oxygenates as well as bulky oxygenates to produce aromatics. However, mordenite and ZSM-5 could not convert the large oxygenates due to size exclusion and pore blockage. Highest yield of aromatics with significant amount of aromatic dimers was obtained over y-zeolite and then yield of aromatics followed in order by mordenite and ZSM-5 at 800 °C.
... We have used proximate analysis based on ASTM standards E 871, E 1755, and E 872, for moisture, ash, and volatile matter, respectively. Fixed carbon content was calculated by %FC � 100-(%ash + %VM), where %FC, % ash, and %VM are the mean of the mass percentage of fixed carbon, ash, and volatile matter of the sample, respectively [24][25][26]. ...
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Biochars from bamboo leaves as a potential energy resource were synthesized by annealing in the oxygen-free environment. Samples were characterized using proximate analysis, Fourier-transform infrared (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS). Heating temperatures are 250°C, 300°C, and 350°C and for each temperature, the time was varied between 30, 60, and 90 minutes. The heating time for 30 minutes results in FC 30.777% and calorific value 15 MJ/Kg at temperature 250°C and decreased to 4.004% and 6 MJ/Kg at temperature 350°C, respectively. EDS shows the time of heating is an important parameter which shows the carbon and nitrogen contents were decreasing with the increase in the heating time, and silicon and oxygen contents were increasing with increase in the heating time. XRD shows broad (002) reflections between 20° and 30°, which indicated disordered carbon with small domains of coherent and parallel stacking of the graphene sheets, which is consistent with surface morphology of the SEM image. The experimental results indicated that heating at 300°C for 30 minutes is an effective and efficient parameter for fabrication of low-cost carbon from bamboo leaves which is a source of useful energy.
... 24 In particular, biomass pyrolysis enables redistribution of the biomass carbon components to the three phases of pyrogenic productschar, biocrude, and syngas. 25 Rearrangement of carbons into pyrogenic products can be manipulated by controlling biomass pyrolysis operating conditions with/ without catalysts. 5 Such a rearrangement of carbons offers a way to valorize the biomass by controlling the carbon chain lengths in the pyrogenic products in conjunction with deoxygenation, functional group addition, complexation, aromaticity control, and so on. ...
Article
As global warming and climate change become perceived as significant, the release of greenhouse gases (GHGs) stored in the Earth’s polar regions are considered a matter of concern. Here, we focussed on exploiting GHG to address potential global warming challenges in the north polar regions. In particular, we used CO2 as a soft oxidant to recover energy as syngas (CO and H2) and to produce biochar from pyrolysis of peat moss. CO2 expedited homogeneous reaction with volatile matters from peat moss pyrolysis, and the mechanistic CO2 role resulted in the conversion of CO2 and peat moss to CO at ≥ 530 ℃. Steel slag waste was then used as an ex-situ catalyst to increase reaction kinetics, addressing the issue of the role of CO2 being limited to ≥ 530 ℃, with the result that substantial H2 and CO formation was achieved at a milder temperature. The porosity of biochar, a solid peat moss pyrolysis product, was modified in the presence of CO2, with a significant improvement in CO2 adsorption capacity compared to those achieved by N2 pyrolysis. Therefore, CO2 has the potential to serve as an initial feedstock in sustainable biomass-to-energy applications and biochar production, mitigating atmospheric carbon concentration.
... But they have similar contents. It mainly contains various proportions of cellulose, hemicellulose and lignin [42][43][44]. ...
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Many new concepts have been constructed by associating many familiar concepts such as tourism, energy, agriculture and development to the term of sustainability. Some of them are; sustainable development, sustainable agriculture and sustainable tourism etc. Undoubtedly, sustainability is mentioned in many areas such as media, politics, economics and academia. This concept is tried to be gained through the information and practices provided about sustainability to the individuals who make up the society. It is known that sustainability in science education is not evaluated with a holistic approach from the perspective of economy, ecology and energy. If it is assumed that individuals have not theoretical background and culture about sustainability, there can be thought that they will have problem for sustainable lifestyle. Therefore, it can be said that theoretical and practical studies which will help individuals are important in order to a more livable World. The purpose of this study is to construct broad a conceptual framework upon renewable energy policies from the sustainability perspective by linking the terms of economy, ecology and energy known in the literature as 3E. In the method of this research, firstly sustainability is examined from a holistic approach and was developed a model. Then starting from sustainability, socio-scientific issues, production, wastes, ecology, sociology, feminism, cultures, developmental differences, energy production, energy storage and transportation, the renewable ones, photosynthesis, biomass and pyrolysis are connected and interrelated in holistic manner by considering chemistry and politics. In the result of the research, it is arisen that conservative and elder women who is the ability to be happy while consuming less which must be followed and obeyed. By this way, new insights can be obtained and deduced for better inhabitable world peacefully.
... Proximate analysis is part of the most important characterization methods for the catalytic conversion of biomass [17]. It provides characteristic information of the thermochemical conversion of biomass, including moisture, ash, volatiles, and fixed carbon. ...
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The purpose of this research is to study the mechanism of catalytic pyrolysis of coconut shell in a microwave pyrolysis reactor, explore the effect of catalytic pyrolysis process parameters on the quality and yield of liquid products, and optimize the pyrolysis process parameters using response surface methodology with Box-Behnken design (RSM-BBD). The process parameters of catalytic pyrolysis are reaction time, heating rate, temperature, nitrogen flow rate, and the operating ranges are 5–20 min, 15–30 °C/min, 400–700 °C, 50–200 ml/min. The three factors of heating rate, temperature, and nitrogen flow rate were used as independent variables, and the relative contents of hydrocarbons and phenols in bio-oil were used as response values to construct the model. For both cases, the quadratic model has proven the reliability. The relative selectivity of hydrocarbons and phenols of the determination coefficient (R2) is 0.9852 and 0.9373, respectively, which proves that the model has a good fit. The best relative contents of hydrocarbons and phenols obtained by fitting are 40.20 area% and 71.33 area%, and the relative contents of hydrocarbons and phenols in the bio-oil used for the verification experiment are 41.00 area% and 72.87 area%; the result is within the allowable range of error. Compared with the relative content of hydrocarbons in the bio-oil under the best single factor conditions, the relative content of hydrocarbons increased by ~ 5 area%, indicating that the response surface method can further optimize the process parameters of the experiment.
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Prediction models for product distribution and bio-oil heating value of biomass pyrolysis, were established in this paper using some artificial intelligence algorithms, i.e. artificial neural network (ANN) and support vector machine (SVM). Correlated samples about biomass pyrolysis were collected as data set. The modeling results showed that both ANN and SVM models can estimate the pyrolytic product yield and bio-oil heating value successfully. In all cases, the ANN model accorded well with the experimental data in the training set while SVMs performed better in the prediction set, which indicated that SVM model has a better predicting performance in biomass pyrolysis. The established prediction model can be used as a good reference of the modeling study of biomass fast pyrolysis.
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Kraft lignin (KL) and castor oil (CO) were used as polyols in the synthesis of bio-based polyurethanes (PUs) in the absence of both solvents and catalysts at room temperature with simultaneous film formation. KL was purified (PKL), and both KL and PKL were fully characterized. CO was mixed with different percentages of PKL (0%, 10%, 30%, and 50%), as well as with polymeric methyl phenyl diisocyanate. After degassing, the reaction mixture was stirred; when the medium viscosity was suitable for spreading, it was poured onto a glass plate, and the thickness was adjusted using an extender. The storage modulus (E', 25 °C) and tensile strength of the lignopolyurethane films (LignoPUCOPKL) were higher than those of the control film (PUCO). LignoPUCOPKL30 and LignoPUCOPKL50 did not break under the conditions that the other films broke under. It was noted phase segregation (rigid and flexible domains) for LignoPUCOPKL30 and LignoPUCOPKL50, and the glass transition temperature (Tg) of the flexible domains (96.2 °C and 52.3 °C, respectively) was higher than that of PUCO (8.4 °C). The formed films were also characterized by scanning electron microscopy, thermogravimetric analysis, X-ray diffraction, contact angles, and swelling tests. To our knowledge, the approach of this study is unprecedented.
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Production of biofuels via biomass pyrolysis has received a strong emphasis since it may produce a wide variety of renewable fuels in liquid (bio-oil), solid (biochar), and gas (syngas) forms. Sugarcane bagasse, waste from the sugar-alcohol industry, is largely produced in Brazil, India, and Thailand and appears as a great biomass option for pyrolysis due to its properties, abundance, and current underutilization. However, sugarcane bagasse properties and pyrolysis operating conditions may directly affect the product properties, distribution, and further application as fuels and chemicals. Thus, it is necessary a thorough study of these subjects. This review brings an overview of biomass and pyrolysis concepts, as well as a collection of improvements in the production of products (bio-oil, biochar, and gas) via sugarcane bagasse pyrolysis. In addition, this review discusses the interaction between process operating conditions and this biomass type to address how the products’ properties and yields are affected.
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In this study, an empirical model for the pyrolysis of major oil palm wastes (OPW) such as palm kernel shell (PKS), empty fruit bunches (EFB), and oil palm frond (OPF), and their blends is developed. Moreover, the techno-economic feasibility of the wastes is investigated to determine the type of waste that would be suitable for the commercialization of different types of products. According to the model results, the bio-oil dominates the pyrolysis process' product output, accounting for 59.21, 50.51, 56.60, and 55.65% of PKS, EFB, OPF, and their blend, respectively. Whereas biochar yield is 23.21, 23.1, 22.95, and 23.08%, gas yield is 17.57, 26.38, 20.44, and 21.27%. The findings demonstrate that the feedstocks under consideration are mostly suitable for producing bio-oil. According to the economic analysis, PKS-based pyrolysis has the highest capital expenses (CAPEX), while EFB-based pyrolysis has the lowest CAPEX of all tested feedstocks. Furthermore, PKS has the highest operating expenses (OPEX) due to its relatively higher market price as well as higher moisture content, which necessitates more energy input during the drying stage. Among the feedstocks, OPF has delivered the highest profit of USD 17 M/year, with a 22% return on investment (ROI). In terms of investment capital payback period, all OPW feedstocks demonstrated a reasonable period of 4-6 years. Bio-oil is the most valuable pyrolysis product, with the highest market value when compared to biochar and syngas. The established prediction model can be utilized as a solid reference for biomass pyrolysis modelling studies. Furthermore, the predicted values are reasonable enough to be used in industrial process design.
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Pyrolytic kinetic parameters of Jatropha seedshell cake (JSC) were determined based on reaction mechanism approach under isothermal condition in a thermobalance reactor. Avrami-Erofeev reaction model represents the pyrolysis conversion of JSC waste well with activation energy of 36.4 kJ mol−1 and frequency factor of 9.18 s−1. The effects of reaction temperature, gas flow rate and feedstock particle size on the products distribution have been determined in a bubbling fluidized bed reactor. Pyrolytic bio-oil yield increases up to 42 wt% at 500 °C with the mean particle size of 1.7 mm and gas flow rate higher than 3Umf , where the maximum heating value of bio-oil was obtained. The pyrolytic bio-oil is characterized by more oxygen, lower HHVs, less sulfur and more nitrogen than petroleum fuel oils. The pyrolytic oil showed plateaus around 360 °C in distribution of components’ boiling point due to high yields of fatty acid and glycerides.
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The paper provides an updated review on thermal conversion of biomass for the production of liquid products referred as bio-oil. This technology is described focusing on the characterization of feedstock, reactor design, products formation and upgrading. For feedstock characterization is covered in terms of several pretreatment methods. The reactor designs are illustrated number of design ranging from fixed bed to circulating fluidized bed. The properties of bio-oil composition have caused increasingly extensive research to be undertaken to address properties that need modification and this area is reviewed in terms of physical, catalytic and chemical upgrading. The mechanism of the products formation is also illustrated by several chemical routes. Reactor parameters such as heating rate, temperature of pyrolysis, catalysts etc are reviewed.
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This article reports experimental results on fast pyrolysis of agricultural residues from cassava plantations, namely cassava rhizome (CR) and cassava stalk (CS), in a fluidised-bed fast pyrolysis reactor unit incorporated with a hot vapour filter. The objective of this research was to investigate the effects of reaction temperatures, biomass particle size and the use of simple hot vapour filtration on pyrolysis product yields and properties. Results showed that the optimum pyrolysis temperatures for CR and CS were 475 °C and 469 °C, which gave maximum bio-oil yields of 69.1 wt% and 61.4 wt% on dry biomass basis, respectively. The optimum particle size for bio-oil production in this study was 250–425 μm. The use of the hot filter led to a reduction of 6–7 wt% of bio-oil yield. Nevertheless, the filtered bio-oils appeared to have a better quality in terms of initial viscosity, solids content, ash content and stability.
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The book covers fluidization engineering. Topics covered include: Industrial applications of fluidized beds; The dense bed: distributors, gas jets, and pumping power; Bubbling fluidized beds. High-velocity fluidization; Particle-to-gas mass and heat transfer; Conversion of gas in catalytic reactions; Heat transfer between fluidized beds and surfaces; Circulation systems. Design of catalytic reactors. Reviews principles and applications of fluidization engineering; coverage of historical and current research influencing the development of this engineering field; bed-wall heat transfer; drying of solids, fast fluidization, heat exchangers, K-L model for catalytic reactions, mass transfer, and particle movement in beds.
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Radiata pine sawdust was pyrolyzed in a bubbling fluidized bed equipped with a char separation system. The influence of the reaction conditions on the production of bio-oil was investigated through the establishment of mass balance, and the examination of the products' chemical and physical characteristics. The optimal reaction temperature for the production of bio-oil was between 673 and 723 K, and the yield was above 50 wt.% of the product. An optimal feed size also existed. In a particle with a size that was less than 0.3 mm, the bio-oil yield decreased due to overheating, which led to gas formation. A higher flow rate and feeding rate were found to be more effective for the production of bio-oil, but did not significantly affect it. The main compounds of bio-oil were phenolics, including cresol, guaiacol, eugenol, benzendiol and their derivatives, ketones, and aldehydes. In addition, high-quality bio-oils, which contained less than 0.005 wt.% of solid, no ash and low concentrations of alkali and alkaline earth metals, were produced due to the char removal system.
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Particle carry-over from the surface of a fluidized bed into the freeboard depends onthe mechanism of bubble eruption. Particles may be ejected into the freeboard from the roofs or wakes of bursting bubbles, depending on bed geometry, fluidizing velocity U and particle type.There are believed to be two alternative ejection mechanisms, as follows:(1) For group B particles with U/Umf < 10–15, ejection is from the roof of each bursting bubble. As a bubble breaks through the surface, its roof attenuates; when the thickness of the roof equals the mean diameter of the particles in the bed, all roof particles are ejected into the freeboard.(2) For group A particles, and for group B particles with U/Umf ⪢ 10–15, ejection into the freeboard is predominantly from bubble wakes, because coalescence is simultaneous with eruption. Rates of surface carry-over and particle ejection velocities are much greater than for mechanism (1).There is some discussion of the effect of segregation on surface carry-over of fine particles.
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Binary systems of particles of different size but equal density are fluidized in a 30-cm diameter bed with a perforated plate distributor. This work described the extensive experimentation, and relates the mixing/segregation properties to the visible bubble flow rate, the particle size ratio, and other parameters of minor influence. Experimental data are expressed as mixing index, correlated in terms of the decisive parameters. Comparison with previous empirical equations for the mixing index is also included. The excess gas flow rate required to avoid segregation in a fluidized bed of wide size distribution powders can be calculated from the expression for the mixing index (Eq. (15)).
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This study examined the kinetics of the pyrolysis of Japanese larch using thermogravimetric analysis (TGA), and fast pyrolysis with a bubbling fluidized bed reactor and a two-staged char removal system under various reaction conditions. The effects of the reaction conditions on the chemical and physical characteristics of bio-oil were also examined. Japanese larch was decomposed at temperatures ranging from 250 to 380 °C. The apparent activation energies ranged from 220 and 1009 kJ mol−1 when the pyrolytic conversion increased from 5 to 95%. The optimal reaction temperature for the production of bio-oil was 450 °C. The bio-oil yield decreased with decreasing feed size due to overheating. The bio-oil yields increased gradually with increasing flow rate and feeding rate but these increases were not significant. The use of the product gas as the fluidizing medium was effective for the production of bio-oil, giving the highest bio-oil yield of 64 wt%, but the introduction of oxygen had a slightly negative effect on the bio-oil yield. In addition, high-quality bio-oil, which contains <0.005 wt% solid, no ash, and low concentrations of alkali and alkaline earth metals, could be produced using the two-staged char removal system. With the exception of the reaction temperature and partial oxidation, the other pyrolysis conditions did not significantly affect the chemical and physical characteristics of bio-oil.
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Biomass is important in energy conversion processes due to their favourable status with respect to greenhouse gas emissions. However, biomass particles have unusual properties which make them difficult to fluidize and handle. This paper reviews recent research on the hydrodynamics and mixing of biomass particles in fluidized beds. Whereas there has been considerable effort to develop new biomass gasification, combustion, pyrolysis and bio-conversion processes, relatively few authors have characterized the relevant flow characteristics of biomass particles in fluidized beds or investigated measures that could assist in resolving flow issues. The limited work that has been reported on biomass fluidization primarily treats means of achieving fluidization, mixing and segregation. Most of the work has been in low-velocity fluidized beds, although circulating fluidized beds are also important. Further research is needed to provide general understanding of interactions among heterogeneous particles and guidance on conditions that can lead to viable and sustainable processes.
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The literature on biomass pyrolysis regarding kinetics, models (single particle and reactor), and experimental results is reviewed from an engineering point of view. Predictions of existing single particle models derived from a detailed description of the transport phenomena and literature data on measured intrinsic chemical kinetics are presented. The main conclusions from the literature and modeling studies can be summarized as follows: (1) the available knowledge on kinetics and transport phenomena has not been integrated properly for reactor design, (2) complex two-dimensional single particle models do not provide more accurate, or otherwise better, information for engineering calculations than do the simple one-dimensional models, and (3) single particle models predict (for all available kinetics) that the influence of the particle size on the liquid yield is limited. This effect can be explained with the effective pyrolysis temperature, a parameter that represents the particle's average temperature at which the conversion is essentially taking place.
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Biomass residues from cassava plants, namely cassava stalk and cassava rhizome, were pyrolysed in a fluidised-bed reactor for production of bio-oil. The aims of this work were to investigate the yields and properties of pyrolysis products produced from both feedstocks as well as to identify the optimum pyrolysis temperature for obtaining the highest organic bio-oil yields. Results showed that the maximum yields of the liquid bio-oils derived from the stalk and rhizome were 62 wt.% and 65 wt.% on dry basis, respectively. The pyrolysis temperatures that gave highest bio-oil yields for both feedstocks were in the range of 475-510 °C. According to the analysis of the bio-oils properties, the bio-oil derived from cassava rhizome showed better quality than that derived from cassava stalk as the former had lower oxygen content, higher heating value and better storage stability.
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Fast pyrolysis of Miscanthus was investigated in a bench-scale fluidized bed reactor for production of bio-oil. Process conditions were varied for temperature (350-550 degrees C), particle size (0.3-1.3mm), feed rate and gas flow rate. Pyrolysis temperature was the most influential parameter upon the yield and properties of bio-oil. The highest bio-oil yield of 69.2wt.% was observed at a temperature of 450 degrees C which corresponded to the end of the thermal composition of hemicellulose and cellulose. In the bio-oil, the water content was 34.5wt.%, and the main compounds in the organic fraction were phenolics and oxygenates. With increasing temperature, the amount of oxygenates in the bio-oil decreased gradually while that of water and aromatics increased rapidly. The bio-oil yield was not significantly affected by particle sizes or feed rates. The use of product gases as a fluidizing medium aided in increasing bio-oil yield.
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A fuelling success: High-quality aromatic fuel additives can be produced directly from solid biomass feedstocks by catalytic fast pyrolysis in a single catalytic reactor at short residence times. High heating rates and catalyst-to-feed ratios are needed to ensure that pyrolized biomass compounds enter the pores of the ZSM5 catalyst and that thermal decomposition is avoided. Product selectivity is a function of the active site and pore structure of the catalyst.
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The powder of the agricultural waste corn cob was pyrolyzed in a tube-typed stainless steel reactor of 200 ml volume under N2 atmosphere. The compositions of the gases and liquid obtained at different pyrolytic temperatures below 600 degrees C at the heating rate of 30 K/min were analyzed. With the increment of the pyrolytic temperature, the yields of the solid and the liquid products were decreased, but the yield of gas products was increased. The liquid products were approximately 34-40.96% (wt%), the gas products were 27-40.96% (wt%) and the solid products 23.6-31.6% (wt%). There were less changes for the yields of these products above 600 degrees C. The gas products were analyzed by gas chromatography (GC) as CO2, CO, H2, CH4, C2H4, C3H6, C3H8, etc. When the temperature was 350-400 degrees C, the gases had CO2 and CO 80-95% (v/v). When the temperature increased continuously, yields of H2, CH4, C2H4, C3H6 and C3H8 gradually increased. The liquid products were identified by GC-MS as phenols, 2-furanmethanol, 2-cyclopentanedione, etc. The Fourier transform infra-red spectrophotometer (FT-IR) analysis of the liquid product showed a strong -OH group absorption peak. Differential thermogravimetric analysis (DTG) showed that thermal decomposition process involves two steps. The heating rate affects not only the activation energy of the decomposition reaction, but also the path of the reaction. With the increment of the heating rate, the maximum rate temperature of the decomposition reaction was shifted to a higher temperature, and the order and activation energy of the total decomposition reaction were decreasing.