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Ani Idris - One of the best experts on this subject based on the ideXlab platform.
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comparison of steam Alkali chemical and microwave Alkali Pretreatment for enhancing the enzymatic saccharification of oil palm trunk
Renewable Energy, 2016Co-Authors: Long Wee Lai, Ani IdrisAbstract:This paper demonstrates two different Pretreatment protocols for oil palm trunks (OPT); steam-Alkali-chemical (SAC) and microwave-Alkali (Mw-A) method. The composition, morphology, structure and crystallinity of OPT before and after Pretreatment were analyzed. The effectiveness of the pretreated methods was investigated by performing enzymatic saccharification on the OPT. The physiochemical factors namely: enzyme ratio (cellulase to β-glucosidase), pH, temperature and substrate loading (w/v) on enzymatic saccharification were also investigated. The pre-determined optimal conditions were then used for further enzymatic hydrolysis of raw and pretreated OPT substrates. The results revealed a huge degree of reduction in lignin, up to 89% for SAC treated OPT and at least 15% for Mw-A treated OPT sample as compared to untreated ones. High glucose accumulation (79.4%) was obtained after 72 h saccharification for both pretreated OPT samples.
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factors affecting delignification of oil palm empty fruit bunch by microwave assisted dilute acid Alkali Pretreatment
Bioresources, 2014Co-Authors: Junaid Akhtar, Chee Loong Teo, Long Wee Lai, Nursia Hassan, Ani Idris, Ramlan AzizAbstract:Microwave-assisted dilute acid/Alkali Pretreatment is an efficient and rapid method of removing lignin and hemicellulose, however, the optimized parameters for the maximum efficiency have to date not been presented in the literature. The purpose of this study was to determine those conditions by examining the effects of three factors: microwave power, temperature, and time on delignification in microwave-assisted dilute acid/Alkali Pretreatment. For the control condition of conventional Pretreatment (CP), empty fruit bunches (EFBs) were soaked in 2.5 M NaOH for two hours in the autoclave. In the experimental condition, EFB were first soaked in dilute sulfuric acid with conventional autoclave heating, which removed 90% of their hemicellulose. The acid-treated EFBs were then soaked in 2.5 M NaOH solution and microwaved at different conditions: microwave power (700 - 100 watts), time (60 - 90 min), and temperature (80 -110 °C). The amount of acid-insoluble lignin was determined by Klason method. Microwave-Alkali (Mw-A) Pretreatment was modeled until it attained maximum delignification. More than twice the rate of delignification that is, 71.9% was attained with microwave-assisted Alkali/acid Pretreatment of 900 W microwave power at 110 °C for 80 min compared to 34.6% with conventional Pretreatment.
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disruption of oil palm trunks and fronds by microwave Alkali Pretreatment
Bioresources, 2013Co-Authors: Long Wee Lai, Ani IdrisAbstract:In this study, lignocellulosic biomass from oil palm trunk (OPT) and oil palm frond (OPF) of oil palm tree, Elaeis guineensis, were treated using the microwave-Alkali (Mw-A) method, and their chemical constituents, namely cellulose, hemicellulose, and lignin, were analyzed. A number of instruments, i.e. FESEM, FT-IR, and XRD, were employed to analyze the morphology and structural changes of biomass. After the Mw-A Pretreatment, it was revealed that the amount of cellulose released was up to 41.55% for OPT and 64.42% for OPF. There was also a huge degree of reduction in hemicellulose, up to 64%, but lignin removal saw a fair reduction with only 15.33% for OPT and 17.97% for OPF. The results revealed that the Mw-A Pretreatment is capable of disrupting the OPT and OPF.
Keikhosro Karimi - One of the best experts on this subject based on the ideXlab platform.
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structural modification of pine and poplar wood by Alkali Pretreatment to improve ethanol production
Industrial Crops and Products, 2020Co-Authors: Mohammad Saber Bay, Keikhosro Karimi, Mohsen Nasr Esfahany, Rajeev KumarAbstract:Abstract The softwood pine and hardwood poplar were subjected to NaOH and Na2CO3 Alkaline Pretreatments for their conversion into ethanol. The resulting solids were characterized in detail for structural modifications. Both Alkaline Pretreatments enhanced ethanol yields, and the NaOH Pretreatment at 93 °C resulted in the highest increase in ethanol yields of 297.5 and 249.5 % for pine and poplar woods, respectively, as compared to untreated woods. In all cases, the content of lignin and hemicellulose in pretreated solids was decreased by the Pretreatments, while glucan contents, accessible surface area, and enzymatic hydrolysis yields were increased. New correlations between the accessible surface area, lignin removal, and the ethanol yields were obtained for both feedstocks, indicating that the accessibility of enzyme to the surface area is the most important factor affecting enzymatic hydrolysis. The results also showed that the solute exclusion technique is a simple approach that can be applied to predict ethanol yields from pine and poplar. Among the Pretreatment conditions employed for soft- and hardwood, the NaOH Pretreatment at 93 °C is the most efficacious. The glucose yields were 8.4 % and 13.1 % for untreated pine and poplar woods, respectively. However, Pretreatment at 93 °C with NaOH increased the glucose yield to 46.5 % and 69.3 % for pine and poplar, respectively.
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dilute Alkali Pretreatment of softwood pine a biorefinery approach
Bioresource Technology, 2017Co-Authors: Ali Asghar Safari, Keikhosro Karimi, Marzieh ShafieiAbstract:Dilute Alkali Pretreatment was performed on softwood pine to maximize ethanol and biogas production via a biorefinery approach. Alkali Pretreatments were performed with 0-2% w/v NaOH at 100-180°C for 1-5h. The liquid fraction of the pretreated substrates was subjected to anaerobic digestion. The solid fraction of the Pretreatment was used for separate enzymatic hydrolysis and fermentation. High ethanol yields of 76.9‒78.0% were achieved by Pretreatment with 2% (w/v) NaOH at 180°C. The highest biogas yield of 244mL/g volatile solid (at 25°C, 1bar) was achieved by the Pretreatment with 1% (w/v) NaOH at 180°C. The highest gasoline equivalent (sum of ethanol and methane) of 197L per ton of pinewood and the lowest ethanol manufacturing cost of 0.75€/L was obtained after Pretreatment with 1% NaOH at 180°C for 5h. The manufacturing cost of ethanol from untreated wood was 4.12€/L.
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detailed study of efficient ethanol production from elmwood by Alkali Pretreatment
Biochemical Engineering Journal, 2016Co-Authors: Mahboubeh S Noori, Keikhosro KarimiAbstract:Abstract An Alkaline Pretreatment was performed on hardwood elm to improve enzymatic hydrolysis and ethanol production. The Pretreatment was conducted with 8% (w/v) NaOH solution at 0, 25, and 80 °C for 2 h, and the best results were obtained by the Pretreatment at 0 °C. The glucose yield from untreated wood was only 8.0% and improved to 71.5% after the Pretreatment at 0 °C, whereas the corresponding ethanol yield was improved from 11.1% to 45.7%. In order to decrease ineffective adsorption of cellulase enzyme on lignin and enhance the enzymatic hydrolysis and fermentation yields, a non-ionic surfactant, Tween-20, was used in the hydrolysis process. The addition of 2.5 g L −1 Tween-20 further favorably modified the yields of enzymatic hydrolysis and ethanol production to 79.8% and 57.3%, respectively. Changes in the wood’s structural properties by the Pretreatment were followed in detail by swelling and buffering capacity measurements as well as SEM and FTIR analyses. Furthermore, the adsorption and desorption of cellulase during the enzymatic hydrolysis were investigated, and a consistent relation was observed between adsorbed and desorbed enzymes and enzymatic hydrolysis yield.
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castor plant for biodiesel biogas and ethanol production with a biorefinery processing perspective
Applied Energy, 2014Co-Authors: Hamed Bateni, Akram Zamani, Keikhosro Karimi, Fatemeh BenakashaniAbstract:Whole parts of castor plant, as a non-edible energy crop, were used for multiple biofuels production. Extracted castor oil was used for biodiesel production by transesterification, whereas the castor plant residues, i.e., stem, seed cake, and leaves, were employed for ethanol and biogas production. Effects of operating conditions, including methanol to oil ratio, temperature, and reaction time on biodiesel production yield were investigated. The optimum biodiesel yield was 88.2%, obtained at 0.4:1 methanol to oil mass ratio at 40°C for 90min. This yield corresponded to 155g biodiesel per kg castor plant. In addition, Pretreatment using 8% w/v NaOH at 0 and 100°C for 30 and 60min was applied to improve ethanol and biogas yields. The best results for both enzymatic hydrolysis and ethanol production by simultaneous saccharification and fermentation (SSF) were obtained after Alkali Pretreatment at 100°C for 60min for all plant residues. The highest ethanol production yield achieved from pretreated castor stem was as high as 82.2%, corresponding to 63g ethanol per kg castor plant. In the case of biogas production, Alkali Pretreatment enhanced the methane production yield from castor stem; however, it could not improve the production yield of castor seed cake and leaves. Furthermore, untreated castor seed cake had the highest methane production yield of 252.1ml/g VS, equal to 68.2L per kg of castor plant.
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improvement of biogas production from pine wood by Alkali Pretreatment
Fuel, 2013Co-Authors: Peyman Salehian, Keikhosro Karimi, Hamid Zilouei, Azam JeihanipourAbstract:Abstract Alkaline Pretreatment with NaOH was used to improve biogas production from softwood pine. The Pretreatments were carried out with 8.0% w/w NaOH solution at two temperatures (0 and 100 °C) for different periods of time (10, 30 and 60 min). By anaerobic digestion of the treated and untreated materials to biogas, significant effects of the Pretreatments on the yield of methane were clearly observed. The best improvement was achieved by the treatment at 100 °C for 10 min, which resulted in 181.2% improvement in the methane production yield. The treatment at 0 °C was also effective, in which 60 min treatment resulted in 118.6% improvement in the methane yield compared to the untreated wood. Fourier transform infrared (FTIR) was used to analyze the changes in chemical structure and physical characteristics of lignin, hemicellulose, and cellulose of the treated wood, which indicated a reduction of crystallinity of cellulose due to the Pretreatment. Furthermore, scanning electron microscopic images revealed that disruption of the recalcitrant structure of the pine wood could be responsible for the improvement of methane yield.
Long Wee Lai - One of the best experts on this subject based on the ideXlab platform.
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comparison of steam Alkali chemical and microwave Alkali Pretreatment for enhancing the enzymatic saccharification of oil palm trunk
Renewable Energy, 2016Co-Authors: Long Wee Lai, Ani IdrisAbstract:This paper demonstrates two different Pretreatment protocols for oil palm trunks (OPT); steam-Alkali-chemical (SAC) and microwave-Alkali (Mw-A) method. The composition, morphology, structure and crystallinity of OPT before and after Pretreatment were analyzed. The effectiveness of the pretreated methods was investigated by performing enzymatic saccharification on the OPT. The physiochemical factors namely: enzyme ratio (cellulase to β-glucosidase), pH, temperature and substrate loading (w/v) on enzymatic saccharification were also investigated. The pre-determined optimal conditions were then used for further enzymatic hydrolysis of raw and pretreated OPT substrates. The results revealed a huge degree of reduction in lignin, up to 89% for SAC treated OPT and at least 15% for Mw-A treated OPT sample as compared to untreated ones. High glucose accumulation (79.4%) was obtained after 72 h saccharification for both pretreated OPT samples.
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factors affecting delignification of oil palm empty fruit bunch by microwave assisted dilute acid Alkali Pretreatment
Bioresources, 2014Co-Authors: Junaid Akhtar, Chee Loong Teo, Long Wee Lai, Nursia Hassan, Ani Idris, Ramlan AzizAbstract:Microwave-assisted dilute acid/Alkali Pretreatment is an efficient and rapid method of removing lignin and hemicellulose, however, the optimized parameters for the maximum efficiency have to date not been presented in the literature. The purpose of this study was to determine those conditions by examining the effects of three factors: microwave power, temperature, and time on delignification in microwave-assisted dilute acid/Alkali Pretreatment. For the control condition of conventional Pretreatment (CP), empty fruit bunches (EFBs) were soaked in 2.5 M NaOH for two hours in the autoclave. In the experimental condition, EFB were first soaked in dilute sulfuric acid with conventional autoclave heating, which removed 90% of their hemicellulose. The acid-treated EFBs were then soaked in 2.5 M NaOH solution and microwaved at different conditions: microwave power (700 - 100 watts), time (60 - 90 min), and temperature (80 -110 °C). The amount of acid-insoluble lignin was determined by Klason method. Microwave-Alkali (Mw-A) Pretreatment was modeled until it attained maximum delignification. More than twice the rate of delignification that is, 71.9% was attained with microwave-assisted Alkali/acid Pretreatment of 900 W microwave power at 110 °C for 80 min compared to 34.6% with conventional Pretreatment.
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disruption of oil palm trunks and fronds by microwave Alkali Pretreatment
Bioresources, 2013Co-Authors: Long Wee Lai, Ani IdrisAbstract:In this study, lignocellulosic biomass from oil palm trunk (OPT) and oil palm frond (OPF) of oil palm tree, Elaeis guineensis, were treated using the microwave-Alkali (Mw-A) method, and their chemical constituents, namely cellulose, hemicellulose, and lignin, were analyzed. A number of instruments, i.e. FESEM, FT-IR, and XRD, were employed to analyze the morphology and structural changes of biomass. After the Mw-A Pretreatment, it was revealed that the amount of cellulose released was up to 41.55% for OPT and 64.42% for OPF. There was also a huge degree of reduction in hemicellulose, up to 64%, but lignin removal saw a fair reduction with only 15.33% for OPT and 17.97% for OPF. The results revealed that the Mw-A Pretreatment is capable of disrupting the OPT and OPF.
Jay J Cheng - One of the best experts on this subject based on the ideXlab platform.
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modeling changes in biomass composition during microwave based Alkali Pretreatment of switchgrass
Biotechnology and Bioengineering, 2010Co-Authors: Deepak R Keshwani, Jay J ChengAbstract:This study used two different approaches to model changes in biomass composition during microwave-based Pretreatment of switchgrass: kinetic modeling using a time-dependent rate coefficient, and a Mamdani-type fuzzy inference system. In both modeling approaches, the dielectric loss tangent of the Alkali reagent and Pretreatment time were used as predictors for changes in amounts of lignin, cellulose, and xylan during the Pretreatment. Training and testing data sets for development and validation of the models were obtained from Pretreatment experiments conducted using 1-3% w/v NaOH (sodium hydroxide) and Pretreatment times ranging from 5 to 20 min. The kinetic modeling approach for lignin and xylan gave comparable results for training and testing data sets, and the differences between the predictions and experimental values were within 2%. The kinetic modeling approach for cellulose was not as effective, and the differences were within 5-7%. The time-dependent rate coefficients of the kinetic models estimated from experimental data were consistent with the heterogeneity of individual biomass components. The Mamdani-type fuzzy inference was shown to be an effective approach to model the Pretreatment process and yielded predictions with less than 2% deviation from the experimental values for lignin and with less than 3% deviation from the experimental values for cellulose and xylan. The entropies of the fuzzy outputs from the Mamdani-type fuzzy inference system were calculated to quantify the uncertainty associated with the predictions. Results indicate that there is no significant difference between the entropies associated with the predictions for lignin, cellulose, and xylan. It is anticipated that these models could be used in process simulations of bioethanol production from lignocellulosic materials.
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microwave based Alkali Pretreatment of switchgrass and coastal bermudagrass for bioethanol production
Biotechnology Progress, 2009Co-Authors: Deepak R Keshwani, Jay J ChengAbstract:Switchgrass and coastal bermudagrass are promising lignocellulosic feedstocks for bioethanol production. However, Pretreatment of lignocelluloses is required to improve production of fermentable sugars from enzymatic hydrolysis. Microwave-based Alkali Pretreatment of switchgrass and coastal bermudagrass was investigated in this study. Pretreatments were carried out by immersing the biomass in dilute Alkali reagents and exposing the slurry to microwave radiation at 250 W for residence times ranging from 5 to 20 min. Simons' stain method was used to quantify changes in biomass porosity as a result of the Pretreatment. Pretreatments were evaluated based on yields of total reducing sugars, glucose, and xylose. An evaluation of different Alkalis identified sodium hydroxide as the most effective Alkali reagent for microwave-based Pretreatment of switchgrass and coastal bermudagrass. 82% glucose and 63% xylose yields were achieved for switchgrass and 87% glucose and 59% xylose yields were achieved for coastal bermudagrass following enzymatic hydrolysis of biomass pretreated under optimal conditions. Dielectric properties for dilute sodium hydroxide solutions were measured and compared with solid losses, lignin reduction, and reducing sugar levels in hydrolyzates. Results indicate that dielectric loss tangent of Alkali solutions is a potential indicator of the severity of microwave-based Pretreatments.
Tony Vancov - One of the best experts on this subject based on the ideXlab platform.
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Alkali Pretreatment of cereal crop residues for second generation biofuels
Energy & Fuels, 2011Co-Authors: Tony Vancov, Shane McintoshAbstract:Mild Alkali cooking of lignocellulosic biomass is an effective Pretreatment method, which improves enzymatic hydrolysis. Here, we report the use of dilute Alkali (NaOH) Pretreatment followed by enzyme saccharification of cereal residues for their potential to serve as feedstock in the production of next-generation biofuels in Australia. After Pretreatment, both solids and lignin content were found to be inversely proportional to treatment severity. We also found that higher temperatures and Alkali strength were quintessential for maximizing sugar recoveries from enzyme saccharifications. Generally, Pretreatment conditions at elevated temperatures led to highly digestible material enriched in both cellulose and hemicellulose components. Increasing cellulase loadings and tailoring enzyme activities with additional β-glucosidases and xylanases delivered greater rates of monosaccharide sugar release and yields throughout enzyme hydrolysis. Considering their abundance, high sugar potential, and apparent ease o...
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enhanced enzyme saccharification of sorghum bicolor straw using dilute Alkali Pretreatment
Bioresource Technology, 2010Co-Authors: Shane Mcintosh, Tony VancovAbstract:Abstract The impacts of varying Pretreatment parameters (temperature, time, and Alkalinity) on enzymatic hydrolysis of sorghum straw were investigated. Following Pretreatment, both solids and lignin content was found to be inversely proportional to the severity of the treatments. Higher temperatures and Alkali strength were quintessential for maximising sugar recoveries from enzyme saccharifications. Total sugar release peaked when sorghum straw was pretreated in 2% NaOH at 121 °C for 60 min; representing a 5.6-fold higher yield compared to samples pretreated at 60 °C in the absence of Alkali. Similarly, 4.3-fold increases in total sugars from samples treated with 2% NaOH at 60 °C for 90 min, confirmed the importance of Alkali inclusion. Addition of β-glucosidase and xylanase to saccharification mixtures enhanced reaction rates and final sugar yields, whilst reducing cellulase dosage 4-fold. Saccharification efficiency of pretreated solids approached 90% and 95% (w/w) with as little as 2.5 and 5.0 FPU cellulase/g, respectively.