Development of integrated biorefinery model for the production of bioethanol from oil palm frond

Application of an efficient pretreatment step is crucial in developing a viable biorefinery system for the production of lignocellulosic bioethanol. Subcritical hydrothermal appears as an economic pretreatment method with high sugar recovery. However, there were limited reports on its application with carbon dioxide (CO2) addition, particularly on oil palm biomass, hence this area should be explored. Moreover, by understanding the mechanism of hemicellulose degradation during pretreatment, the sugar produced hence bioethanol yield could be maximized. Although the integrated biorefinery approach for the production of bioethanol from oil palm frond (OPF) at the oil palm mill was reported promising, assessment of its environmental impact was equally important. Therefore, in this study, subcritical hydrothermal pretreatment of OPF pressed fiber (OPFPF) was conducted using stainless steel tube reactor and miniclave at various temperature, time and CO2 pressure, to evaluate the effect of CO2 addition on glucose production. Similarly, a kinetic study was performed to determine the kinetics of hemicellulose (xylan) degradation during the pretreatment using miniclave. In addition, the environmental and economic viability of integrated biorefinery model for bioethanol production from OPF was assessed by Life Cycle Analysis and cost analysis, each, based on three different case studies. Maximum glucose yield of 57.1% (g/g OPFPF) was obtained with application of tube reactor at 180°C, 1 MPa CO2 for 20 min, and further enhanced to 78.6% using miniclave at similar temperature and pressure for 30 min. Moreover, the rise of temperature and CO2 addition was found to improve the xylan autohydrolysis, with 180°C and 0.5 MPa CO2 as the most suitable condition for high glucose recovery from OPFPF. Furthermore, the integrated biorefinery model for the production of bioethanol from the OPF juice offers the best environmental and economic approach with production cost of $0.25/ L. Based on this study, subcritical hydrothermal pretreatment is a promising method for application at the integrated biorefinery system at the oil palm mill in the future

Life Cycle Assessment for Bioethanol Production from Oil Palm Frond Juice in an Oil Palm Based Biorefinery

A study was conducted to estimate the possible environmental impacts arising from the generation of bioethanol from oil palm frond sugar juice in a theoretical oil palm based biorefinery model. A life cycle assessment (LCA) with the gate-to-gate approach was performed with the aid of SimaPro version 8.0 whereby ten impact categories were evaluated. The scope included frond collection and transportation, frond sugar juice extraction, and bioethanol fermentation and purification. Evaluation on the processes involved indicated that fermentation contributed to the environmental problems the most, with a contribution range of 52% to 97% for all the impact categories. This was due to a substantial usage of nutrient during this process, which consumes high energy for its production thus contributing a significant burden to the surrounding. Nevertheless, the present system offers a great option for biofuel generation as it utilizes sugar juice from the readily available oil palm waste. Not only solving the issue of land utilization for feedstock cultivation, the enzymatic saccharification step, which commonly necessary for lignocellulosic sugar recovery could also be eliminated

Kinetics of xylan autohydrolysis during subcritical hydrothermal pretreatment of oil palm frond pressed fiber

A kinetic study was performed to determine the kinetics of hemicellulose (xylan) hydrolysis during subcritical hydrothermal pretreatment of OPFPF. The trend of xylan conversion was observed over 40-min treatment time at two different conditions: without CO2 addition at four different temperatures (170, 180, 190, and 200 °C), and with CO2 addition of 0.5 and 1 MPa at 180 °C. Experimental data obtained was subsequently fitted into the selected first-order kinetic model. It was demonstrated that the experimental data was comparable to the predicted values, indicating the suitability of the chosen model for quantitative interpretation of the experimental results. In addition, the reaction rate was found to improve with the rise of temperature and the presence of CO2, as indicated by the increasing values of reaction rate constants, k. The relationship between k and temperature was successfully established through Arrhenius equation, where the activation energies for xylan conversion were found in the range of 43.49 to 170.16 kJ/mol. Based on the results, subcritical pretreatment of OPFPF at 180 °C and 0.5 MPa CO2 was suggested suitable for high glucose recovery from OPFPF due to high xylan removal rate and low generation of hydrolysis byproduct which is beneficial for successful saccharification and fermentation. This study provides knowledge in the kinetics of xylan autohydrolysis in oil palm frond, and hence could contribute in the process design for recovery of glucose and hemicellulose derivatives such as XOS and furfural from oil palm residues

Formulation of Fish Feed with Optimum Protein-bound Lysine for African Catfish (Clarias Gariepinus) Fingerlings

AbstractEarthworm powder is a potential source of lysine, a first limiting amino acid which is essential in fish diet. The incorporation of other feed ingredients with acceptable composition of lysine can help to enhance lysine content in fish feeds. The focus of this study is to optimize lysine content in fish feeds with difference percentages of each selected feeds ingredients. The optimization study was conducted using central composite design (CCD) as statistical tool. The optimum lysine content was obtained at 25.00%, 20.88%, 10.00% and 20.00% of earthworm powder, soybean waste, leucaena leucocephala leaves and fish meal, respectively. The lysine content in formulated fish feeds was significantly affected by the composition of earthworm powder and fish meal in fish feed formulation. Earthworm powder and fish meal have contributed the largest portion of lysine in fish feed due to high lysine content which were 4.48% w/w and 3.60% w/w, respectively. The optimized fish feed shows high lysine content of 23.39% w/w which doubles the lysine content in commercial fish feed (11.21% w/w). The composition of fish feed obtained from this study can be used as guidelines for formulation of high lysine fish feeds for African catfish fingerlings

Life Cycle Assessment for Bioethanol Production from Oil Palm Frond Juice in an Oil Palm Based Biorefinery

A study was conducted to estimate the possible environmental impacts arising from the generation of bioethanol from oil palm frond sugar juice in a theoretical oil palm based biorefinery model. A life cycle assessment (LCA) with the gate-to-gate approach was performed with the aid of SimaPro version 8.0 whereby ten impact categories were evaluated. The scope included frond collection and transportation, frond sugar juice extraction, and bioethanol fermentation and purification. Evaluation on the processes involved indicated that fermentation contributed to the environmental problems the most, with a contribution range of 52% to 97% for all the impact categories. This was due to a substantial usage of nutrient during this process, which consumes high energy for its production thus contributing a significant burden to the surrounding. Nevertheless, the present system offers a great option for biofuel generation as it utilizes sugar juice from the readily available oil palm waste. Not only solving the issue of land utilization for feedstock cultivation, the enzymatic saccharification step, which commonly necessary for lignocellulosic sugar recovery could also be eliminated

Life cycle assessment for bioethanol production from oil palm frond juice in an oil palm based biorefinery

A study was conducted to estimate the possible environmental impacts arising from the generation of bioethanol from oil palm frond sugar juice in a theoretical oil palm based biorefinery model. A life cycle assessment (LCA) with the gate-to-gate approach was performed with the aid of SimaPro version 8.0 whereby ten impact categories were evaluated. The scope included frond collection and transportation, frond sugar juice extraction, and bioethanol fermentation and purification. Evaluation on the processes involved indicated that fermentation contributed to the environmental problems the most, with a contribution range of 52% to 97% for all the impact categories. This was due to a substantial usage of nutrient during this process, which consumes high energy for its production thus contributing a significant burden to the surrounding. Nevertheless, the present system offers a great option for biofuel generation as it utilizes sugar juice from the readily available oil palm waste. Not only solving the issue of land utilization for feedstock cultivation, the enzymatic saccharification step, which commonly necessary for lignocellulosic sugar recovery could also be eliminated

Life Cycle Assessment for Bioethanol Production from Oil Palm Frond Juice in an Oil Palm Based Biorefinery

A study was conducted to estimate the possible environmental impacts arising from the generation of bioethanol from oil palm frond sugar juice in a theoretical oil palm based biorefinery model. A life cycle assessment (LCA) with the gate-to-gate approach was performed with the aid of SimaPro version 8.0 whereby ten impact categories were evaluated. The scope included frond collection and transportation, frond sugar juice extraction, and bioethanol fermentation and purification. Evaluation on the processes involved indicated that fermentation contributed to the environmental problems the most, with a contribution range of 52% to 97% for all the impact categories. This was due to a substantial usage of nutrient during this process, which consumes high energy for its production thus contributing a significant burden to the surrounding. Nevertheless, the present system offers a great option for biofuel generation as it utilizes sugar juice from the readily available oil palm waste. Not only solving the issue of land utilization for feedstock cultivation, the enzymatic saccharification step, which commonly necessary for lignocellulosic sugar recovery could also be eliminated