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Introduction: Fossil fuels are the main sources of water, soil, and air pollution that threaten human life and other organisms on Earth. Nowadays, the climate change and pollution are critical issues; however, many countries still use polluting fossil fuels. Therefore, finding alternative and clean fuels is a concern for many environmental activists and scientists. One of these alternative fuels is ethanol, which ignites cleaner due to its higher hydroxyl groups and lack of sulfur and nitrogen in its formula. Ethanol can be produced both chemically and biologically. Till now, four generations of bioethanol have been introduced. In the second generation, lignocellulosic materials are used as the main source for bioethanol production. These materials are frequently found in plant biomasses and agricultural residues, which are inexpensive and environmentally sustainable. Therefore, it is of importance to improve the production process and find novel techniques that increase final yields and process efficacy. In this study, the structural properties of lignocellulosic materials, pretreatment techniques, the second-generation bioethanol production process, and the effective bacterial and fungal strains in this procedure are investigated.Materials and Methods: This review study is a narrative review in which a logical search approach was selected. For data analysis, a comparative approach between the different methods was expressed in each section.Results: Among four bioethanol generations, the second generation has received remarkable attention due to its non-competition with human food and its industrial potential rather than other generations. Therefore, it is of particular significance to improve the production process of bioethanol second generation. A deep understanding of lignocellulosic components, pretreatment methods optimization, and increasing hydrolysis and fermentation processes efficiency make bioethanol production industrially possible and cost-effective.Discussion and Conclusion: However, despite extensive studies to select the most suitable microorganisms during the fermentation stage, Saccharomyces cerevisiae and Zymomonas mobilis are still at the forefront of studies.

Introduction: Fossil fuels are the main sources of water, soil, and air pollution that threaten human life and other organisms on Earth. Nowadays, the climate change and pollution are critical issues; however, many countries still use polluting fossil fuels. Therefore, finding alternative and clean fuels is a concern for many environmental activists and scientists. One of these alternative fuels is ethanol, which ignites cleaner due to its higher hydroxyl groups and lack of sulfur and nitrogen in its formula. Ethanol can be produced both chemically and biologically. Till now, four generations of bioethanol have been introduced. In the second generation, lignocellulosic materials are used as the main source for bioethanol production. These materials are frequently found in plant biomasses and agricultural residues, which are inexpensive and environmentally sustainable. Therefore, it is of importance to improve the production process and find novel techniques that increase final yields and process efficacy. In this study, the structural properties of lignocellulosic materials, pretreatment techniques, the second-generation bioethanol production process, and the effective bacterial and fungal strains in this procedure are investigated. Materials and Methods: This review study is a narrative review in which a logical search approach was selected. For data analysis, a comparative approach between the different methods was expressed in each section. Results: Among four bioethanol generations, the second generation has received remarkable attention due to its non-competition with human food and its industrial potential rather than other generations. Therefore, it is of particular significance to improve the production process of bioethanol second generation. A deep understanding of lignocellulosic components, pretreatment methods optimization, and increasing hydrolysis and fermentation processes efficiency make bioethanol production industrially possible and cost-effective. Discussion and Conclusion: However, despite extensive studies to select the most suitable microorganisms during the fermentation stage, Saccharomyces cerevisiae and Zymomonas mobilis are still at the forefront of studies. [ABSTRACT FROM AUTHOR]

In this study, the mechanical properties of kenaf cement composite were investigated using different amounts of kenaf particles (mixture of kenaf core and bark and kenaf core particles). Kenaf-cement composites were manufactured at different levels (10, 15 and 20%) of different kenaf particles. Also, Portland cement and calcium chloride (as cement accelerating additive) were used in this research. Calcium chloride and water were mixed well and then kenaf particles were added to the mixture. At next stage, cement was added to the prepared mixture and all component were mixed well. Prepared mixture was molded to the wooden mold and kenaf cement composites were produced. The results obtained from mechanical evaluation of kenaf-cement composites showed the highest bending strength in 10% kenaf bark-cement composites. Also results revealed that highest modulus of elasticity of 10% kenaf core-cement products were obtained. The results of this research revealed the potential of kenaf particles as reinforcement in cement composite production. [ABSTRACT FROM AUTHOR]

In this study the effect of type of polymer including polyvinyl chloride and high density polyethylene in production of wood plastic composite by using of canola straw waste in two forms, with and without pith (depithed), in combination with wood flour were investigated. Five levels of lignocellulosic materials were used consisting of 100 % wood flour, 100% canola flour including pith, 100% depithed canola flour, 50% wood flour plus 50% canola flour with pith and 50% wood flour plus 50% depithed canola flour. Physical properties of boards including, thickness swelling and water absorption after 2 and 24 hours immersion in water and mechanical properties such as screw withdrawal strength perpendicular on the surface, flexural strength and modulus of elasticity according to EN were evaluated. The results of this study showed that wood plastic composite made of high density polyethylene had better physical and mechanical properties compared with polyvinyl chloride and using of canola flour combined with wood flour lead to increasing flexural strength and modulus of elasticity, but decreased screw withdrawal strength perpendicular on the surface. Using of lignocellulosic filler material by combining of 50% wood flour plus 50 % depithed canola flour combined with high density polyethylene powder can be produced wood plastic composite board with suitable physical and mechanical properties.

To improve the mechanical properties of wood plastics composites, four lignocellulosic materials (bagasse, rice straw, wheat straw and poplar wood powder) was used as the reinforcing material. The amount of nano-clay at different levels (0, 3 and 6%) were examined on the performance of wood plastic composites. Tensile, flexural and impact properties were measured in accordance with ASTM standard test methods. Scanning electron microscope imaging (SEM) and transmission electron microscope imaging (TEM) were performed to interpret the results. The applocation of bagasse and poplar wood powder compared with wheat and rice straws increased the strength of wood plastics composites. Using 3% nanoclay particles increased the strength properties to the maximum values. Imaging the morphology of nanoclay by X-ray diffraction and electron microscopy showed the distribution of nanoclay particles in polymer structure. With increasing the amount of nanoclay to 3%, the distance between layers increased.

In this study two imidazole-based Ionic liquids, 1- butyl -3 - methyl -1 - Imidazolium chloride (BMIMCl) and 1- butyl -3 - Methyl Imidazolium Methyl sulfate ([BMIM][MeSo4]), were used to dissolve wood flour, cellulose and CMP pulp. The overall evaluation indicates the inability of ([BMIM][MeSo4]) in full dissolution of lignocellulosic materials and sample treatment with this solvent was lead to water soluble degradation products. However, dissolution trials using BMIMCl was able to dissolve Lignocellulosics. Density, clarity, water absorption and thickness swelling of regenerated cellulose films were significantly higher than that of CMP and wood flour, and CMP, higher than wood flour. Also, cellulose film have the lowest water vapor permeability compared to wood flour and CMP. Tensile strength, Young's modulus and strain at breaking point of cellulose film were significantly higher than the CMP and wood flour samples.