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In recent years, palm kernel shell (PKS) has become a viable feedstock for making biofuels and value-added commodities using a variety of thermal conversion routes. Therefore, significant conservation is required for PKS as a resource for fuel production in biofuel facilities. Thus, this research was intended to elucidate the effects on PKS as a solid fuel through torrefaction and the production of bio-char and bio-oil by single and co-pyrolysis of PKS and polyethylene (PE). The PKS was treated through torrefaction at different temperatures and holding times. The optimum parameters for torrefaction were a temperature of 250 oC and a holding time of 60 min. Then the PKS and PE were pyrolyzed in a fixed-bed reactor at different temperatures and ratios. The product yield was analysed for single and co-pyrolysis of PKS and PE for pyrolysis. The properties of the product composition for single and co-pyrolysis of the PKS and PE were determined by proximate analysis, Fourier transform infrared (FTIR) analysis, and gas chromatography-mass spectrometry (GC-MS). The optimum parameter obtained for biochar and bio-oil production from co-pyrolysis of PKS and PE was at temperature of 500 oC at a ratio of 1:2 (PKS: PE). The ester and phenol compounds were increased around 19.02 to 23.18% and 32.51 to 34.80 %, respectively, while amide and amine decreased around 4.94 to 18.87% and 0.63 to 32.39 %, respectively, compared to the single pyrolysis of PKS. Therefore, the PKS and PE co-pyrolysis significantly increased the amount of phenol and ester compounds while slightly reducing the amount of amide and amine compounds in the bio-oil product. As a conclusion, biomass conservation enables the manufacturing of value-added chemicals. [ABSTRACT FROM AUTHOR]

In this study, co-gasification of palm kernel shell (PKS) and low-rank Malaysian coal (MB) was carried out in a fixed bed reactor. For the pretreated samples, PKS was torrefied at 270°C (PKSTo) and MB was preheated at 250°C (MBPr) for 1 h, respectively, prior to co-gasification at 767°C, with a biomass blending ratio of 52% and a steam flow rate of 55 mL/min. The effect of different blending combinations was investigated towards product yields, namely gas, tar, char and gases composition. The co-gasification on both pretreated (PKSTo/MBPr) and catalyst-pretreated (Cat-PKSTo/MBPr) produced a greater gas yield, with lesser tar and char yield than both untreated PKS and MB (PKSUn/MBUn) and pretreated PKS and untreated MB (PKSTo/MBUn). The PKSTo/MBPr was found to enhance the H2 production by 63.9% and 41% than PKSUn/MBUn and PKSTo/MBUn, respectively, at 45 min of reaction time. Thus, the pretreatment on both samples had a significant impact on the distribution and composition of product yields during co-gasification. As a conclusion, the pretreated sample, which has been upgraded on characteristics such as higher carbon and lower oxygen content than the untreated sample was revealed to enhance gas yield and H2 production during co-gasification. [ABSTRACT FROM AUTHOR]

The present work aimed to improve catalytic efficiency of Trichoderma reesei cellulase for enhanced saccharification. The cellulase was immobilized on two nanomatrices i.e. magnetic and silica nanoparticles with immobilization efficiency of 85% and 76% respectively. The nanobioconjugates exhibited increase in V max , temperature optimum, pH and thermal stability as compared with free enzyme. These could be efficiently reused for five repeated cycles and were stable in 1-ethyl-3-methylimidazoliumacetate [EMIM][Ac], an ionic liquid. Ionic liquids (IL) are used as green solvents to dissolve lignocellulosic biomass and facilitate better saccharification. The cellulase immobilized on magnetic nanoparticles was used for in situ saccharification of [EMIM][Ac] pretreated sugarcane bagasse and wheat straw for two cycles. The structural deconstruction and decrease in biomass crystallinity was confirmed by SEM, XRD and FTIR. The high hydrolysis yields (∼89%) obtained in this one-pot process coupled with IL stability and recycled use of immobilized cellulase, potentiates its usefulness in biorefineries. [ABSTRACT FROM AUTHOR]

New and renewable fuels are the major alternative to conventional fossil fuels. Biomass is a form of agricultural residues and is becoming popular among new renewable energy sources especially in an agricultural country such as Malaysia. Among the biomass, rice husk represents one of the highest agricultural wastes in Malaysia. Pyrolysis of biomass is one of the most important thermal conversion processes to produce bio-oil. The aim of the present study is to determine the characteristics and thermal degradation behavior of rice husk via thermal gravimeiric analysis (TGA). Chemical analyses show that rice husk contains a high amount of organic constituents of hemi-cellulose (24%), cellulose (29%), and lignin (12.2%). Furthermore, the TG results show that the lignin is relatively more thermally stable than hemi-cellulose and cellulose. Evaluation of biomass resources as potential feedstock for conversion to bio-fuel generally requires information about proximate analysis, ultimate analysis, organic component analysis (hemi-cellulose, cellulose and lignin contents), and calorific value determination. [ABSTRACT FROM AUTHOR]

Microalgae have been identified as one of the new feedstocks for renewable energy production. The conversion of microalgae into various valuable products has also been increasing in the last decade. Microalgae harvesting, one of the most important stages in microalgae production, has been studied and reviewed by many researchers. However, most harvesting methods still utilize chemicals during the process, which make harvested biomass not directly ready for food/feed production and pharmaceutical-related processes. Biocoagulants/bioflocculants are emerging compounds that can be used during the harvesting of microalgae because their existence does not introduce toxicity in the harvested biomass. Considering its potential to produce ready-to-use biomass, biocoagulants/bioflocculants have a bright future in microalgal biomass production processes. This review article highlights simultaneous wastewater treatment and microalgal biomass production as an emerging method in accommodating a circular economy paradigm. This paper juxtaposes the utilization of chemical-based coagulants/flocculants and biocoagulants/bioflocculants in harvesting microalgae. Biodegradability, effectiveness, harvested biomass characteristics, and potential of medium reuse are emphasized in the discussion. The agglomeration mechanisms of microalgae during harvesting, recent advances in the microalgal biomass conversions, and future challenges related to the utilization of biocoagulants/bioflocculants are also described in detail. Microalgae harvesting by using biocoagulants/bioflocculants is a feasible and promising environmentally friendly technology for microalgal biomass production. [Display omitted] • Performances of microalgae harvesting using biocoagulants/bioflocculants are discussed. • Cultivation of microalgae using wastewater is discussed. • Mechanisms of microalgae harvesting are elaborated. • Conversion of microalgae biomass into valuable products are highlighted. • Future challenges on algae harvesting using biocoagulants/bioflocculants are discussed. [ABSTRACT FROM AUTHOR]