ABSTRACT
The abundant availability of various kinds of biomass and their use as feedstock for the production of gaseous and liquid biofuels has been considered a viable, eco-friendly, and sustainable mode of energy generation. Gaseous fuels like biogas and liquid fuels, e.g., bioethanol, biodiesel, and biomethanol derived from biological sources, have been theorized to produce numerous industrially relevant organic compounds replacing the traditional practice of employing fossil fuels as a raw material. Among the biofuels explored, biomethanol has shown promising potential to be a future product addressing multifactorial issues concerning sustainable energy and associated process developments. The presented mini-review has explored the importance and application of biomethanol as a value-added product. The biomethanol production process was well reviewed by focusing on different thermochemical and biochemical conversion processes. Syngas and biogas have been acknowledged as potential resources for biomethanol synthesis. The emphasis on biochemical processes is laid on the principal metabolic pathways and enzymatic machinery involved or used by microbial physiology to convert feedstock into biomethanol under normal temperature and pressure conditions. The advantage of minimizing the cost of production by utilizing suggested modifications to the overall process of biomethanol production that involves metabolic and genetic engineering in microbial strains used in the production process has been delineated. The challenges that exist in our current knowledge domain, impeding large-scale commercial production potential of biomethanol at a cost-effective rate, and strategies to overcome them along with its future scenarios have also been pointed out.
ABSTRACT
The major global concern on energy is focused on conventional fossil resources. The burning of fossil fuels is an origin of greenhouse gas emissions resulting in the utmost threat to the environment and subsequently which leads to global climate changes. As far as sustainability is concerned, fuels and materials derived from organic or plant wastes overcome this downside establishing the solution to the fossil resource crisis. In this context, exploration of agricultural residue appears to be a suitable alternative of non-renewable resources to support the environmental feasibility and meet the high energy crisis. The use of agricultural waste as a feedstock for the biorefinery approach emerges to be an eco-friendly process for the production of biofuel and value-added chemicals, intensifying energy security. Therefore, a prospective choice of this renewable biomass for the synthesis of green fuel and other green biochemicals comes up with a favorable outcome in terms of cost-effectiveness and sustainability. Exploiting different agricultural biomass and exploring various biomass conversion techniques, biorefinery generates bioenergy in a strategic way which eventually fits in a circular bioeconomy. Sources and production of agricultural waste are critically explained in this paper, which provides a path for further value addition by various technologies. Biorefinery solutions, along with a life cycle assessment of agricultural waste biomass toward a wide array of value-added products aiding the bioeconomy, are summarized in this paper.
Subject(s)
Fossil Fuels , Plants , Biofuels , Biomass , Prospective Studies , RecyclingABSTRACT
The primary focus of this work was to recover lignin and investigate the structural changes in sugarcane bagasse after pretreatment with ionic liquid 1-ethyl-3-methylimidazolium acetate ([EMIM]oAc). 90% lignin recovery was achieved while bagasse was treated with [EMIM]oAc at 140 °C, 120 min reaction time and 1:20 bagasse to the ionic liquid ratio (w/w). The impact of ionic liquid pretreatment on bagasse was confirmed by qualitative analysis of untreated and pretreated bagasse. Scanning electron microscopy analysis exhibited the porous and irregular structure of bagasse after pretreatment. X-ray powder diffraction analysis verified a decrease in crystallinity as a result of the pretreatment process by showing a 14.7% reduction of Crystallinity index after ionic liquid treatment. The efficacy of [EMIM]oAc on bagasse treatment was also examined by enzymatic hydrolysis which manifested an increase in reducing sugar yield as a result of pretreatment. Maximum yield of 54.3% reducing sugar was obtained after 72 h enzymatic hydrolysis of pretreated bagasse. Recovered lignin was analyzed qualitatively. 1D NMR spectroscopy of lignin revealed the presence of essential functional groups whereas 2D NMR spectroscopy showed the dominance of etherified syringyl unit. Further ionic liquid recovery and reuse were substantiated by Gel permeation chromatography analysis of lignin. Weight average molecular weight (Mw) of lignin extracted by fresh [EMIM]oAc was obtained as 1769 g/mol (in the previous study) while lignin recovered by recycled [EMIM]oAc showed almost equal Mw 1765 g/mol in this study. Thus, the current investigation corroborated satisfactory performance of [EMIM]oAc in lignocellulose processing which further enhanced enzymatic hydrolysis in the subsequent step.
ABSTRACT
Demand for microbial amylase production persists because of its immense importance in wide spectrum industries. The present work has been initiated with a goal of optimization of solid state fermentation condition for amylase using agroindustrial waste and microbial strain like B. amyloliquefaciens (MTCC 1270). In an aim to improve the productivity of amylase, fermentation has been carried out in the presence of calcium (Ca(+2)), Nitrate (NO3 (-)), and chloride ions (Cl(-)) as well as in the presence of D-inositol and mannitol. Amylase needs calcium ion for the preservation of its structure, activity and stability that proves beneficial also for amylase production using solid state fermentation. The inclusion of ions and sugars in the SSF media is promising which can be explained by the protection offered by them against thermal decay of amylase at various incubation periods at 37°C.
