Sustainable economic and industrial growth requires safe, sustainable resources of energy. For the future re-arrangement of a sustainable economy to biological raw materials, completely new approaches in research and development, production, and economy are necessary. The ‘first-generation’ biofuels appear unsustainable because of the potential stress that their production places on food commodities. For organic chemicals and materials these needs to follow a biorefinery model under environmentally sustainable conditions. Where these operate at present, their product range is largely limited to simple materials (i.e. cellulose, ethanol, and biofuels). Second generation biorefineries need to build on the need for sustainable chemical products through modern and proven green chemical technologies such as bioprocessing including pyrolysis, Fisher Tropsch, and other catalytic processes in order to make more complex molecules and materials on which a future sustainable society will be based. This review focus on cost effective technologies and the processes to convert biomass into useful liquid biofuels and bioproducts, with particular focus on some biorefinery concepts based on different feedstocks aiming at the integral utilization of these feedstocks for the production of value added chemicals.

http://staff.cimap.res.in/PublicationFiles/Renew_Sustain_Energ_Rev_14_578.pdf

Production of first and second generation biofuels: A comprehensive review

This critical review provides a survey illustrated by recent references of different strategies to achieve a sustainable conversion of biomass to bioproducts. Because of the huge number of chemical products that can be potentially manufactured, a selection of starting materials and targeted chemicals has been done. Also, thermochemical conversion processes such as biomass pyrolysis or gasification as well as the synthesis of biofuels were not considered. The synthesis of chemicals by conversion of platform molecules obtained by depolymerisation and fermentation of biopolymers is presently the most widely envisioned approach. Successful catalytic conversion of these building blocks into intermediates, specialties and fine chemicals will be examined. However, the platform molecule value chain is in competition with well-optimised, cost-effective synthesis routes from fossil resources to produce chemicals that have already a market. The literature covering alternative value chains whereby biopolymers are converted in one or few steps to functional materials will be analysed. This approach which does not require the use of isolated, pure chemicals is well adapted to produce high tonnage products, such as paper additives, paints, resins, foams, surfactants, lubricants, and plasticisers. Another objective of the review was to examine critically the green character of conversion processes because using renewables as raw materials does not exempt from abiding by green chemistry principles (368 references).

Conversion of biomass to selected chemical products

Cerium dioxide (CeO2, ceria) is becoming an ubiquitous constituent in catalytic systems for a variety of applications. 2016 sees the 40th anniversary since ceria was first employed by Ford Motor Company as an oxygen storage component in car converters, to become in the years since its inception an irreplaceable component in three-way catalysts (TWCs). Apart from this well-established use, ceria is looming as a catalyst component for a wide range of catalytic applications. For some of these, such as fuel cells, CeO2-based materials have almost reached the market stage, while for some other catalytic reactions, such as reforming processes, photocatalysis, water-gas shift reaction, thermochemical water splitting, and organic reactions, ceria is emerging as a unique material, holding great promise for future market breakthroughs. While much knowledge about the fundamental characteristics of CeO2-based materials has already been acquired, new characterization techniques and powerful theoretical methods are dee...

Fundamentals and Catalytic Applications of CeO2-Based Materials

Lignocellulosic biomass pyrolysis mechanism: A state-of-the-art review

https://www.cell.com/trends/biotechnology/pdf/S0167-7799(06)00254-X.pdf

Bio-ethanol--the fuel of tomorrow from the residues of today.

Effect of ammonia removal and biochar detoxification on anaerobic digestion of aqueous phase from municipal sludge hydrothermal liquefaction.

The economic viability of heat and power generation from biomass gasification is strongly influenced by the supply radius due to the low energy density of biomass relative to fossil fuels Consequently, localized production of heat and electricity from biomass gasification is expected to play an eminent role in the future In this study, an economic analysis was performed on a micro-scale heat and power generation plant using urban waste from the city of Fultondale in Alabama, USA The plant economics of heat and power production from urban biomass waste collected in Fultondale were analyzed by using a modular economic model with drying, chipping, gasification, power generation, and grid connection modules Three gasification systems – fluidized bed, downdraft and updraft – and three power generation systems – internal combustion, steam turbine, and gas turbine – were assessed resulting in nine plant configuration scenarios The fluidized bed gasifier and internal combustion engine plant configuration resulted in the lowest cost of electricity at ¢14/kWh for a micro-scale installed capacity of 100kWe for a plant operating at 85% capacity with an annual green waste processing capacity of 1811 tons The equipment and installation costs made up the largest contribution to the total capital investment whereas the operating labor and plant overhead make the largest contribution to the total annual production cost Sensitivity analysis revealed that the plant capacity factor and the rate of return of investment had the strongest effect on the levelized cost of electricity under the best configuration

Economic analysis of municipal power generation from gasification of urban green wastes: case study of Fultondale, Alabama, USA

Direct use of syngas, a cheaper hydrogen-rich gas, instead of pure hydrogen, as a deoxygenating agent for biohydrogenated diesel (BHD) production is presented in this study. Low-cost palm fatty acid distillate (PFAD), an inedible byproduct from refining palm oil, is used as a feedstock in the presence of a Pd/C catalyst. The results indicate that syngas can be effectively used in BHD production, while the achieved BHD yield is slightly lower than that obtained from pure hydrogen. The liquid products contain mostly n-C15 and n-C17, which fall into a diesel range. Decarbonylation is a prominent pathway under both hydrogen and syngas atmospheres. It was found that CO in syngas can act as a reducing agent, which can remove an oxygen atom from fatty acid molecules to form alkenol that could be further reduced to alkene and then cyclized to cycloparaffins. After reactivation, the activity of the catalyst could be fully recovered for at least 4 reused cycles. Reaction pathways for the catalytic deoxygenation und...

Alternative Hydrocarbon Biofuel Production via Hydrotreating under a Synthesis Gas Atmosphere

This paper presents the performance of a 2·88 kWp household grid-connected PV system installed in a house at Bangkok. This was one of the 10 houses identified for a household rooftop PV grid-connected demonstration project by the Electricity Generating Authority of Thailand in 1997. Data measured over 12 months was used to estimate the PV array output, inverter output, inverter efficiency, system efficiency, yields (reference yield, array yield, final yield) performance ratio (PR) and the losses. The variations of these parameters over time indicate that the yields are high during June and July in Bangkok. The annual final yield and the average performance ratio were found to be 1166 kW h/kWp and 0ċ73 respectively. The monthly highest final yield was 129 kW h/kWp during June and July. The inverter efficiency was greater than 80% throughout the study period and the maximum system efficiency was 5·4%. The result of the study indicates that the system installed in Bangkok worked satisfactorily. Following the success of the demonstration project, a second phase of 50 households has recently been initiated. Copyright © 2003 John Wiley & Sons, Ltd.

Sushil Adhikari

Papers

Effect of ammonia removal and biochar detoxification on anaerobic digestion of aqueous phase from municipal sludge hydrothermal liquefaction.

Economic analysis of municipal power generation from gasification of urban green wastes: case study of Fultondale, Alabama, USA

Alternative Hydrocarbon Biofuel Production via Hydrotreating under a Synthesis Gas Atmosphere

Performance of household grid-connected PV system in Thailand

Fast pyrolysis bio‐oil as precursor of thermosetting epoxy resins