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.

Bamboo is a potential feedstock for bioenergy production. Pseudosasa amabilis is a common bamboo species in south China and commonly known as Tonkin Cane. It has a high biomass yield, and its prope...

Dynamic Variation of Fuel Properties of Tonkin Cane ( Pseudosasa amabilis ) during Maturation

Hydrothermal liquefaction of biomass model compounds (cellulose, xylan, and lignin) was carried out between 350 and 400 °C using calcium formate (Ca(HCOO)2) as the in situ hydrogen source. In this study, high temperatures have been adopted for liquefaction as calcium formate acts as a hydrogen donor in that range. Ca(HCOO)2 catalyzes lignin degradation toward liquefaction and, consequently, increases the biocrude yields by about 80%. Conversely, cellulose biocrude yields decreased when Ca(HCOO)2 was introduced due to pronounced gasification. It was also observed that Ca(HCOO)2 did not have any effect on xylan biocrude yield which remained almost the same. The maximum biocrude yields of cellulose, xylan, and lignin in the presence of Ca(HCOO)2 were 7, 13, and 32 wt %, respectively. The excess hydrogen from Ca(HCOO)2 was successful in upgrading the biocrude by removing oxygen which was confirmed by a significant decrease in atomic O/C ratio and increase in heating values (by 34.6%). The formate salt slightl...

Effect of Calcium Formate on Hydrodeoxygenation of Biomass Model Compounds

In this study, gasification of different biomass feedstocks, including pine wood chips, sawdust, peanut hulls, and poultry litter (the latter three in pelletized form), was conducted in a 25 kWe commercially available, mobile downdraft gasifier. Ultimate and proximate analyses were carried out to characterize the biomass feedstocks used for gasification. The synthesis gas obtained from different feedstocks and different operating conditions (biomass flow rate and moisture content) was analyzed using an on-site gas analyzer. Gasification of peanut hull pellets showed the highest heating value (6.1 MJ per normal cubic meter, Nm-3) of synthesis gas, whereas poultry litter gasification gave the lowest heating value (4.8 MJ Nm-3).

Gasification of Wood Chips, Agricultural Residues, and Waste in a Commercial Downdraft Gasifier

The objectives of this study were to utilize bio-oil-based epoxy resin in oriented strand board (OSB) production and investigate the effect of bio-oil substitution in epoxy resin as an adhesive for OSB production. Bio-oil was produced by the fast pyrolysis (FP) process using southern yellow pine (Pinus spp.). Bio-oil-based epoxy resin was synthesized by the modification of epoxy resin with FP bio-oil at various substitution levels. Acetone extraction using a Soxhlet process indicated a superior cured reaction of bio-oil and epoxy resin at 20% bio-oil substitution. FTIR spectra corroborated the Soxhlet extraction with the removal of the epoxide peak signature within the cross-linked polymer. Images from the scanning electron microscopy suggested bulk phase homogeneity. OSB panels were tested according to ASTM D1037-12. The modulus of rupture (MOR), modulus of elasticity (MOE), internal bond strength, and water resistance (thickness swell and water absorption) properties of the OSB panels were feasible at bio-oil substitution up to 30% in the epoxy resin system.

/pdf/fast-pyrolysis-bio-oil-based-epoxy-as-an-adhesive-in-2olzfwaf.pdf

Fast Pyrolysis Bio-Oil-Based Epoxy as an Adhesive in Oriented Strand Board Production

In this study, the contamination of H+ZSM-5 catalyst by calcium, potassium and sodium was investigated by deactivating the catalyst with various concentrations of these inorganics, and the subsequent changes in the properties of the catalyst are reported. Specific surface area analysis of the catalysts revealed a progressive reduction with increasing concentrations of the inorganics, which could be attributed to pore blocking and diffusion resistance. Chemisorption studies (NH3-TPD) showed that the Bronsted acid sites on the catalyst had reacted with potassium and sodium, resulting in a clear loss of active sites, whereas the presence of calcium did not appear to cause extensive chemical deactivation. Pyrolysis experiments revealed the progressive loss in catalytic activity, evident due the shift in selectivity from producing only aromatic hydrocarbons (benzene, toluene, xylene, naphthalenes and others) with the fresh catalyst to oxygenated compounds such as phenols, guaiacols, furans and ketones with increasing contamination by the inorganics. The carbon yield of aromatic hydrocarbons decreased from 22.3% with the fresh catalyst to 1.4% and 2.1% when deactivated by potassium and sodium at 2 wt %, respectively. However, calcium appears to only cause physical deactivation.

/pdf/influence-of-biomass-inorganics-on-the-functionality-of-h-17px7gyfj3.pdf

Sushil Adhikari

Papers

Dynamic Variation of Fuel Properties of Tonkin Cane ( Pseudosasa amabilis ) during Maturation

Effect of Calcium Formate on Hydrodeoxygenation of Biomass Model Compounds

Gasification of Wood Chips, Agricultural Residues, and Waste in a Commercial Downdraft Gasifier

Fast Pyrolysis Bio-Oil-Based Epoxy as an Adhesive in Oriented Strand Board Production

Influence of Biomass Inorganics on the Functionality of H+ZSM-5 Catalyst during In-Situ Catalytic Fast Pyrolysis