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.

HighlightsBio-oil was used to produce novolac resin.Bio-oil interacted with phenol and altered the reaction rate and equilibrium.Comparable performance was observed with a low amount of substitution.Abstract. Commercially produced bio-oil with a high content of pyrolytic lignin was substituted for phenol in novolac phenol-formaldehyde (PF) resin production. The reaction progress was tracked, and products were analyzed. Bio-oil substitution resulted in lower conversion rates for both formaldehyde and phenol. Substitution higher than 10 mol% increased the ortho to para ratio and enhanced thermal decomposition of resin by providing an oxidative environment, while 10 and 20 mol% of substitution did not reduce the shear strength of the novolac resin. When mixed with hexamethylenetetramine (HMTA), the bio-oil substituted resins precipitated quickly around char particles, which allowed more resin application on the wood bonding surface. Further investigation found that bio-oil substitution (higher than 10 mol%) might have changed the reaction equilibrium and promoted reverse reactions releasing formaldehyde. Overall, less than 20 mol% phenol substitution by bio-oil with a high content of pyrolytic lignin can be effective in producing novolac resin. Keywords: Bio-oil, Formaldehyde, Lignocellulosic biomass, Novolac, Phenol, Pyrolysis.

Production of novolac resin after partial substitution of phenol from bio-oil.

Physical and flow properties of fractionated loblolly pine grinds

Conversion of underutilized forest biomass to bio-oil could be a niche market for energy production. In this work, bio-oil was produced from underutilized forest biomass at selected temperatures between 425–500°C using an auger reactor. Physical properties of bio-oil, such as pH, density, heating value, ash, and water, were analyzed and compared with an ASTM standard to document the effect of pyrolysis temperature. All of the properties analyzed in this study, except for the ash content of the bio-oil, met the ASTM standard. Chemical composition of bio-oil was also analyzed, and the concentration of each species was compared at different temperatures.

/pdf/production-of-bio-oil-from-underutilized-forest-biomass-4cufnf4ljl.pdf

Production of bio-oil from underutilized forest biomass using an auger reactor

Biomass feedstocks generate dusts when they are preprocessed prior to preparation for conversion into fuels, chemicals, and products. Since dusts have the potential to cause fire and explosions in biomass processing plants and storage depots, the goal of this study was to quantify the physical, chemical, ignition, and volatilization properties of dusts of eight biomass feedstocks (Bermuda grass, corn cobs, corn stover, Eucalyptus, loblolly pine, sugarcane bagasse, sweetgum, and switchgrass). Ash contents of the biomass dusts were two to three fold higher than the biomass feedstock from which they were obtained. The bulk and particle densities of the dust samples varied from 112.3 to 217.6 kg m -3 and from 1167.3 to 1500.9 kg m -3 , respectively. Dusts energy (16.69 to 20.55 MJ kg -1 ) contents were also linearly related to their carbon (45.3% to 52.4% d.b.) contents. In addition, volatilization properties (onset temperature of rapid volatilization that ranged between 266.1°C and 306.1°C, and temperature of maximum volatilization release that ranged between 312.4°C and 348.8°C) can be used to estimate the temperature at which a hot surface will ignite dust (275°C to 315°C). The results from this study will be useful in designing and selecting equipment and systems that minimize the risk of dust causing ignition, fire, and explosion in biomass processing plants.

Physical, Ignition, and Volatilization Properties of Biomass Feedstock Dusts

In addition to primary gases, biomass-derived producer gas contains nonnegligible concentrations of undesirable byproducts collectively known as contaminants. Syngas contaminants are composed of tar-, nitrogen-, and sulfur-based compounds and halides and other trace metals that must be minimize their negative impacts on downstream processes or to adhere to environmental regulations. The producer gas cleanup consists of all processes that are employed to reduce the concentration of contaminants in raw producer gas prior to conditioning and utilization in downstream applications. This chapter discusses primary contaminants, the impact of operating conditions on them, their mitigation and regulations governing their emissions. Additionally, best of available technology (BAT) are discussed for select contaminants.

Sushil Adhikari

Papers

Production of novolac resin after partial substitution of phenol from bio-oil.

Physical and flow properties of fractionated loblolly pine grinds

Production of bio-oil from underutilized forest biomass using an auger reactor

Physical, Ignition, and Volatilization Properties of Biomass Feedstock Dusts

Biomass gasification producer gas cleanup