1.0. Introduction 4044 2.0. Biomass Chemistry and Growth Rates 4047 2.1. Lignocellulose and Starch-Based Plants 4047 2.2. Triglyceride-Producing Plants 4049 2.3. Algae 4050 2.4. Terpenes and Rubber-Producing Plants 4052 3.0. Biomass Gasification 4052 3.1. Gasification Chemistry 4052 3.2. Gasification Reactors 4054 3.3. Supercritical Gasification 4054 3.4. Solar Gasification 4055 3.5. Gas Conditioning 4055 4.0. Syn-Gas Utilization 4056 4.1. Hydrogen Production by Water−Gas Shift Reaction 4056

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Synthesis of transportation fuels from biomass: chemistry, catalysts, and engineering.

Mesoporous organic-inorganic hybrid materials, a new class of materials characterized by large specific surface areas and pore sizes between 2 and 15 nm, have been obtained through the coupling of inorganic and organic components by template synthesis. The incorporation of functionalities can be achieved in three ways: by subsequent attachment of organic components onto a pure silica matrix (grafting), by simultaneous reaction of condensable inorganic silica species and silylated organic compounds (co-condensation, one-pot synthesis), and by the use of bissilylated organic precursors that lead to periodic mesoporous organosilicas (PMOs). This Review gives an overview of the preparation, properties, and potential applications of these materials in the areas of catalysis, sorption, chromatography, and the construction of systems for controlled release of active compounds, as well as molecular switches, with the main focus being on PMOs.

Silica-based mesoporous organic-inorganic hybrid materials.

Biodiesel is synthesized via the transesterification of lipid feedstocks with low molecular weight alcohols. Currently, alkaline bases are used to catalyze the reaction. These catalysts require anhydrous conditions and feedstocks with low levels of free fatty acids (FFAs). Inexpensive feedstocks containing high levels of FFAs cannot be directly used with the base catalysts currently employed. Strong liquid acid catalysts are less sensitive to FFAs and can simultaneously conduct esterification and transesterification. However, they are slower and necessitate higher reaction temperatures. Nonetheless, acid-catalyzed processes could produce biodiesel from low-cost feedstocks, lowering production costs. Better yet, if solid acid catalysts could replace liquid acids, the corrosion and environmental problems associated with them could be avoided and product purification protocols reduced, significantly simplifying biodiesel production and reducing cost. This article reviews some of the research related to biodi...

Synthesis of Biodiesel via Acid Catalysis

Silicate mesoporous materials have received widespread interest because of their potential applications as supports for catalysis, separation, selective adsorption, novel functional materials, and use as hosts to confine guest molecules, due to their extremely high surface areas combined with large and uniform pore sizes. Over time a constant demand has developed for larger pores with well-defined pore structures. Silicate materials, with well-defined pore sizes of about 2.0–10.0 nm, surpass the pore-size constraint ( 700 m2 g−1) and narrow pore size distributions. Instead of using small organic molecules as templating compounds, as in the case of zeolites, long chain surfactant molecules were employed as the structure-directing agent during the synthesis of these highly ordered materials. The structure, composition, and pore size of these materials can be tailored during synthesis by variation of the reactant stoichiometry, the nature of the surfactant molecule, the auxiliary chemicals, the reaction conditions, or by post-synthesis functionalization techniques. This review focuses mainly on a concise overview of silicate mesoporous materials together with their applications. Perusal of the review will enable researchers to obtain succinct information about microporous and mesoporous materials.

https://www.mdpi.com/1996-1944/5/12/2874/pdf

A Review: Fundamental Aspects of Silicate Mesoporous Materials

The world is confronted with the twin crises of fossil fuel depletion and environmental degradation. The indiscriminate extraction and consumption of fossil fuels have led to a reduction in petroleum reserves. Petroleum based fuels are obtained from limited reserves. These finite reserves are highly concentrated in certain region of the world. Therefore, those countries not having these resources are facing a foreign exchange crisis, mainly due to the import of crude petroleum oil. Hence it is necessary to look for alternative fuels, which can be produced from materials available within the country. Although vegetative oils can be fuel for diesel engines, but their high viscosities, low volatilities and poor cold flow properties have led to the investigation of its various derivatives. Among the different possible sources, fatty acid methyl esters, known as Biodiesel fuel derived from triglycerides (vegetable oil and animal fates) by transesterification with methanol, present the promising alternative substitute to diesel fuels and have received the most attention now a day. The main advantages of using Biodiesel are its renewability, better quality exhaust gas emission, its biodegradability and the organic carbon present in it is photosynthetic in origin. It does not contribute to a rise in the level of carbon dioxide in the atmosphere and consequently to the green house effect. This paper reviews the source of production and characterization of vegetable oils and their methyl ester as the substitute of the petroleum fuel and future possibilities of Biodiesel production.

Biodiesel production through the use of different sources and characterization of oils and their esters as the substitute of diesel: A review

Organosulfonic acid-functionalized mesoporous silicas for the esterification of fatty acid

Design of multifunctionalized mesoporous silicas for esterification of fatty acid

Natural oils and fats are emerging as a biobased alternative feedstock to conventional crude oil in the production of chemicals and transportation fuel. However, many of these biobased chemicals are not currently cost competitive with petrochemicals because of high raw material and production costs. To improve the economic outlook of the biobased chemicals, the use of suitable catalysts becomes imperative. Recently, the discovery of advanced material synthesis strategies such as supramolecular-assembled mesoporous materials has created new opportunities in tailoring catalyst properties specifically for the conversion challenges encountered with oils and fats. These nanostructured materials have a combination of extremely high surface areas and flexible pore sizes that makes them attractive for catalysis applications. This article reviews the application of this new class of advanced materials for the conversion of oils and fats to biobased chemicals.

Conversion of oils and fats using advanced mesoporous heterogeneous catalysts

Propylsulfonic acid-functionalized mesoporous silica materials were synthesized using a co-condensation technique. The catalytic performance of the resulting acidic mesoporous materials was evaluated in the methanol esterification of free fatty acids in beef tallow as a pretreatment step for alkyl ester production. The multicycle stability of the acid-functionalized mesoporous silica catalysts was studied. Issues concerning impurities in the feedstocks as well as a means of improving performance of the acidic solid catalyst through alternative strategies are discussed. Introduction of a hydrophobic group into the organosulfonic acid-functionalized mesoporous silica catalyst significantly enhanced the catalytic performance of the catalyst. The catalytic activity of the synthesized catalysts was compared to commercially available homogeneous and heterogeneous acidic catalysts.

https://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=1225&context=cbe_pubs

Isa K. Mbaraka

Papers

Organosulfonic acid-functionalized mesoporous silicas for the esterification of fatty acid

Design of multifunctionalized mesoporous silicas for esterification of fatty acid

Conversion of oils and fats using advanced mesoporous heterogeneous catalysts

Acidic mesoporous silica for the catalytic conversion of fatty acids in beef tallow

Acid strength variation due to spatial location of organosulfonic acid groups on mesoporous silica