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.

http://www.kiwiscience.com/JournalArticles/EnvironPoll2011.pdf

A review of biochars’ potential role in the remediation, revegetation and restoration of contaminated soils

The conversion of biomass by thermochemical means is very promising for the substitution of fossil materials in many energy applications. Given the complexity of biomass the main challenge in its use is to obtain products with high yield and purity. For a better understanding of biomass thermochemical conversion, many authors have studied in TG analyzer or at bed scale the individual pyrolysis of its main constituents (i.e. cellulose, hemicelluloses and lignin). Based on these studies, this original work synthesizes the main steps of conversion and the composition of the products obtained from each constituent. Pyrolysis conversion can be described as the superposition of three main pathways (char formation, depolymerization and fragmentation) and secondary reactions. Lignin, which is composed of many benzene rings, gives the highest char yield and its depolymerization leads to various phenols. The depolymerization of the polysaccharides is a source of anhydro-saccharides and furan compounds. The fragmentation of the different constituents and the secondary reactions produce CO, CO2 and small chain compounds. For temperature higher than 500 °C, the residues obtained from the different constituents present a similar structure, which evolves towards a more condensed polyaromatic form by releasing CH4, CO and H2. As the aromatic rings and their substituent composition have a critical influence on the reactivity of pyrolysis products, a particular attention has been given to their formation. Some mechanisms are proposed to explain the formation of the main products. From the results of this study it is possible to predict the reactivity and energy content of the pyrolysis products and evaluate their potential use as biofuels in renewable applications.

A review on pyrolysis of biomass constituents: Mechanisms and composition of the products obtained from the conversion of cellulose, hemicelluloses and lignin

The structure of lignin suggests that it can be a valuable source of chemicals, particularly phenolics. However, lignin depolymerization with selective bond cleavage is the major challenge for converting it into value-added chemicals. Pyrolysis (thermolysis), gasification, hydrogenolysis, chemical oxidation, and hydrolysis under supercritical conditions are the major thermochemical methods studied with regard to lignin depolymerization. Pyrolytic oil and syngases are the primary products obtained from pyrolysis and gasification. A significant amount of char is also produced during pyrolysis. Thermal treatment in a hydrogen environment seems very promising for converting lignin to liquid fuel and chemicals like phenols, while oxidation can produce phenolic aldehydes. Reaction severity, solvents, and catalysts are the factors of prime importance that control yield and composition of the product.

Lignin Depolymerization and Conversion: A Review of Thermochemical Methods

http://www.adktroutguide.com/files/2003_Pyrolysis_of_biomass_and_sludge_to_produce_fuels_and_chemical_feedstocks.pdf

Pyrolysis of biomass to produce fuels and chemical feedstocks

Characterization of chars from pyrolysis of lignin

Characterization of chars from biomass-derived materials: pectin chars

Preparation and characterization of (3-aminopropyl)triethoxysilane-modified mesoporous SBA-15 silica molecular sieves

The composition of char from heated Avicel cellulose was monitored as a function of heating time and temperature, using 13C cross-polarization magic-angle spinning (CPMAS) NMR. Complex NMR line shapes observed in the carbohydrate region of the spectra are indicative of the presence of multiple carbohydrate forms. By successive spectral subtractions of the 300 °C pyrolysis char, the complex line shapes were separated into three distinct carbohydrate components that correspond to the crystalline cellulose starting material (SM), an intermediate cellulose (IC) that resembles a low degree-of-polymerization (low-DP) amorphous cellulose, and a disordered final carbohydrate (FC) that is characterized by a very broad 13C line width. Curve fitting was used to monitor the changes in the approximate abundance of these different carbohydrate forms relative to the aliphatic, aromatic, carboxyl, and ketone clusters of compounds of the char. The time evolution of the IC, together with its spectral line shapes, associate...

Observation and Characterization of Cellulose Pyrolysis Intermediates by 13C CPMAS NMR. A New Mechanistic Model

Pyrolysis of tobacco was studied in oxidative and nonoxidative (inert) environments at atmospheric pressure and temperatures ranging from 150 to 750 °C. The objective was to study the effect of pyr...

Jan B. Wooten

Papers

Characterization of chars from pyrolysis of lignin

Characterization of chars from biomass-derived materials: pectin chars

Preparation and characterization of (3-aminopropyl)triethoxysilane-modified mesoporous SBA-15 silica molecular sieves

Observation and Characterization of Cellulose Pyrolysis Intermediates by 13C CPMAS NMR. A New Mechanistic Model

Characterization of char from the pyrolysis of tobacco.