Pyrolysis

About: Pyrolysis is a research topic. Over the lifetime, 34918 publications have been published within this topic receiving 833524 citations.

Pyrolysis of Biomass to Produce Fuels and Chemical Feedstocks

Abstract: This review presents the summary of new studies on pyrolysis of biomass to produce fuels and chemical feedstocks. A number of biomass species, varying from woody and herbaceous biomass to municipal solid waste, food processing residues and industrial wastes, were subjected to different pyrolysis conditions to obtain liquid, gas and solid products. The results of various biomass pyrolysis investigations connected with the chemical composition and some properties of the pyrolysis products as a result of the applied pyrolysis conditions were combined. The characteristics of the liquid products from pyrolysis were examined, and some methods, such as catalytic upgrading or steam reforming, were considered to improve the physical and chemical properties of the liquids to convert them to economic and environmentally acceptable liquid fuels or chemical feedstocks. Outcomes from the kinetic studies performed by applying thermogravimetric analysis were also presented.

Decomposition of hydrocarbons to hydrogen and carbon

Abstract: This review assesses technologies and catalysts pertaining to the catalytic decomposition of hydrocarbons for the CO2-free generation of hydrogen for fuel cell applications through a single-step cracking (decomposition, decarbonization, dehydrogenation, pyrolysis, splitting, or dissociation) of hydrocarbons. It discusses and systematically categorizes the options for hydrocarbon decomposition to hydrogen and carbon. This decomposition helps to reduce green house gases by co-producing valuable carbon products such as carbon black or graphite-like carbon (carbon nanotubes or carbon filaments). The catalytic approach comprises metal and carbon-based catalysts while plasma-based decomposition depends on thermal or non-thermal methods. Almost all the proposed processes are applicable to a variety of gaseous and liquid hydrocarbon fuels, and some of these processes can potentially produce a stream of high-purity hydrogen. There have been successful attempts to use catalysts to reduce the maximum temperature of the thermal decomposition of hydrocarbons. Common catalysts used are noble and transition metals such as Ni, Fe, Pd, Co, Mo, etc., supported on high surface area ceramic substrates such as A12O3 and SiO2, etc. Several other publications disclose the use of carbon-based materials as catalysts for decomposition of hydrocarbons into H2 and carbon. The other non-catalytic decomposition methods include non-thermal low-temperature plasmas such as RF (radio frequency), dc (direct current) generators, microwave plasmatrons, and arc plasma jet.

NMR Characterization of Pyrolysis Oils from Kraft Lignin

Abstract: The pyrolysis of softwood (SW) kraft lignin was examined at 400, 500, 600, and 700 °C. The yields of pyrolysis oil, char, and gas were determined to be 35−44%, 57−38% and 8−18%, respectively. The pyrolysis oil has a comparable heating value with ethanol and coal. The elevated temperature of 700 °C was found as the point of primary decomposition of lignin and the secondary decomposition of pyrolysis oil. Gel permeation chromatography (GPC) and quantitative 13C and 31P NMR were used to characterize the pyrolysis oil. A 13C NMR database was created to provide a more accurate chemical shift assignment database for analysis of pyrolysis oils. On the basis of the results of 13C and 31P NMR for the pyrolysis oil, aliphatic hydroxyl, carboxyl, and methoxyl groups are eliminated during pyrolysis. Cleavage of ether bonds in lignin was also shown to be a primary decomposition reaction occurring during thermal treatment. The results of GPC analysis indicated that lower pyrolysis temperatures yielded a bio-oil that ha...