Pyrolysis of Torrefied Biomass

The torrefaction process changes the pyrolysis characteristics of biomass, including the reaction process, kinetic parameters, and product distribution and properties. Torrefaction affects the ratio and chemical composition of pyrolysis products, improves the product quality and conversion process, and increases conversion efficiency during the pyrolysis process. Most torrefied biomass pyrolysis research has been conducted in laboratory-scale fixed beds at a relatively low temperature, and continuous reactors still need to be investigated and pilot-scale studies need to be performed. Catalytic pyrolysis of torrefied biomass is a promising technology to convert biomass into useful chemicals. Pyrolysis, one of the most promising thermal conversion technologies for biomass conversion, can decompose biomass into solid bio-char, liquid bio-oil, and combustible gas to meet different energy needs. However, pyrolysis efficiency and product quality are not as good as expected when raw biomass is used owing to the properties of raw biomass (e.g., high moisture, oxygen, and alkali metal contents). Torrefaction is an emerging biomass pretreatment technology that can improve the physical and chemical properties of raw biomass, and pyrolysis efficiency and final product quality can therefore be improved by using torrefied biomass. We review several advantages of pyrolysis of torrefied biomass in terms of the conversion process and final product quality. Pyrolysis, one of the most promising thermal conversion technologies for biomass conversion, can decompose biomass into solid bio-char, liquid bio-oil, and combustible gas to meet different energy needs. However, pyrolysis efficiency and product quality are not as good as expected when raw biomass is used owing to the properties of raw biomass (e.g., high moisture, oxygen, and alkali metal contents). Torrefaction is an emerging biomass pretreatment technology that can improve the physical and chemical properties of raw biomass, and pyrolysis efficiency and final product quality can therefore be improved by using torrefied biomass. We review several advantages of pyrolysis of torrefied biomass in terms of the conversion process and final product quality. an important kinetic parameter that describes the energy required for a molecule to change from a normal to an active state. diverse organisms that are produced through photosynthesis using the atmosphere, water, land, and other natural resources. In general, all living organic substances and their byproducts can be considered as biomass. Plant biomass is the most abundant sustainable organic material, containing mainly hemicellulose, cellulose, lignin, and extractives. Hemicellulose is the most reactive component, followed by cellulose and lignin. in an oxygen-rich environment, biomass is mainly converted into heat through thermal decomposition. Similarly to the combustion of coal, the combustion of biomass has three main stages: drying, fast pyrolysis to form coke and volatiles followed by burning, and then burnout of the remaining coke. a natural process that converts materials to a more chemically stable form, but at the cost of the gradual destruction of the materials. reducing size by applying pressure, thus increasing the density or concentration. the removal of oxygen from biomass. High moisture and oxygen contents in biomass are the main drawbacks that can restrict the use of products of thermal conversion technology. in certain thermodynamic conditions, in the presence of oxygen and moisture, biomass decomposes to low molecular weight molecules including CO, H2, and other combustible gases through polymer pyrolysis, oxidation, and reduction reactions. the ability to break solid materials down into small particles by grinding, crushing, or cutting. also known as calorific values, the energy that is contained in biomass. a physical property of materials that repel water. transporting biomass across long distances. Generally, biomass energy production requires feedstocks produced far away, and pretreatment technology is therefore important to reduce the transportation cost. in a thermodynamic context, the highest decomposition speed. an important kinetic parameter, a constant that is independent of the reaction temperature and the concentration of matter in the reaction. direct thermochemical degradation of organic materials in an oxygen-free environment and at a relatively high temperature. The products of the process are solid bio-char, liquid bio-oil, and gaseous combustible bio-gas. also referred to as thermochemical conversion technology, the degradation of biomass into high-quality products. The technology consists of direct combustion, gasification, pyrolysis, and liquefaction technologies. the ratio of net heat output to energy input. When the feedstocks are ground into fine particles, the heat-transfer surface areas are increased, improving the thermal efficiency. mild pyrolysis of biomass and light matter, mainly the removal of moisture and hemicellulose. Torrefaction is conventionally carried out in the temperature range of 200–300°C, in inert environments at atmospheric pressure. Wet torrefaction, also referred to as hydrothermal torrefaction, can decompose biomass under pressures from 1–250 MPa at 180–265°C in an inert environment.