Gasification pyrolytic

Techniques for the chemical recycling of plastics into monomers and petrochemical feedstocks are described, including chemical and thermal depolymerisation, pyrolytic liquefaction, pyrolytic gasification and partial oxidation. BRITISH PETROLEUM CO.PLC... 

This paper discusses in depth advanced technologies for recycled materials from solid waste streams. Chemical depolymerisation, thermal depolymerisation, pyrolytic liquefaction, pyrolytic gasification, partial oxidation, and feedstock compatibility are all explained. The economic feasibility of the methods are considered. 

The pyrolytic gasification of biomass has been interpreted to involve the decomposition of carbohydrates by depolymerization and dehydration followed by steam-carbon and steam-carbon fragment reactions. So the chemistries of coal and biomass gasification are quite similar in terms of the steam-carbon chemistry and are essentially identical after a certain point is reached in the gasification process. Note, however, that biomass is much more reactive than most coals. Biomass contains more volatile matter than coal, and the pyrolytic chars from biomass are more reactive than pyrolytic coal chars. 

One of the more innovative pyrolytic gasification processes is an indirectly heated, fluid-hed system (c/. Alpert et al, 1972 Bailie, 1981 Paisley, Feldmann, and Appelbaum, 1984). This system uses two fluid-bed reactors containing sand as a heat transfer medium. Combustion of char formed in the pyrolysis reactor takes place with air within the combustion reactor. The heat released supplies the energy for pyrolysis of the combustible fraction in the pyrolysis reactor. Heat transfer is accomplished by flow of hot sand from the combustion reactor at 950°C to the pyrolysis reactor at 800°C and return of the sand to the combustion reactor (Fig. 9.5). This configuration separates the combustion... 

Coconut shell, groundnut shell, wood, coconut coir and rice husk are better suited candidates compared to the other biomass studied for pyrolytic gasification applications. 

Pyrolytic Gasification of Na-, Ca-, and Mg-Base Spent Pulping Liquors in an AST Reactor... 

The data in this paper are drawn from a number of studies performed at Pacific Northwest Laboratory (3,7-9). We have examined biomass pyrolysis tar samples from many types of pyrolytic gasification and liquefaction systems through the U.S. Department of Energy support of domestic biomass thermochemical conversion research and international cooperative efforts. Many of these can be compared directly as a function of temperature since they are all produced at short residence time, approximately one second. Others produced at longer residence time or pressure require discussion separately. 

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