Method and system for biomass hydrogasification

摘要

Certain aspects of the system and method concern producing hydrocarbons from biomass. The method is particularly useful for producing substitute natural gas from forestry residues. A biomass feedstock may be converted into a product hydrocarbon by fast pyrolysis. The resulting pyrolysis gas is converted to the product hydrocarbon and carbon dioxide in the presence of hydrogen and steam while simultaneously generating the required hydrogen by reaction with steam under prescribed conditions for self-sufficiency of hydrogen. Methane is a preferred hydrocarbon product. A system also is described for cycling the catalyst between steam reforming, methanation and regeneration zones.

主权项

1. A method for converting a biomass feedstock into a product hydrocarbon, comprising:
subjecting feedstock to fast pyrolysis in substantial absence of oxygen in order to generate fractions of pyrolysis gas and char; converting at least a portion of the pyrolysis gas to product hydrocarbon and carbon dioxide over a catalyst in the presence of hydrogen and steam; generating at least a portion of the hydrogen by reaction between steam and a portion of the pyrolysis gas or the hydrocarbon product over the catalyst; separating carbon dioxide; separating recycle hydrogen from the hydrocarbon product; and regenerating the catalyst used to produce the hydrogen and the hydrocarbon.