Solids circulation system and method for capture and conversion of reactive solids

摘要

A solids circulation system receives a gas stream containing char or other reacting solids from a first reactor. The solids circulation system includes a cyclone configured to receive the gas stream from the first reactor, a dipleg from the cyclone to a second reactor, and a riser from the second reactor which merges with the gas stream received by the cyclone. The second reactor has a dense fluid bed and converts the received materials to gaseous products. A conveying fluid transports a portion of the bed media from the second reactor through the riser to mix with the gas stream prior to cyclone entry. The bed media helps manipulate the solids that is received by the cyclone to facilitate flow of solids down the dipleg into the second reactor. The second reactor provides additional residence time, mixing and gas-solid contact for efficient conversion of char or reacting solids.

主权项

1. A system for processing a carbonaceous feedstock to create a final product gas stream, comprising:
a first reactor (500) having a fluidized bed and configured to receive a feedstock and steam, and output a syngas stream (600) via a first conduit (602), the syngas stream (600) comprising syngas, char, condensable organic compounds and aromatic hydrocarbons; a second conduit (612) connected to the first conduit (602), the second conduit (612) configured to receive a portion of said syngas stream (602) as a first-stage product gas stream (610); a restriction orifice (660) positioned in the second conduit (612) and configured to reduce a pressure of said first-stage product gas stream (610); and a second reactor (100) configured to receive char from the syngas gas stream (600) and an oxygen containing gas, and operated under conditions sufficient to convert the char into a second-stage product gas stream (910); wherein: the system is further configured to combine said first-stage product gas stream (610) and said second-stage product gas stream (910), downstream of the restriction orifice (660) to form the final product gas stream (950).