Patent ID: 8617271

Claim:
A method of retrofitting a coal gasifier for fuel flexibility, comprising the steps of: dividing said coal gasifier into at least two zones; providing at least one injector for injecting coal in a first zone, the at least one injector for injecting coal coupled to a source of coal; providing at least one injector for injecting an oxidant in the first zone, the at least one injector for injecting the oxidant coupled to a source of the oxidant; providing at least one injector for injecting steam in the first zone, the at least one injector for injecting steam coupled to a source of steam, and configured separate and apart from the at least one injector for injecting coal, and wherein the at least one injector for injecting coal is not coupled to the source of steam; providing at least one injector for injecting a low-calorific-value, high oxygen-content (LCV HOC) feedstock in a second zone; providing at least one injector for injecting steam in the second zone, the at least one injector for injecting steam coupled to a source of steam, and configured separate and apart from the at least one injector for injecting the low-calorific-value, high oxygen-content (LCV HOC) feedstock, and wherein the at least one injector for injecting the low-calorific-value, high oxygen-content (LCV HOC) feedstock is not coupled to the source of steam; and locating said second zone downstream of said first zone and relative to said first zone such that the oxidant injected during operation is substantially consumed within said first zone.