Sulfur removal by sorbent injection in secondary combustion zones.

摘要

Sulfur sorbent and secondary oxidant are added to products of combustion passing from a slagging combustor to an associated heat-utilization equipment to form a reaction stream at a temperature from 1600 DEG F to 2300 DEG F where sulfur is captured by reaction with an alkaline earth metal containing sulfur sorbent, such as pulverized limestone. Combustion stoichiometry in the end use apparatus is between 1.1 and 1.3, at an effective calcium-to-sulfur molar ratio of from about 2 to about 5. Combustion conditions within the slagging combustor are regulated to produce a stream of fuel rich gaseous products, minimize formation of NOx and separately remove most of the fuel's non-combustible minerals. This hot gas clean up, prior to combining the gaseous products with sulfur sorbent and supplementary oxidizer, significantly enhances removal of sulfur constituents before the gaseous products pass from the heat-utilization equipment into the atmosphere.