Simultaneous control of SO.sub.2, NO.sub.x, HCl, and particulates by in- furnace high-temperature sorbent injection and particulate removal

摘要

A method for the simultaneous control of SO.sub.2, NO.sub.x, HCl, air toxins, metal fumes, and particulate emissions (ash, soot, metal oxides) from fossil fuel burning combustion processes is provided by injecting a sorbent upstream of a filter in the furnace and collecting sorbent and particulates in the filter. Collecting the sorbent in the filter increases its residence time in the process. The sorbent is injected in the post-flame region of a furnace, where it reacts with the SO.sub.2, the NO.sub.x, the HCl, and the air toxics in the effluent gas. A surface filter that can withstand temperatures of approximately 1000. degree. C. is mounted, either fixedly or rotatably, in the furnace downstream of the sorbent injection region. The gas flows through the filter, and the sorbent and other particulates become embedded in the surface layer of the filter. Gases continue to flow through the filter past the embedded sorbent, where the reactions with the sorbent may continue for a long time, on the order of minutes, allowing high utilization of the sorbent to be achieved. The filter is periodically cleaned aerodynamically with a counterflow stream of compressed air, blown in pulses, through a section of the filter. Dislodged particulates are collected in a hopper.