Method for adjusting the sulfur dioxide concentration in flue gases

摘要

When burning coal and natural gas or oil u. a. the gas sulfur dioxide, which is a major cause of forest dying. German utility companies have invested heavily in recent years in installing flue gas desulphurisation (REA) systems. As a method of extracting the harmful sulfur dioxide from the flue gas, the so-called wet process is most frequently used. Here, the unpurified flue gas in a scrubbing tower, also called absorber tower, with a mixture of water and limestone, a so-called scrubbing suspension, sprayed, whereby the sulfur dioxide is largely absorbed by chemical reactions. By injecting an oxidant, usually air (oxidation), the liquid is enriched with oxygen and it creates a gypsum suspension. DOLLAR A In the invention, the oxidant used is enriched with pure oxygen or at least partially replaced by this, so as to bring about an increase in capacity of the flue gas desulfurization. According to the invention thereby the SO¶2¶ content is measured in the gas to be purified and / or the purified exhaust gas and used as a control parameter for the metering of oxygen in the form of air or enriched air. This ensures a particularly economical and efficiency-increasing use of the flue gas desulphurisation plant.