Acids burdened with organic impurities are reusable if the impurities evaporate with water or are destroyed by oxidation. Waste acids with high levels of non-volatile organic impurities can only be processed by thermal cracking. The processing costs of a thermal cracking system are determined by the process gas volume flow as well as its sulphur dioxide concentration.
By enriching the air with oxygen, an increase in capacity can be achieved. A targeted feed ensures the required excess of oxygen for a more complete reaction to SO3.