Effective abatement of VOC and CO from acrylic acid and related production waste gas by catalytic oxidation

Abstract

Waste gasses containing volatile organic compounds (VOC) are arising mainly form industrial production in which organic materials are processed. These VOC must be treated to levels so that they meet the local applicable legislation limits. Momentive specialty chemicals is a company which produces acrylic acid, acrylic acid esters, and acrylate polymers in Sokolov (Czech Republic). A mixed waste stream which contains 6,000–10,000 mg TOC/Nm3 of VOC is treated. The management would like to lower the operating costs of the thermal incineration unit used. It seems suitable in this case to replace the existing incinerator with a catalytic oxidation unit with use of a Pt–Pd/Al2O3 catalyst for VOC abatement. A full-scale unit was designed according to the waste gas composition and flow. Mass and energy balances were carried out, and it was discovered that the catalytic bed must be divided into two parts to prevent the reactor overheating and irreversible damage to the catalyst. A pilot plant was designed and implemented due to the potential threat of catalyst fouling by solid impurities and to confirm the expected conversion of VOC and CO. It also proves the long-term reliability of the catalytic reactor. The performed pilot tests confirmed that catalytic oxidation is suitable for the disposal of waste gas from acrylic acid and acrylates production (for this application and treated inlet concentration of VOC). VOC and CO removal efficiencies during pilot trials were 98.3 and 98.5 %, respectively.