MECS® Spent Acid Recovery Process

MECS® Spent Acid Recovery Process

MECS® builds spent sulfuric acid recovery plants with our own innovative and world-leading technologies. Our processes and designs improve performance, efficiency, cost-effectiveness, and emissions control for refiners and chemical processors.

Our expert engineers leverage over two centuries of combined experience acquired by MECS® and DuPont in building over 1000 acid plants worldwide, as well as in building and operating 10 DuPont own sulfuric acid plants. Our experts can customize our spent acid recovery process to regenerate sulfuric acid from spent acid and/or hydrogen sulfide for your refinery or chemical processing plant. Our solutions can meet stringent pollution requirements, even as they increase the efficiency and cost-effectiveness of your facility. And MECS® processes and plant designs feature our own breakthrough technologies, many of which have revolutionized performance, cost controls and quality for the sulfuric acid industry.


MECS® Spent Acid Recovery Process Description

Spent acid and/or hydrogen sulfide is burned at elevated temperatures to provide SO2 gas. In the case of spent acid, fuel is burned along with the spent acid in the combustion chamber, to achieve the required decomposition temperature. The wet SO2 combustion gas is then cooled in a steam boiler to recover energy prior to entering the primary MECS® DynaWave® Jet Scrubber . From the scrubber on, the process equipment arrangement will have some variation, depending on the amount of insoluble material generated in the combustion chamber. 

In the contact section of the plant the gas is dried in a MECS® ZeCor® Drying Tower with MECS® Brink® Mist Eliminators and then flows to the main gas blower which is the primary mover in the plant. The gas flows through three passes of MECS® GEAR™ and Cesium Catalyst and their respective cooling equipment and is then absorbed with 98% sulfuric acid (H2SO4) in the ZeCor® Interpass Absorption Tower. The lean SO2 gas flows through another MECS® Brink® Mist Eliminator to remove fine mist particles, protecting downstream equipment. The clean gas is then reheated and enters the converter to complete the fourth conversion pass of SO2 to SO3 using MECS® Super Cesium Catalyst SCX-2000 to achieve the highest possible conversion. The resulting SO3 is absorbed in 98% H2SO4 in the ZeCor® Final Absorbing Tower. Brink® Mist Eliminators are installed in the final tower to ensure the stack gas will meet acid mist environmental regulations.


A Commitment to Innovation and Quality

Our focus and commitment to technology development are primary drivers for our business. MECS® design and technical service offerings are supported by a team of expert chemical and mechanical engineers, as well as state-of-the-art Research and Development facilities and staff. We are focused on continuing to achieve new performance gains, and to solve crucial plant operations bottlenecks. Our expert engineers can custom-design your sulfur burning acid plant to meet your specific application and environmental requirements. Our innovative solutions deliver consistently superior quality, emissions control, energy recovery, and efficiency, using technologies that typically reduce maintenance and lifecycle costs.