(28a) Safehr: Increasing Safety and Energy Recovery in Sulfuric Acid Plants

Sulfuric acid is one of the most produced chemical in the world. Production of sulfuric acid is generally associated with energy production as Sulphur burning and SO2 to SO3 conversion are highly exothermic processes taken at high temperatures. These oxidation stages are the main sources of heat in sulfuric acid plants, which is used to produce steam – making energy recovery a fundamental approach for sulfuric acid plants economic viability.

SO3 absorption into sulfuric acid is another exothermic step which can contribute to overall energy recovery. While there are some successful technologies dedicated to recovering part of absorption energy present in the acid stream, there are still barriers that hold some of these technologies from being standardized solutions. Corrosion, potential shut-down and risks of explosion are some concerns.

During acid-water heat exchanger leaks, a quick and exothermic dilution reaction takes place exponentially increasing corrosion rates and producing hydrogen. In the recent past there were several reported sulfuric acid plant incidents and explosions due to corrosion and hydrogen generation. Some of these failures were catastrophic.

This dangerous scenario can be avoided by means of engineered solutions revolving novel fluid applications. Clark Solutions SAFEHR®, patented Safe Heat Recovery Technology for Sulfuric Acid Plants, is an innovative process that uses inert, immiscible fluids to cool sulfuric acid, virtually eliminating the risk of acid-water contact and its hazards.

SAFEHR® creates a new scenario where corrosion and explosion risks associated with boiler or heat exchanger corrosion failures are virtually eliminated while allows the increase of roughly 40-50% in heat recovery and reduction of cooling water requirements in acid plants.