Sulphuric Acid Concentration

The Global Antico Sulphuric Acid Concentration Plant is a high-performance vacuum evaporation system engineered to concentrate dilute sulphuric acid streams — typically 20–70% H₂SO₄ from industrial processes — up to commercial concentrations of 96–98%+ w/w. The process exploits the boiling point elevation of H₂SO₄ under reduced pressure, allowing water removal at significantly lower temperatures than atmospheric evaporation, preserving equipment integrity and reducing energy consumption. The dilute acid feed is introduced into a falling-film or forced-circulation evaporator where vacuum is maintained by a two-stage ejector or liquid ring vacuum system. Water vapour liberated during evaporation is drawn off and condensed, while concentrated acid is progressively recycled through the evaporator until the target concentration is achieved.

Heat input to the evaporator is provided by steam, hot water, or waste heat via indirect heating through acid-resistant heat transfer surfaces — typically tantalum tube bundles, borosilicate glass, or silicon carbide (SiC) shell-and-tube exchangers. An acid-mist scrubbing system downstream of the vacuum condenser captures acid carry-over before non-condensable gas is vented. An integrated heat recovery loop — using condensate heat to pre-warm incoming dilute acid — improves overall thermal efficiency by 25–35%. The plant operates continuously with automatic concentration monitoring via inline density measurement or refractometry, and automatic feed/draw-off rate adjustment. Available capacities range from 500 kg/day to 50,000 kg/day of concentrated acid output. Optional crystallization prevention heating circuits are included for high-concentration operation above 93% H₂SO₄.