ENAP sulfur calculation irregularities prompt investigation requests in Chile

The Mayor of Hualpén, Miguel Rivera, has requested that the Comptroller General investigate whether irregularities in sulfur calculation methodologies discovered at ENAP’s Aconcagua Refinery have also occurred at the company’s plant in the Bío Bío region.

At the Aconcagua Refinery in Valparaíso, investigations revealed that the methodology used to calculate the sulfur balance did not match the procedures approved by environmental authorities. This has led to an internal investigation and criminal complaints. Local authorities in Hualpén expressed concern that monitoring stations have been inactive during significant pollution events, complicating the assessment of local impact.

Experts note that during oil refining, sulfur is released primarily as hydrogen sulfide gas. While industrial processes like the Claus process are designed to capture this and convert it into harmless elemental sulfur, inconsistencies in emission reporting raise questions regarding public health and air quality in affected zones.