(263b) CAPE-OPEN Models for Hg Speciation and Partitioning Flowsheet Development

Mercury exists in a variety of forms in hydrocarbon production.  CAPE-OPEN models were used to develop a flowsheet to accurately predict the distribution and speciation of elemental mercury (Hg⁰) and meta-cinnabar (HgS) throughout process equipment in an oil and gas processing facility. The speciation of total mercury between Hg⁰ and HgS is critical to reducing the risk of projects, since the equipment required to remove each species is entirely different and the HgS can convert back to Hg⁰ at high temperatures.  Mercury distribution and contamination of the gas, condensate, and water export fluids impacts both commercial and regulatory feasibility for the facility process selection.  HgS has minimal risk if defined and intercepted properly in the production process design, but failure to properly handle the HgS risks conversion of a benign compound to elemental Hg by the production process.  Appropriate definition and distribution prediction of HgS and Hg is thus critical to managing overall mercury risk on projects. The use of CAPE-OPEN models within COFE allowed for simulation of multiple phases (including mercury and solids) along with an appropriate property package to manage hydrocarbons, water and alcohols simultaneously.