Minimization of air pollutants emissions by process improvement of catalytic reforming unit in an Iranian old refinery

The old oil refineries are largest chemical industries that are responsible for emission of several pollutants and GHGs. It is possible to minimize energy usage as well as air pollution by some process modification. The main objectives of this investigation were the minimization of air pollution and CO₂ emissions in catalytic reforming unit in an oldest and largest refinery in Iran. To assess the air quality, ten sampling stations were selected for measurement of CO, H₂S, SO₂, and PM₁₀ in ambient air. Also concentrations of C₁–C₅, H₂S, and CO₂ were measured in selected unit. In final, structural and process flaws were identified by analyzing real functional circumstances and they were modified. Results show that SO₂, H₂S, and PM₁₀ concentrations are higher than ambient air standard levels in all seasons. Also, according to achieved results, the cold separator gas flow rate is reduced from 38,936 kg/day (once-through gas process) to 9,649 kg/day (recycle gas process). Beside CO₂ and SO₂ emission rates will be reduced 1803 and 136.5 kg/day in this unit, respectively. Furthermore, the modification of this process causes prevention of 1654 kg CO₂ emission into the atmosphere, during each coke burning and catalytic regeneration.