Greenhouse gas emission reduction and energy impact of electrifying upgraders in refineries using plasma processing technology

Abstract

Climate change and global warming are happening at an alarming rate. Meanwhile, conventional oil reserves are also being depleted. With the increasing energy demand, a new climate-positive pathway is essential to transition from CO₂-intensive thermal processes in refineries to greener processes with reduced emissions. Electrifying upgraders in refineries using a plasma processing technology integrated with renewable energy provides an attractive solution to process hydrocarbons with minimal emissions. This paper evaluates the energy requirements, associated greenhouse gas emissions, and energy economics of using plasma processing technology for heavy oil upgrading in refineries by replacing the fluid catalytic cracker unit using a model called petroleum refinery life cycle inventory model. The plasma calculations were performed based on bench-scale laboratory experimental results assuming similar conversion and linear scaleup. Two refinery configurations were analyzed and compared with the plasma processing technology. The first refinery configuration comprised of a traditional medium refinery with West Texas Intermediate as the crude oil input while the second comprised of a traditional deep refinery with Lloydminster Blend as the crude oil input. Implementing plasma processing technology increases energy consumption by 18% in the medium refinery and 14% in the deep refinery which translates to <2% energy content of a barrel of oil. The greenhouse gas emissions were reduced significantly with 21% reduction for medium and 35% reduction for deep refinery configuration. With a carbon tax incorporated, plasma processing technology increases the energy consumption cost by <$0.30 per barrel. A sensitivity analysis performed shows that varying the renewable energy cost, carbon tax, specific energy input to plasma for similar conversion, and plasma processing hydrogen yield can make plasma processing technology an economically feasible and competitive model. Finally, the life cycle assessment and the well to tank analysis were conducted for the plasma deep refinery configuration. Electrifying upgraders using plasma in a deep refinery reduces emissions from 166 kg CO_2eq per barrel of bitumen for the entire life cycle from the well to tank to 148 kg CO_2eq per barrel, a reduction of 11.5%. Integrating such technology in just 3% of United States refineries can reduce emissions by 2 million metric ton CO_2eq per year, a significant milestone toward energy transition.