Use of Refinery Off Gas (ROG) As CO2 Emission Reduction and Natural Gas (NG) Savings in Hydrogen (H2) Production

Hydrogen has become a crucial link to the 2050 carbon-neutrality goal. Industry is actively pursuing Steam Methane Reforming (SMR) of NG and RNG. The industry is pursuing energy efficient SMR process by heat integration for hydrogen production with low carbon-footprint compared to commercial SMR. CO₂ emissions from conventional SMR process is more than 7 kg CO₂ / kg H₂; therefore, achieving the goal of 1 kg CO₂/kg H₂ requires CO₂ recovery of 90%. Furthermore, to enhance the economics of H₂ and achieve target cost of H_2, CO₂ must be converted to high-value products with expanding global market demands. Process analysis is performed of chemical CO₂ capture and conversion to alkyl carbonates for achieving both of these goals. A trade-off analysis is performed for chemical capture of CO₂ from three locations in the SMR process for 90% capture with favorable economics. The process development builds upon E3Tec’s process development of CO₂ capture and conversion to high-purity alkyl carbonates. E3Tec has developed a conceptual adsorbent catalytic reactor (ACR) using an integrated solid adsorbent and catalyst for direct capture from the primary CO₂ source and its conversion to high value alkyl carbonates. Case studies consist of conversion of ethylene or propylene oxide to their corresponding carbonates with further conversion dimethyl carbonate (DMC) with selective coproduction of glycols using Heat-Integrated Reactive Distillation (HIRD) process. The formation of high-value alkyl carbonates, with an increased need in the expanding market of lithium-ion batteries, will have positive impact on H₂ economics with low carbon-footprint.