The petrochemical industry accounts for approximately 20% of global industrial CO2 emissions. Ethylene manufacturing is one of the major components and has a high carbon footprint. This study explores the use of proton-conducting electrochemical cells (PCECs) for ethylene production - the WINNER process. This non-oxidative dehydrogenation (NODH) reaction is still thermochemical, but the hydrogen is electrochemically removed, enhancing the conversion of ethane.
The electrochemically enhanced production of ethylene demonstrates substantial improvements over conventional steam cracking. It decreases Specific Energy Consumption (SEC) by approximately 20%, curtails thermal energy demand by 80% and enables operations at a lower temperature of 550°C. Some parameters are less favourable, but nonetheless, the reduction in SEC indicates a promising potential to decrease carbon emissions attributed to utility consumption.
Economically, the WINNER process outperforms the steam cracking benchmark, with a nearly doubled margin, almost tripled Net Present Value (NPV), and a seven-times higher Internal Rate of Return (IRR). The Minimum Selling Price (MSP) of ethylene reduces by roughly 30% in the WINNER process. Additionally, the WINNER process produces pure, pressurized hydrogen as a high-value byproduct, adding to the economic viability of the process. A sensitivity analysis indicates that the most influential parameters are the prices of ethylene, ethane, and fuel gas.
Under current U.S. grid conditions, the Product Carbon Footprints (PCFs) of the WINNER process and the steam cracking benchmark are approximately equal. An increased contribution from renewable energy sources would enable the WINNER process to lower the utility-based PCF of ethylene production.
In conclusion, the WINNER process exhibits superior techno-economic performance and potential environmental advantages over the steam cracking benchmark, making it a promising alternative for sustainable ethylene production. Therefore, this work lays the groundwork for a sustainable and profitable transition in ethylene production, leveraging advances in electrochemistry.