(121a) Co-Production of Ethylene and Hydrogen Via Electrochemical Non-Oxidative Deprotonation of Ethane: A Low-Thermal-Budget and Low-Carbon-Footprint Approach

Authors: 
Ding, D., Idaho National Laboratory
Zhang, Y., Idaho National Laboratory
Wu, W., Idaho National Laboratory
He, T., Idaho National Laboratory
The shale gas revolution in the United States in recent years has resulted in an oversupply of methane and ethane, the major components of natural gas and natural gas liquids, respectively, and this trend will continue for the foreseeable future. Due largely to these cheap resources, e.g., the current price of ethane is less than 20 cents/gal, the chemical industry has moved manufacturing plants back to the United States, creating thousands of jobs, while enjoying healthy margins compared to international rivals that typically use more expensive oil-based naphtha as feedstock. However, the ethylene production from ethane or naphtha is energy intensive and represents the single most energy consuming process in the chemical industry. To fully exploit the potential of ethane as a feedstock, low-thermal-budget and low-carbon footprint processes are required. We demonstrated, for the first time, co-production of ethylene and hydrogen through an electrochemical non-oxidative deprotonation process (NDP) at 400oC, with an ethylene selectivity close to 100% and a hydrogen generation rate of 0.448 mol cm-2 per day. Compared to the commercial ethane steam cracking process, the NDP can achieve a 65% in process energy saving and reduce the carbon footprint by as much as 72% or even more (> 90%) if renewable electricity and heat are used. If the heating value of produced hydrogen is taken into account, the electrochemical deprotonation process actually has a net gain in processing energy.