Non-catalytic ethane cracking using concentrated solar energy

Non-catalytic ethane cracking - a highly endothermic process - was carried out using simulated, concentrated sunlight. A mesoscale reactor suitable for the direct utilization of solar thermal energy for the purpose of ethane cracking was designed, built and tested. The effect of different process conditions (temperatures of 800-1000 °C, steam-to-ethane ratios of 0-3.3, and mean residence times of 0.14-0.44 s) on the system performance was investigated using a dilute mixture of ethane (3%) in nitrogen. Single-pass, ethane conversions as high as 69% were observed with high selectivity towards ethylene. The efficiency of chemical conversion was calculated to be within 1-2%. The reported efficiency is low due to the dilute system used and the relatively low temperature of the inlet gas; however, efficiency can be greatly improved through use of a more concentrated feed stream and enhanced gas recuperation. This work demonstrates a new and promising approach to effective utilization of solar thermal energy for value added chemical production.