A Compact Natural Gas Pyrolysis Reactor for Hydrogen Fueling Stations

Abstract

With the increasing amount of greenhouse gases causing more natural disasters and sea level rise, there is a clear need for a global energy transition to less polluting fuels. A possible solution to this problem is converting a portion of the transportation sector fuel to hydrogen. In this thesis, the issues associated with such a transition are discussed and reasonable solutions are proposed. Numerous methods of hydrogen production are explored and compared on the basis of electricity consumption and CO2 emission. A plant size of 1250 kg liq. H2/day is chosen based on California regulated hydrogen refueling credits (HRI) that guarantee payment for produced hydrogen, regardless of the amount sold. A process simulation for hydrogen generation and liquefaction is carried out using Aspen Plus V10® to estimate equipment sizes. CAPEX and OPEX cost are estimated using correlations based on industrial standards. It was determined that, at this scale, only hydrogen generation is currently profitable. The high capital and operating cost of liquefaction is not justified unless intended for long term storage. Instead, high pressure or hydride tanks are recommended as storage media for modular filling stations.