Gold Hydrogen - New Opportunities from Surface Processing Perspective

Abstract The term "Gold hydrogen" or "white hydrogen" typically refers to hydrogen naturally found in subsurface reservoirs. The discovery and recovery of this natural hydrogen is still limited at large scale, however it is emerging as a potential hydrogen source to be explored, as the world moves towards Energy Transition and hydrogen as clean energy fuel source of the future. To effectively produce and export hydrogen from the reservoir, new surface facility design considerations and changes need to be adopted and implemented that are different from a typical natural gas production process. Production of natural hydrogen provides several advantages compared to industrial methods of hydrogen production which are associated with high energy cost for water electrolysis and CO2 emissions from steam methane reforming process. However, literature sources indicate that hydrogen content in the produced gas from the subsurface ranges from 0-100%, and usually is accompanied with presence of other gases such as CO2 (up to 3.7%), nitrogen (up to 99%), hydrocarbon gases (up to 50%), helium (up to 8%) and argon (up to 0.5%). Due to the difference in compositional range among all gases, different processing schemes are required. The key challenge faced is the purification of hydrogen from other gases especially in the presence of helium which is closer to the molecular size of hydrogen making typical separation technology such as Pressure Swing Adsorption (PSA) ineffective. Due to the commercial potential of helium, it is also worthwhile to separate helium for sales, with one potential technology identified is metal hydride separation. This proposed concept of hydrogen recovery (consisting of bulk separation, purification and hydrogen-helium separation) is planned to be deployed at a pilot-scale natural hydrogen production facility at an onshore site.