Process analysis of a low emissions hydrogen and steam generation technology for oil sands operations

Abstract

A conceptually simple and powerful method to reduce CO2 emissions from Alberta oil sands operations by decarbonizing natural gas (NG) fuel prior to combustion is proposed, thus removing carbon from the process up front. The natural gas decarbonization (NGD) process can be integrated with either in situ bitumen recovery or upgrading processes or both. The process generates hydrogen and carbon black, a stable marketable form of carbon. Decarbonizing the NG fuel to hydrogen reduces downstream CO2 emissions and obviates the requirement for CO2 sequestration since the carbon is stored in a solid form. The hydrogen can be used as either a fuel for steam generation or for hydrotreating. In addition, steam is generated from the hydrogen combustion reaction itself. A near-zero emissions process is achievable by using the hydrogen generated as the fuel for decarbonization. We used process modeling to assess the performance of hydrogen production and steam generation using two major process integration concepts: (i) Oxy-NG combustion integrated with the NGD process and (ii) Substantially zero emissions concept via an autothermal process using hydrogen product as the energy source for the process NGD process. Though energy penalties are incurred in the decarbonization process, we identify several potential practical process options. The proposed technology is particularly suitable for heavy oil recovery and upgrading, and fuel combustion for power generation.