Life cycle flaring emissions mitigation potential of a novel Fischer-Tropsch gas-to-liquid microreactor technology for synthetic crude oil production.

This paper compares the environmental impacts of the operation of a novel Gas-to-Liquid (GtL) process for synthetic crude oil production with conventional crude oil production. This process uses novel microreactor technology (NetMIX) applied in Steam Methane Reforming and Fischer-Tropsch (FT-SMR) for the conversion of associated gas originated on offshore Oil and Gas exploration. Data from literature for Oil and Gas extraction together with data obtained from Aspen Plus ® simulations was used to build the life cycle inventory. An attributional Life Cycle Assessment (LCA) was performed to compare the FT-SMR pathway to conventional crude oil production, using 1 MJ LHV as the functional unit. An additional assessment was also conducted by reporting the impact to 1 barrel. This is done to assess the effect that the add-on technology may have on the impact of current crude production. Converting associated gas using the FT-SMR pathway produces a synthetic crude with negative net GWP impacts. This is because the amount of avoided emissions is larger than the emissions due to the operation of the pathway. The remaining impact categories increase since the FT-SMR has additional intermediary steps, with added fuel energy needs, and additional process emissions. Moreover, the amount of natural gas required to produce 1 MJ of synthetic crude oil (abbreviated in the text as syncrude) results in larger impacts in the extraction phase, than those associated with the extraction of 1 MJ of conventional crude. The obtained syncrude has a GWP impact of -0.34 [-0.62, -0.14] kg CO2 eq/MJ, in comparison to 0.012 [0.009, 0.017] kg CO2 eq/MJ of conventional crude. A reduction of 8% to the impacts per daily barrel of crude (70.3 kg CO2 eq/barrel and 64.6 kg CO2 eq/barrel before and after using the FT-SMR pathway) was observed for a reduction of 34% of the total flared gas mass.