Carbon Footprint Analysis of Chemical Production: A Case Study of Blue Hydrogen Production

Interest in hydrogen has grown as a means to decarbonize future energy systems. To maximize hydrogen’s potential as the main energy carrier, the infrastructure for hydrogen production, distribution, and storage needs to be designed and developed at a global scale. Carbon footprint analysis is an important metric for ensuring that the environmental impact of the developed plant is kept at a minimum. However, application of conventional methods during the conceptual design stage is challenging due to lack of detailed process data coupled with the large number of potential designs to be vetted. As a result, there is a need to develop rapid screening techniques that can be used during the conceptual design stage to gauge potential carbon footprints. To address this issue, a simplified carbon footprint analysis method is proposed in this work. Two indices are introduced, i.e., “product carbon intensity” and “economic carbon intensity”, to allow comprehensive analysis of the performance of design alternatives. By limiting the scope and basic economic analysis, the simplified carbon footprint analysis requires less data, and hence expedite the analysis process. The methodology is demonstrated through analysis of four design scenarios for blue hydrogen production. Among the scenarios, hydrogen production with both carbon capture and pre-reforming yielded better results based on product carbon intensity (2.43 kg CO2/kg H2), while design with only carbon capture performed better based on economic carbon intensity (11.25 kg CO2/USD). Thus, high potential design scenarios were successfully identified based on the newly introduced indices.