Blue, green, and turquoise pathways for minimizing hydrogen production costs from steam methane reforming with CO2 capture

Rising climate change ambitions require large-scale clean hydrogen production in the near term. Blue hydrogen from conventional steam methane reforming (SMR) with pre-combustion CO2 capture can fulfil this role. This study therefore presents techno-economic assessments of a range of SMR process configurations to minimize hydrogen production costs. Results showed that pre-combustion capture can avoid up to 80% of CO2 emissions cheaply at 35 euro/ton, but the final 20% of CO2 capture is much more expensive at a marginal CO2 avoidance cost around 150 euro/ton. Thus, post-combustion CO2 capture should be a better solution for avoiding the final 20% of CO2. Furthermore, an advanced heat integration scheme that recovers most of the steam conden-sation enthalpy before the CO2 capture unit can reduce hydrogen production costs by about 6%. Two hybrid hydrogen production options were also assessed. First, a blue-green hydrogen plant that uses clean electricity to heat the reformer achieved similar hydrogen production costs to the pure blue configuration. Second, a blue-turquoise configuration that replaces the pre-reformer with molten salt pyrolysis for converting higher hy-drocarbons to a pure carbon product can significantly reduce costs if carbon has a similar value to hydrogen. In conclusion, conventional pre-combustion CO2 capture from SMR is confirmed as a good solution for kickstarting the hydrogen economy, and it can be tailored to various market conditions with respect to CO2, electricity, and pure carbon prices.

Automated summary

This study evaluates the techno-economic aspects of blue hydrogen production using steam methane reforming (SMR). The findings suggest that pre-combustion CO2 capture is a cost-effective method to reduce CO2 emissions, while post-combustion CO2 capture can be a better solution for the final 20% of emissions. Additionally, an advanced heat integration scheme and hybrid production options show potential for cost reduction.