Innovative high temperature heat pump concepts for an economic decarbonization of a carbon capture unit

Abstract

Achieving global net-zero emissions requires widespread adoption of Carbon Capture Utilization and Storage (CCUS) technologies. However, the current state-of-the-art using amines relies on fossil fuel-based thermal energy for solvent regeneration, offsetting some emission reductions. This study proposes and validates an economically viable decarbonization strategy for carbon capture units. The carbon capture unit is evaluated in isolation, proposing different cases focused on varying levels of decarbonization. The methodology utilizes available process waste heat while reducing dependence on external heat supply. A techno-economic evaluation against the background of Germany, considering both the high electricity-fuel price ratio and fossil-heavy electrical supply to be important deterrents. Using Aspen Plus™, an industrial pilot CC unit was simulated, and a conventional High Temperature Heat Pump (HTHP) solution employing hydrocarbons was integrated, reducing external heat demand by 27 % with minor process modifications. More complex integration systems can achieve total decarbonization of the heat supply, albeit at higher costs. The study also investigates the role of carbon credits as both a cost and revenue source, along with sensitivity analyses on process costs and emissions. The present work introduces a novel approach for economic decarbonization of solvent-based carbon capture units. Minor modifications to the operating pressure in the regeneration column were found to increase heat demand and emissions, but also permitted the use of novel HTHP technologies, resulting in even lower process costs and emissions at high electrification levels. The results offer valuable insights for researchers, technology providers, and policymakers seeking to reduce emissions from emission-intensive industries.