Enhancing early-stage techno-economic comparative assessment with site-specific factors for decarbonization pathways in carbon-intensive process industry

Abstract

Site-specific factors are expected to influence the indication of cost-optimal decarbonization technology for the carbon-intensive process industry. This work presents a framework methodology to enhance the comparative analysis of decarbonization alternatives using site-specific techno-economic analysis, incorporating pertinent site-specific factors to obtain an enhanced indication of the optimal decarbonization solution. Site-specific cost factors such as energy supply options, space availability, site-layout constraints, local CO₂ interconnections, forced downtime, and premature decommissioning are considered. Qualitative site-specific factors and technology-specific attributes are assessed via expert elicitation with a retrofitability assessment matrix, generalizable to other process industries considering their site-level conditions. The framework methodology is demonstrated with a steam cracker plant case study, considering post-combustion CO₂ capture and pre-combustion CO₂ capture with hydrogen-firing in the cracker furnaces as decarbonization options. Results complemented with factor-specific sensitivity analysis highlight the extent of cost-escalation due to site-specific factors. The primary cost-contributing factor to retrofitability was the impact on production in existing sites, followed by the opportunity cost of utilizing valuable space on-site. Finally, pre-combustion CO₂ capture was found to be the optimal solution, offering significant site-specific advantages, with the lowest CO₂ avoidance cost and reduced overall risk over the residual lifetime of the host plant.