System Synthesis Approach To Regional CCUS Systems Considering Safety And Economic Objectives

A large portion of anthropogenic CO₂ emissions come from large point sources such as power plants,oil refineries and large industrial facilities.Capturing and storing CO₂ from large point sources is a carbon reduction solution.Carbon capture,utilization and storage（CCUS）is one of the various strategies for carbon management,which captures CO₂ emissions from point sources and then reuses or stores them,and CCUS technology can significantly reduce these CO₂ emissions.In this study,a carbon management network optimization model for planning a regional CCUS network is proposed through a mixed integer nonlinear programming（MINLP）approach.The optimization objective of the model is the optimal combination of cost and risk,and the optimal results are provided by examining different net reduction targets of the carbon management network according to the acceptable level of cost and risk to decision makers.A region-wide source-sink model is developed based on carbon life-cycle metabolism analysis.The model considers various types of emission point sources,various methods of CO₂ capture（pre-combustion capture,post-combustion capture,and oxygen-enriched combustion）,various modes of transport,and various types of storage or utilization of sinks.Potential utilization storage sites and carbon management networks are studied considering carbon reduction targets for different regions.A hypothetical case study of two CO₂ point sources in Dongying,Shandong Province was conducted.Chemisorption using ethanolamine（MEA）was considered as a capture technology,conversion of CO₂ into methanol,urea and greenhouse barns as utilization sinks,and enhanced oil recovery as a storage sink.The optimal carbon management network was finally determined for 20%,40%,50%and 60%reduction targets in the region.The results show the potential of model-based optimization of CCUS technology in reducing atmospheric CO₂ levels,and the approach is useful in helping designers and decision makers to identify carbon footprint reduction options for the region and in providing decision support for investigating the cost and inherent safety levels of CCUS systems.In addition,the largest reduction is 0.003 Gt of CO₂per year when the carbon reduction target is 60%,at which point the total cost of the CCUS system is$78 per ton of CO₂ per year,with the largest share of cost being transportation costs and the largest share of risk being CO₂ capture risk,for which the required risk monitoring actions need to be completed for the capture unit.