User-Friendly Computer-Aided Tool for Optimization of Multi-Path CO2 capture and Utilization Superstructure

Abstract

A carbon capture and utilization (CCU) is a concept of capturing CO2 from industrial sources (e.g. flue gases) and utilizing them in making new products. A CCU superstructure is a systemic way to model all potential pathways from multiple carbon sources to multiple product candidates through various processing routes. This systemic approach is needed as the number of possible combinations of CO2 sources, capture technologies, conversion technologies, and final products can be huge and numerous processing routes may need to be evaluated from the viewpoint of economics and environmental impact. The profitability and sustainability of the processing routes may change with circumstances such as a change of the electricity source from a fossil-fuel based one to a renewable kind1. To aid such modeling and evaluation efforts, we have developed a user-friendly software tool that can help build a superstructure and identify and visualize the best processing routes within the built superstructure. The tool is named Aramco-KAIST Tool for CO2 Capture and Conversion (ArKaTAC3), and we describe a major upgrade from a previously released version which was capable of evaluating a single processing route2. Generic models3 and network models are implemented in the tool so that a superstructure with an arbitrary size can be built conveniently and optimized in a manner of both mixed integer linear program (MILP) and nonlinear program (NLP). The database for various conversion and separation processes’ mass and energy balance parameters, techno-economic parameters, and life cycle inventory parameters are constructed and connected with the evaluation tool. A graphic user interface is also built to specify and visualize a superstructure network and pathways in a convenient and intuitive way. As case studies, exemplary CCU superstructures for various industrial sectors (e.g. refinery, iron and steel, cement, and power generation) are built. The superstructures are optimized under multiple scenarios: Korea / United States / Saudi Arabia as different countries as well as the current energy makeup, future energy makeup, and global recession as potential scenarios of different price and carbon footprints of the raw materials, products, and energy sources.