Search

Energy efficiency improvement is an effective strategy for CO2 reduction as well as cost savings in the industrial sector. Petroleum refineries generate significant amounts of hot and wet flue gas containing CO2 given their large fuel consumption due to energy intensive processes. In addition, for those locations where the climate is arid, sustainable water supply turns out to be a serious problem to meet the large demand for steam. This paper proposes to synthesize an optimal heat and water recovery system (HWRS) using a superstructure based method to achieve CO2 reduction, cost savings, and water recovery all simultaneously. The water recovery rate is obtained using Aspen Plus® and the HEN is designed by formulating an MINLP problem and solving it using GAMS. As a result, the HWRS could achieve 4.348% CO2 reduction and 28 k$/day of cost savings with 29% lower water demand from the desalination plant.

CO2 capture and utilization technologies (CCU) are recently attracting attention as ways to reduce CO2 emission and generate economic benefits at the same time. Since numerous potential products from CO2 may be considered and multiple processing pathways are possible for each product, there is a growing demand for a tool that can aid in techno-economic and life cycle CO2 analyses of a large number of CCU options, in order to identify promising ones. This work introduces a computer-aided analysis tool called ArKa-TAC3 tailored for this purpose. ArKa-TAC3 can calculate both techno-economic and CO2 reduction metrics of CCU processes in a fast and convenient manner. Sufficient flexibility is assured by adopting a superstructure model framework, which allows the user to conveniently describe a CCU processing network composed of multiple processing steps with a large number of technical options. To demonstrate the tool, a CCU process of acetic acid production is designed and its sustainability is analyzed by using it. By implementing the designed process in four different countries, it is verified that the CCU process can be made sustainable by adopting the process substitution strategies its implementation. Some perspectives on potential applications of the developed tool are given.