Identification and Screening of Potential Organic Solvents for the Liquid-Liquid Extraction of Aromatics

There is increasing focus on the replacement of commonly used solvents in the liquid-liquid extraction of aromatics with solvents that result in improved process economics as well as reduced risk in terms of health, safety, and environment. In this work, a selection of organic chemicals are proposed for further study as replacement solvents that meet the technological requirements for the process of aromatics extraction from alkanes and have not been conventionally considered previously for this application. There were 52,654 organic chemicals screened with the use of a search algorithm based on the process requirements in terms of physical properties, capacity, selectivity, and performance index. Nine organic chemicals were identified (not being previously considered) that met all the criteria imposed by the search algorithm. A risk assessment further screened the identified chemicals, filtering out the potential solvents with adverse impacts on health, safety, and environment. Process designs were developed with the use of ASPEN plus in order to ascertain the effects of solvent choice on process economics via the use of total annual costs. The screening process in this work produced significant insights due to its holistic approach. The incorporation of factors such as solvent price, solvent loss, utilities, capital costs, health, and environmental impact showed that several of the solvents identified may be sustainable and cost-effective alternatives to conventionally used solvents. This highlights the need for a robust and broad perspective in considering the impact of solvent choice.