New coupling technology of phenols extraction in coal tar and carbon dioxide capture: Modeling, optimization and techno-economic analysis

•The process for phenols extraction and CO2 capturing synergistically was developed.•The feasibility of the coupling process was demonstrated by cyclic experiments.•The mathematical models were constructed and applied to simulate the design process.•The process has cost and environmental advantages over industrial processes. A new coupling process for highly efficient extracting phenols from coal tar and capturing carbon dioxide in exhaust gas employing aqueous amine was developed, which improved the shortcomings of high cost and environment pollution of single industrial process by process coupling and strengthening. The cyclic experiment of this process with monoethanolamine solution as extractant reached a stable state after 4 cycles. Under the steady-state, the total extraction yield of phenols and the total recovery yield of monoethanolamine and water were 100%, 98.8% and 90.9%, respectively. In addition, the empirical and semi-empirical models based on the experimental and literature data were constructed, and the models were linked to Aspen Plus software to simulate and optimize the coupling process. The optimization results showed that the unit production cost of present green process was 274.79 CNY·t−1, which only 25.4% and 65.6% of the cost for the traditional and improved industrial processes, respectively. Especially, the consumption of mineral resources and pollutant emissions in this process were reduced compared to the industrial processes. This work provides an industrially promising method for extracting phenolic compounds from coal tar and synergistically capturing carbon dioxide in industrial exhaust gas, and lays an engineering foundation.