Abstract
This paper deals with the design of two new, intensified pressure-swing flowsheets for the separation of di-n-propyl ether and n-propanol based on direct heat integration and vapor recompression. Such alternatives are then compared with the conventional scheme regarding thermoeconomic performance and environmental impacts. The thermodynamic evaluation was based on the processes’ energy consumptions, exergetic efficiencies and exergy intensities. The economic analysis was performed by estimating their investment costs and production expenses (water, energy and wastewater treatment), whereas the environmental assessment was based on the CO2 emissions, water consumption and wastewater generation. The overall performances of said designs were compared through a joint evaluation index, showing that the proposed vapor-recompressed and heat-integrated alternatives are 89.90 % and 55.04 % more sustainable than the conventional process, respectively. More specifically, said intensified flowsheets showed to be, respectively, about 83.85 % and 64.14 % more thermodynamically efficient, 68.69 % and 39.54 % more economically attractive, and 99.96 % and 69.09 % more ecologically friendly than the conventional design. A sensitivity analysis is then carried out to assess how different design criteria (operating pressure and feed flow rate) and the location where the plants are installed affect the sustainability results.