Rethinking energy use in distillation processes for a more sustainable chemical industry

Abstract

The need for greater sustainability for the production of fuels and chemicals has spurred significant research to rethink energy use in the chemical industry, and eventually substitute fossil fuel sources by renewable sources. Nowadays, the chemical industry is responsible for about one third of the total energy used - and the associated CO2 emissions - in the industrial sector. Among the energy intensive operations, distillation alone is responsible for about 40% of the energy used in the chemical industry, but there is clearly much room for improvement. This paper aims to provide an informative perspective on the current energy use in the chemical industry, with a focus on distillation – the undisputed king of industrial separation processes – and potential improvements for a more sustainable future. There is clearly an increasing need and scope for advanced distillation technologies (e.g. reactive distillation, dividing-wall columns, thermal coupling, cyclic distillation, heat pump assisted distillation, and heat integrated distillation columns) that can significantly reduce the energy usage and the carbon footprint of modern chemical plants. However, these advanced distillation technologies must be considered, along with conventional distillation operations, in the context of the process as a whole. Based on the overview provided, several challenges and opportunities for research directions are highlighted towards rethinking the energy use in distillation processes, for a more sustainable chemical industry.