Comprehensive analysis and energy efficient process design for separation of four high purity components from organosilicon system

Abstract

The separation and purification of methyl-chlorosilanes play an important role in the organosilicon industry. NSGA-II algorithm was applied to the multi-objective optimization of traditional organosilicon distillation. In order to save energy, pinch technology and vapor recompression technology were introduced. Two heat integration enhancement schemes, which were heat integrated distillation process (HIDP) and vapor recompression assisted heat integrated distillation process (VRC-HIDP), were designed. The results show that the key to reducing energy consumption lies on the energy saving of M1/M2 separation column. Hence, the pressure-regulating heat integrated distillation process (PR-HIDP) and the vapor recompression assisted pressure-regulating heat integrated distillation process (VRC-PR-HIDP) were proposed. The pressure of M1/M2 separation column was increased to make better use of overhead steam to exchange heat for other columns in the PR-HIDP and VRC-PR-HIDP. The results show the gas emissions and total annual cost (TAC) of the four improved energy-saving schemes are reduced significantly. The VRC-PR-HIDP has the best economic and environmental performance, with TAC reduced by 44.46 % and gas emissions reduced by 70.96 % compared with the traditional distillation process (TDP).