Performance Enhancement of Heat Pump with Preheater-Assisted Pressure-Swing Distillation Process

Abstract

A heat pump is applied in pressure-swing distillation (PSD) for separating an isobutanol/isobutyl acetate mixture in this paper. To ensure dry compression and prevent compressor damage, a preheater is added before the compressor based on the dry fluid property of the isobutanol/isobutyl acetate mixture. In addition, the optimal preheated temperature of the overhead vapor stream may further improve the performance of the heat pump-assisted PSD process. Through optimization and analysis, the optimum superheat values of overhead vapor streams from two columns are 12 and 8.4 °C, respectively. The coefficients of performance of heat pumps achieve maximum values of 17.18 and 20, and the total annual cost of the process is minimum. Moreover, a heat exchanger network (HEN) is applied in the heat pump with preheater-assisted PSD (HPPSD) to reduce the use of steam in preheaters. Compared with the conventional PSD, the total annual costs, energy consumption, and CO2 emission of the HPPSD-HEN process are decreased by 69.8, 83.99, and 79.58%, respectively.

Reducing CO2 emissions and process cost in vinyl acetate/acetic acid/acetic anhydride ternary mixture via heat pumps with heat exchange network

“…According to Supporting Information S12, a preheater should be added in the CH 3 COOH MVRHP distillation, and other processes could just remain unchanged at the same time (Supporting Information S13). When the preheater P1 is installed overhead the compressor COMPR2 at the top of T2 column, the superheat of the overhead steam has unavoidable influences on the compressor brake power and compression ratio 49 …”

“…When the preheater P1 is installed overhead the compressor COMPR2 at the top of T2 column, the superheat of the overhead steam has unavoidable influences on the compressor brake power and compression ratio. 49 Table 4 presents the effects of superheat on TAC and CO 2 emission. The CO 2 emission increases with the increase of superheat.…”

Global Modeling of Heat-Integrated Distillation Column Based on Limited Local Measurements

“…Numerous scholars have conducted extensive research to explore the feasibility of heat-integrated distillation energy-saving technology. Much of this research focuses on the conceptual design of heat-integrated distillation columns in different scenarios, such as standard forms of heat-integrated distillation columns [6][7][8][9], heat-integrated pressure-swing columns [10][11][12], heat-integrated extractive distillation columns [13][14][15][16], heat-integrated air-separation columns [17][18][19][20], and heat-integrated reactive distillation columns [21][22][23][24]. Most of the works are primarily implemented through specific process simulation software.…”

Multi‐objective optimization and dynamic control of heat exchanger network for heat pump distillation of acetic acid/acetic anhydride binary system

“…For example, Yang et al 9 and Chen et al 10 optimized the separation process of industrial wastewater, and the results show that the MVRHP‐HEN technology has good energy saving and emission reduction effect. Wang et al 11 proposed a new type of heat pump distillation structure, by adding a preheater to the compressor to avoid the liquid in the compressor, and the heat exchanger in the system was integrated and optimized. Recently, our research group has studied the optimization of the separation process of vinyl acetate/acetic acid/acetic anhydride ternary system and confirmed that the MVRHP‐HEN has better economy and environmental protection than conventional distillation 12 .…”