Characteristic Analysis and Optimal Design on Heat-Transfer Capacity for Energy Saving of Heat-Integrated Air Separation Columns

Abstract

Research on characterizing and optimizing heat-transfer capacity (UA), an important design parameter determining separation efficiency and energy consumption in heat-integrated air separation columns (HIASC), is presented. The mathematical mechanism model of HIASC is built first, then characteristics of UA are explored. It is discovered that on one hand increasing of UA will lead to higher compressor load and thus brings higher energy consumption; however on the other hand increasing of UA will benefit mass transfer and conversely reduces energy consumption. For this reason, the optimal design on UA makes available the maximum energy efficiency together with considerable savings of the equipment investment, which provides guidelines for further designing of HIASC. Furthermore, an optimal partially coupled structure of HIASC is developed to exploit energy saving potential by lowering minimum temperature difference. The obtained optimization results show that the optimal design of UA for a fully coupled HIASC has achieved a 41.5% reduction in energy consumption compared to conventional air separation columns (CASCs) and up to 46.9% energy reduction is achieved by applying the optimal partially coupled design.

Optimization of Number of Stages for Energy Conservation and Economic Feasibility of the Heat-Integrated Air Separation Column

“…Three cases are considered in this study. Case 1 has the same number of stages as were in the previous study . Case 2 is obtained by optimizing the number of stages regarding the minimum energy consumption considering the heat-transfer capacity described in section .…”

“…Case 1 has the same number of stages as were in the previous study. 29 Case 2 is obtained by optimizing the number of stages regarding the minimum energy consumption considering the heat-transfer capacity described in section 3.2. Case 3 is obtained by the optimization with respect to minimum TAC defined in section 3.3.…”

“…Van der Ham et al studied the number of heat-integrated stages of the HIASC based on exergy analysis and entropy production. In our previous research, the optimization of the heat-transfer capacity was studied, and an improved structure with higher energy efficiency was proposed. However, few studies on the number of stages in the HIASC exist in the open literature, and researchers usually assume a fixed value for the number of stages. ,, …”

Temperature Inferential Control of Heat‐Integrated Distillation Column Based on Variable Sensitive Stage Temperature Set‐point

“…Distillation is the most widely‐used separation technology in the chemical engineering field . However, distillation has also resulted in severe environmental and energy‐related consequences because of its high energy consumption and low efficiency .…”

“…D istillation is the most widely-used separation technology in the chemical engineering field. [1][2][3] However, distillation has also resulted in severe environmental and energy-related consequences because of its high energy consumption and low efficiency. [4][5][6][7] Therefore, the improvement of distillation technology has become a widely-discussed topic in recent years.…”