Assessing the performance improvement of an intensified heat integration scheme: Reactive pressure-swing distillation

This paper aims at intensifying the synthesis process of solketal by the reactive dividing wall column (RDWC) through experiments and simulation optimization and proposes a high-efficiency production process of solketal. A lab-scale RDWC was set up to verify the feasibility of synthesizing solketal in the RDWC. The effects of different operating parameters, such as reflux ratio, liquid split ratio, molar ratio of acetone to glycerol, feeding method, and the mass flow rate of side stream, on the experimental process have also been demonstrated and analyzed. Furthermore, an equilibrium-stage model developed by Aspen Plus and verified through comparison with experiments was used for the following simulation to optimize and analyze the solketal synthesis process. The response surface methodology (RSM) was employed to optimize the multiobjective problem in RDWC. As a result, a novel competitive solketal synthesis process with an upper partition position RDWC was put forward, which could obtain 99.78% conversion and 99.22 wt % solketal product purity at a 2:1 molar ratio of acetone to glycerol and had a lower energy consumption per unit mass product of 2509.2 J·g–1 compared with other processes. The achievements of this research provide a new way to produce solketal and a significant guideline for the industrial applications of solketal synthesis in the reactive dividing wall column.

Section: Introductionmentioning

confidence: 99%

Experimental Investigation, Process Design, and Optimization Analysis on the Production of Solketal in the Reactive Dividing Wall Column

Liu

Cong

et al. 2021

“…DWC, which can realize the separation of multiple components by integrating the distillation column sequence into a column shell, has been studied by a lot of researchers in its advantages of drastically reducing capital and operating costs. − The DWC can also be combined with CD technology to form the catalytic dividing wall column (CDWC) which can integrate reaction and multicomponent separation to save more energy than direct or indirect distillation sequences. − The VRHP which acts as a typical heat-integrated technology is to improve the pressure level of the overhead vapor to be the heat source and substitute for the high-quality steam in the bottom reboiler by the use of compressors. It is applicable for close-boiling point systems to improve energy efficiency. , The VRHP technology can assist with other processes such as DWC, HIDiC, and batch distillation for further energy saving. − Under the assistance of compressors, the HIDiC with compressors has received extensive attention due to its high energy savings of around 30–50% in the separation of various mixtures compared to the conventional column. − Mane and Jana proposed a novel intensified heat integration named int-HIDiC based on the structure of HIDiC and applied it in the separation of a benzene/toluene mixture . MED is extensively involved in the chemical industry due to its energy-saving superiority by integrating the top vapor of the high-pressure column to the bottom liquid derived from the low-pressure column.…”

Section: Introductionmentioning

confidence: 99%

Efficient Synthesis of Isobutylene Dimerization by Catalytic Distillation with Advanced Heat-Integrated Technology

Chen

Zhang

Zhou

et al. 2021

For the purpose of resolving issues of high production costs due to targeting intermediate products from tandem reaction systems in the isobutylene (IB) dimerization process with tert-butanol as a polymerization inhibitor, a potentially sustainable catalytic distillation (CD) process is proposed as the base case for efficient continuous diisobutylene production in this paper. This study covers the extensive design of the novel CD process with 99 wt % diisobutylene and 90 wt % oligomers as the final products, using a simulation-based optimization framework on the simulator Aspen Plus with a FORTRAN subroutine of Langmuir–Hinshelwood model for kinetics. Furthermore, the advanced heat-integrated manufacturing process by exploiting catalytic dividing wall distillation and double-effect catalytic distillation with/without vapor-recompressed heat pump (DECD-VRHP) technologies achieves a total reduction in energy and cost, compared to the base case with rigorous optimal CD. The results showed that the DECD-VRHP scheme performs better with the largest total annual cost saving of about 34% among the heat-integrated schemes compared with the CD process. Overall results demonstrate that the DECD-VRHP technology is a promising approach for the synthesis of IB dimerization.

“…In chemical and allied industries, distillation has been considered an energy-intensive separation unit for a long time. , It has attracted researchers to enhance energy efficiency because of its low energy utilization. , Therefore, heat integration distillation schemes have received considerable attention to improve the energy efficiency. Among the various heat integrated techniques, vapor recompression columns (VRCs), , dividing wall columns (DWCs), and internally heat integrated distillation columns (HIDiCs) , have been widely investigated. Compared with the other two schemes, the HIDiC has the highest energy efficiency. − However, the HIDiC involves high design complexity and large equipment investment.…”

Section: Introductionmentioning

confidence: 99%

“…3,4 Therefore, heat integration distillation schemes have received considerable attention to improve the energy efficiency. Among the various heat integrated techniques, vapor recompression columns (VRCs), 5,6 dividing wall columns (DWCs), 7 and internally heat integrated distillation columns (HIDiCs) 8,9 have been widely investigated. Compared with the other two schemes, the HIDiC has the highest energy efficiency.…”

Section: Introductionmentioning

confidence: 99%

Nonlinear-Model-Based Control of a Heat Integrated Distillation Column Using Model Updating Based on Distributed Wave Velocity

Cong

Liu

2019

A nonlinear-model-based control scheme for concentration profile position control of a heat integrated distillation column (HIDiC) is presented. First, a nonlinear wave model of the HIDiC is introduced to describe the concentration profile and its propagation velocity. Second, a distributed concentration wave profile velocity is developed to analyze the degree of the entire concentration profile deformation. Then, on the basis of the distributed wave velocity, a model updating method is proposed to determine a proper model parameter updating frequency so as to reduce the computing redundancy while guaranteeing the model accuracy. Finally, the nonlinear wave model and its updating method are combined to generate a model-based control scheme for the HIDiC, and controllers based on different model updating strategies are compared to evaluate the performance of the proposed model updating method.