Heat Exchanger Network System Research Articles

Enhancing Energy Efficiency of Hydrodealkylation (HDA) Toluene for Benzene Production through Optimizing Utility Tool (Pinch Analysis)

Benzene is one of the chemicals widely used in domestic and industrial products. There have been many extensive studies conducted on hydrodealkylation processes to produce benzene from toluene to achieve the optimum result. Aspen hysys V.11 used to simulate hydrodealkylation process. In this study, this work aims to optimize energy efficiency and manage the heat generated by the highly exothermic hydrodealkylation reaction by adjusting the utility type of the heater and cooler. The results of the analysis and calculations, the utility modifications in the heat exchanger network system have proven to have a positive impact on energy efficiency and overall performance. With high energy efficiency, the system is able to reduce reliance on auxiliary utilities while improving the sustainability of the production process. This approach is not only beneficial from an operational perspective but also contributes significantly to cost savings and reduced environmental impact, making it a very viable solution to implement. Copyright © 2024 by Authors, Published by Universitas Diponegoro and BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Cleaning Schedule Optimization of Heat Exchanger Network Using Moving Window Decision-Making Algorithm

A moving window decision-making algorithm is proposed for the cleaning schedule optimization of heat exchanger network system subject to fouling in refinery crude preheat train. This algorithm is designed by incorporating the moving window scheme into a conventional multi-period optimal control problem (OCP) framework and has a distinct feature that it can efficiently handle a complex problem where a long-time horizon is considered. When compared with the conventional multi-period OCP method using fixed time horizon, our algorithm always shows an excellent performance regarding the computational time, still finding a compatible optimal solution. In our moving window decision-making algorithm, it is important to determine the optimal moving window size for the given time horizon as it significantly influences the optimization performance.

Heat Exchanger Process Optimization in A Typical Brewery Plant

The research attempts to improve upon the performance efficiency of the heat exchanger network system of Pabod Brewery, Port Harcourt, Rivers State, Nigeria. It swaps the heat system of the plant by the use of Pinch Technology to recover waste heat and integrating the recovered energy for process application. The application software is Microsoft Excel and Problem Table Method was employed in the numerical analysis of data. The gross energy expenditure by the plant is 10.44MW at production capacity of 400,000 liters of beer per day. On quantitative aggregate 6.157MW goes for heating and 4.267MW for cooling. A temperature pinch or minimum approach temperature (ΔTmin)of 100C was used in the pinch analysis of the heat exchangers performance. The research findings confirmed minimum heating utility of 5.04MW and cooling utility of 3.09MW. with energy upturn of 1.08MW and 1.23MW for the hot and cold flows respectively. This correlates to energy conservation of 18% for hot utility and 21% for the cold utility. The hot stream pinch temperature is 710C while that of the cold stream is 610C. Heat exchangers network configuration design were performed above and below the pinch The network designs were produced and integrated to produce improved heat exchanger network system for the Brewery plant.

Heat Exchanger Process Optimization in A Typical Brewery Plant

The research attempts to improve upon the performance efficiency of the heat exchanger network system of Pabod Brewery, Port Harcourt, Rivers State, Nigeria. It swaps the heat system of the plant by the use of Pinch Technology to recover waste heat and integrating the recovered energy for process application. The application software is Microsoft Excel and Problem Table Method was employed in the numerical analysis of data. The gross energy expenditure by the plant is 10.44MW at production capacity of 400,000 liters of beer per day. On quantitative aggregate 6.157MW goes for heating and 4.267MW for cooling. A temperature pinch or minimum approach temperature (?Tmin)of 100C was used in the pinch analysis of the heat exchangers performance. The research findings confirmed minimum heating utility of 5.04MW and cooling utility of 3.09MW. with energy upturn of 1.08MW and 1.23MW for the hot and cold flows respectively. This correlates to energy conservation of 18% for hot utility and 21% for the cold utility. The hot stream pinch temperature is 710C while that of the cold stream is 610C. Heat exchangers network configuration design were performed above and below the pinch The network designs were produced and integrated to produce improved heat exchanger network system for the Brewery plant.

A Novel Sensitivity Analysis Method for the Energy Consumption of Coupled Reactor and Heat Exchanger Network System

Since the inlet feed and outlet product of the reactor generally are the cold or hot streams of the heat exchanger network (HEN), it is necessary to analyze the relation between reactor parameters and the energy consumption (EC) of a HEN based on integration. An integration-based sensitivity analysis methodology is proposed to analyze the relation among conversion, inlet/outlet temperature of a continuous stirred tank reactor (CSTR), and EC of HEN. Equations are derived to show their relations, and the influence of temperature on HEN is analyzed with both positions of inlet/outlet streams and reaction’s endothermic/exothermic characteristics considered. The S–Q–T–X diagram is proposed to show the relation between reactor parameters and energy consumption of HEN, and perform the sensitivity analysis of the energy consumption along conversion; the results can guide the design of the reactors. A case study shows that, for the studied selective hydrogenation process from benzene to cyclohexene, the EC for pro...

Flexible heat exchanger network design of an ethanol processor for hydrogen production. A model-based multi-objective optimization approach

This work addresses the optimal design of a flexible heat exchanger network using model-based optimization, applied to hydrogen production by means of an ethanol steam reforming process. High efficiencies are obtained at different hydrogen production levels ranging from 25 to 100% of a nominal output. System structure, heat exchanger sizing, and operation conditions are simultaneously settled, ensuring both operational feasibility and optimality. The system involves a reforming reactor, vaporization and reheating equipment, combustors, and a heat exchanger network system. A multi-period nonlinear optimization problem (NLP) was formulated to account for the production level distribution. Equipment sizing constraints and structural constraints link the different scenarios. The trade-off between area and efficiency is analyzed using a multi-objective epsilon-constraint approach. Models were developed in the GAMS environment. The resulting solutions, for the maximum area case, maintain alcohol combustion at low levels showing efficiencies around 63% in each operational level. Pareto Optimal diagram shows that a 1% reduction of efficiency allows a 50% decrease in total required heat exchanger area by 50%.

Energy and environmental sustainability assessment of a crude oil refinery by thermodynamic analysis

Summary This study presents the assessment of energy and environmental sustainability metrics for a crude oil refinery consisting of three distillation columns. The assessments of the current operation and the retrofits for possible improvements are suggested by the thermodynamic analysis and energy analyzer. The main objective is to explore the scope of reducing the thermal energy consumption and CO2 emissions for a more sustainable refinery operation. Thermodynamic analysis is carried out by using the thermal analysis capability of ‘column targeting tool’ to address the ‘energy intensity metrics’ and the ‘energy analyzer’ to design and improve the performance of the heat exchanger network system for process heat integration. Environmental pollution impact metrics are estimated from the ‘carbon tracking’ options with a selected CO2 emission data source of US-EPA-Rule-E9-5711 and using crude oil as a primary fuel source for the hot utilities. The results indicate that column targeting tool, energy analyzer, and carbon tracking can estimate the energy and environmental sustainability metrics of an existing design and determine the scope of considerable improvements for reducing the costs of thermal energy required and emissions of carbon dioxide in a crude oil refinery operation. Copyright © 2015 John Wiley & Sons, Ltd.

Exponential Stability and Transfer Functions of Processes Governed by Symmetric Hyperbolic Systems

In this paper we study the frequency and time domain behaviour of a heat exchanger network system. The system is governed by hyperbolic partial differential equations. Both the control operator and the observation operator are unbounded but admissible. Using the theory of symmetric hyperbolic systems, we prove exponential stability of the underlying semigroup for the heat exchanger network. Applying the recent theory of well-posed infinite-dimensional linear systems, we prove that the system is regular and derive various properties of its transfer functions, which are potentially useful for controller design. Our results remain valid for a wide class of processes governed by symmetric hyperbolic systems.