This paper presents both the results of a study of the existing heat exchanger network (HEN) of an industrial unit for ethylbenzene (EB) production by the alkylation of benzene with ethylene, and an analysis of four different HEN retrofit projects carried out using process integration methods. The project of modernization of HEN was carried out using classical methods of Pinch analysis. For this case, the value of ΔTmin is determined, which is limited by the technological conditions of the process. Additionally, two different heat pump (HP) integration options and the joint retrofit Pinch project with HP integration are under consideration. The economic analysis of each of the projects was carried out. It is shown that the best results will be obtained when implementing the joint project. As a result, steam consumption will be reduced by 34% and carbon dioxide emissions will be decreased by the same amount.

This paper presents the approach to predict the future performance of a heat exchanger network based on Pinch retrofit design and detailed historical performance of the unit to improve the operation efficiency, save an energy and increase a throughput. The main input is a finding of a profitable solution of heat exchanger network based on Pinch Analysis, fouling predictive management and a start-up and shut-down time. The approach demonstrates the importance of a dynamic assessment of the retrofit design and operation modes. The case study was developed for crude oil distillation unit with annual capacity of 6 Mt. Dynamic fouling models were built to assist with designing and revamping of heat exchanger network, to reduce the fouling and increase the throughput. Rigorous modelling of refinery heat exchangers network and Pinch Analysis were executed to achieve increased throughput, reduce operation cost and harmful emissions. A new heat exchangers network with improved operation conditions predicting efficient exchanger cleaning schedules under various economic and operational constraints was obtained. The calculations use an HTRI shell-and-tube heat exchanger models, operation data, properties of crude oil and cleaning schedule. Process Integration steps were done by HILECT software and new operation schedule of efficient heat exchangers network was created by HTRI software. The strategy and recommendations for the optimal operation of the retrofitted network were proposed taking into account the economic and process constraints such as exchanger by-passes, operation budget, furnace duty and pumping limit.

The new Benchmarking methodology (Anselm) is based on the Pinch Analysis, statistical analysis and analysis of the best available technologies presented in this paper. Using the Pinch Analysis, 12 energy efficiency indexes were developed. The data obtained as a result of Pinch Analysis was processed by statistical methods. Dependencies that allow to identify the energy saving potential in oil refining processes without a detailed survey were obtained. An approach is proposed in which it is justified that only an economic evaluation of the proposed solutions to reduce gaps shows the most profitable way to increase the energy efficiency of enterprises. Anselm makes it possible to decompose all possible costly measures related to increasing energy efficiency or reducing emissions. This approach permits to propose a list of conditionally independent projects in different areas of activity and to propose projects according to the criterion of maximum energy efficiency or economic feasibility, in accordance with economic prerequisites. This paper gives an example of calculating the energy efficiency index (Anselm) for ten primary petroleum refining process.

This paper presents the retrofit of the two-flow heat-exchange system with utility paths in order to optimize the heat recuperation capacity under the technical limitation conditions. Analytical dependences of heat load of the existing heat exchangers and utilities on the surface area of the new heat exchanger are obtained. The work shows that the determination of technological parameters for existing heat exchangers during the retrofit of the heat exchange system is an important task because they affect the cost of retrofit. For case study, two streams problem for heat transfer in heat network at the crude and gas separation units is considered in this paper. The existing system has three heat exchangers. The temperature measurements were fulfilled for all heat exchangers and the heat loads for heat exchangers and utility were calculated. The installation of one heat exchanger at the cool side of the system is proposed in retrofit. The dependences of the temperature changes for the hot and cold process stream from the value of the additional surface were obtained for each heat exchanger. Utility capacity and capacity recovery of thermal energy in the system is also analyzed.

Ukraine is the largest consumer of hydrocarbons per unit of production in Europe (Ukraine policy review, 2006). The most important point is a reduction of energy consumption in chemical and metallurgical industries as a biggest consumer. This paper deals with energy savings potential of light hydrocarbons separation process. Energy consumption of light hydrocarbons separation process processes typical of Eastern European countries were analysed. Process Integration (PI) was used to perform a preliminary analysis of different units and fulfil the retrofit project of Total Site Integration (TSI). A new heat exchanger network (HEN) were developed and the equipment was calculated with use of the Pinch principles. A complex method was developed and applied to integrate several units at the enterprise site demonstrating the possibility to use heat pumps. Heat pump integration increases heat recovery and offers a solution in order to increase energy savings and project profitability. The heat transfer area and number of heat exchangers for a retrofitted heat exchanger network have been identified. The estimated payback period for integration Heat Pump of Gas Separation Enterprise is about 127 days and the pathways of plant modernization have been also proposed.

The process of benzene distillation and process of coal tar distillation being typical for East European countries is analyzed in this paper. The pinch analysis method was selected to perform a reconstruction project. According to principles of pinch analysis, new network diagrams are designed and capacity of heat-exchange equipment is calculated. The using of «Total Site Profiles» showed the feasibility of heat pump integration. Heat pump integration allowed to reduce the external hot utilities usage on 368 kW and cold utilities usage on 368 kW. This project let to decrease the external hot utilities usage on 23 % and cold utilities usage on 24,13 %, and also offered the way of step-by-step retrofit of the plant.