Sharif Digital Repository

Water is used as a key material in different processes of chemical industries. Considering abundant demand of chemical industries for water, pollution that threats this valuable material and the fact that there is currently no proper substitute for water, an urgent necessity is felt for economic utilization of water in industrial processes and optimal use of water resources. A variety of methods have been developed for analysis of water consumption in industrial processes, amongst are Pinch methodology and Mathematical Programming approach. In this thesis a Petroleum Refinery has been preferred as a case study in which optimization of water consumption in the aforementioned petroleum... 

The aim of this research is retrofit of a crude oil distillation refinery unit in terms of water and energy. To do this, the refinery distillation unit is ategorized to different zones from the perspective of water and energy to determine the saving potentials. The energy network consists of the four sub-types includes exchangers and the water network consist of seven sub-sets including water and steam. In the next stage, the retrofit of the energy network and the process heat exchangers are done by using pinch analysis in the commercial software and discussed the economical possibility of pinch analysis for 20 heat exchangers in the crude oil preheating unit. Using the flow of flashed crude... 

In this project, a comprehensive model is developed for energy and exergy analysis in refineries. By studying Tehran’s North Refinery unit as a case study, the Reference Energy System as the conceptual model of the thesis and also Energy & Exergy Balance table is prepared. Through the exergy balance table, the Exergy efficiency defined. These factors help to settle priority for efficiency improvement investment. Then, the economic and technical relations and costraints are formulized using linear programming model. In this model, the CO2 emission and exergy destruction costs are intended. Using Energy System Model (ESM) software, the thesis model is advanced as RESM stands for Refinery... 

The design and optimization of processes was focused in the past on economic issues such as profitability and return on investment, and less attention has been paid to environmental issues. In recent years, by introducing environmental criterion as pillars of sustainable development, environmental optimization of processes has becoming an inseparable element of the process engineering. Therefore, it is necessary to examine the compatibility of environmental indicators with economic objective. The purpose of this study is to investigate environmental indicators and economic objective function in optimizing the Crude Distillation Unit (CDU) of an oil refinery. The CDU is one of the most... 

This work presents a mathematical model for retrofitting the steam power plants in a refinery site. This problem is formulated as a mixed-integer nonlinear program (MINLP). Feasible retrofit alternatives suggested by experienced field engineers are investigated in sequence to examine the saving of those possible modifications. Furthermore, techno economic simulation of water and energy recovery systems from boiler flue gasses has been examined to obtain the optimal condition of these systems. For heat recovery, a systematic model for using organic Rankine cycle has been developed and results showed that toluene is the best possible working fluid in this case. Finally, water absorption cycle... 

The Fourth Industrial Revolution brought about a fundamental change in the system of management and production, especially in the field of industry, which was accompanied by the development of technology in the fields of artificial intelligence, robotics, nanotechnology and biotechnology. In line with these changes, the industry needs a new method to evaluate the reliability of operational equipment using artificial intelligence and intelligent systems, which aims to optimize the balance between a variety of repair methods with the possibility of timely replacement of parts. In this new method, the life of the parts is increased and the unplanned maintenance costs and labor are reduced. One...