Application of exergy analysis to improve the heat integration efficiency in a hydrocracking process

Abstract

Heat integration techniques are now widely used for energy saving in petroleum processes. In this paper, an industrial hydrocracking process (UOP license) is retrofitted by pinch analysis as a significant tool for heat integration. The hydrocracking process is a main important conversion process in oil refineries and there has been sustained effort to improve its energy efficiency. Application of pinch analysis in retrofit of this process shows the heat exchanger network is operated efficiently. However, a large amount of energy is wasted from the hydrocracking unit, which their condition make no of use directly by the process during pinch analysis. Actually, most of the refining petroleum processes use considerably more energy than the operational minimum energy requirements because of their energy losses. These external energy losses are due to many factors, including normally inefficient or outdated equipment and process design, inadequate heat recovery, and poor integration of heat sources and sinks. However, without identifying the quality of the energy losses, it is difficult to determine how much of that energy is feasible to recover under realistic plant operating conditions. This is where exergy analysis can significantly assist in determining energy recovery opportunities. Thus, this paper is addressed to researchers who are assessing the quality of energy wasted in hydrocracking process, by using the principles of both pinch and exergy analysis. Based on the result obtained, the flue gas exhaust and the high pressure drop in reaction section can be considered as the exergy loss sources in this process. Moreover, the portion of waste energy that can be practically recovered is quantified.

Exergy analysis of petroleum refinery hydrogen network integration based on reaction system

“…Considering the desired products of HC unit, the reactor outlet streams are cooled in some exchangers and the vapor and liquid are separated in high-pressure and low-pressure separators to remove light ends in fractionation section. The low-pressure liquid is pumped to the recycle splitter flash drum and after heating in a furnace, it goes to recycle splitter for producing main products [36]. By adding this type of fractionation section to the simulation, the excess hydrogen, naphtha, kerosene, diesel and gasoline can be separated from the desired outlet stream, and thus practical exergetic efficiency could also be obtained.…”

“…Even though lots of pinch analysis studies on the refinery also performed [7,[30][31][32], the addition of exergy analysis to hydrogen network has been a new trend for the last years [33][34][35]. To improve the heat integration efficiency of refinery plant units, the exergy was used instead of enthalpy in pinch analysis [36,37]. Lou et al [12] developed the entropy change-based design method for multi-contaminant hydrogen network by using mathematical approach.…”

Dynamic simulation‐based quantitative hazard and operability process hazard analysis for a hydrocracking unit

“…With the popular use of computers, process simulation software is widely applied in the petroleum and chemical industry for process development, design, production operation control, and optimization 17–19 . Similarly, it can also be used effectively for process hazard analysis of production units in the refining and chemical industry.…”

“…With the popular use of computers, process simulation software is widely applied in the petroleum and chemical industry for process development, design, production operation control, and optimization. [17][18][19] Similarly, it can also be used effectively for process hazard analysis of production units in the refining and chemical industry. As such, chemical engineering process simulation software should be introduced to simulate the actual operating conditions to identify more accurately and efficiently the changes of key parameters in the various operating conditions of the hydrogenation unit.…”

Graphical Prediction of Optimum Pinch Point Value with AEA Software Simulation and Validation Applied in Closed Cycle Gas Power Plant

“…Such that energy saving can minimize the operating cost in the process [2] and optimum retrofit for HEN [3]. Applying PA IN the WTPS Wanakbori Gujarat power plant to reach an optimum plant design.…”