M. Hassan Panjeshahi

University of Tehran | UT · School of Chemical Engineering

One of the most efficient methods of exergy recovery during the regasification process is integrating the LNG stream with an Organic Rankine Cycle (ORC) to generate electricity. This study employs a cascade structure of ORC consisting of two double-stage condensations operating at 6 bar regasification pressure. To obtain an optimal ORC system integ...

Process Integration

Early production in oil fields can cause problems related to oil specifications in the existing process unit, especially in the stabilization tower. This study aims to improve the performance of a crude oil treatment unit for an Iranian oil field. The process involves a two-stage desalting unit followed by a stabilizer tower. First, the desalting p...

Energy integration using pinch technology in a Total Site (TS) has been widely used for optimization and energy saving. In this paper, wind and solar energy are integrated into a TS system using pinch concepts to reduce environmental pollution. A new procedure of Total Site Heat Storage Cascade (TS-HSC) construction is proposed, which is shorter th...

In this research, a new graphical tool entitled Omega Total Site Profile (OTSP) is introduced to simply calculate the exergy destruction and losses within a total site. This new diagram is obtained by the development of Omega Composite Curves (OCC) used for exergy destruction and loss calculations within an individual process. The OTSP diagram is l...

In this study, a novel methodology is extended for the Total Site minimum energy requirement and area targeting, in which streams' optimum pressure drops are used for each individual process. Two case studies on Total Site systems are investigated by two different approaches to approve the accuracy of the mentioned methodology. The conventional app...

While extracting oil and gas from underground reservoirs, a large amount of water is produced, which increases during the reservoir's life. Given the scarcity of water supplies and the high volumes of water produced, proper management and usage in various applications are essential. The main objective of this study is to adsorb the remaining oil fr...

A gas flare is a safety device in oil, gas and petrochemical plants, but excessive flaring causes remarkable material and energy losses as well as environmental and economic problems. In the current study, the optimal start-up procedures for an olefin dynamic operation are presented. The flaring locations that have been identified showed that the m...

Chiller plants are the most energy consuming system during summer season in residential, commercial and hospital buildings. The highly variable cooling demand of the buildings connected to a hybrid chiller plant included absorption and vapor compression chillers to achieve higher energy efficiencies is one of the important issues. Cooling load shar...

The novel NiAl2O4 spinel was used as support to synthesis cobalt catalysts and investigated for Fischer‐Tropsch synthesis. The physicochemical properties of the synthesized catalysts (Co/NiAl2O4, Co/Rh/NiAl2O4, Co/Ru/NiAl2O4 and Co/γ‐Al2O3) were characterized by XRD, BET, ICP, SEM, FESEM, HRTEM, TPR and TGA analysis before reaction. It was shown th...

This paper presents new graphical tools, which can quickly identify all thermal exergy losses occurring in process design particularly in condensers/evaporators of low-temperature processes. Although the Ω -H diagram is a powerful tool for getting insights about exergy loss in a Heat Exchanger Network, the calculation of the enclosed area is not st...

The autothermal dry reforming of methane was performed using the novel CoAl2O4 spinel as a catalyst support on the monolithic and fixed bed reactors. X/CoAl2O4 (X = Ni, Co, Rh, Ru) and Ni/γ-Al2O3 nanocrystalline mesoporous catalysts were characterized by XRD, BET, SEM, FESEM, HRTEM and TGA. The effects of different experimental parameters, such as...

There is a wide range of resources for CO2 emissions. The net amount of CO2 emissions in the cement industry due to the consumption of fossil fuels and the chemical processes of cement production under heating raw materials is reported to be in the range of 15–25%; this industry, among all the industries and after the power plants and refineries, i...

Benchmarking of process industries with respect to energy consumption has always been a challenging issue for effective management of energy resources. Having developed a precise model for estimating the energy consumption, we have a powerful tool to measure and identify the opportunities for improvements through a plant. In this study, a mathemati...

Carbon dioxide is the most important greenhouse gas in the atmosphere. In fact, carbon dioxide exists naturally and constitutes about 4% of atmosphere and plants use it in the process of photosynthesis in order to produce oxygen. Almost all additional carbon dioxide emissions in atmosphere are produced by fossil fuels combustion needed for energy a...

Cement industry is considered as an energy intensive industry, owing to the huge amount of heat consumed in pyro-process unit. There are many conventional methods around, which can be applied to carry out energy targeting in a cement production plant, including conceptual, mathematical or even hybrid. However, full application of these approaches w...

The olefin plant cold-end is aimed at separating cracked gas into ethylene, propylene and other heavier by-products using low-temperature gas separation processes. This process is energy-intensive and hence retrofitting for energy saving would be desirable. However, a full retrofit study requires a lot of time and costly engineering work. So, a nov...

Carbon dioxide emissions from the chimneys of thermal power plants create major environmental risks. Therefore, an important step toward reducing the emissions in these power plants can be the carbon dioxide pre-combustion capture process. In this paper, a 150 MW thermal steam cycle power plant fueled by bagasse was studied. The power plant has an...

Power generation with high efficiency and low CO2 emission is a crucial issue for power production industry. In this research, a retrofit design for a power plant was proposed to use of solar irradiation before combustion section of gas turbine cycle. To do so, a solar tower with heliostat field was employed for compressed air preheating. A steady-...

The high price of crude oil, strict environmental regulations and ever-increasing demand for energy have made refineries adopt a more holistic approach to integrating energy, economics and environment in their design and operation. Gas flaring is a major factor for the wastage of energy in oil and gas industries that could be better utilized and ev...

This book provides some of the analyses needed to rethink Irans’s energy strategy and to grasp the chances. The authors hope to make a contribution to the emerging and rapidly growing discussion within Iran as well as between Iran and other countries such as Germany on bet-ter energy alternatives and the respective opportunities for investment, inn...

A techno-economic evaluation for efficient use of energy in a large scale industrial plant of methanol is carried out. This assessment is based on integration of a gas turbine with an existing plant of methanol in which the outlet gas products of exothermic reactor is expanded to power generation. Also, it is decided that methanol production rate i...

Gas flaring is one of the most GHG emitting sources in the oil and gas industries. It is also a major way for wasting such an energy that could be better utilized and even generates revenue. Minimize flaring is an effective approach for reducing GHG emissions and also conserving energy in flaring systems. Integrating waste and flared gases into the...

Gas flaring is one of the most GHG emitting sources in the oil and gas industries. It is also a major way for wasting such an energy that could be better utilized and even generates revenue. Minimize flaring is an effective approach for reducing GHG emissions and also conserving energy in flaring systems. Integrating waste and flared gases into the...

An integrated gasification combined cycle (IGCC) may be used to generate steam and power while providing a capture-ready CO2 stream. This work addresses techno-economic optimization of an IGCC integrated with the utility system for a process site, with the aim of cost-effective reduction of CO2 emissions. The IGCC can generate power and produce ste...

The combustion of fossil fuels for providing heat and power in the process industries is a major contributor of CO2 emissions. Heat integration methods have been widely used for energy-saving retrofit projects to improve the energy efficiency of process plants, reducing fuel consumed and consequently CO2 emissions. It is not straightforward to iden...

In this chapter, energy- and water-consuming systems in oil re� ning and petrochemical complexes are classi� ed into three groups: heat and power systems, water and wastewater networks, and ef! uent treatment systems. In the � rst section, Heat and Power Integration methods for optimum design and retro� t in oil and petrochemical plants are demonst...

A modified method for the design of multi-stream plate-fin heat exchangers that considers variable physical properties is proposed in this paper. The new method, based on Pinch Technology, exploits the dependency of physical properties (heat capacity, viscosity, density and thermal conductivity) on temperature variations. A set of temperature corre...

This paper is intended to investigate how one can improve the overall energy efficiency of an ammonia process. A gas turbine is integrated with the process to reduce the exergy loss associated with ammonia synthesis loop and produce electricity. Combined Pinch and Exergy Analysis is applied to identify how exergy loss is distributed throughout heat...

Environmental legislation, with its increasing pressure on the energy sector to control greenhouse gases, is a driving force to reduce CO2 emissions. In this paper, pre-combustion CO2 capture through integration of a site utility system with an integrated gasification combined cycle (IGCC) is investigated as an option to provide a compressed CO2-ri...

Concerns about global warming have led governments to regulate CO2 emissions, including through emissions caps,trading and penalties, thus creating economic incentives to reduce CO2 emissions. This paper presents a mathematical model based on a MINLP formulation to address the problem of CO2 emissions from large-scale sites in the process industrie...

This paper introduces two new approaches in the thermo-hydraulic design of multi-stream heat exchangers (MSHEs). In both approaches, geometrical aspects of the MSHE (e.g. exchanger dimensions, fin type, etc.) are optimised with a genetic algorithm (GA) using the Total Annual Cost (TAC) as an objective function. The first approach is capable of util...

Pinch Technology is one of the best methods for designing a multi stream heat exchanger (MSHE) through a network; current pinch-based methods, however, lead to a larger and more complicated design problems. The major drawback of the current methods is they result in designs having more individual MSHE sections than essential, correspond to the enth...

Extensive use of hydrogen in refineries and petrochemical plants is an incentive for designing integrated hydrogen networks to utilize hydrogen more efficiently. On the other hand, hydrogen, as an important byproduct, is not properly used in some petrochemical complexes and mostly sent to the fuel system. Few works have been reported in literature...

This paper presented a new approach to estimate the degradation of environmental resources in a Wastewater Treatment Plant (WWTP) using exergy analysis. In first part, a method was described to calculate various quantities of the wastewater exergy. Furthermore, units were analysed to determine the most defective unit. In second part, a case study w...

The goal of this research is simulating an optimum reactor to eliminate greenhouse gases, mainly CO2, through combined cycle in stacks of power plant, using a strong base (sodium hydroxide) thinned by water. During this process sodium bicarbonate salt is generated together with water and the produced salty water is desalinated and its useful salts...

Concerns about global warming have led governments to regulate CO2 emissions, including through emissions caps, trading and penalties, thus creating economic incentives to reduce CO2 emissions. Two retrofit approaches for CO2 emissions reduction in a process site are introduced, addressing strategies such as heat exchanger network (HEN) retrofit, o...

Environmental legislation pressure on the energy sector to control greenhouse gas emissions is increasing. Regulations typically impose a limit on carbon emissions released by industries and set an emissions reduction target. If emissions reduction targets are not met, economic penalties are applied. Over the last decade, worldwide commitments to m...

Purpose Iran as an energy‐rich country faces many challenges in the optimal utilization of its vast resources. High rates of population and economic growth, a generous subsidies program, and poor resource management have contributed to rapidly growing energy consumption and high energy intensity over the past decades. The continuing trend of rising...

Cogeneration is one of the best methods for energy saving which makes a better use of fuels by using recovered heat and producing heat and power simultaneously. In this study, the implementation of a cogeneration system (CHP) integrated with an industrial pulp and paper mill is studied. The cogeneration system consists of an air compressor, a combu...

Hydrogen is an important utility gas, which is used in various operations in petroleum refineries and petrochemical complexes. Although hydrogen is produced as by-product in petrochemical complexes, however it is not efficiently used and mostly sent to fuel. Most current works have applied hydrogen optimization approach for refineries. Therefore, t...

Utilization of fossil fuel, as one of the major contributors in CO2 emission production, provides driving force behind global warming. Increasing energy efficiency through energy retrofit of process plants can reduce fuel requirement and hence reduce CO2 emission production. The current practice for reducing CO2 emissions often selects the retrofit...

The total annual cost (TAC) of a Heat Exchanger Network (HEN) is decreased by using Multi-Stream Heat Exchangers (MSHE), enabling a simultaneous heat exchange between more than two streams in a single unit. Several methods have been developed based on pinch concepts to design an MSHE; however, they lead to designs which are both larger and more com...

Retrofit and optimization of low-temperature gas separation processes is a challenging task owing to complicated interactions between the core process (separation columns), refrigeration cycles, and the associated heat exchanger network. In this paper, the performance of cold section of an olefin plant is optimized. A comprehensive screening of all...

Iran as an energy-rich country faces many challenges in optimal utilization of its vast resources. High population and economic growth, generous subsidies program, and poor resource management have contributed to rapidly growing energy consumption and high energy intensity for the past decades. The continuing trend of energy consumption will bring...

Prediction of minimum required area and energy consumption (Targeting Stage) for heat recovery systems is one of the most important subjects in the synthesis of heat exchanger networks. This stage opens new insights to develop novel techniques for improving the current methods resulting in more realistic algorithms. Although, Pinch Technology conta...

Export Date: 4 January 2015

Export Date: 4 January 2015

The present paper describes the designing of a thermally and economically optimum mechanical draft counter-flow wet cooling tower. The design model allows the use of a variety of packing materials in the cooling tower toward optimizing heat transfer. Once the optimum packing type is chosen, a compact cooling tower with low fan power consumption is...

This paper presents two main contributions. Firstly, a new exergy graphical method is proposed for optimal design of distillation column with minimum exergy lost. The method is applicable to both grass-root and retrofit cases, respectively. The effect of design and operating parameters of a distillation column on the exergy lost is graphically visu...

Greenhouse gases (GHG) emissions from fossil fuel combustion in industrial processes contribute significantly to global warming. A reduction in GHG emissions can only be achieved by a conversion to renewable energy sources and a simultaneous increase in energy efficiency; therefore, the application of renewable energies for evaluating the site util...

In this study pinch technology has been improved for wastewater temperature reduction. Having considered design grouping rules on the basis of pinch technology, a new debottlenecking procedure for thermal treatment of the wastewater network, has been introduced. In the presented procedure, better thermal treatment of effluent network using the new...

In the synthesis of heat exchanger networks, estimation of minimum area and energy requirement (targeting stage) plays an important role, since it allows the prediction of investment requirement ahead of design. On the other hand, Heat exchanger networks in chemical and process industries often require different heat transfer devices. The economic...

In this paper, the performances of two popular stochastic methods, the genetic algorithm (GA) and simulated annealing (SA), are verified in the optimization of low-temperature gas separation processes. While the feasibility of GA optimization of low-temperature processes has recently been addressed, our work studied the quality of GA solutions. Hav...

A great deal of attention has been paid to design and optimization of low-temperature liquefaction and gas separation problems over the past years, due to their difficult nature. In this paper, two approaches featuring sequential and simultaneous methods for selection and arrangement of sub-ambient separation systems and their associated refrigerat...

Energy conservation is becoming increasingly important in energy intensive industries, including oil and gas refining and petrochemical plants. Economic pressures and rising fuel costs encourage more efficient use of energy within these industries so that operating costs can be reduced. Regulatory pressures are also forcing these plants to become m...

In this paper, Genetic Algorithms (GA) has been used to achieve optimum use of stream pressure drops when designing a Heat Exchanger Network comprising of Multi-Stream Heat Exchangers (MSHE). The MSHE consists of several block sections with intermediate entry and exit points along the length of unit, determined by the composite curves. Three differ...

Export Date: 4 January 2015

Export Date: 4 January 2015

Nowadays, the visible impact of releases to the ambient has become a matter of greater concern due to the awareness of environmental degradation and protection among the society. Therefore, the contribution of renewable energies as the free and clean sources can provide environment-friendly solutions. However, little attention has been paid to the...