مجله فرآیند نو
پیاپی 78 (تابستان 1401)

Heat integration using pinch analysis is one of the most important practical tools to achieve solutions that reduce energy consumption in operational units. Using this tool and determining the targeting, the conditions of the process in which the maximum potential of energy savings can be achieved are examined and evaluated. The method of this paper is to analyze the best energy saving opportunities using the pinch analysis method in the Ethane extraction unit of Pars Petrochemical Company. In this research, the approach based on the limitations of the industry and the application of solutions that impose the less modifications and investment costs on the industrial unit have been used.Technical and operational studies show that the most opportunities for energy savings occur in heat integration between air coolers and heat exchangers. According to the two final solutions, 12,950 Kilowatt of energy will be saved annually in this unit.

Vibrations exceeding the permissible limits in piping systems causes cyclic loads that lead to fatigue, damage, and fracture. The present study addresses vibration reduction in an actual piping system in a petroleum refinery. CAESAR II was used to model the piping system based on the maximum displacement and the corresponding frequency. The stresses exerted on the flanges and supports, displacements, natural frequencies, and system mode shapes are obtained from dynamic analysis. To reduce vibrations, we propose a cantilever beam with a lumped mass at the free end (named a “beam DVA” in this paper) as the vibration absorber. CAESAR II’s dynamic analysis results indicate that using an optimal beam DVA can lower pipe displacement by 73%. Next, the beam DVA is constructed and installed in the actual piping system to validate the modeling results. Experimental measurements show that installing the beam DVA reduces the vibration level of the pipe by 69%. Hence, a good agreement exists between the modeling and experimental results.

Biogas is a sustainable energy source produced from organic waste. Raw biogas can be used to generate electricity, but since the energy content of biogas is directly related to methane concentration, it is necessary to improve the biogas and remove its carbon dioxide and other impurities to inject it into the gas grid. This article represents the biogas-improving process based on low-pressure steam compression, which is optimized with an expansion of the clean solvent exiting from the reboiler of the solvent recovery tower, and sending dense hot steam to the reboiler. Two common and optimal modes have been simulated by Aspan-Hasys software based on pure amine solvents. The obtained results showed an increase in the amount of carbon dioxide recovery, and a decrease in the heat load of the reboiler of the disposal tower to the amount of 3.62 GJ/tCO2, which is a 28.74% reduction compared to the base process.

In this research, it was tried to use a reactor containing plates covered with Graphene nanoparticles and placing it after the anaerobic biological treatment unit of dyeing treatment plant will reduce the pollution load for the next stages of treatment by absorbing aromatic substances resulting from the anaerobic biological destruction stage. The results of the field emission electron microscope (FE-SEM) analysis showed that the Graphene layers on the reactor plates were multi-layered. Then the effect of three parameters of effluent concentration (COD: 70, 100, 150 mg/L), pH (5, 7, 9) and temperature (20, 30 and 40 ˚C) on the amount of removal of aromatic compounds, COD and effluent turbidity were investigated. The results showed that high concentration of COD had faster and better absorption by Graphene than its low concentration. Among the three tested temperatures, a higher absorption rate was observed at the higher temperature. Also, with the increase of pH from 5 to 9, the amount of absorption increased. This system showed relatively good performance in absorbing aromatic substances and reducing COD. Optimum conditions of reactor performance were determined as COD: 150 mg/L, pH = 9 and temperature 40 ˚C.

Concrete oil tanks are one of the most important storage structures. These reservoirs require management and maintenance during their operation period to deal with various risks. Lack of maintenance management of concrete tanks can lead to life, environmental, economic and social risks. According to the geographical location of Iran, oil extraction, consumption and export, and concrete tanks have become very important, and the need for maintenance management is felt. This research focuses on the introduction of risks, risk-based management and maintenance methods for petroleum concrete storage tanks. First, the definitions, types of maintenance, risk cycle and research related to reservoir risks are reviewed. The basis for future research and suggestions for research, based on previous studies, can be considered by providing risk-based maintenance management.

Light olefins such as ethylene and propylene are the main foundations of the petrochemical industry. These materials are used in various industries such as the production of resin, polyethylene, polypropylene, ethylene oxide, fibers and other chemicals. The use of these materials as feedstock has led to a rapid increase in demand for them in recent years. Catalytic Cracking due to lower energy consumption and less emission of greenhouse gases can be a somewhat effective way to replace the method. Thermal cracking with vapor to produce olefins. In this paper, high performance catalysts in the naphtha catalytic cracking process to produce light olefins are investigated and compared.