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Fractionation process within natural gas processing facility is an essential step that allows to obtain liquid light hydrocarbons that are often used as feedstocks in petrochemical industries. In this article, a process scenario that includes a heat integrated distillation column is proposed for natural gas liquids (NGL) recovery and assessed throu...
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Context 1
... for liquefaction gas stream (or pipeline-quality dry natural gas) can be quite complex as it involves several processing steps. The types of techniques to be used depend mainly on the source and makeup of the wellhead production stream [2]; schematic representation of the process flow diagram (PFD) for natural gas processing facility is shown in Fig. ...
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... the ethane in the natural gas, ethane rejection process. For this case study, ethane is priced relatively to propane price [31]. Ethane product value from the proposed process is the greatest and almost doubles that recovered from ISS process; moreover, the product values for propane and gasoline are slightly greater than those of other processes (Fig. ...
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... where cold utility of a cold stream is used to cool down a hot stream within the same process. Thus, the later consideration reduced remarkably the operating cost, Table 4. Regarding the operating cost and feed compositions, operating cost for normal feed gas to NGL recovery process is relatively high in comparison with that of lean feed gas. Fig. 11 summarizes processes operating costs percentage comparison; the highest operating cost corresponds to TRAP process and the lowest corresponds to the proposed process. For lean gas feed, both Fluor and TRAP processes require almost same operating costs. In summary, among the processes considered the proposed process requires the lowest ...
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... refrigerated condenser of TDWC produces overhead product (gas) and liquid reflux to column section in which the refrigerated condenser is built-in, see Fig. A1. Overhead gas product from the refrigerated condenser of TDWC is compressed and introduced into absorber at the top and be mixed with absorber top stream; the absorber overhead is mixed with the residue gas that precooled the feed gas and then used as mixed refrigerant into the refrigerated condenser. To limit propane and other heavy ...
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... and introduced into absorber at the top and be mixed with absorber top stream; the absorber overhead is mixed with the residue gas that precooled the feed gas and then used as mixed refrigerant into the refrigerated condenser. To limit propane and other heavy components from entering into methane-ethane rich stream, a heat exchanger (he, see Fig. A1) is suggested where cold liquid from phase separator_2 partially condenses heavy components into absorber top stream. Other parts of this process resemble those of the process presented into section ...
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In this study, two novel integrated single mixed refrigerant (SMR) processes are proposed to coproduce liquefied natural gas (LNG) and high-purity liquid ethane, which are suitable for improving the economic benefits of high ethane-containing natural gas. In Process 1, cryogenic distillation and conventional SMR process are integrated to separate e...
Citations
... Although turbo expanders have massive equipment to further cool the gas and segregate the NGLs for shipping, they have a substantial cooling impact similar to the JT expansion method, where the gas is cooled as it expands. It was created in the 1960s and is one of the most innovative NGL recovery technologies [41], [42]. However, they require a huge capital investment, a large number of auxiliary equipment to function, and turbines embedded in turboexpanders require extensive and regular preventive maintenance [31]. ...
Since finding cost-effective solutions for optimal Methane and NGL recovery has become a priority. The goal of this project was to improve the existing plant framework of a tray absorption column. Aspen HYSYS simulator Version 8.6 was utilized for this study, and the feed gas composition was picked from Technip's Western Libya Gas Project. A simulation was conducted for 10 trays, 20 trays, and 30 trays to determine the optimum points for methane and NGL recovery. The number of trays used to determine the optimum NGL fraction was discovered to decrease as the number of trays increase while that of methane increased as the number of trays increased. It was further identified that the recovery affected the compressor duty as it increases as NGL recovery increases but reduces on recovery of methane. The results were exported to Microsoft Excel, and correlations were generated for predicting optimum Methane and NGL recovery.
... Natural gas is the raw materials that can be utilized in many sectors such as power generation; petrochemical industries mainly for ammonia and urea production; residential consumption and transportation (International Energy Agency (IEA) 2022). Treatment of natural gas consists of highpressure separator (HP Separator) to separate C 10+ hydrocarbon and produced water, amine treating to remove acid gas (H 2 S and CO 2 ), dehydration unit for water removal and dew point control unit (DPCU) for C 5+ separation (Uwitonze et al. 2020). These processes are required to meet the specification of sales gas that is transported by pipeline. ...
Demand of natural gas is predicted to increase since many valuable products can be produced. Water and heavy hydrocarbon content are the key for gas pipeline facility. To meet requirement of natural gas transportation, dehydration unit (DHU) and hydrocarbon dew point control unit (DPCU) are necessary to avoid water and hydrocarbon condensation during transmission. The conventional dehydration technology, TEG contactor, can lower water content from 1,304 mg/m3 to 80.35 mg/m3 where the maximum limit of water content in natural gas is 97 mg/m3 to prevent hydrate formation. DPCU is installed to remove heavy hydrocarbon, especially C5+. Integration of JT valve and turboexpander was employed to obtain the low gas dew point. The hot gas stream that entered the JT valve was observed. The lower hot bypass gas was applied, the lower hydrocarbon dew point and the more condensate flowrate was achieved. The highest power generation can be gained at low hot gas flow ratio which also influenced the exit pressure and temperature of compressor. In pipeline simulation, the pressure and temperature drop occurred at the high hot gas rate. To examine the arrival condition, dew point curves were generated and showed that the limitation of hot gas flow ratio has to be below 0.6 to prevent heavy hydrocarbon condensation in pipeline.
... Existen diversos métodos en los sistemas de destilación para ahorrar energía, entre los que destacan, los sistemas térmicamente acoplados como la columna Petluyk (equivalente termodinámicamente a la DWC, Dividing Wall Column, por sus siglas en inglés), la cual muestra ahorros energéticos entre el 30-50% [1,2] minimizando así, los costos de operación [3,4]. ...
La industria energética impacta directamente en la economía global mundial; la principal aplicación del fraccionamiento de gas natural se refleja en las industrias química y petroquímica, para la obtención de fuentes combustibles y productos químicos. Por otra parte, la destilación es la operación de separación mayormente empleada en los procesos químicos y consume una gran cantidad de energía. La recuperación de hidrocarburos puros representa más valor agregado que la mezcla entre ellos y con la finalidad de generar procesos sustentables en la configuración de proceso y operación de la planta, que mejoren el rendimiento del fraccionamiento del gas natural licuado y que impacten en la minimización de costos operativos en planta; en este trabajo se presenta una comparación y un análisis económico de un proceso
convencional contra un proceso térmicamente acoplado, denominada columna de pared divisoria; para dos columnas: una desetanizadora y una despropanizadora. Se observa que el sistema DWC mejora el rendimiento energético del proceso de desetanización y despropanización, debido a la ausencia del
rehervidor y condensador que existe entre las dos columnas del sistema de destilación convencional. Los costos de operación, los cuales son los más importantes en el costo total anual, están relacionados directamente con los precios de los combustibles. La variación del costo del combustible es errática, debido a diversos factores involucrados, por lo que es complejo proporcionar como tal, una proyección, por lo que en este trabajo se presenta un análisis económico en el proceso descrito anteriormente.
... The NGL separation process has been extensively explored in the literature by numerous authors including Manning and Thompson (1991), Long and Lee (2012), Lee et al. (2012), Park et al. (2015), Mokhatab et al. (2015), Kherbeck and Chebbi (2015) and Uwitonze et al. (2020). However, in those studies, the complexity of the dynamics involved in the process and their control are not considered. ...
In recent years the attention on natural gas production and utilization is growing due to different fundamental aspects. First, the availability of natural gas has increased thanks to technological improvements in the extraction techniques that have made possible the production from unconventional reservoirs. Second, the interest in clean energy is growing, aiming to reduce CO2 emission and thus global warming. Natural gas is a cleaner fossil fuel compared with other traditional energy sources such as oil and coal. Another reason that drives the attention on this fossil fuel is the increasing economic interest of recovering the heavier hydrocarbon fractions contained in it. The fractionation of natural gas liquids (NGL) is an energy-demanding process, often conducted with a separation train that includes cryogenic distillation columns. This work is intended to show how to achieve an energy-efficient recovery of NGLs with a proper control strategy and without composition analyzers. In particular, the effects of a combined cascade control with boilup approximation plus a pressure compensator control for the demethanizer section, on the desired NGL extraction product targets are investigated and compared under feed flowrate disturbances with conventional direct temperature controllers. Overall, it is shown that the cascade control plus pressure compensator provides the best performance and the lowest energy consumption.
... The specific volume of liquefied natural gas (LNG) is about 1/625 that of gaseous natural gas, which presents a considerable advantage in terms of the transportation, storage, and utilization of natural gas (He et al., 2019;Uwitonze et al., 2020). The LNG industry has developed rapidly around the world recently. ...
Small-scale natural gas liquefaction processes have several clear advantages, particularly in the exploitation of ‘unconventional’ natural gas (NG) from sources such as difficult-to-access and offshore gas fields. Moreover, conventional liquefaction processes have a number of disadvantages such as high energy consumption, large cooling loads required in the refrigeration cycle, and non-uniform matching of cold and hot flows in liquified natural gas (LNG) heat exchanger (HE). The main objective of this study was to optimize the most commonly used mixed refrigerant process. The liquefaction performance of the optimized process was analyzed and the influence of gas parameters on the power consumption, exergy loss, freezing mixture circulation, and cooling water load were investigated. The results show that compressor power consumption can be reduced by 29.8%, the cooling water load can be reduced by 21.3%, and the system exergy efficiency can be increased by 41% with the optimized process. Furthermore, throttling and compression of the freezing mixture were increased during the refrigeration stage. It can be concluded that reducing the feed gas temperature and increasing the feed gas pressure can reduce the total power consumption, exergy loss, freezing mixture circulation, and cooling water load, which can significantly improve liquefaction performance.
... They introduced an absorption refrigeration mixed refrigerant (AR-MR) system to provide the required cooling and compared the results with propane mixed refrigerant (C3-MR) and dual mixed refrigerant (DMR) processes. Moreover, Uwitonze et al. [16] applied a process intensification approach to the NGL process to enhance the economics. Their results showed a considerable savings in annual operating costs [16]. ...
... Moreover, Uwitonze et al. [16] applied a process intensification approach to the NGL process to enhance the economics. Their results showed a considerable savings in annual operating costs [16]. ...
... Although these advancements are not limited to process integration, researchers have also focused on NGLs process intensification, i.e., the application of a dividing wall column (DWC) [16], thermally coupled distillation sequence (TCDS) [38], and heat pump (HP) [39]. TCDS can save approximately 44.55 % of the operating cost compared to conventional distillation sequences [38]. ...
Although many improved conceptual designs of natural gas liquids (NGLs) recovery processes have been introduced to enhance the economics and efficiency, real-world applications remain elusive because of the communication gap between researchers and practitioners. To bridge this gap, a state-of-the-art assessment of the NGLs recovery processes is presented along with an overall outline considering the feed conditions, product recovery, purity, specific energy consumption (SEC), process economics, and analysis software using the equation of state model. Lower NGL components in the feed have a higher SEC and lower operating costs than a rich feed. It was also found that the conceptual processes are more energy intensive and complex than commercial processes. The major challenges associated with NGL recovery were assessed, including a high energy consumption, varying feed composition, flexibility in the product recovery, and design considerations for offshore NGL processing. Future directions are proposed, including the application of hybrid separation processes and a process intensification to enhance the compactness, particularly for offshore applications, process optimization, and heat integration. Further, an economic policy study is conducted that provides insight into market dynamics. The development of new natural gas (NG) reserves will boost the NGL market and NG business.
... include external forces are not explored yet. The appealing economic advantages and compactness of DWCs over conventional distillation columns have seduced different authors and researchers, and have proposed those column systems into offshore process applications for natural gas liquid recovery processes [31][32][33][34]. ...
... Specifications of the selected DWC distillation test[34]. ...
Packed distillation columns are key equipment in natural gas pre-treatment process within LNG production process train operated at offshore. In this work, the impact of offshore operating conditions and that of divided wall column shape were explored via developing transient three-dimensional CFD model for a divided wall distillation column filled with structured packing. Inter-phase drag force, porous resistance force, mass transfer, and liquid dispersion were incorporated into volume averaged equations to map the distortion in liquid distribution in response to column oscillatory motion. The results show that introducing a dividing-wall into distillation column affects fluids partition and distribution. Column motions induce complex fluid flows in radial direction that result in oscillatory patterns around the steady-state solution of vertical column. Furthermore, liquid distributions in a divided wall column under influence of column motion differ with respect to column system positions throughout rotational axes, mass transfer also fluctuates according to column oscillations. A position with a dividing wall making an angle of 45˚ with rotational axis gives a scenario in which rolling motion resembles to pitching motion. The thereof position leads to moderate liquid maldistribution in comparison to liquid maldistribution from scenario with dividing wall parallel to rotational axis.
... Olefins production (specially ethylene) are the valuable and strategic products in petrochemical and oil refinery (Barza, Mehri, and Pirouzfar 2018;Barza, Shourije, and Pirouzfar 2019;Cavalcanti and Barton 2020;Malang, Kumar, and Saptoro 2015;Patel and Majumder 2011;Virla et al. 2020). Ethylene and heavier hydrocarbons are separated in four intermediate temperature levels through low temperature distillation (about −130°C) (Bouck 2014;Cavalcanti and Barton 2020;Kianfar et al. 2018;Olsen 2018;Pirouzfar and Omidkhah 2016;Saleh, Pirouzfar, and Alihosseini 2019;Uwitonze, Hwang, and Lee 2020;Virla et al. 2020). The main separation step occurs in demethanizer tower (T-401). ...
Ethylene is one of the most primary and widely used petrochemical products in today’s world and is considered as a chemical building block in the petrochemical industry. In this research, ethylene production from ethane and natural gas is evaluated in terms of cost and optimum conditions. Also, a comprehensive economic and technical comparison is made to achieve the optimal conditions for ethylene production concerning feed diversity. Nowadays most ethylene production units run with ethane feed. If it is possible to implement gas-ethylene processes with an inexpensive natural gas feed, it will be a significant step for technical and economic optimization. Thus, some methods are introduced and compared, and finally an economic review about best condition for ethylene production from ethane and natural gas/investment with regard to cost and economic efficiency of the methods is provided. The investment cost for Gas to Ethylene (GTE) and Ethane to Ethylene (ETE) processes is 363–701 million dollars per year, respectively. Also, rate of return (ROR) of 24 and 19% is calculated for GTE and ETE processes, respectively.
... Olefins production (specially ethylene) are the valuable and strategic products in petrochemical and oil refinery (Barza, Mehri, and Pirouzfar 2018;Barza, Shourije, and Pirouzfar 2019;Cavalcanti and Barton 2020;Malang, Kumar, and Saptoro 2015;Patel and Majumder 2011;Virla et al. 2020). Ethylene and heavier hydrocarbons are separated in four intermediate temperature levels through low temperature distillation (about −130°C) (Bouck 2014;Cavalcanti and Barton 2020;Kianfar et al. 2018;Olsen 2018;Pirouzfar and Omidkhah 2016;Saleh, Pirouzfar, and Alihosseini 2019;Uwitonze, Hwang, and Lee 2020;Virla et al. 2020). The main separation step occurs in demethanizer tower (T-401). ...
The demethanizer tower of Kavian olefin plant had a problem in more than 77% of the nominal capacity. Its performance was reduced by flooding with considering the inside pressure drop and fluctuation of the bottom liquid level increase. For this reason, a study was performed and the simulation results (with PRO II and SULCOL) were successfully implemented. Finally, troubleshooting and practical solutions were compared with simulation results. In order to tower modifications, an instruction had been issued so that all 40 trays had to be completely discharged and then the tower was refilled with 16 ton packing. According to this solution, the volume of ethylene as final product was increases about 23% and reaches the designed nominal capacity.
... This is not sufficient, and the implementation is still under the 167 average growth in the petrochemical industries field, especially in the non-OECD countries. 168 ...
Implementation of Process Intensification (PI) in the oil and gas (O&G) represents the most promising way to achieve sustainable development of this industry in an environmentally friendly manner. Multi novel PI technologies were investigated, but only a few were applied to petrochemical processes and on a limited commercial scale. This inconsistency between implementation and research interest could be attributed to the absence of a special methodology or a road map for PI implementation in O&G particularly. Previous works used methodologies that did not emphasize on the O&G industries. Accordingly, establishing such a special methodology becomes mandatory to enhance implementation. This paper presents a complete and concise PI framework, which depends on rated energy consumption as a key driver for implementation, where the rating considers implicitly multiple other criteria. The framework also newly classifies the potential PI tools for the O&G into separation and reaction tools, while the PI traditional hierarchy classifies them into equipment and methods. The process-based classification reflects better the specifics of O&G facilitates for proper tools selection by designers. According to this framework, the paper examines the potentials of important technologies found in the literature. Drivers and constraints concepts are considered, and a map of the PI implementation in the main O&G facilities is provided.
