Gas Liquefaction Research Articles

Design and analysis of a novel self-refrigerated natural gas liquefaction system integrated with helium recovery and CO2 liquefaction processes

Utilizing the high-pressure exergy of a pipeline gas is a route to overcome the challenge of high power consumption in liquefying natural gas. Through the expansion in city gate stations (CGSs), a notable cold duty is achieved that can liquefy a part of a natural gas feed. Based on this concept, the present research proposes a novel system for natural gas liquefaction utilizing pipeline exergy integrated with helium recovery and innovative carbon dioxide capturing and liquefaction. The process was evaluated by energy, exergy, economic, and exergoeconomic analyses. Results showed that the proposed system can co-produce LNG, liquid helium, and liquid CO2 products with low energy consumption, simplicity, and high profitability. The specific power consumption (SPC) and the exergy efficiency of the natural gas liquefaction system are 0.227 kWh/kgLNG and 64.24%, respectively, which shows a desirable performance as well as a notable potential for improvement. The process equipment of the helium liquefaction system also offers a higher total cost rate, mostly constituting an exergy destruction cost rate. The integrated system exhibits appropriate profitability by the internal rate of return of 47% and the payback period of 3.25 years.

Natural gas hydrate exploitation and recovered natural gas liquefaction driven by wind power: Process modelling and energy performance evaluation

Current oceanic hydrate research mainly focuses on its exploitation, but the subsequent storage and transportation of recovered gas is also necessary. To accelerate its commercial application and clarify the potential of liquefaction after hydrate exploitation, a rigorous simulation modelling was firstly conducted on the depressurization exploitation of hydrate coupled with recovered gas liquefaction in this paper. The energy performance was evaluated by energy consumption and efficiency analysis. The energy efficiency of the gas and liquid production process, liquefaction process, and the key influence factors of the whole process were studied separately. Results show that the energy efficiency ratio for depressurization exploitation reaches between 4.9 and 19.4, while that for the whole system of hydrate exploitation and liquefaction is only between 1.3 and 2.7 considering recovered gas combustion for power generation. The energy efficiency ratio of the whole system increases to between 2.6 and 4.3 powered by offshore wind farm. The largest energy efficiency reduction is up to 77.8% after recovered gas liquefaction compared with exploitation process. Therefore the storage process with lower energy consumption should be prioritized or the energy consumption should be optimized for the storage and transportation process after hydrate exploitation.

Multi-membrane integrated processes for helium and methane synergistic recovery after flash-vaporization units in LNG plants

The residual gases emitted after natural gas liquefaction are the major sources for industrial helium generation. Besides, methane remaining in these streams is valuable for reclamation. In order to make sufficient and efficient utilization, multi-membrane integrated processes, in which both the glassy and the rubbery polymeric membranes are invested for significant tasks, meanwhile they are synergistic with each other under specific process frameworks, are established in this research. Furthermore, the multi-membrane separation unit is meticulously integrated with the flash-vaporization units to reduce nitrogen accumulation during cryogenic operation. Based on the classical LNG plant using two-stage flash-vaporization units, in which the feedstock is about 4780 Nm3/h in flow rate and 0.174 mol% in helium content, the customized multi-membrane process behaved excellent with helium recovered by 99.8% and concurrently LNG harvest increased by 9.7%. The economical assessment revealed that the annual gross benefit can be strikingly increased by 25.16 million CNY, while the annual operation cost is increased by only about 3.96 million CNY, and the additional investment for membrane unit is about 5.48 million CNY, respectively. On the whole, the multi-membrane integrated system using the glassy and the rubbery polymeric membranes synergistically should be a highly promising approach to reclaim valuable components in the residual gases after natural gas liquefaction.

Process analysis and optimization of high-N2 natural gas liquefaction

The demand for natural gas (NG) is increasing rapidly due to the world energy crisis. Liquefied Natural Gas (LNG) technology is one of the most flexible and reliable supply solutions, which has already been a major research hotpot in energy use. However, NG with high-N2 content lowers the gas calorific value and value of the gas and increases the energy consumption for production and transport. To address this issue, this study established nitrogen removal from the NG process using a single-column cryogenic distillation process based on Aspen HYSYS® in this study. An expanding refrigeration process using N2-CH4 was selected to provide the required cold energy for this plant, and the process power consumption and LNG specific power consumption was used as evaluation indicators. Results from sensitivity analysis showed that by the increase of natural gas feed temperature T1, the distillation column operation pressure Pc, and refrigerant high pressure P3, the LNG specific power consumption also demonstrated an increasing trend. The variables of natural gas inlet pressure P1, the outlet temperature of natural gas from pre-cooler T2, the ratio of return RR, the methane content ZCH4, the temperature of refrigerant after pre-cooler T4 and refrigerant low pressure P5 had a negative impact on the LNG specific power consumption. After conducting an optimization algorithm, the minimum LNG specific power consumption was determined to be 56.17 kJ/mol. Exergy analysis demonstrated that the total exergy destruction was 2076.13 kW. The compressor and expander components accounted for 31.57% and 26.29% of the total exergy losses respectively. This research provides valuable insights into optimizing LNG production processes by mitigating the impact of high nitrogen content, and it contributes to the advancement of LNG technology and energy efficiency in the industry.

Compositions optimization method based on the effective refrigeration effect for Mixed-refrigerant Joule-Thomson refrigerators cooling distributed-temperature heat loads

Mixed-refrigerant Joule-Thomson refrigeration (MJTR) is the dominant technology for cooling distributed-temperature heat loads, such as natural gas liquefaction. The mixed refrigerant determines the refrigeration cycle's performance (cooling temperature and efficiency, etc.). However, the current mathematical methods for mixed refrigerants’ optimization are time-consuming. In this paper, a mixed refrigerant optimization method based on the effective refrigeration effect is proposed. The equivalent enthalpy (EH˙) of temperature difference is proposed to predict the temperature difference distribution in the recuperator without cycle simulation. The optimization objective is to optimizeEH˙much closer to zero. In each step, only one component is adjusted, which is determined through its’ effective refrigeration effect, i.e., the partial molar enthalpy difference, in the optimization process. This method is applied to natural gas liquefaction (LNG), nitrogen liquefaction (LN2) and Cryo-compressed hydrogen storage (CcH2) systems. The exergy efficiencies in LNG, LN2 and CcH2 systems are 0.462, 0.390 and 0.421, which increase about 23.9%, 22.4% and 23.5% compared to references, respectively. The optimization time is less than 10 min per case in this study. This method can optimize mixed refrigerants in MJTR cooling various distributed-temperature heat loads.

Condensation heat transfer and correlation analysis in helical tube of mixed carbon-hydro refrigerant

The heat transfer coefficient of the mixed carbon-hydrogen refrigerant (hmix) in a helically tube has been confirmed as the core parameter related to natural gas liquefaction. Moreover, an experimental system of the two-phase flow in the helical pipe was designed, and a simulation model was built to analyze the changing law of hmix. The effects of operating parameters (operating pressure (2–4 MP), mass flux (200–600 kg/(m2·s), and vapor quality (0–1)) and structural parameters (spiral diameter (1–3 m), helix angle (4–14°), and inner diameter (8–12 mm)) on hmix of methane/ethane/propane in the spiral tube were examined. Subsequently, 11 heat transfer correlations were analyzed and then compared. As indicated by the comparison results, the correlations of Boyko were the most accurate among the above-mentioned correlations, laying a basis for this type of hmix. Furthermore, the mean absolute relative deviation and determination coefficient of Boyko's correlation were obtained as 20.30% and 0.48, respectively.

Thermodynamic evaluation of mixed refrigerant selection in dual mixed refrigerant NG liquefaction process with respect to 3E's (Energy, Exergy, Economics)

The dual mixed-refrigeration process makes it possible to achieve higher liquefaction of natural gas with the advancement in both the refrigeration cycles and refrigerant combinations of components. This is made possible by the fact that the process uses multiple mixed refrigerants. This has a significant impact on the overall improved performance of natural gas liquefaction by having a negative influence on the quantity of energy that is consumed. This study proposes a methodology for selecting the MR components based on their thermodynamic behavior in both warm and cold refrigerant streams. As a result, eighteen alternative scenarios are simulated for this study, each based on (i) fixing the warm loop components or (ii) fixing the cold loop components. The procedure was investigated from the point of view of process engineering, with the 3E model of energy, exergy, and economics serving as the decision-making factor. The findings indicate that increasing the number of components for pre-cooling and subcooling cycles from three to five results in specific energy consumption of 0.49 kW.kgLNG−1, which seems to be a reduction of 54% in terms of the amount of energy that is consumed in comparison to the process that is based on three components. The irreversibilities of the process were uncovered by doing an exergy analysis. It identified the cases based on five refrigerant components providing reduced exergy destruction of 3505.02 kW with 59% exergy efficiency. The viability of the proposed process is assessed even further through economic analysis. It was observed that five MR-based processes save 22.93% of the total capital cost, 43.56% of the overall operating cost, and 33.61 %of the total annualized cost.

Experimental research on the performance of high-pressure single screw compressor for portable natural gas liquefaction system

The expansion natural gas liquefaction process combining two-stage compression and two-stage expansion is generally utilized for the portable liquefied natural gas system. Two-stage compression includes a low-pressure compressor and a high-pressure compressor. Thus, the compressors’ performance directly affects the natural gas liquefaction process. A high-pressure single screw compressor was designed and manufactured in this study to obtain the performance of the high-pressure compressor. Its performance test system was built under the rotation frequency from 35 Hz to 50 Hz and at the exhaust pressure from 1.5 to 3.5 MPa. The experimental results show that, when the compressor works at a rotation frequency of 50 Hz and an exhaust pressure of 3.5 MPa, its actual flow rate, shaft power, specific power and volumetric efficiency are 0.752 Nm3/min, 20.48 kW, 27.23 kW/(m3·min) and 0.52, respectively. The experimental results show that the compressor’s performance meets the design requirements, which can be used for natural gas liquefaction.

A novel small-scale biomethane liquefaction process: Assessment through a detailed theoretical analysis

The use of biomethane as fuel in the transport and power generation sectors is widely considered an effective tool to pursue the goals of carbon neutrality and energy security. Therefore, it is very important to promote not only the production and upgrading processes of biomethane from carbon neutral biomass, but also biomethane liquefaction processes, which can allow effective transportation of biomethane, thanks to the fact that the density of the liquid is higher than that of the compressed gas. Biomethane liquefaction plants can benefit from the technologies already used for the liquefaction of natural gas, but the size of biomethane liquefaction plants must be significantly smaller because of the limited quantities of biomethane generated by production and upgrading plants. Biomethane liquefaction plants have still limited diffusion; the most used technologies for the biomethane liquefaction are the Reverse Brayton cycle, the Lynde cycle, and the heat exchange with liquid Nitrogen. Single mixed refrigerant (SMR) processes, which are very effective for the liquefaction of natural gas, have a high potential for the biomethane liquefaction too, but the high specific energy consumption and high plant costs (mainly caused by typical multi-flow heat exchangers employed) are the major issues associated with SMR processes when applied to the very small size of biomethane liquefaction plants, characterised by very low biomethane flow rates. The aim of this paper is to propose a novel SMR process for biomethane liquefaction, which can overcome the above-mentioned issues, contributing towards the implementation of SMR processes for the liquefaction of biomethane and providing a valid alternative to currently used biomethane liquefaction plants; the proposed solution consists in using simple pipe-in-pipe heat exchangers in place of the more complex multi-flow heat exchangers. The validity of this solution is theoretically assessed using a detailed thermodynamic model based on well-stablished equations. Using this tool, it is shown that, by adjusting crucial parameters, such as the molar composition of the refrigerant, the heat exchange is satisfied with an affordable length of the heat exchangers, negligible pressure drops and good levels of the coefficient of performance with reference to such a small-scale application. The predicted specific energy consumption (accounting also for the biomethane compression and pre-cooling) for a biomethane flow rate of 0.03 kg/s is of the order of 0.8 kWh/kgCH4, which is a very good performance level compared to current commercial biomethane liquefaction processes.

OPTIMIZATION OF TECHNICAL AND ECONOMIC PARAMETERS FOR THE NATURAL GAS LIQUEFACTION PROCESS AT A LOW-TONNAGE UNIT WITH A MIXED REFRIGERANT

Liquefaction technologies of natural gas using a mixed refrigerant cycle provide a high liquefaction coefficient at low specific energy consumption, but are characterized by high requirements for the organization of production. There is no methodology for simultaneous optimization of the technical and economic parameters for the production process of liquefied natural gas and the composition of the refrigerant in publications, and therefore a combined optimization criterion is needed to achieve the minimum cost of liquefied natural gas. The aim of the work is to determine optimal pressure for natural gas inlet compression, taking into account the minimization of the complex criterion – the conditionally variable part of the cost of liquefied natural gas. The results were obtained using an applied calculation program, and the method of differential evolution was chosen as an optimization method. The optimization was carried out using the OCMR PEGAZ 1.0 program. The article considers the influence of the discharge pressure of the low-pressure natural gas inlet compressor on the technical characteristics of heat exchange equipment, the energy efficiency of the liquefaction process and the economic characteristics of a low-tonnage liquefied natural gas production plant under conditions of optimized composition and flow rate of mixed refrigerant. A method of optimizing process parameters taking into account economic indicators is proposed, regularities of changes in the optimal composition of mixed refrigerant depending on the discharge pressure of the natural gas inlet compressor are determined. It is determined that with an increase in the discharge pressure of the natural gas inlet compressor, the optimal content of components in the mixed refrigerant changes as follows: methane and n-pentane decrease, and ethane and isobutane increase. It is shown that the optimal discharge pressure range of the natural gas inlet compressor is 6,0±0,5 MPag, which leads to the best total energy efficiency of inlet compression and circulation of mixed refrigerant, equal to 0,25 kWh/kg of LNG, and its cost is minimal. The assessment of capital costs at this pressure will allow choosing the optimal technology of natural gas liquefaction at the FEED stage, which will reduce the cost of production of liquefied natural gas and reduce the payback period to 5 years.

Advanced natural gas liquefaction and regasification processes: Liquefied natural gas supply chain with cryogenic carbon capture and storage

Natural gas combined cycle power plants generate substantial amounts of CO2. Also, since natural gas is produced in limited sites, the liquefied natural gas (LNG) supply chain consumes considerable energy in transporting natural gas overwide. Herein, advanced natural gas liquefaction and regasification processes using an LNG supply chain with cryogenic CO2 capture and storage (CCS) are proposed using Aspen Plus® V11. This solves three significant problems associated with conventional LNG supply chains. First, through the utilization of LNG cold energy, the cryogenic CCS process reduces the efficiency penalty of power generation from 14.34 to 4.45%. Second, solid CO2 from cryogenic CCS is used as an additional cold source in the natural gas liquefaction process by conveying it to the liquefaction site via the returning LNG ship. As a result, the power consumption in the refrigerant cycle is reduced by up to 67.17% than single mixed refrigerant (SMR) process. Finally, the LNG supply chain with cryogenic CCS minimizes the sustained energy waste between the natural gas liquefaction and regasification stages owing to the geographical separation. LNG cold energy from the regasification stage is utilized in the form of solid CO2 in the CCS and liquefaction stages. Consequently, the exergy efficiency in the overall LNG supply chain increases from 18.18 to 46.39%. The findings of this study can potentially provide environmentally friendly design guidelines for various LNG processes that use LNG cold energy in CCS and natural gas liquefaction.

Consideration of liquefied natural gas as an alternative source of gas supply to Ukraine

The object of research is the energy sector of Ukraine, specifically the gas supply system of the national economy. One of the most problematic places is the dependence of the Ukrainian economy on the import of natural gas (NG). Ukraine is rich in various natural resources, in particular, in natural and associated gas. However, own wells for NG extraction are not enough for gas supply to industrial enterprises and the population. Therefore, part of the necessary gas is imported. In the course of the study, methods of alternative supplies were analyzed, namely, liquefied natural gas (LNG), options for its supply with subsequent regasification were analyzed. The global market for liquefied natural gas (LNG) was studied and it was shown that the production and consumption of LNG is constantly increasing. Since Ukraine is part of Europe, and the main suppliers of LNG for European countries are the USA and Norway, one of the options for gas supply for Ukraine considered the supply of LNG to the territory of Poland by sea transport, its regasification and subsequent transportation to consumers through existing pipelines. The second option is the supply of LNG to the Ukrainian coast of the Black Sea. To do this, it is necessary to study prospective transportation routes, build logistics and terminals for receiving and regasifying LNG. Since the depth of the channels from the Mediterranean to the Black Sea is small, the option of supplying natural gas from Central Asia by pipeline to the Black Sea coast of Georgia, its liquefaction, transportation by sea and regasification is proposed. This option requires significant capital expenditures for the construction of a natural gas liquefaction plant on the territory of Georgia and a regasification complex on the Ukrainian coast or a floating terminal. In the course of the work, LNG quality criteria used in the world were studied, and it was noted that for the purchase and use of LNG in Ukraine, it is necessary to develop own standards for controlling its composition. Because the technology of providing the consumer with natural gas using LNG is more flexible than pipeline transport. Its implementation will make it possible to provide Ukraine with natural gas in the required quantities and, if necessary, to promptly change the volume of deliveries.

THE PROBLEM OF LIQUEFACTION OF NATURAL GAS CONTAINING NITROGEN IN SMALL-SCALE PLANTS

One of the problems in the implementation of natural gas liquefaction technology in a closed high-pressure cycle is the accumulation of low-boiling components, in particular, nitrogen in the circulating gas stream, as a result of which the throttle effect decreases and, accordingly, the specific energy consumption of the liquefaction plant increases. The nitrogen concentration influence on the liquefaction plant operation in the throttle cycle of high-pressure natural gas with a nitrogen content of 0 to 6 % was studied using the GazCondNafta software system for computer simulation of technological processes. To solve the problem of liquefaction of nitrogen-containing gases, a liquefaction scheme with two stages of throttling and intermediate separation with nitrogen vapor stripping is proposed. The effect of gas pressure in the nitrogen separator was determined from the point of view of minimizing losses of the main component of natural gas — methane — with stripping gas with a relatively small decrease in energy efficiency. Bibl. 14, Fig. 6, Tab. 4.

Comparison of mixed refrigerant cycles for natural gas liquefaction: From single mixed refrigerant to mixed fluid cascade processes

Comparison of mixed refrigerant cycles for natural gas liquefaction: From single mixed refrigerant to mixed fluid cascade processes

MODERNIZATION OF THE NATURAL GAS LIQUEFACTION CYCLE AT GAS DISTRIBUTION STATIONS

The possibility of developing the liquefied natural gas (LNG) market in the Russian Federation can be realized by increasing the projects of low-tonnage LNG production. The development of LNG production projects at gas distribution stations should be a priority, since in this case it is possible to implement various production schemes: expander, throttle or cycle with a vortex pipe. To assess the efficiency of the use of low-tonnage LNG production at gas distribution stations (GDS), the dynamics of changes in maximum and minimum pressure values in the main gas pipeline, as well as the distribution of GDS by seasonal change in pressure drop and throughput are presented. To assess the operability and applicability of the work, a design model of the natural gas liquefaction throttle cycle was built and numerical modeling of its operation was carried out at seasonal fluctuations in pressures and GDS costs, which showed a strong dependence on these fluctuations and a low degree of natural gas liquefaction. In order to further modernize the liquefaction cycles of natural gas, modeling was carried out according to the turbo expander cycle, which also showed a dependence on seasonality, but a higher degree of liquefaction of natural gas, which during modeling reached more than 8%. The final stage was the construction of a design model of the combined technology — throttling and turbo expander cycles, as well as numerical modeling, which showed the possibility of increasing the liquefaction of natural gas at GDS to 19%, but the impact of seasonal fluctuations also remains significant. Summing up, it can be said that the work has worked out options for the transition from the throttle cycle to the throttle-expander and turbo-expander, as a result of which it was concluded that the operation of each cycle is effective, due to which it is possible to expand the LNG production network at the GDS at various input pressures, flow rates and the required degree of liquefaction of natural gas.

Analysis of Condensation Flow and Heat Transfer Characteristics Inside Spiral Tubes

Spiral wound tube heat exchanger (SWHE) was confirmed as the core equipment of natural gas liquefaction (LNG). However, there was rare experimental research on large-scale SWHE for LNG, and the theory of heat transfer is not perfect. To investigate the tube-side flow and heat transfer characteristics in spiral tubes, an experimental system was proposed. To ensure the accuracy of the experimental data, the heat transfer coefficients of liquid propane under different conditions were measured, and the data acquired through the experiment were compared with two classical heat transfer correlation (Dittus–Boelter and Geielinski) under the identical working conditions. The applicability of the existing correlation was analyzed using the experimental data, and a novel heat transfer correlation was developed. As indicated by the results, the deviation between the experimental system and the classical correlation under the identical working condition was lower than ±10%. Furthermore, the error comparison between the novel correlation prediction value and the experimental data was less than ±15%.

On the high-field characterization of magnetocaloric materials using pulsed magnetic fields

Magnetic refrigeration is a highly active field of research. The recent studies in materials and methods for hydrogen liquefaction and innovative techniques based on multicaloric materials have significantly expanded the scope of the field. For this reason, the proper characterization of materials is now more crucial than ever. This makes it necessary to determine the magnetocaloric and other physical properties under various stimuli such as magnetic fields and mechanical loads. In this work, we present an overview of the characterization techniques established at the Dresden High Magnetic Field Laboratory in recent years, which specializes in using pulsed magnetic fields. The short duration of magnetic-field pulses, lasting only some ten milliseconds, simplifies the process of ensuring adiabatic conditions for the determination of temperature changes, . The possibility to measure in the temperature range from 10 to 400 K allows us to study magnetocaloric materials for both room-temperature applications and gas liquefaction. With magnetic-field strengths of up to 50 T, almost every first-order material can be transformed completely. The high field-change rates allow us to observe dynamic effects of phase transitions driven by nucleation and growth as well. We discuss the experimental challenges and advantages of the investigation method using pulsed magnetic fields. We summarize examples for some of the most important material classes including Gd, Laves phases, La–Fe–Si, Mn–Fe–P–Si, Heusler alloys and Fe–Rh. Further, we present the recent developments in simultaneous measurements of temperature change, strain, and magnetization, and introduce a technique to characterize multicaloric materials under applied magnetic field and uniaxial load. We conclude by demonstrating how the use of pulsed fields opens the door to new magnetic-refrigeration principles based on multicalorics and the ‘exploiting-hysteresis’ approach.

Effect of fluid property variations on the effectiveness of a cryogenic heat exchanger

AbstractCryogenic heat exchangers are commonly used for industrial processes, such as air separation and natural gas liquefaction. Generally, the performance of heat exchangers is analyzed adopting constant properties for the working fluid. But, in cryogenic heat exchangers, fluids reach their critical states with significant variations in their properties. The current work is based on the effect of fluid property variations in the performance analysis of a two‐fluid countercurrent cryogenic heat exchanger subject to ambient heat in a leak. Finite element method–subdomain method is used to conduct the performance analysis. The effect of fluid property variations is analyzed considering effectiveness, ∈, as the performance parameter. The percentage deviation in the effectiveness value on considering fluid property variation is determined. The relationship between effectiveness ∈ and the number of transfer units (NTUs) is obtained by plotting the ∈‐NTU curve by varying the mass flow rate of the fluid flow. A maximum deviation of 16.108% in the effectiveness and 58.734% in the hot fluid exit temperature is obtained by considering fluid property variation.

A new optimization method of energy consumption for dynamic boil-off gas

Related research on refrigerant optimization based on the dynamic BOG has yet to be proposed. This study offers a new dynamic optimization method for boil-off gas (BOG) re-liquefaction system to improve the system's energy efficiency. The performance of C3MR (the propane precooling mixed refrigerant cycle) is analyzed based on the steady state model of leading liquefaction equipment in the process simulation in Aspen HYSYS software. And the principle of the energy consumption variation law of propane precooled compressor and mixed refrigerant compressor, based on the actual possible disturbance range obtained in the natural gas liquefaction process, is applied to construct the multi-objective optimization model with minimum energy consumption and maximum heat exchanger efficiency. Finally, the dynamic responses of disturbances were achieved and discussed with the aid of GA (Genetic Algorithm) and PSO (particle swarm optimization). The optimized performance of the dynamic liquefaction cycle is 34.8% better than the steady condition system in terms of energy efficiency, and the maximum energy consumption can be reduced by 50.60%. The advantage of the proposed optimization framework is its adaptability to other dynamic liquefaction processes. It has practical reference significance for the cost control of the BOG re-liquefaction recovery project.

Simulation and technical, economic, and environmental analyses of natural gas liquefaction cycle using different configurations

This paper aims to improve the performance of the simple C3MR natural gas liquefaction cycle from the thermodynamic, economic, and environmental aspects. Four processes are proposed where the first system uses heat recovery with the ORC cycle and boil-off gas cooling, and the second proposed plant uses the first plant with a distillation tower added for the separation of ethane plus and simultaneous production of NGL/LNG. The third scenario adds a Proton Exchange Membrane, gas turbine cycle, steam turbine, and electrolyzer to the second scenario. And the fourth scenario is in which a Rankine ammonia cycle is added to the structure of the second scenario to recover more wasted heat. Regarding exergy analysis, the third scenario represents 64.32% exergetic efficiency, while the base, 1st, 2nd, and 4th scenarios have 35.4, 47.35, 12.64%, and 17.1% exergetic efficiency, respectively. The LNG production requires 260.76, 941, 469, and 893 kWh/ tonLNG energy for the 1st, 2nd, 3rd, and 4th scenarios. According to the economic analysis, the first scenario with 0.0034 $/kg total cost rate of products has the best economic performance compared to 0.0037, 0.042, 0.059 $/kg, and 0.055 total cost rate of products for the base, 2nd, 3rd, and 4th scenarios, respectively. The environmental assessment results reveal that the first scenario with 72,567 kgCO2/h has the minimum CO2 emission. The overall results indicate that the first scenario is the best, but considering the trigeneration, the third scenario is a proper system.