2024-03-29T12:50:44Z
https://www.jgt.irangi.org/?_action=export&rf=summon&issue=34500
Journal of Gas Technology
JGT
2017
2
1
A Novel Design for Plate Heat Exchangers in LNG Liquefaction Cycle
Mohamad Reza Jafari Nasr
Jafari Nasr
Elham
Mohammadi
LNG production is an intense and complex process, in which the liquefaction accounts for more than 50% of costs. In recent years, design engineers have been made several attempts to optimize this process. The main objective was to increase the production yield and capacity, and minimize the costs. The most important process equipment in liquefaction stage is devoted to compact heat exchangers of Plate Fin or Spiral Wounded types. This article described the simulation of liquefaction cycle of Iran LNG project with triple mixed refrigerant to provide a new method for designing the plate heat exchanger used in this cycle; in addition, a simple method was introduced for selecting the best secondary surface based on the conceptual development of the volume performance index (VPI). The designed exchanger had the minimum surface area and volume. The reduction of required heat transfer surface area had a significant role in the reduction of investment capital cost in LNG production process.The liquefaction cycle of Iran LNG was fully investigated in this article as an industrial case. According to the simulation, the cold and hot surface areas of the plate heat exchanger, used in the given process, are as large as 3001m2 and 1933m2 with the overall heat transfer coefficient of 425 W/m2K°; whereas, designing this exchanger by developed rapid design algorithm (RDA) significantly can be reduced the required cold and hot surface areas by 5.2 and 3.3 times, respectively. The overall heat transfer coefficient was also increased by 2 times.
Liquefied Natural Gas
Volume Performance Index
Rapid Design Algorithm
2017
05
31
4
15
https://www.jgt.irangi.org/article_251601_45c6372e1bbe86aba9a0071ebe634374.pdf
Journal of Gas Technology
JGT
2017
2
1
Wettability Alteration in Near-Wellbore Regions of Gas Reservoirs to Mitigate Liquid Blockage Using Super Water- and Oil-Repellent ZnO/SiO2 Nanofluid Treatment
Pouriya
Esmaeilzadeh
Mohammad Taghi
Sadeghi
Alireza
Bahramian
In gas-condensate reservoirs as the bottom hole pressure drops below the hydrocarbon dew point of the reservoir fluid, liquids drop out from the gas phase and establish condensate banking near the wellbore, resulting in lower gas productivity. Changing the reservoir rock wettability from liquid-wetting to gas-wetting has outstanding potential in improving the productivity of gas wells. In this work, we report the highly water- and oil-repellent properties of carbonate reservoir rocks treated with a nanofluid based on synthesized ZnO/SiO2 nanocomposites and fluoro-containing materials PTFE, TFE, and PFOS. Carbonate plates coated with the prepared nanofluid exhibits a high contact angle of 162° for brine (contact angle hysteresis=0° and roll-off angle <2°), together with 135° for liquid gas-condensate, supporting significant super-amphiphobicity with self-cleaning properties. Surface characterization of the rock using SEM, SP, and EDX analyses reveals that the rough morphology of ZnO/SiO2 nanocomposites combined with low surface energy of fluorochemical provides the surface superamphiphobicity. Moreover, the efficiency of the nanofluid in wettability alteration of carbonate core from liquid-wetting to ultra gas-wetting under reservoir conditions was investigated by performing gas/liquid two-phase flow tests with single-phase liquid-injection into the gas-saturated core. The results indicate that the mobility of liquid for both gas/brine and gas/liquid-condensate systems increases significantly after wettability alteration.
Gas-wetness
wettability alteration
nanofluid
ZnO/SiO2 nanocomposites
Gas condensate reservoir
liquid-repellent
2017
07
23
16
30
https://www.jgt.irangi.org/article_251609_9d652352fce1ff210458d1aa6fa4b088.pdf
Journal of Gas Technology
JGT
2017
2
1
Asphaltene and Normal Paraffin Effect on Gas-Oil Interfacial Tension During CO2 Injection into Asphaltenic Oil Reservoir
Masoud
Riazi
Yousef
Kazemzadeh
Rafat
Parsaei
Asphaltene precipitation in oil reservoirs has been involved with numerous problems. Therefore, it is imperative to understand the precipitation mechanisms in detail. There are several ways to detect asphaltene precipitation, i.e. interfacial tension method. In this study, for more accurate evaluation of asphaltene precipitation by using IFT versus pressure plots, synthetic oil solutions made up of toluene and normal paraffins are used. Solutions with different compositions of toluene and normal paraffins with and without asphaltene (extracted from crude oil) are prepared. Then, the IFT of the solutions in the proximity of CO2 at different pressure conditions is measured. By plotting the IFT data versus pressure, the onset of asphaltene precipitation and the impact of different parameters on this phenomenon are investigated. Experimental results show that the presence of asphaltene in synthetic solutions changes the behavior of IFT data with pressure. For a solution containing asphaltene, the IFT of the solution in presence of CO2 decreases linearly with two different slopes. The results confirm that the presence of n-paraffin intensifies asphaltene precipitation. The experimental results also show that the higher the mass fraction of asphaltene is, the larger would be the intensity of the asphaltene precipitation for the attempted mass fractions.
Asphaltene precipitation
Interfacial tension
Surface Coverage
Carbon dioxide
Normal Paraffin
2017
05
22
31
42
https://www.jgt.irangi.org/article_251610_46f3e952686e9e5d3b8e07aaba82e55c.pdf
Journal of Gas Technology
JGT
2017
2
1
Reducing Energy Consumption in Gas Purification Plants (MDEA base) by Retrofit Design
Omid
Sabbagh
Maysam
Vahidi Ferdowsi
Mohammad Ali
Fanaei
This study evaluates the effect of Structural modifications on energy consumption of gas treatment units of BIDBOLAND refinery (Iran’s first gas refinery). To this aim, Aspen HYSYS (V.8.3) software was employed for the unit simulation in rate based method. The results show that as CO2 content in inlet sour gas is less than 2 percent and MDEA solution is used as solvent, using multiple feeds to the absorption column, static mixers and absorption column sidestream cannot reduce energy consumption level; while using desorption column sidestream and a flash unit can reduce the unit energy consumption up to 10 percent.
ASPEN HYSYS
Superstructure optimization
MDEA
energy consumption
Natural gas sweetening
2017
05
22
43
49
https://www.jgt.irangi.org/article_251611_f8b8a14a3d32964e24ffc8fba39fc3cf.pdf
Journal of Gas Technology
JGT
2017
2
1
Utilizing Chemical Looping Combustion instead of Fired-Furnace in a Steam Methane Reforming for Enhancement of Hydrogen Production in a Multi Tubular Reactor
Sedigheh
Kabiri
Mohammadreza
Rahimpour
A novel thermally coupled reactor containing steam methane reforming in the endothermic side and chemical looping combustion as an exothermic side has been investigated in this study. In this innovative configuration, huge fired furnace of conventional steam reforming process is substituted by chemical looping combustion in a recuperative coupled reactor. This reactor has three concentric tubes where the steam methane reforming is supposed to occur in the middle tube and the inner and outer tubes are considered to be air and fuel reactors of chemical looping combustion, respectively. Copper is selected as solid oxygen carrier in the chemical looping combustion process. Both oxidation and reduction of Cu in the air and fuel reactor are exothermic and used as heat sources for endothermic steam methane reforming. A steady state heterogeneous model of fixed bed for steam reformer and a moving bed for chemical looping combustion reactor predict the performance of this new configuration. The counter-current mode is investigated and simulation results are compared with corresponding predictions of the conventional steam reformer. The results prove that synthesis gas production is increased in thermally coupled reactor in comparison with conventional steam reformer.
Hydrogen production
Steam reforming of methane
Thermally coupled reactor
Chemical looping combustion
Cu- based oxygen carrier
2017
05
22
50
66
https://www.jgt.irangi.org/article_251613_c56afd2e1ee6ba910d95a643f48189ce.pdf
Journal of Gas Technology
JGT
2017
2
1
A New Method to Enhance Separation of Acid Gas from Natural Gas by Mixed Amine Solution
Abolfazl
Gharibi Kharaji
Vahid
Madadi Avergani
Parviz
Darvishi
Application of mixed amine solution in gas sweetening unit decreases the operation cost and corrosion rate. Also it increases the amount of sulfur in acid gas stream that exits from sweetening and enters to sulfur recovery units. Gas sweetening unit of Bidboland gas refinery (BGR) was simulated by Hysys software. Simulation of BGR had good agreement with industrial data. The parameters such as CS (carbon dioxide in sweet gas), SSRU (the amount of H2S in outlet acid gas stream from stripper to sulfur recovery unit), RAL (rich amine loading) and HPA (reboiler duty per amine circulation rate), were compared for ten blends of DEA (Diethanolamine) and MDEA (Methyl Diethanolamine). According to technical specified parameters, mixed amine with composition of 40 wt. % MDEA and 10 wt. % DEA identified as a good amine blend for gas sweetening unit in BGR. JOGPT. Because Photonics is produced in DOC, strict adherence to format is required. The use of this template is useful for estimating the length of the papers strict adherence to format is required. The use of this tem.
gas sweetening
Bidboland Gas Refinery
Hysys
Mixed Amine
Hydrogen Sulfide
2017
05
22
67
74
https://www.jgt.irangi.org/article_251614_808e9581573f3d8bc707d0b539687b06.pdf