Pollutant Sources and Foaming Control Measures of Decarbonization Solution in Natural Gas Purification Plant

Yanbei project of Schlumberger Copower Oilfield Engineering Co.,Ltd.-natural gas purification plant decarbonization unit is equipped with two sets of decarbonization systems(parallel operation).The two sets of systems adopt two tower process,full lean liquid circulation regeneration process,one tower absorption(absorption pressure 5.4mpag),one tower regeneration(regeneration temperature 95℃-110℃),purified natural gas carbon dioxide content≤2.5vol%,single set The treatment capacity is 2300 KM3/d.This paper introduces the problems existing in the decarbonization solution of the decarbonization unit in the natural gas purification plant in recent three years,analyzes the causes of pollutants affecting the quality of the decarbonization solution,and probes into the control measures for the pollution of the decarbonization solution,so as to provide reference.

A Scalable Pillar Layered Metal-Organic Framework for Natural Gas Purification

One-step harvest of high-purity methane(CH_(4))from ternary propane/ethane/methane(C_(3)H_(8)/C_(2)H_(6)/CH_(4))mixtures remains a desirable yet challenging goal for natural gas purification.However,adsorbents either suffer from high capacity and selectivity,or are caught in a dilemma of scalable synthesis.Herein,we demonstrate a scalable pillar layered metal-organic framework Ni-MOF for highly efficient one-step CH_(4)purification.Ni-MOF exhibits high C_(2)H_(6)and C_(3)H_(8)uptakes of 83.3 and 86.1 cm^(3)/g at 298 K and 100 kPa and remarkable C_(2)H_(6)/CH_(4)(50/50,volume ratio,21.5)and C_(3)H_(8)/CH_(4)(50/50,volume ratio,212.0)selectivities.Notably,high C_(2)H_(6)(42.2 cm^(3)/g at 10 kPa)and C_(3)H_(8)(64.7 cm^(3)/g at 5 kPa)capacities in the low-pressure region at 298 K were realized on Ni-MOF,suggesting the strong affinities of Ni-MOF towards C_(2)H_(6)and C_(3)H_(8).Furthermore,the dynamic breakthrough experiments revealed that purifying CH_(4)from natural gas in one-step can be achieved in Ni-MOF with high-purity(>99.8%)and productivity(346.0 cm^(3)/g).Most significantly,the production of Ni-MOF can be scalably synthesized at room temperature,rendering it promising potential for industrial application.The combined advantages of exceptional separation performance,scalability,and cycle stability of Ni-MOF pave the way for one-step CH_(4)purification from natural gas.

Study on Pressure Swing Adsorption Removing C_(2)^(+) from Natural Gas as Raw Material for Thermal Chlorination

The experimental investigation demonstrates that a satisfactory result can be expected for pressure swing adsorption (PSA) purification of natural gas as raw material for thermal chlorination process. Using hh-4 molecular sieve as adsorbent for removing C+2 components, the suitable adsorption pressure is 0.4-0.45 MPa, desorption vacuum is 0.08-0.09 MPa and circulation time is 20-21 min.

High-performance SSZ-13 membranes prepared using ball-milled nanosized seeds for carbon dioxide and nitrogen separations from methane

SSZ-13 membranes with high separation performances were prepared using ball-milled nanosized seeds by once hydrothermal synthesis.Separation performances of SSZ-13 membranes in CO2/CH4 and N2/CH4 mixtures were enhanced after synthesis modification.Single-gas permeances of CO2,N2 and CH4 and ideal selectivities were recorded through SSZ-13 membranes.The effects of temperature,pressure,feed flow rate and humidity on separation performance of the membranes were discussed.Three membranes prepared after synthesis modifications had an average CO2 permeance of 1.16×10-6 mol·(m2·s·Pa)-1(equal to 3554 GPU)with an average CO2/CH4 selectivity of 213 in a 50 vol%/50 vol%CO2/CH4 mixture.It suggests that membrane synthesis has a good reproducible.The membrane also displayed a N2 permeance of 1.07×10-7 mol·(m2·s·Pa)-1(equal to 320 GPU)with a N2/CH4 selectivity of 13 for a 50 vol%/50 vol%N2/CH4 mixture.SSZ-13 membrane displayed stable and good separation performance in the wet CO2/CH4 mixture for a long test period over 100 h at 348 K.The current SSZ-13 membranes show great potentials for the simultaneous removals of CO2 and N2 in natural gas purification as a facile process suitable for industrial application.

Boosting selective C_(2)H_(2)/CH_(4),C_(2)H_(4)/CH_(4) and CO_(2)/CH_(4) adsorption performance via 1,2,3-triazole functionalized triazine-based porous organic polymers

Nitrogen-rich porous organic polymers have shown great potentials in gas adsorption/separation,photocatalysis,electrochemistry,sensing and so on.Herein,1,2,3-triazole functionalized triazine-based porous organic polymers(TT-POPs)have been synthesized by the copper-catalyzed azide-alkyne cycloaddition(Cu-AAC)polymerization reactions of 1,3,5-tris(4-azidophenyl)-triazine with 1,4-diacetylene benzene and 1,3,5-triacetylenebenzene,respectively.The characterizations of N2 adsorption at 77 K show TTPOPs possess permanent porosity with BET surface areas of 666 m^(2)·g^(-1)(TT-POP-1)and 406 m^(2)·g^(-1)(TT-POP-2).The adsorption capacities of TT-POPs for CO_(2),CH4,C2H2 and C2H4,as well as the selective separation abilities of CO_(2)/N2,CO_(2)/CH_(4),C_(2)H_(2)/CH_(4) and C_(2)H_(4)/CH_(4) were evaluated.The gas selective separation ratio of TT-POPs was calculated by the ideal adsorbed solution theory(IAST)method,wherein the selective separation ratios of C_(2)H_(2)/CH_(4) and C_(2)H_(4)/CH_(4) of TT-POP-2 was 48.4 and 13.6(298 K,0.1 MPa),which is comparable to other adsorbents(5.6–120.6 for C_(2)H_(2)/CH_(4),10–26 for C_(2)H_(4)/CH_(4)).This work shows that the 1,2,3-triazole functionalized triazine-based porous organic polymer has a good application prospect in natural gas purification.

Fluorinated metal-organic framework for methane purification from a ternary CH_(4)/C_(2)H_(6)/C_(3)H_(8)mixture

Herein we present a fluorinated metal-organic framework of{(Me_(2)NH_(2))[Ni_(3)(μ_(3)-OH)(CF_(3)-BPDC-CF_(3))_(3)(tpt)]}_(n)(1)constructed from 2,2'-bis(trifluoromethyl)biphenyl-4,4'-dicarboxylic(CF_(3)-BPDC-CF_(3)^(2-))and 2,4,6-tri(4-pyridyl)-1,3,5-triazine(tpt)ligands,which is developed for separating propane(C_(3)H_(8))and ethane(C_(2)H_(6))from natural gas.Compound 1 preferentially adsorbs C_(3)H_(8)and C_(2)H_(6)over CH_(4)demonstrated by gas adsorption experiments.The presence of trifluoromethyl groups on the biphenyl-4,4'-dicarboxylic ligands facilitates the highly polarized micropore environments for compound 1,thus providing suitable micorpores for capturing the C_(3)H_(8)and C_(2)H_(6)molecules with larger polarizabilities and sizes compared to CH_(4)molecule.The dynamic mixture breakthrough experiments showed that compound 1 can separate C_(3)H_(8)and C_(2)H_(6)from the ternary CH_(4)/C_(2)H_(6)/C_(3)H_(8)mixtures efficiently,endowing compound 1 with excellent methane purification ability.

Review on cryogenic technologies for CO_(2) removal from natural gas

CO_(2) in natural gas(NG)is prone to condense directly from gas to solid or solidify from liquid to solid at low temperatures due to its high triple point and boiling temperature,which can cause a block of equipment.Meanwhile,CO_(2) will also affect the calorific value of NG.Based on the above reasons,CO_(2) must be removed during the NG liquefaction process.Compared with conventional methods,cryogenic technologies for CO_(2) removal from NG have attracted wide attention due to their nonpolluting and low-cost advantages.Its integration with NG liquefaction can make rational use of the cold energy and realize the purification of NG and the production of byproduct liquid CO_(2).In this paper,the phase behavior of the CH_(4)-CO_(2) binary mixture is summarized,which provides a basis for the process design of cryogenic CO_(2) removal from NG.Then,the detailed techniques of design and optimization for cryogenic CO_(2) removal in recent years are summarized,including the gas-liquid phase change technique and the gas-solid phase change technique.Finally,several improvements for further development of the cryogenic CO_(2) removal process are proposed.The removal process in combination with the phase change and the traditional techniques with renewable energy will be the broad prospect for future development.

High and selective capture of low-concentration CO2 with an anion-functionalized ultramicroporous metal-organic framework

CO2 capture,especially under low-pressure range,is of significance to maintain long-duration human operation in confined spaces and decrease the CO2 corrosion and freezing effect for the liquefaction of natural gas.Herein,we for the first time report a novel anion-functionalized ZU-16-Co(TIFSIX-3-Co,TIFSIX=hexafluorotitanate(TiF62−),3=pyrazine),which exhibits one-dimensional pore channels decorated by abundant F atoms,for efficient CO2 capture at a concentration around 400–10,000 ppm.Among its isostructural MFSIX-3(M=Si,Ti,Ge)family materials,ZU-16-Co with fine-tuned pore size of 3.62Åexhibits the highest CO2 uptake at 0.01 bar(10,000 ppm)and 1 bar(2.63 and 2.87 mmol g−,respectively).The high CO2 capture ability of ZU-16-Co originates from the fine-tuned pore dimensions with strong F⋯C=O host-guest interactions and relatively large pore volumes coming from its longer coordinated Ti-F-Co distance(3.9Å)in c direction.The excellent carbon trapping performance was further verified by dynamic breakthrough tests for CO2/N2(1/99 and 15/85)and CO2/CH4(50/50)mixtures.The adsorption and separation performances,resulting from the fine-tuned pore system with periodic arrays of exposed functionalities,demonstrate that ultramicroporous ZU-16-Co can be a promising adsorbent for low-concentration carbon capture.