A Novel Process Simulation Study of Coalbed Methane Enrichment by Solvent

2014 ◽  
Vol 953-954 ◽  
pp. 1315-1318
Author(s):  
Zi Run Xuan ◽  
Zhi Yuan Yang ◽  
De Chao Wang ◽  
Si Tong Wang ◽  
Shui Jing Cao
Keyword(s):  
Coalbed Methane ◽  
Methane Concentration ◽  
Simulation Method ◽  
Molar Ratio ◽  
Feed Ratio ◽  
Operating Pressure ◽  
Solvent Absorption ◽  
Industrial Utilization ◽  
Enrichment Process ◽  
Feed Molar Ratio

A type of novel solvent absorption method using propyl ether as absorbent was proposed, which the coalbed methane (CBM) was concentrated and simulated in the form of physical absorption. The reasonable process had been designed and analyzed by Aspen Plus v7.3 . Through the simulation method PSRK, effects of the number of theoretical stages and the optimal operating pressure, temperature, amount of fresh absorbent added were studied respectively. The optimal enrichment effect of CH4/N2 feed ratio was determined. Simulation results show that when the feed molar ratio of CH4/N2 is 3:7, it can improve methane concentration to 67.44% with a recovery ratio of 87.11%. When feeding methane concentration increased to more than 50%, it can be enriched to more than 80%, which is suitable for the CBM civil and industrial utilization value. The enrichment process designed can provide an idea for the enrichment of CBM.

Synthesis of AM-co-NVP and Thermal Stability in Hostile Saline Solution

2012 ◽  
Vol 602-604 ◽  
pp. 1349-1354 ◽  
Author(s):  
Rui Liu ◽  
Wan Fen Pu ◽  
Qin Peng ◽  
Feng Sheng Yao
Keyword(s):  
Thermal Stability ◽  
Saline Solution ◽  
Heat Stability ◽  
Structure Characterization ◽  
Vinyl Pyrrolidone ◽  
Molar Ratio ◽  
Mass Ratio ◽  
Excellent Thermal Stability ◽  
Hydrolyzed Polyacrylamide ◽  
Feed Molar Ratio

copolymer preparation; structure characterization; thermal stability; brines solution. Abstract. The copolymer (AM-co-NVP) of acrylamide (AM) and vinyl pyrrolidone (NVP) was carried out in the presence of 2,2'-azobis[2-methylpropionamidine] dihydrochloride（V50）as initiator by free radical polymerization. The copolymer was characterized by its chemical structure with Fourier transform infrared spectroscopy (FTIR). The heat resistance of AM-co-NVP at 100°C and 120°C in harsh saline solution with high mineralized concentration ranging from 5×104 mg/L to 20×104 mg/L containing 2.5% (mass ratio) CaCl2, 2.5% (mass ratio) MgCl2 and 95% NaCl (mass ratio) was investigated. The experimental results indicate that AM-co-NVP has excellent thermal stability in saline solution compared to partially hydrolyzed polyacrylamide (HPAM). What is more, the copolymer exhibited the most perfect thermal tolerance in high divalent saline solution when the feed molar ratio of AM and NVP is 91.5 to 8.5. The microstructures of the copolymer samples after thermal aging in hostile environment captured by scanning electron microscope (SEM）further proved the NVP monomer was effectively introduced leading to the copolymer favorable heat stability in particularly high mineralized solution.

Nickel and cobalt phosphides as effective catalysts for oxygen removal of dibenzofuran: role of contact time, hydrogen pressure and hydrogen/feed molar ratio

2015 ◽  
Vol 5 (6) ◽  
pp. 3403-3415 ◽  
Author(s):  
A. Infantes-Molina ◽  
E. Gralberg ◽  
J. A. Cecilia ◽  
Elisabetta Finocchio ◽  
E. Rodríguez-Castellón
Keyword(s):  
Catalytic Activity ◽  
Contact Time ◽  
Hydrogen Pressure ◽  
Oxygen Removal ◽  
Molar Ratio ◽  
Metal Loading ◽  
Molar Ratios ◽  
Feed Molar Ratio

The catalytic activity of nickel and cobalt phosphides, with a metal loading of 5 wt.%, supported on silica was investigated in the hydrodeoxygenation reaction (HDO) of dibenzofuran (DBF) as a model oxygenated compound at different contact times, H2 pressures and H2/DBF molar ratios.

Process Intensification of Methane Production via Catalytic Hydrogenation in the Presence of Ni-CeO2/Cr2O3 Using a Micro-Channel Reactor

Catalysts ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1224
Author(s):  
Vut Tongnan ◽  
Youssef Ait-lahcen ◽  
Chuthamas Wongsartsai ◽  
Chalempol Khajonvittayakul ◽  
Nuchanart Siri-Nguan ◽  
...  
Keyword(s):  
Activation Energy ◽  
Process Intensification ◽  
Catalytic Performance ◽  
Molar Ratio ◽  
Micro Channel ◽  
Co2 Conversion ◽  
Channel Reactor ◽  
Mechanistic Pathway ◽  
Slight Amount ◽  
Feed Molar Ratio

A slight amount of Cr2O3 segregation in 40 wt% NiO/Ce0.5Cr0.5O2 was presented at the surface. The best catalytic performance towards the reaction was achieved at 74% of CO2 conversion and 100% CH4 selectivity at 310 °C, the reactant (H2/CO2) feed molar ratio was 4, and the WHSV was 56,500 mlN·h−1·g−1cat. The mechanistic pathway was proposed through carbonates and formates as a mediator during CO2 and H2 interaction. Activation energy was estimated at 4.85 kJ/mol, when the orders of the reaction were ranging from 0.33 to 1.07 for nth-order, and 0.40 to 0.53 for mth-order.

The Catalytic Performance of Sol-Gel Alumina Supported Ti-Ce Catalysts for H2S Selective Oxidation to Elemental Sulfur

2018 ◽  
Vol 17 (5) ◽  
Author(s):  
H. Mehmet Tasdemir ◽  
Yavuz Yagizatli ◽  
Sena Yasyerli ◽  
Nail Yasyerli
Keyword(s):  
Reaction Time ◽  
Selective Oxidation ◽  
Elemental Sulfur ◽  
Sol Gel ◽  
Lewis Acidity ◽  
Molar Ratio ◽  
Feed Ratio ◽  
Impregnation Method ◽  
Durability Test ◽  
Adsorption Desorption

Abstract In this study, alumina supported Ti-Ce catalysts (10 % by weight and Ti/Ce molar ratio is 4:1) were prepared by using wet impregnation method and their catalytic activities were tested in H2S selective oxidation to elemental sulfur. The support alumina was synthesized by classical (SGC) and modified (SGM) sol-gel methods. The N2 adsorption-desorption, XRD, XPS, EDS and FTIR techniques were used to characterize the synthesized catalysts. The N2 adsorption-desorption isotherms showed that both catalysts have mesoporous structure. Only γ-Al2O3 crystalline phase together with amorphous structure were observed in the XRD patterns. The pyridine adsorbed FTIR analyzes showed that 10 %Ti-Ce@SGC and 10 %Ti-Ce@SGM catalysts have the same Lewis acidity. The activity tests were carried out at 250 °C and with a stoichiometric feed ratio of O2 to H2S being 0.5 for two different reaction times as 150 and 510 min. Complete conversion of H2S was obtained during 180 min. and 330 min. of reaction time over 10 %Ti-Ce@SGC and 10 %Ti-Ce@SGM, respectively. However, all catalysts showed very high sulfur selectivity. Sulfur deposition was detected over 10 %Ti-Ce@SGC catalyst both 150 and 510 min. of reaction time while it was observed after 510 min. of durability test over 10 %Ti-Ce@SGM catalyst. This can be the reason for the earlier loss of catalytic activity 10 %Ti-Ce@SGC than 10 %Ti-Ce@SGM.

scholarly journals A feasible synthetic strategy for three-armed star poly(ester amine) via Michael addition polymerization

e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Wei Yang ◽  
Cai-Yuan Pan
Keyword(s):  
Molecular Weight ◽  
Michael Addition ◽  
Monomer Concentration ◽  
Gel Permeation Chromatography ◽  
Molar Ratio ◽  
Glycol Diacrylate ◽  
H Nmr ◽  
Synthetic Strategy ◽  
Addition Polymerization ◽  
Feed Molar Ratio

AbstractThree-armed star-shaped poly(ester amine) was synthesized by Michael addition polymerizations of equal molar ratio of ethylene glycol diacrylate (EGDA) and piperazine (PZ) in the presence of a small amount of multifunctional monomer, 1,3,5-triacryloylhexa-hydro-1,3,5-triazine (TT) in CHCl3. When the polymerization proceeded almost completely, the molecular weight of the polymers formed were determined by the feed molar ratio of difunctional monomer to multifunctional monomer, and the molecular weight distribution (Mw/Mn) approached the theoretical value (Mw/Mn =1+1/f). The mechanism of the polymerization was investigated by 1H NMR and Gel permeation chromatography (GPC). The monomer concentration and the molar ratio of difunctional monomers/multifunctional monomer played an important role in the polymerization.

scholarly journals A Theoretical Analysis on a Multi-Bed Pervaporation Membrane Reactor during Levulinic Acid Esterification Using the Computational Fluid Dynamic Method

Membranes ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 635
Author(s):  
Milad Ghahremani ◽  
Kamran Ghasemzadeh ◽  
Elham Jalilnejad ◽  
Adolfo Iulianelli
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Levulinic Acid ◽  
Membrane Reactor ◽  
Molar Ratio ◽  
Catalyst Loading ◽  
Water Removal ◽  
Feed Flow Rate ◽  
Pervaporation Membrane ◽  
Feed Molar Ratio

Pervaporation is a peculiar membrane separation process, which is considered for integration with a variety of reactions in promising new applications. Pervaporation membrane reactors have some specific uses in sustainable chemistry, such as the esterification processes. This theoretical study based on the computational fluid dynamics method aims to evaluate the performance of a multi-bed pervaporation membrane reactor (including poly (vinyl alcohol) membrane) to produce ethyl levulinate as a significant fuel additive, coming from the esterification of levulinic acid. For comparison, an equivalent multi-bed traditional reactor is also studied at the same operating conditions of the aforementioned pervaporation membrane reactor. A computational fluid dynamics model was developed and validated by experimental literature data. The effects of reaction temperature, catalyst loading, feed molar ratio, and feed flow rate on the reactor’s performance in terms of levulinic acid conversion and water removal were hence studied. The simulations indicated that the multi-bed pervaporation membrane reactor results to be the best solution over the multi-bed traditional reactor, presenting the best simulation results at 343 K, 2 bar, catalyst loading 8.6 g, feed flow rate 7 mm3/s, and feed molar ratio 3 with levulinic acid conversion equal to 95.3% and 91.1% water removal.

scholarly journals Crystalline Defects Induced during MPCVD Lateral Homoepitaxial Diamond Growth

Nanomaterials ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 814
Author(s):  
Fernando Lloret ◽  
David Eon ◽  
Etienne Bustarret ◽  
Daniel Araujo
Keyword(s):  
Methane Concentration ◽  
Microwave Plasma ◽  
Chemical Vapor ◽  
Diamond Growth ◽  
Molar Ratio ◽  
Dislocation Generation ◽  
Burgers Vector ◽  
Partial Dislocations ◽  
Transmission Electron ◽  
Level Versus

The development of new power devices taking full advantage of the potential of diamond has prompted the design of innovative 3D structures. This implies the overgrowth towards various crystallographic orientations. To understand the consequences of such growth geometries on the defects generation, a Transmission Electron Microscopy (TEM) study of overgrown, mesa-patterned, homoepitaxial, microwave-plasma-enhanced, chemical vapor deposition (MPCVD) diamond is presented. Samples have been grown under quite different conditions of doping and methane concentration in order to identify and distinguish the factors involved in the defects generation. TEM is used to reveal threading dislocations and planar defects. Sources of dislocation generation have been evidenced: (i) doping level versus growth plane, and (ii) methane concentration. The first source of dislocations was shown to generate <110> Burgers vector dislocations above a critical boron concentration, while the second induces <112> type Burgers vector above a critical methane/hydrogen molar ratio. The latter is attributed to partial dislocations whose origin is related to the dissociation of perfect ones by a Shockley process. This dissociation generated stacking faults that likely resulted in penetration twins, which were also observed on these samples. Lateral growth performed at low methane and boron content did not exhibit any dislocation.

Synthesis and characterization of novel β-cyclodextrin cored poly(α-caprolactone)s by anionic ring opening polymerization

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Yingzhi Guo ◽  
Changjiang Yu ◽  
Zhongwei Gu
Keyword(s):  
Molecular Weight ◽  
Physical Properties ◽  
Ring Opening ◽  
Monomer Conversion ◽  
Ring Opening Polymerization ◽  
Molar Ratio ◽  
Molecular Weights ◽  
Molar Ratios ◽  
Anionic Ring ◽  
Feed Molar Ratio

Abstract By anionic ring opening polymerization initiated by cyclodextrin oxyanions generated from NaH and β-cyclodextrin(β-CD), novel biodegradable β- CD cored star-shaped poly(ε-caprolactone)s (s-PCLs) were synthesized and then characterized by means of FTIR, GPC, 1H-NMR. The effects of different feed molar ratios of NaH and β-CD on arm number and on the molecular weight of s-PCLs, and the relationship between the polymerization time and monomer conversion were investigated. Moreover, the physical properties of linear PCL (l-PCL) and s- PCLs with similar molecular weights but different arm number were studied and compared by DSC, SEM and intrinsic viscosity measurement, respectively. It was found that the feed molar ratio of NaH and β-CD is an important factor which influences both the molecular weight and arm number. The melting points and intrinsic viscosities of s-PCLs with similar molecular weights were lower than that of l-PCL, and were found to decrease with increasing arm number. Both SEM and AFM showed that the surface morphology of s-PCL films was different from that of l-PCL. These results indicated that s-PCL with different arms and physical properties could be synthesized using just a β-CD core by adjusting the feed molar ratio of NaH and β-CD

scholarly journals Experimental Study on Distillation Column Parameters for Liquefaction Device of Low Concentration Coalbed Methane

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 606
Author(s):  
Lu Xiao ◽  
Jinhua Chen
Keyword(s):  
Recovery Rate ◽  
Coalbed Methane ◽  
Distillation Column ◽  
Industrial Plant ◽  
Operating Pressure ◽  
Plant Design ◽  
Methane Recovery ◽  
Low Concentration ◽  
Operation Process ◽  
Actual Operation

The input-output ratio and comprehensive energy consumption of low concentration coalbed methane cryogenic liquefaction devices are determined by the process parameters in control of the distillation column. In order to accurately control the actual operation process of the distillation column, the effect of the operating temperature of the distillation column on the liquefaction performance of a cold box was studied experimentally, and the optimal control parameters of the distillation column were obtained. The results show that the recovery rate of methane decreases with the increase in temperature at the top of the distillation column, and when this temperature is higher than −178 °C, the methane recovery rate drops sharply to below 90%. When the temperature at the bottom of the distillation column rises from −154 °C to −142.7 °C, the purity of LNG products is improved, and when this temperature is increased to −143.5 °C, the purity of products at the bottom of the distillation column reaches the standard, and can be stored safely. In actual operation, the evaporation temperature at the bottom of the column should not be higher than −140 °C. In the process of industrial plant design, measures should be taken to reduce the interaction of the temperature regulation at the top and bottom of the distillation column. When selecting the refrigerant circulation compressor, the leakage of the refrigerant should be considered to maintain the operating pressure of the refrigeration cycle.

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