scholarly journals Characteristics of mass transfer between gas-liquid phases in a higee reactor

2014 ◽  
Vol 20 (4) ◽  
pp. 523-530 ◽  
Author(s):  
Zhang Zhenzhen ◽  
Guo Kai ◽  
Luo Huijuan ◽  
Song Junnan ◽  
Qian Zhi

In the absorption process of gas-liquid phases in Rotating Packed Bed (RPB), the liquid flow on packing was assumed to be film-flow. Based on Higbie?s penetration theory, the diffusion-reaction model in RPB was introduced to calculate the rate of gas absorption. Taking CO2 (10%)+N2(90%) gas mixture and N-methyldiethanolamine (MDEA) aqueous solution as objects, the experiments of gas absorption were carried out at different gas flow rates, rotating speeds, temperatures, liquid flow rates and MDEA mass concentrations. The experimental data were compared with calculation results to found a good agreement in the rotating speed range of 400-1100r/min. In this range, the rate of decarburization was in direct proportion to rotating speed, temperature and liquid flow rate, and inversely proportion to gas flow rate and MEDA mass concentration. The maximum deviation between experimental data and calculation results was 10%. Beyond the rotating speed of 1100 r/min, the rate of decarburization was dependent on the dynamic balance of gas-liquid system. In this area, the rate of decarburization was inversely proportion to rotating speed.

SPE Journal ◽  
2006 ◽  
Vol 11 (02) ◽  
pp. 199-205 ◽  
Author(s):  
David I. Atkinson ◽  
Oyvind Reksten ◽  
Gerald Smith ◽  
Helge Moe

Summary Dedicated wet-gas flowmeters are now commercially available for the measurement of gas and liquid flow rates and offer a more compact measurement solution than does the traditional separator approach. The interpretation models of traditional multiphase flowmeters emphasize the liquid rate measurements and have been used to well test and meter mostly liquid-rich flow streams. These models were not developed for the measurement of gas flow rates, particularly those of wet gas. A new interpretation is described that allows a traditional multiphase flowmeter to operate in a dual mode either as a multiphase meter or as a wet-gas meter in 90 to 100% gas. The new interpretation model was developed for a commercially available multiphase flowmeter consisting of a venturi and a dual-energy composition meter. This combination results in excellent predictions of the gas flow rate; the liquid rate prediction is made with acceptable accuracy and no additional measurements. The wet gas and low-liquid-volume-fraction interpretation model is described together with the multiphase flowmeter. Examples of applying this model to data collected on flow loops are presented, with comparison to reference flow rates. The data from the Sintef and NEL flow loops show an error (including the reference meter error) in the gas flow rate, better than ± 2% reading (95% confidence interval), at line conditions; the absolute error (including the reference meter error) in the measured total liquid flow rate at line conditions was better than ± 2 m3/h (< ± 300 B/D: 95% confidence interval). This new interpretation model offers a significant advance in the metering of wet-gas multiphase flows and yields the possibility of high accuracies to meet the needs of gas-well testing and production allocation applications without the use of separators. Introduction There has been considerable focus in recent years on the development of new flow-measurement techniques for application to surface well testing and flow-measurement allocation in multiphase conditions without separating the phases. This has resulted in new technology from the industry for both gas and oil production. Today, there are wet-gas flowmeters, dedicated to the metering of wet-gas flows, and multiphase meters, for the metering of multiphase liquid flows. The common approach to wet-gas measurement relates gas and liquid flows to a "pseudo-gas flow rate" calculated from the standard single-phase equations. This addresses the need for gas measurement in the presence of liquids and can be applied to a limit of liquid flow [or gas volume fraction, (GVF)], though the accuracy of this approach decreases with decreasing GVF. The accurate determination of liquid rates by wet-gas meters is restricted in range. The application and performance of multiphase meters has been well documented through technical papers and industry forums, and after several years of development is maturing (Scheers 2004). Some multiphase measurement techniques can perform better, and the meters provide a more compact solution, than the traditional separation approach. It is not surprising that the use of multiphase flowmeters has grown significantly, the worldwide number doubling in little over a 2-year period (Mehdizadeh et al. 2002). Multiphase-flowmeter interpretation emphasizes the liquid rate measurement, and the application of multiphase flowmeters has been predominantly for liquid-rich flow stream allocation and well testing.


2021 ◽  
Author(s):  
Serhii Matkivskyi ◽  
Liliia Khaidarova

The overwhelming majority of natural gas fields are at the final stage of development, which, along with other features, is characterized by selective watering of productive deposits and production wells. The difficulty of extracting residual gas reserves under such development conditions is associated with depletion of productive reservoirs, accumulation of fluid at the bottom of wells, corrosion of downhole equipment and the inability to reduce wellhead pressures due to restrictions on the supply and preparation of hydrocarbon products with the existing surface infrastructure. Production wells in conditions of formation water inflow into productive deposits are decommissioned after relatively small gas withdrawals. This is due both to the insufficient implementation of methods for intensifying the removal of fluid from the bottom of the wells, and to the peculiarities of the arrangement of fields, which are usually not designed for the collection and preparation of hydrocarbon products with a high liquid content. In order to remove the gas-liquid mixture from the bottom of the wells, many techniques and inventions have been developed that are widely used in production. The developed technologies are characterized by different efficiency and have a number of technological limitations, mainly due to the peculiarities of the geological structure of hydrocarbon deposits. Considering the above, there is a need for additional research in order to improve the existing and develop new technologies for the operation of water cut wells. Using the special software package, studies were carried out to optimize the operating conditions for a water cut well under conditions of active formation water inflow into gas-saturated horizons. The study was carried out for various depths of gas-lift valves (3500 m; 3000 m; 2500 m; 2000 m; 1500 m; 1000 m) and liquid flow rates (22.5 m3/day; 33.75 m3/day and 45 m3/day). Based on the research results, graphical dependences of gas flow rates and bottomhole pressure on the amount of gas-lift gas were built; the maximum gas flow rate and the required amount of gas-lift gas from the liquid flow rate; maximum gas flow rate versus liquid flow rate at different depths of gas-lift valve installation. Based on the results of statistical processing of the calculated data for each value of the liquid flow rate, the optimal value of the depth of the gas-lift valve was established. According to the results of the studies performed, to ensure the stable operation of high-water cut gas wells, it is effective to locate the gas-lift valve at a distance of 55-58 % from the wellhead of the tubing (2033-2137 m).


Konversi ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 6
Author(s):  
Erlinda Ningsih ◽  
Abas Sato ◽  
Mochammad Alfan Nafiuddin ◽  
Wisnu Setyo Putranto

Abstract- One of the most widely used processes for CO2 gas removal is Absorption. Carbon dioxide is the result of the fuel combustion process which of the hazardous gases. The aim of this research is to determine the total mass transfer coefficient and analyze the effect of the absorbent flow rate of the absorbent solution with the promoter and the gas flow rate to the total mass transfer coefficient value. The variables consisted of liquid flow rate: 1, 2, 3, 4, 5 liter/min, gas flow rate: 15, 25, 30, 40, 50 liter/min and MSG concentration: 0%, 1%, 3% and 5% by weight. The solution of Pottasium Carbonate as absorbent with MSG promoter is flowed through top column and CO2 gas flowed from bottom packed column. Liquids were analyzed by titration and the gas output was analyzed by GC. From this research, it is found that the flow rate of gas and the liquid flow rate is directly proportional to the value of KGa. The liquid flow rate variable 5 liters / minute, gas flow rate 15 l / min obtained value of KGa 11,1102 at concentration of MSG 5%. Keywords:  Absorption, CO2,  K2CO3, MSG. 


2011 ◽  
Vol 201-203 ◽  
pp. 399-403 ◽  
Author(s):  
Hong Qing Song ◽  
Ming Yue ◽  
Wei Yao Zhu ◽  
Dong Bo He ◽  
Huai Jian Yi

Porous media containing water is the prerequisite of existence of threshold pressure gradient (TPG) for gas flow. Based on theory of fluid mechanics in porous medium considering TPG, the non-Darcy flow mathematical model is established for formation pressure analysis of water-bearing tight gas reservoirs. It could provide semi-analytic solution of unsteady radial non-Darcy flow. According to the solution of unsteady radial non-Darcy flow, an easy and accurate calculation method for formation pressure analysis is presented. It can provide theoretical foundation for development design of water-bearing tight gas reservoirs. The analysis of calculation results demonstrates that the higher TPG is, the smaller formation pressure of water-bearing tight gas reservoirs spreads. In the same output, the reservoir sweep of non-Darcy gas flow is larger than that of non-Darcy liquid flow. And the pressure drop near wellbore is smaller than that of non-Darcy liquid flow, which is different from Darcy flow.


2021 ◽  
pp. 1-14
Author(s):  
T. G. Ahmed ◽  
P. A. Russell ◽  
N. Makwashi ◽  
F. Hamad ◽  
S. Gooneratne

Summary In the first part of this work, the development of a capital cost optimization model for sizing three-phase separators was described. The developed model uses generalized reduced gradient nonlinear algorithms to determine the minimum cost associated with the construction of horizontal separators subject to four sets of constraints. In the second part, an experimental test rig was designed and used to investigate the effect of gas flow rate, liquid flow rate, and slenderness ratio (L/D) on the separation performance of horizontal three-phase separators. The results indicated an inverse relationship between an increase in gas and liquid flow rate and the separator outlet quality. It also indicated a direct relationship between an increase in slenderness ratio and separator outlet quality. The results also showed that the gradient change of the percentage of water in the oil outlet with respect to slenderness ratio decreased to ratios of 6:1. Hence, the separation rate increased. At ratios greater than 6:1, the separation still increases, but the gradient change in separation drops off, implying that the benefit in terms of separation is diminishing beyond this point. Therefore, the optimal slenderness ratio for technical reasons is 6:1.


2020 ◽  
Vol 10 (13) ◽  
pp. 4617
Author(s):  
Adel Almoslh ◽  
Falah Alobaid ◽  
Christian Heinze ◽  
Bernd Epple

The influence of pressure on the gas/liquid interfacial area is investigated in the pressure range of 0.2–0.3 MPa by using a tray column test rig. A simulated waste gas, which consisted of 30% CO2 and 70% air, was used in this study. Distilled water was employed as an absorbent. The temperature of the inlet water was 19 °C. The inlet volumetric flow rate of water was 0.17 m3/h. Two series of experiments were performed; the first series was performed at inlet gas flow rate 15 Nm3/h, whereas the second series was at 20 Nm3/h of inlet gas flow rate. The results showed that the gas/liquid interfacial area decreases when the total pressure is increased. The effect of pressure on the gas/liquid interfacial area at high inlet volumetric gas flow rates is more significant than at low inlet volumetric gas flow rates. The authors studied the effect of decreasing the interfacial area on the performance of a tray column for CO2 capture.


2020 ◽  
Vol 842 ◽  
pp. 279-284
Author(s):  
Zhong Ren ◽  
Xing Yuan Huang

During the manufacture of plastic micro-pipe, a certain volume of gas should be properly injected into the inner cavity to overcome the collapse and adhesion problems. In this work, the extrusion forming of plastic micro-tube under the role of inner cavity’s gas were numerically studied. At the same time, the effect of inner cavity’s gas flow rate on the extrusion deformation of plastic micro-pipe was also numerically investigated by using the finite element method. A kind of 2D two-phase fluid geometric model and finite element mesh were established and some reasonable boundary conditions and material parameters were imposed. Under a fixed volume flow rate of melt, different flow rates of inner cavity gas were imposed on the inlet of inner cavity’s gas. The extrusion deformation profile and deformation ratio of plastic micro-pipe under different flow rates of gas were all obtained. To ascertain the mechanisms of effect of inner cavity’s gas flow rate on the extrusion deformation of plastic micro-tube, the flow velocities, pressure, shear rate, normal stress, and the first normal stress difference of melt all obtained and analyzed. Numerical results show that with the increase of inner cavity’s gas flow rate, the radial velocity, axial velocity, pressure, shear rate, normal stress, and the first normal stress difference of melt all increase, which makes the extrusion deformation become more and more serious. In practice, reasonable controlling of the inner cavity’s gas flow rate is very important. In the other hand, it can adjust the size of extruded plastic micro-pipe.


1994 ◽  
Vol 29 (10-11) ◽  
pp. 231-241 ◽  
Author(s):  
H. T. Chang ◽  
B. E. Rittmann

This paper presents a unified model that inter-relates gas flow rate, liquid flow rate, and hold-ups of each of the liquid, gas, and solid phases in three-phase, fluidized-bed biofilm (TPFBB) process. It describes how carrier properties, biofilm properties, and gas and liquid flow velocities control the system dynamics, which ultimately will affect the density, thickness, and distribution of the biofilm. The paper describes the development of the mathematical model to correlate the effects of gas flow rate, liquid flow rate, solid concentration, and biofilm thickness and density. This knowledge is critically needed in light of the use of TPFBB processes in treating industrial wastewater, which often has high substrate concentration. For example, the proper design of the TPFBB process requires mathematical description of the cause-effect relationship between biofilm growth and fluidization.


Author(s):  
M. K. Mittal ◽  
R. Kumar ◽  
A. Gupta

The objective of this study is to investigate the effect of coiling on the flow characteristics of R-407C in an adiabatic spiral capillary tube. The characteristic coiling parameter for a spiral capillary tube is the coil pitch; hence, the effect of the coil pitch on the mass flow rate of R-407C was studied on several capillary tube test sections. It was observed that the coiling of the capillary tube significantly reduced the mass flow rate of R-407C in the adiabatic spiral capillary tube. In order to quantify the effect of coiling, the experiments were also conducted for straight a capillary tube, and it was observed that the coiling of the capillary tube reduced the mass flow rate in the spiral tube in the range of 9–18% as compared with that in the straight capillary tube. A generalized nondimensional correlation for the prediction of the mass flow rates of various refrigerants was developed for the straight capillary tube on the basis of the experimental data of R-407C of the present study, and the data of R-134a, R-22, and R-410A measured by other researchers. Additionally, a refrigerant-specific correlation for the spiral capillary was also proposed on the basis of the experimental data of R-407C of the present study.


Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5793
Author(s):  
Eero Inkeri ◽  
Tero Tynjälä

The demand for carbon capture is increasing over time due to rising CO2 levels in the atmosphere. Even though fossil emission could be decreased or even eliminated, there is a need to start removing CO2 from the atmosphere. The removed CO2 could be either stored permanently to a reservoir (CCS, Carbon Capture and Storage) or utilized as a raw material in a long-lasting product (CCU, Carbon Capture and Utilization). The capture of CO2 could be done by direct air capture, or capturing CO2 from biogenic sources. Amine absorption is the state-of-the-art method to capture CO2, but it has some drawbacks: toxicity, high heat demand, and sorbent sensitivity towards impurities such as sulfur compounds and degradation in cyclic operation. Another potential solvent for CO2 could be water, which is easily available and safe to use in many applications. The problem with water is the poorer solubility of CO2, compared with amines, which leads to larger required flow rates. This study analyzed the technical feasibility of water absorption in a counterflow bubble column reactor. A dynamic, one-dimensional multiphase model was developed. The gas phase was modeled with plug flow assumption, and the liquid phase was treated as axially dispersed plug flow. CO2 capture efficiency, produced CO2 mass flow rate, and the product gas CO2 content were estimated as a function of inlet gas and liquid flow rate. In addition, the energy consumption per produced CO2-tonne was calculated. The CO2 capture efficiency was improved by increasing the liquid flow rate, while the CO2 content in product gas was decreased. For some of the studied liquid flow rates, an optimum gas flow rate was found to minimize the specific energy consumption. Further research is required to study the integration and dynamical operation of the system in a realistic operation environment.


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