scholarly journals Biogas Upgrading to Biomethane by CO2 Removal using Water Absorber with Microbubble Technique

2021 ◽  
Vol 18 (10) ◽  
Author(s):  
Chananchida DUMRUANGSRI ◽  
Prukraya PONGYEELA ◽  
Juntima CHUNGSIRIPORN
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Gas Flow ◽  
Water Flow Rate ◽  
Operating Conditions ◽  
Experimental Unit ◽  
Co2 Removal ◽  
Gas Flow Rate ◽  
Biogas Upgrading ◽  
Absorption Column

Biogas upgraded to biomethane can be utilized as a renewable energy source to substitute LPG in households and industry. This study explored biogas upgrading by CO2 removal from 20 - 75 % CO2-N2 simulated biogas mixture. The experimental unit using the microbubble technique combined with the water absorption column was set up and used for CO2 removal from the gas. Microbubble sizes of 20 - 30 µm were generated by a venturi ejector and measured with an automated bubble size measurement. The experiments confirmed that a microbubble with an inline mixer could enhance the effectiveness of the absorption process. The tests demonstrated over 85.80 % removal of CO2 from the simulated biogas by the experimental unit. The effects of various parameters, including the size of venturi ejector, gas flow rate, water flow rate, liquid-gas ratio, and initial concentration of CO2, were investigated. The results revealed that 2 L/min gas flow rate, 15 L/min water flow rate, L/G ratio 7.5, and venturi ejector size 0.50 inches are the optimum conditions. The use of the tube absorber gave much higher CH4 recovery than an absorption column. The appropriate operating conditions gave over 96 % CH4 concentration or less than 4 % CO2 concentration, matching the CH4 purity required by biomethane specifications. The results indicated that the new technique demonstrated in this study can upgrade biogas to biomethane.

scholarly journals Dynamic Characteristics of Offshore Natural Gas Hydrate Dissociation by Depressurization in Marine Sediments

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Xinfu Liu ◽  
Chunhua Liu ◽  
Jianjun Wu
Keyword(s):  
Natural Gas ◽  
Water Flow ◽  
Marine Sediments ◽  
Flow Rate ◽  
Gas Flow ◽  
Water Flow Rate ◽  
Water Production ◽  
Gas Flow Rate ◽  
Natural Gas Hydrate ◽  
Natural Gas Flow

Dynamic characteristics of offshore natural gas hydrate (NGH) dissociation will provide the theoretical basis to analyze technical issues of oceanic hydrate exploitation. A mathematical model is developed to simulate offshore NGH dissociation by depressurization in marine sediments. Different phase combination statuses are involved in the process of NGH dissociation by taking ice melting and water freezing into account. The proposed methodology can analyze the processes of hydrate and water phase transitions, decomposition kinetics and thermodynamics, viscosity and permeability, ice-water phase equilibrium, and natural gas and water production. A set of an experimental system is built and consists of one 3-D visual reactor vessel, one isothermal seawater vessel, one natural gas and water separator, and one data acquisition unit. The experiments on offshore NGH dissociation by depressurization in 3-D marine sediments are carried out, and this methodology is validated against the full-scale experimental data measured. The results show that during the prophase, natural gas flow is preceded by water flow into the production wellbore and natural gas occupies more continuous flow channels than water under a large pressure gradient. Then, the natural gas flow rate begins to decline accompanied by an increase of water production. During the second phase, natural gas flow rate decreases slowly because of the decreased temperature of hydrate-bearing formation and low pressure gradient. The lower the intrinsic permeability in marine sediments, the later the water flow rate reaches the peak production. And the space interval of the production wellbore should be enlarged by an increase of the intrinsic permeability. The stable period of natural gas production enhances, and the water flow rate reduces with the increase of bottom-hole pressure in production wellbores. The main reason is the slow offshore NGH dissociation under the low producing pressure and the restriction of heat conductivity under the low temperature.

Removal of NO from Gas by Corona Discharge with H2O2 Solution Oxidation

2013 ◽  
Vol 742 ◽  
pp. 323-326 ◽  
Author(s):  
Ji Wu Li ◽  
Zhi Peng Tang ◽  
Jie Yu
Keyword(s):  
Corona Discharge ◽  
Water Flow ◽  
Flow Rate ◽  
Flue Gas ◽  
Gas Flow ◽  
Supply Voltage ◽  
Removal Rate ◽  
Water Flow Rate ◽  
Gas Flow Rate ◽  
No Removal

The effects of the supply voltage, water flow rate, concentration of H2O2absorption and flue gas flow rate on NO removal rate were studied. The chemical reaction mechanism of NO removal was discussed. It was concluded that the NO removal rate increased the increasing of supply voltage, water flow rate and concentration of H2O2, and decreased with the increasing of the flue gas flow rate on the experimental conditions. On the synergy with corona discharge and H2O2solution oxidation, NO removal rate reached 60.2%.

Experimental Study on the Desalination System Using Humidification-Dehumidification Technology

2020 ◽  
Vol 1008 ◽  
pp. 177-185
Author(s):  
Hamed Abbady ◽  
Mahmoud Salem Ahmed ◽  
Hamdy Hassan ◽  
A.S.A. Mohamed
Keyword(s):  
Water Temperature ◽  
Water Flow ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Cooling Water ◽  
Operating Conditions ◽  
Outlet Temperature ◽  
Major Objective ◽  
Cooling Water Flow Rate ◽  
Output Ratio

In this paper, an experimental work studies the principal operating parameters of a proposed desalination process using air humidification-dehumidification method. The major objective of this work is to determine the humid air behavior through the desalination system. Different operating conditions including the effect of the water temperature at the entry to the humidifier, the ratio of the mass of water to the air, the air/water flow rate, and cooling water at entry the dehumidifier on the desalination performance were studied. The results show that the freshwater increases with increasing the water temperature at the inlet of the humidifier, the ratio of the mass of water to air, and cooling water flow rate in the dehumidifier. Cooling water outlet temperature at the condenser increases with increasing the water temperature at humidifier inlet. Also, it decreases as increasing cooling water flow rate while the ratio of the mass of water to air achieves the highest productivity and gained output ratio (GOR). The achieved mass ratio (MR) is 4.5 and the mass flow rate of air is 0.8 kg/min.

scholarly journals Numerical Investigation on the Effect of Flow Parameters in CO2 Capturing Using Aqueous MEA Absorbent in HFMC Systems

2020 ◽  
Keyword(s):  
Flow Rate ◽  
Liquid Flow ◽  
Gas Flow ◽  
Liquid Flow Rate ◽  
Hollow Fiber Membrane ◽  
Diffusion Method ◽  
Co2 Removal ◽  
Gas Flow Rate ◽  
Human Environment ◽  
Co2 Capturing

Nowadays, CO2 as the product of fossil fuel combustions, is polluting the air and the human environment, and it causes global warming. To reduce the negative effect of CO2 presence, it should be removed from the air by capturing methods. Hollow fiber membrane contactor (HFMC) system is one of the most efficient method for CO2 capturing than the other feasible capturing methods. In the present paper an HFMC absorbing system has been simulated using COMSOL Multiphysics software and the effect of flow rates of gas and liquid on the amount of CO2 removal has been studied. Aqueous solution of Mono-ethanolamine (MEA) is entered as the absorbent liquid in the tubes, and CO2 is removed from the shell side by the diffusion phenomena by participating in the chemical reaction with MEA. The results show that the higher liquid flow rate the higher %CO2 removal from the inserted gas. Against this result, the percentage of CO2 removal decreases with increasing the gas flow rate as expected. Higher gas flow rate leads the gas velocity to higher values and less possibility of absorbing by the diffusion method. The rate of the CO2 removal variation with liquid flow rate is higher than the CO2 removal variation whit the gas flow rate.

scholarly journals Research of the Influence of Temperature Factor on Express Control of Natural Gas Combustion Heat

2020 ◽  
pp. 44-50
Author(s):  
O. E. Seredyuk ◽  
N. M. Malisevich
Keyword(s):  
Natural Gas ◽  
Temperature Measurement ◽  
Flow Rate ◽  
Gas Flow ◽  
Flame Temperature ◽  
Operating Conditions ◽  
Gas Flow Rate ◽  
Combustion Heat ◽  
Gas Combustion ◽  
Functional Scheme

The article is devoted to the study of the influence of the qualitative and quantitative composition of gas environments on the flame temperature of the combusted gas at different values of gas flow rate and changes volume ratio gas-air in its combustion. The functional scheme of the developed labo­ratory stand (Fig. 1), which provides temperature measurement during combustion of natural gas or propane-butane mixture, is considered. The design of the developed burner is described and the expe­rimental researches are carried out when measuring the flame temperature of the combusted gas during the operation of the laboratory stand. The opera­ting conditions of different thermocouples in measuring the temperature of the flared gas are investigated (Fig. 2). The temperature instability in the lower and upper flames was experimentally determined (Fig. 3) and its difference from the reference data [12, 13]. The measurement of the flame temperature with a uncased thermocouple and two thermocouples of different types with protective housings is reali­zed. Methodical error of temperature measurement by different thermocouples was estimated (Fig. 5). An algorithm for the implementation of measurement control in determining the heat of combustion of natural gas according to the patented method is outlined [11]. Experimental studies of temperature changes of combusted gas mixtures at different gas flow rates and different ratios with air, which is additionally supplied for gas combustion, were carried out (Figs. 4, 7). The computer simulation (Figs. 6, 8) of the change in the flame temperature was performed on the basis of the experimental data, which allowed to obtain approximate equations of the functional dependence of the flame temperature on the gas flow rate and the ratio of the additional air and gas consumption. The possibility of realization of the device of express control of the heating value of natural gas by measuring the combustion temperature of the investigated gases, which is based on the expe­rimentally confirmed increase in the flame temperature of the investigated gases with increasing their calorific value, is substantiated (Fig. 9). The necessity of further investigation of the optimization design characteristics of the burner and the operating conditions of combustion of the gases under rapid cont­rol of their combustion heat was established (Fig. 9).

scholarly journals Optimization of Working Conditions for Perovskite-Based Gas Sensor Devices by Multiregression Analysis

2019 ◽  
Vol 2019 ◽  
pp. 1-19 ◽  
Author(s):  
Fabio Zaza ◽  
Vanessa Pallozzi ◽  
Emanuele Serra
Keyword(s):  
Carbon Monoxide ◽  
Mathematical Models ◽  
Gas Sensor ◽  
Flow Rate ◽  
Gas Flow ◽  
Resource Depletion ◽  
Productive Efficiency ◽  
Operating Conditions ◽  
Gas Flow Rate ◽  
Sensor Devices

Environmental degradation and resource depletion drive scientific research priorities to develop technologies for sustainable productive systems. Among them, chemical sensing technology plays a key role for regulating energetic, ecological, and productive efficiency by monitoring and controlling the industrial processes. Semiconducting metal oxide sensors are particularly attractive technology because of their simplicity in function, small size, and projected low cost. The aim of this work is to synthesize Ti-substituted lanthanum ferrite perovskite, LaFe0.8Ti0.2O3, in order to develop a resistive sensor device for monitoring carbon monoxide. Since sensor performances are affected by experimental factors, such as temperature, target gas concentration, and gas flow rate, the aim of the authors was to define the optimum working condition by performing multiple regression analyses. The investigated ranges of operating conditions were temperature from 300 to 480°C, carbon monoxide concentration from 100 to 200 ppm, and inlet-gas flow rate from 40 to 100 cm3/min. The results confirm that the applied systematic analysis is a powerful method for studying the direct and indirect effects of every experimental factor on sensor performance and for computing mathematical models with predictive ability, that are useful tools for defining the optimum chemiresistors’ operating conditions. In addition, mathematical models are able to be used as multiple-factor surface calibration for restive gas sensor devices.

scholarly journals Investigation of the influence of operation conditions on the discharge of PCM ceiling panels.

2019 ◽  
Vol 111 ◽  
pp. 03021
Author(s):  
José Quesada Allerhand ◽  
Ongun Berk Kazanci ◽  
Bjarne W. Olesen
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Thermal Environment ◽  
Water Discharge ◽  
Water Flow Rate ◽  
Water Circulation ◽  
Operating Conditions ◽  
Cooling Period ◽  
Operation Conditions ◽  
Office Rooms

The aim of this study was to determine favorable operation conditions for ceiling panels containing phase change materials (PCM) for cooling applications in office rooms. A recently renovated room in the Technical University of Denmark was used to have realistic boundary conditions. Using TRNSYS 17, the performance of the PCM panels during the cooling season in passive operation, discharge by air, and discharge by water circulation were investigated. A set of simulations were performed during a representative week in the cooling period. The room was simulated with no climatic systems, PCM without active discharge, ventilation during occupied hours only, and PCM with ventilation during occupied hours. Afterwards, two discharge methods were investigated, night ventilation at different flow rates and water circulation in pipes embedded in the panels. A parametric analysis was performed to identify the influence of operation factors in the thermal environment of the room. The parameters studied were the water flow rate, supply water temperature and circulation schedule as well as the conductivity of the PCM. After selecting different operating conditions of the water discharge, simulations were performed from May to October to observe the performance of the selected operation conditions. The results show that the PCM is more effective to provide adequate indoor thermal conditions if it is discharged actively by means of water. The parameters that affect the thermal indoor environment the most are the water circulation schedule, the water supply temperature, and the PCM thermal conductivity. The water flow rate did not have a significant influence. The study shows the importance of selecting an appropriate operation and control strategy for the PCM system. The process used in the study can be potentially used as a procedure for the design of similar climatic systems to determine if active discharge of the PCM is needed and if yes, which discharge method is needed.

scholarly journals Particle deposition characteristics in entrained flow coal gasifier

2012 ◽  
Vol 16 (5) ◽  
pp. 1544-1548
Author(s):  
Sheng Liu ◽  
Ying-Li Hao
Keyword(s):  
Numerical Simulation ◽  
Flow Rate ◽  
Particle Deposition ◽  
Gas Flow ◽  
Water Flow Rate ◽  
Deposition Process ◽  
The Other ◽  
Central Channel ◽  
Gas Flow Rate ◽  
Coal Gasifier

Cold state experiment and numerical simulation are carried out to study particle deposition process. The deposit mass can be divided into two parts, one directly collides with the wall and the other is brought by the backflow. The deposit flux increases with the increase of gas flow rate or water flow rate or both, and decreases with the increase of the central channel gas flow rate.

scholarly journals Experimental Study for Biogas Upgrading by Water Scrubbing under Low Pressure

2015 ◽  
Vol 9 (1) ◽  
pp. 34-38 ◽  
Author(s):  
Li Huang ◽  
Chunyao Qing ◽  
Hongge Tao ◽  
YanJin Wang ◽  
Xinping Liu
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Volume Fraction ◽  
Removal Rate ◽  
Rural China ◽  
Water Flow Rate ◽  
Normal Pressure ◽  
Low Pressure ◽  
Flow Rate Ratio ◽  
Biogas Upgrading

Biogas fuels is effective to alleviate the problem of energy shortage and ecological environment for sustainable developing in rural China. But CO2 and other impurity in biogas will impede its use for generating high quality energy. In this paper, water scrubbing technology has been used for biogas upgrading under low scrubbing pressure, and the influence of CO2 removal rate and CO2 solubility caused by different experimental parameters including the feed gas flow rate, water flow rate and scrubbing pressure were examined, and the experiments dates were analyzed by SPSS17.0, and then the corresponding mathematical models were established. The result showed that, under the three scrubbing pressure level(with normal pressure, 0. 15 Mpa and 0. 3 Mpa), the improve rate of CH volume fraction increased about 15%, and CO2 volume fraction declined about 20% when scrubbing pressure raised in each level, and under 0.3 Mpa of pressure, with 0.28 of flow rate ratio of gas and liquid, CO2 removal rate gotten as high as 73.14%.So the method of water scrubbing under low pressure could be used for biogas preliminary upgrading processing when there is rich of water.

scholarly journals Development of a New Phase Change Biogas for Renewable Energy Storage System

KnE Energy ◽  
2015 ◽  
Vol 1 (1) ◽  
pp. 115 ◽  
Author(s):  
Muhammad Kismurtono ◽  
Satriyo K.W ◽  
Roni M ◽  
Dan Wahyu A. R
Keyword(s):  
Water Column ◽  
Flow Rate ◽  
Gas Flow ◽  
Storage System ◽  
Packed Column ◽  
Isothermal Condition ◽  
Chicken Manure ◽  
Cow Dung ◽  
Co2 Removal ◽  
Gas Flow Rate

<p>The aims of this study are to decrease the concentration of organic matter are to cooking and generate electricity from biomass. The methods were the preparation of fixed dome reactor, unit of CO2 removal, preparation and fermentation of cow dung, water, chicken manure running and sampling periodically every one hour and data analysis. Therefore, CO2 must be eliminated from the biogas and the corresponding phenomena of mass transfer with chemical reaction of packed column have to be studied. This study assumed steady state and isothermal condition. The system studied consists of packed column (stainless steel 304) 10 cm in diameter filled with 2 mm in diameter bead (zeolite) to the height of 80 cm and storage system of methane.. The gas flow rate was held constant at F = 800 ml/s, liquid flow rate (L) was 100 ml/s, pressure (P) was varied from: 350 to 700 mm water column (WC), and the concentration of aqueous NaOH 1.5 M inlet absorbent was held constant. The results showed that the percentage of absorbed CO2 can be enhanced by increasing the pressure. Using column with packing height of 100 cm. gas flow rate of 800 ml/s, using absorbent containing NaOH1.5 M with flow rate: 100 ml/s and at pressure of 350 mm water column (WC) and temperature of 30o C , the percentage recovery of CO2 reacted was 85%. The biogas then will be used to generate electricity.</p><p><strong>Keywords</strong>: Aqueous NaOH 1.5 M, Biogas purification, CO2 removal, Storage system</p>

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