Greenhouse gases, air scrubbing technology, nitrogen oxides, sulfur oxides introduction an innovative proprietary process, using a different application for chlorine dioxide than has been previously used in nox and so 2 scrubbing, has been developed and is now on the market. The conventional requirement for carrying out gas absorption operation is the. An example of the uses of absorption and stripping is a gas treatment plant, shown in figure 8. A solvent comparison study by anusha kothandaraman submitted to the department of chemical engineering on may 20, 2010 in partial fulfillment of the requirements of the degree of doctor of philosophy in chemical engineering practice abstract. Nahle scientist, university professor and director of scientific research division at biology cabinet mexico abstract. Natural gas purification technologies major advances for co 2 separation and future directions 237 again, according to the international energy outlook 2010 on its june 2011 release, natural gas was reported to be one of the main ener gy sources for industrial and electrical power generation applications. The main points to note about this operation are as follow. The absorption of contaminants from the gas to the solvent depends on gas velocity, liquid gas distribution, and the tube surface condition. The solvent is often recovered in a subsequent stripping or. It is shown that the counter current process is superior to the co current process for the same set of parameters and operating conditions.
Gas absorption in a packed tower was the focal point of this experiment, and the tower was used. Chemical engineering department, federal university of technology, minna, nigeria. In co current absorption, there is no minimum liquidto gas ratio and it is less efficient than counter current operation. Gas liquid interaction in the molecular level, the twofilm theory. The result obtained is to be compared between theoretical values that has been calculated. Two methods of operation in gas absorption exist, which are counter current and co current operations.
Gas absorption in cocurrent flow connecting repositories. Oct 10, 2015 gas absorption is usually carried out in vertical counter current columns. Industrial absorption current status and future aspects robin thiele and janmartin lo. Determination of the total emissivity of a mixture of gases containing 5% of water vapor and 0. To characterize the absorption a few experiments with so 2 absorption were made. The advantage of concurrent operation is the lack of flooding limitation, and high gas flow rate can. The effects of lv liquid gas ratio and f gas phase loading factor on the so2 absorptivity were both investigated. Sep 19, 2011 a co current operation for so2 absorption by water was performed in a laboratoryscale packed column. Countercurrent exchange is a mechanism occurring in nature and mimicked in industry and engineering, in which there is a crossover of some property, usually heat or some chemical, between two flowing bodies flowing in opposite directions to each other. The absorbed substence is washed out by the solvent and leaves the absorber at the bottom as a liquid solution. The species transferred to the liquid phase are referred to as solutes or absorbate.
Also, in the analysis of gas absorption, we will need to know the minimum liquid rate that can be used for a given separation, i. One ghg mitigation alternative is postcombustion carbon dioxide co2 capture using chemical absorption, which is a promising alternative due to its proven technology and the relative ease to install on existing coalfired power plants. An analytical study of laminar cocurrent flow gas absorption. The report has resulted due to the large amounts of carbon dioxide released into the atmosphere, mainly from fossilfired power plants.
Gas absorption lab report abstract the gas absorption. Natural gas purification technologies major advances for co 2. Gas absorption is usually carried out in vertical counter current columns. Most absorption or stripping operations are carried out in counter current flow processes, in which the gas flow is introduced in the bottom of the.
The effect of cocurrent and countercurrent gas shear on entrance. An analytical study of laminar cocurrent flow gas absorption through a parallelplate gasliquid membrane contactor article in journal of membrane science 2781. Pdf che504 lab report on gas absorption l8 2018 nurlina. Modeling gas absorption worcester polytechnic institute. Feb 06, 2018 where the transfer vector has the correct signal to be applied in the equation. Among the most studied cases are the absorption of co. Printed in great britain mass transfer in packed columns. Gas enters at the bottom or top to produce counter current or co current flow.
This immediately puts the coldest material in contact with the hottest gas in the kiln, resulting in a rapid initial temperature change. Packed tower with rashchig rings packings is used in the experiment. The solvent is fed at the top of the absorber, whereas the gas mixture enters from the bottom. I get a reasonable solution when simulating it in co current volume flow vl0, but when trying in counter current vl co 2 from a gas stream, containing co 2 and air. Additionally, a computer modeling program, comsol multiphysics, was studied as an alternative to analyze and understand the fundamentals of absorption. Although absorption has reached a high level in theoretical. Gas absorption is mass transfer operation where one or more species is removed from a gaseous stream by dissolution in a liquid. Cocurrent flow pipeline reactors would have several advantages for gas. An analytical as well as a numerical method to determine the steadystate solution of the corresponding convectiondiffusion equation for the two flowfields is presented.
Osmotically driven membrane processes approach, development and current status, chapter. Membrane gas absorption and stripping process is a gas liquid contacting. Comparison of cocurrent and countercurrent flow fields on. Moses aderemi olutoye and elizabeth jumoke eterigho.
Pdf is countercurrent flow always better than cocurrent. This separation equipment centers on distillation and gas absorption, the two most. Background research on the description of the absorption process, uses, and common absorbateabsorbent systems for carbon dioxide is presented. Operating line for gas absorption lies above the equilibrium line. Introduction gas absorption is a process in which the soluble parts of a gas mixture are transferred to or dissolved in a liquid. Abstract the absorption of carbon dioxide into aqueous ammonia solution using packed column was investigated. Co current air flow, which is also referred to as parallel flow, is when the products of combustion flow in the same direction as the material. Finally, if the hzs is present only in traces, we can remove these traces with an aqueous solution of. Full text of gas absorption in co current flow see other formats gas absorption in co current flow by linchuan cha b.
Abstract a mathematical model is presented for gas absorption accompanied by chemical reaction in downflow cocurrent packed columns. From the values of volume of co 2 absorbed and applying a series of equations, the values of overall mass transfer coefficient were obtained for each condition of system flow rates of water, air and co 2. Membrane gas absorption and stripping process is a gasliquid contacting. Sharma department of chemical technology, university of bombay, matunga road, bombay400019, india received 10 december 1973 abstractthe theory of gas absorption accompanied by fast pseudom order reaction was used to obtain values of. Greenhouse gas ghg emission control has been extensively studied over the past decade.
Department of energy and process engineering sept 20 2 absorption definition absorption, in chemical technology, is a process in which atoms or molecules transfer from a gas phase into a liquid phase. Full text of gas absorption in cocurrent flow see other formats gas absorption in cocurrent flow by linchuan cha b. Stripping coupling of absorber and stripper equipments eqqpguilibrium curve and operating line. Predictions of average film thickness and mass transfer coefficients in the entrance region of gas absorption with high cocurrent and countercurrent gas fl. The experiment was conducted using an armfield uop7 gas absorption column filled with 10 mm x 10 mm raschig rings. Determination of the total emissivity of a mixture of gases.
In this experiment in particular, the absorptive capabilities of two kinds of packings, dumped and structured, were compared. Countercurrent gas absorption separation processes. Pdf penetration theory solution for gas absorption and. Study of co2 absorption and desorption in a packed column. A mathematical formulation for a laminar cocurrent gas absorption process was developed in a parallelplate gasliquid membrane contactor that indepe. Professor department of energy and process engineering. Gas absorption in horizontal cocurrent bubble flow scott 1966. Dynamic modelling and control of mea absorption processes for. Absorbers visual encyclopedia of chemical engineering. The model incorporates an axial dispersed plug flow for the bulk gas and dynamic liquid phases and a fickian type equation for the stagnant liquid phase. In this diploma work, the absorption of co 2 in different liquid solutions was studied by gas absorption in a randomly packed column.
Packed column is one of the commonly used gas absorption equipment. The difference between absorption and adsorption is that in absorption the molecules are taken up by. Study of co 2 absorption and desorption in a packed. However, design data are lacking, particularly for absorption. The absorptivity for co current increased with the increase of lv and the percentage of absorptivity increase at higher lv is larger. Packed column, modeling, simulation, gas absorption, qbasic. Modelling of a gas absorption column for co 2naoh system under unsteadystate regime. Packed column can be operated in cocurrent as well as counter currently. Penetration theory solution for gas absorption and chemical reaction in cocurrent and countercurrent flow wettedwall columns. Design of packed column absorber based on the individual.
Absorption and stripping in addition to the distillation, there are other unit operations used for separating substances absorption is the unit operation in which one or more components of a gas stream are removed from the gas mixture by being absorbed onto a nonvolatile liquid called a solvent in this case, the solvent is the separating. The main objective of the experiment is to examine. Nox scrubbing technology breakthrough products finishing. The ideal operating conditions for the tower were determined in the first week, when the column was run with only water and air. Pdf on mar 28, 2018, julio romero figueroa and others published. This report examines different scenarios involving a moving bed adsorption process and shows why in some cases a cocurrent flow arrangement is an improvement over equivalent countercurrent. Modeling of a gas absorption column for co2naoh system under. The solvent enters at the top and falls down the tube as a film. This report examines different scenarios involving a moving bed adsorption process and shows why in some cases a co current flow arrangement is an improvement over equivalent counter current.
100 1406 728 1101 1127 269 1114 1376 45 1021 469 1316 266 1169 890 565 1370 574 156 1236 627 668 1441 312 114 554 827 1112 17 814 1460 151 1365 512 732 1413 1416 676