Absorber multistage

C02 can be separated from the shifted syngas stream in a Selexol type of absorber. Multistage flash drums can be used to extract C02 from absorbed solvents at various pressure levels typically ranging from atmospheric pressure to 400 psi. The C02 product stream is usually compressed to high pressure (llObar) for geologic storage or enhanced oil recovery. 

Rose et al. (1958) and Hanson and Sommerville (1963) have applied relaxation methods to the solution of the unsteady-state equations to obtain the steady-state values. The application of this method to the design of multistage columns is described by Hanson and Sommerville (1963). They give a program listing and worked examples for a distillation column with side-streams, and for a reboiled absorber. 

The most common enzyme label in IAs and ILAs is horseradish peroxidase (HRP) due to its high turnover number, the sensitivity of its colorimetric and luminometric assays, its suitability for diverse conjugation procedures, and relative small molecular size (40 kDa compared to 100 kDa for alkaline phosphatase). The use of labeled enzymes as tracers allows qualitative and quantitative assay procedures that are not dependent on instrumentation. Thus absorbance, luminescent, electrochemical, or multistage assay systems could be performed (Fig. 10) [23]. 

Absorption is another gas-liquid process with two phases. Packed bed absorbers have three phases when also taking the solid packing of the column into consideration. Both continuous, i.e., packed bed, and multistage absorption are common in the chemical and biological industry. 

We assume that in our system the component A is absorbed from the gas phase into the liquid phase. Figure 6.17 describes the jth stage (or tray) of a multistage system in terms of the following variables ... 

Another multistage method included in the program is the absorption and stripping factor method of Edmister (25). ASFPH, as it is called, can simulate simple and reboiled absorbers and also fractionators. The method used does not have very good convergence characteristics however, it is of value in studying plant performance data. 

The main objective of absorption processes is the removal of one or more components from a gas stream using selective solvents. Figure 3 shows a typical absorption process in which, with the help of a selective solvent (absorbent), the undesired compounds (in this case, HjS, COj) are removed from the raw gas (in this case, natural gas) in a multistage countercurrent process. While the purified gas leaves the absorber (saturated with the selective solvent), the absorbent is regenerated in a second column (desorber) and is recycled to the absorber. In the case of absorption, one can distinguish between physical and chemical absorption processes. In the case of physical absorption, the absorber is operated at high pressures and low temperatures while for the desorber the opposite conditions are used. 

Phototransformation of polymers is, in general case, complex multistage process. Ultraviolet absorbers, ultra-violet shields, suppressors of excited states, inhibitors-acceptors of radicals and inhibitors, destroying products, in which photobranching takes place, are used to... 

Mathematical solution of absorbers, like other multistage separation processes, involves setting up material and energy balance equations and vapor-liquid equilibrium relations that describe the entire column. The resulting set of simultaneous equations is then solved by some suitable technique. 

Distillation columns and other multistage columns generally require heat addition and/or removal, which normally take place at the reboiler and/or condenser. For a variety of reasons, it may be desirable in certain types of columns to add or remove heat at intermediate trays aside from the condenser and reboiler. Examples of such columns include demethanizers that utilize a side reboiler alongside the bottom reboiler, multi-product columns where intermediate condensers are associated with some of the side products, and absorber intercoolers used for partial removal of the heat of absorption. The method most commonly employed for exchanging heat between a column tray and a heat source or sink is the pumparound, where a fluid is drawn from the tray, sent to a heat exchanger, then pumped back to the column. The following sections pertain to the various applications of side heaters and coolers and the different types of pumparounds. 

Dietary cobalamin is absorbed from animal food sources by a multistage process shown in Figure 42-2. Cobalamin absorption requires the presence of a protein (the intrinsic factor, IF) secreted from the parietal cells of the stomach to bind cobalamin and aid in its absorption in the ileum. The protein is released into the ileum while the cobalamin is transported to the blood stream where it binds specialized serum proteins, the transcobalamins (TC), which transport it to other tissues such as liver where cobalamin can be stored (usually several milligrams are present in liver). In the absence of the intrinsic factor... 

Absorber Using the nomenclature introduced for multistage cascades, and the results of Example 3.7 ... 

The BP and SR methods for vapor-liquid contacting converge only with difficulty or not at all for separations involving very nonideal liquid mixtures (e.g., in extractive distillation) or for cases where the separator is like an absorber or stripper in one section and a fractionator in another section (e.g., a reboiled absorber). Furthermore, BP and SR methods are generally restricted to the very limited specifications stated above. More general procedures capable of solving ail types of multicomponent, multistage separation problems are based on the solution of all the MESH equations, or combinations thereof, by simultaneous correction (SC) techniques. 

Kremser originated the group method. He derived overall species material balances for a multistage countercurrent absorber. Subsequent articles by Souders and Brown, Horton and Franklin, and Edmister improved the method. The treatment presented here is similar to that of Edmister for general application to vapor-liquid separation operations. Another treatment by Smith and Brinkley emphasizes liquid-liquid separations. 

The extraction of heavy hydrocarbons from the gas is conducted in a special multistage absorber equipped with devices for condensate deflation. A higher efficiency of extraction of heavy hydrocarbons from the separated gas and a higher quality of condensate stabilization is achieved as the result. 

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