Ammonia, absorption

Puriftcatioa of the cracked gas is accompHshed by water scmbbiag, an electrostatic precipitator, and Hquid ammonia absorption. 

E] Ammonia absorption into water from air at 70 F. Gas-film resistance controls. Thin-waUed polyethylene Raschig rings and 1-inch Intalox saddles. Fit 25%. See Reiss for fit. Terms defined as above. 

Note that the group on the left side of Eq. (14-182) is dimensionless. When turbulence promoters are used at the inlet-gas seclion, an improvement in gas mass-transfer coefficient for absorption of water vapor by sulfuric acid was obsei ved by Greenewalt [Ind. Eng. Chem., 18, 1291 (1926)]. A falhug off of the rate of mass transfer below that indicated in Eq. (14-182) was obsei ved by Cogan and Cogan (thesis, Massachusetts Institute of Technology, 1932) when a cauTiiug zone preceded the gas inlet in ammonia absorption (Fig. 14-76). 

Steam and cooling water requirements for ammonia absorption refrigeration systems are shown in Table 1 for single-stage and two-stage units. The tables are based upon cooling water to the condenser of 85°F with 100°F condensing temperature. Water from the condenser is used in the absorbers. 

Steam and Cooling Water Required for Ammonia Absorption Refrigeration Systems... 

Example 9-12 Design of Ammonia Absorption Tower, figures 9-74A and B... 

Figure 9-84. Effect of water temperature on ammonia absorption. Used by permission of Chin-Yling Wen, thesis. West Virginia University (1953).

Figure 11-14. Ammonia absorption system typical flow diagram. (Used by permission Frick , Div. of York International.)...

This type of system is similar in basic principle to the ammonia absorption, and some of the advantages are the same ... 

York Ammonia Absorption Systems, Bui. 40454-2, York Corp., York, PA (1940). 

Bogart, M., Ammonia Absorption Refrigeration in Industrial Process, Gulf Publishing Co., Houston, Texas (1981). 

Drivers for Performing Ammonia Absorption in Micro Reactors... 

This reaction serves as a known model reaction to characterize mass transfer efficiency in micro reactors [7]. As it is a very fast reaction, mass transfer can be analysed solely The analysis can be done simply by monitoring color changes from pH indicators. Ammonia absorption in aqueous acidic solutions generally is even faster than carbon dioxide absorption in alkaline solutions. 

Beneficial Micro Reactor Properties for Ammonia Absorption... 

Ammonia absorption is used for the above-mentioned purpose and hence is an analytical tool for judging micro-reactor performance [7]. 

GL 28] [R 2] [P 30] Ammonia absorption in dilute acidic solution containing Cresol Purple indicator was rapid, as expected [7]. By appropriate choice of processing parameters, neutralization was achieved close to the gas/liquid contacting zone or distributed over the full contact length. This is evidence for having controls by both solution and gas-phase transport. 

Figure 5.203. Steady-state ammonia absorption column.

The advantage of the H — x chart lies in the fact that the heat quantities required for the distillation are clearly indicated. Thus, the higher the reflux ratio the more heat must be removed per mole of product, and point N rises. This immediately shows that both qc and Qb are increased. The use of this method is illustrated by considering the separation of ammonia from an ammonia-water mixture, as occurs in the ammonia absorption unit for refrigeration. 

RUHEMANN, M. Trans. Inst. Chem. Eng. 25 (1947) 143. The ammonia absorption machine. Ibid. 152. A study of the generator and rectifier of an ammonia absorption machine. 

Ammonia absorption refrigeration is particularly applicable when low level heat is available for operation of the stripper reboiler and power costs are high. Steam jet refrigeration is the large scale system of choice when chilled water is cold enough, that is above 40T or so. 

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