The circulation rates for amine systems can be determined from the acid gas flow rates by selecting a solution concentration and an acid gas loading. The following equations can be used: For design, the following solution strengths and loadings are recommended to provide an effective system without an excess of corrosion: For the recommended concentrations… Read More »
The iron-sponge process generally uses a single vessel to contain the hydrated ferric oxide wood shavings. A drawing of an iron-sponge unit showing typical provisions for internal and external design requirements was presented in Figure 7-3. The inlet gas line should have taps for gas sampling, temperature measurement, pressure measurement, and for an injection nozzle… Read More »
Each of the previous treating processes has advantages relative to the others for certain applications; therefore, in selection of the appropriate process, the following facts should be considered: 1. The type of acid contaminants present in the gas stream. 2. The concentrations of each contaminant and degree of removal desired. 3. The volume of gas… Read More »
Gas permeation is based on the mass transfer principles of gas diffusion through a permeable membrane. In its most basic form, a membrane separation system consists of a vessel divided by a single flat membrane into a high- and a low-pressure section. Feed entering the high-pressure side selectively loses the fast-permeating components to the low-pressure… Read More »
The Ryan-Holmes distillation process uses cryogenic distillation to remove acid gases from a gas stream. This process is applied to remove CO2 for LPG separation or where it is desired to produce CO2 at high pressure for reservoir injection.
Sour gas sweetening may also be carried out continuously in the flowline by continuous injection of H2S scavengers, such as amine-aldehyde condensates. Contact time between the scavenger and the sour gas is the most critical factor in the design of the scavenger treatment process. Contact times shorter than 30 sec can be accommodated with faster… Read More »
The molecular sieve process uses synthetically manufactured solid crystalline zeolite in a dry bed to remove gas impurities. The crystalline structure of the solids provides a very porous solid material with all the pores exactly the same size. Within the pores the crystal structure creates a large number of localized polar charges called active sites.… Read More »
The zinc oxide process is similar to the iron sponge process. It uses a solid bed of granular zinc oxide to react with the H2S to form water and zinc sulfide: The rate of reaction is controlled by the diffusion process, as the sulfide ion must first diffuse to the surface of the zinc oxide… Read More »