Ethanolamine processes Absorber

After cooling, the gas enters the amine absorber where essentially all of the hydrogen sulfide is removed, but only a portion of the carbon dioxide is coab.sorbed. The rich amine solution is stripped of acid gas in the regenerator by application of indirect heat supplied by a steam heated rehoiler, and the acid gas is returned to the Claus unit. This portion of the process is quite similar to the conventional selective ethanolamine processes discussed in Chapter 2. 

Ethanolamines are important absorbents of acid gases in natural gas treatment processes. Another major use of ethanolamines is the production of surfactants. The reaction between ethanolamines and fatty acids... 

It should also be noted that absorption has been used to remove contaminants from natural gas streams during processing. In the early 1930s di-ethanolamine was used as an absorbent for both hydrogen sulfide and carbon dioxide.This process became known as the Gerbitol Process. Other alkanolamines such as mono-ethanolamine and di-isopropanolamine have also found wide application. 

Sedghi, S.M., Brisson, J., Rodrigue, D., Iliuta, M.C. 2011. Chemical alteration of LDPE hollow fibers exposed to mono-ethanolamine solutions used as absorbent for COj capture process. Sep. Purif. Technol. 80 338-344. 

Qatar Petroleum s NGL-3 plant Gas Sweetening Facility treats 1020 mmscfd of Non-associated Natural gas containing approx. 0.6 % H2S and 2.4 % C02 in two trains of Acid gas removal units (AGRU) using aqueous Methyl Di-Ethanolamine (MDEA) solution absorbent. Recovered Acid gas is processed in a single train Sulphur Reeovery Unit (SRU) with two catalytie conversion stages. 

Most of the waste waters from oil refinery plants arise from stripping of acidic waste gases that are produced by distillation or gas production. In this process, the H2S and CO2 components are absorbed by a counterflow of amine solutions (mono-ethanolamine (MEA) or diethanolamine (DEA)). The absorption solution is recycled after thermal removal of the acidic gases. The heat exchangers used in this process are subjected to the conditions given as an example in Table 7. 

The Townsend process, which was disclosed by Reid and Townsend (1958) and Townsend and Reid (1958), and described in a patent granted to Townsend (1965), was proposed as a method for high-pressure natural gas desulfurization and elemental sulfur production in one operation, thus combining the conventional process of absorbing hydrogen sulfide in an aqueous alkaline solution (e.g., ethanolamine), followed by processing the stripped H2S in a Claus-type sulfur plant. However, the process is claimed to be equally applicable to the treatment of acid-gas streams, such as the effluents from ethanolamine plant regenerators. In this application, the Townsend process would be a substitute for the Claus plant. 

The UCBSRP process is claimed to have significantly lower capital and operating costs than the combination of an ethanolamine absorber/stripper unit plus a Claus plant plus a SCOT tail gas unit. Most of the energy consumed by the process is connected with the recovery and fractionation of propane and heavier hydrocarbons. Approximately 92% of the electrical power usage and 89% of the cooling requirements are associated with hydrocarbon recovery and separation (Sciamanna et al., 1988). The heat generated by the sulfur furnace more than offsets the heat demand required by the desulfurization of the natural gas stream. 

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