Carbon dioxide removal technologies

Carbon dioxide removal by reactive absorption in amine solutions is also applied on the commercial scale, for instance, in the treatment of flue gas (see later in this chapter). Another possible application field of the technique is gas desulfurization, in which H2S is removed and converted to sulfur by means of reactive absorption. Aqueous solutions of ferric chelates (160-162) as well as tetramethylene sulfone, pyridine, quinoline, and polyglycol ether solutions of S02 (163,164) have been proposed as solvents. Reactive absorption can also be used for NOx reduction and removal from flue or exhaust gases (165,166). The separation of light olefins and paraffins by means of a reversible chemical com-plexation of olefins with Ag(I) or Cu(I) compounds in aqueous and nonaqueous solutions is another very interesting example of reactive absorption, one that could possibly replace the conventional cryogenic distillation technology (167). 

The design of the system clean-up operations and the selection of appropriate carbon dioxide extraction technology is dependent on the gasifier type and the amount of non-synthesis gas present which has to be removed. 

Feron PHM, Jansen AE, and Klaassen R, Membrane technology in carbon dioxide removal, TNO Environmental and Energy Research, Publication No. 92-075, 1992. 

P.L Bondor, applications of carbon dioxide in enhanced oil recovery. Proceedings of the First International Conference on Carbon Dioxide Removal, Amsterdam 4-6 March (1992) 579-586 Liu Deshun, Ouyang Lihui and Zhang Yanlin, Feasibility of AIJ Pilot Options CFBC CHP in China, Case Study Cogeneration power plant by using CFBC boiler. International Conference on Technology for AIJ, May 26-29 (1997), Vanacouver, Canada. 

Suda, T., Fujii, M., and Yoshida, K. Development of flue gas carbon dioxide recovery technology. Proceedings of the First International Conference on Carbon Dioxide Removal. Amsterdam, 1992. 

The technology developed by NKK Corporation in Japan to produce DME from coal-bed methane is shown in Fig. 4. The process scheme consists of four sections syngas reformer, carbon dioxide removal, DME synthesis, and DME separation/purification. Because the H2/CO ratios of synthesis gas obtained by the coal gasification range from 0.5 to 1.0, the gas composition is adjusted by the shift reaction so that... 

Carbon Dioxide Removal (CDR) Geoengineering techniques and technologies that remove carbon dioxide from the atmosphere in an attempt to combat climate change and global warming. 

When synthesis gas is purified for the production of pure hydrogen or anunonia, carbon monoxide is generally removed by a combination of processes, including shift conversion, carbon dioxide removal, and methanation. However, when a pure CO byproduct is desired, this approach is not applicable. Three technologies that can be employed to remove and recover carbon monoxide from synthesis and other gases are adsorption (see Chapter 12) cryogenics, as discussed in the preceding section and absorption by a liquid, which is discussed next. 

After bulk removal of carbon monoxide in the shift conversion section and of carbon dioxide in the carbon dioxide removal section, the synthesis gas still contains typically 0.2-0.5 vol% carbon monoxide and 0.01-0.2 vol% carbon dioxide. These compounds must, together with any water present, be removed quantitatively, i.e. to low ppm levels, before the gas can be admitted to the synthesis converter, because all oxygen containing compounds are poisons to the ammonia synthesis catalysts [238]. The most important technologies for this final purification are discussed in the following. 

Gas permeation constitutes the latest carbon dioxide extraction technology applied to natural gas treatment and, as such, had to gain its place against (or with) well-proven absorption-based sour gas removal processes. 

Glassy polymer membranes have been used by gas processors for more than 30 years. Their main current applieation is the removal of carbon dioxide from natural gas. Despite several obvious advantages (compactness, modularity), membrane technology still occupies a minor, though continuously growing, part in the natural gas treatment market, if compared to other conventional solvent solutions. The main limit of commercial carbon dioxide removal membranes resides in their relatively moderate CO2/CH4 selectivity. Consistent R D efforts are presently eonducted to overcome this limitation on a wide... 

Celgard LLC markets Hoechst Celanese modular membrane technology (Liqui-Cel ) to remove both oxygen and carbon dioxide from boiler MU water and FW. 

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