Desulfurization of gases

Recovery of iodine hy action of sulfur dioxide on aqueous sodium iodate Hydrogenation of vegetable oils with gaseous hydrogen Desulfurization of gases by scrubbing with aqueous ethauolamiues... 

Gianna, R., and Sisto, R., Desulfurization of gases containing hydrogen sulfide. Patent No. EP0811416. Dec. 10, 1997. 

Sublette, K. L., Microbiological desulfurization of gases. Patent No. EP0218958. 1987, April 22. 

Claus process for the desulfurization of gases, y-Ala03 catalyst deposited in the pores of the membrane. 

Lime/fly ash pozzolanic processes combine the properties of lime and fly ash to produce low-strength cementation. Kiln dust processes involve the addition of kiln dust to eliminate free liquids and usually form a low-strength solid. Lime-based processes for solidification use reactions of lime with water and pozzolanic (siliceous) materials, such as fly ash or dust from cement kilns, to form concrete, called a pozzolanic concrete. Wastes of desulfurization of gases and other inorganic wastes can be immobilized by this method. 

Drying acid gases (Mordenite) Desulfurization of gases (A,Y)... 

Increasingly stringent air quality requirements and legislation have encouraged the development of new technologies for the desulfurization of gases and transportation fuels. Electrochemical techniques have attracted the attention of researchers and refiners because of their inherent sustainability as an environmental friendly alternative. In this section, the applications of desulfurization processes for gases and transportation fuels are summarized. 

As aforementioned, electrochemical desulfurization of gases can be achieved by inner-ceU and outer-cell processes, as shown in Figure 14.1. 

Coming back to the desulfurization of gases, the original configuration of the inner-cell electrolysis process is depicted in Figure 14.2. The first step is the... 

Figure 14.2 A membrane reactor setup for desulfurization of gases.

The other type of electrochemical desulfurization of gases is the reduction of dissolved SO2 to monomeric sulfur at potentials less than 0.45 V, which is described by Eqn (14.10) (Bard, Parsons, Jordan, 1985) ... 

In recent years, there have been numerous inner-cell systems implemented for electrochemical desulfurization. Some membrane reactors for desulfurization via electrooxidation are listed in Table 14.1. Different types of electrodes and electrolytes have been used in the process of desulfurization of gases. In addition to oxidation, the reduction of the dissolved SO2 can obtain sulfur by controlling the applied potential. 

Therefore, membrane reactors for desulfurization of gases must be carefully... 

There are two types of membrane reactor processes adaptable to the electrochemical desulfurization of gases inner-cell process and outer-cell process (Figure 14.1 in Section 14.1.2.1). In an inner-cell process, the electrolyser is usually composed of a proton exchange membrane and two electrodes, in which the cathodic compartment and anodic compartment are divided by membrane. The electrodes are immersed in the electrolyte adjacent to the membrane surfaces. In the outer-cell process, there are various conhgurations able to be integrated into the existing desulfurization units for regenerating desulfurization adsorbent and recovery. 

The scaling-up of the membrane reactor for desulfurization of gases can be implemented according to the following flow sheet (Figure 14.8). 

Improvements in membrane reactor performance may also be obtained by further developments on new processes and methods for scaling up. Electrochemical desulfurization of gases by a membrane reactor is a promising and proven technology. 

In this chapter, the chemical principles of electrochemical desulfurization of gases and transportation fuels using a membrane reactor were introduced. Theory, applications, and design in the development of membrane reactors to remove sulfur-containing compounds or sulfur dioxide were described. Lastly, future trends in the developments of membrane reactors for ECDS were covered. We sincerely expect an increasing number of researchers and achievements will contribute to the development of ECDS processes in the near future. 

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