Transportation fuels, electrochemical desulfurization

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. 

D Eha Camacho et al. (2011) proposed a novel concept using an assisted electrochemical reaction to produce atomic hydrogen from water electrolysis for different heterorganic compounds conversion. The electrochemical reactor is divided into two compartments by a palladium membrane in which atomic hydrogen is absorbed and permeated. Organic sulfur in the oil can be desulfurized and transformed to H2S in the electrochemical compartment. In addition, Lam et al. (2012) recently presented a review of electrochemical desulfurization technologies for fossil fuels. Various electrodes and electrolytes that have been used for desulfurization accomphshed by oxidation, reduction, or both were summarized by Lam et al. in their paper. Some electrochemical desulfurization processes for transportation fuels were chosen for listing in Table 14.2. 

Table 14.2 Some electrochemical desulfurization processes for transportation fuels...

The electrochemical desulfurization (ECDS) of transportation fuels includes two methods oxidation and reduction. The electrochemical reduction of sulfur-containing fuels was presented in Section 14.1.1 using Eqn (14.1). The organic sulfur compounds will be reduced to hydrogen sulfide form, which can be subsequently removed by a gas/liquid separation process. 

In summary, the design of membrane reactors for electrochemical desulfurization of transportation fuels should take into consideration the issues shown in Figure 14.10. 

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. 

---