To find some new desulfurizers for the smelter off-gas containing high levels of SO 2 , both the sulfur recovery performance and the regeneration performance of the sulfides of alkali metals and alkaline-earth metals were compared in both simulation and experiment. Although sodium sulfide (Na 2 S) showed a good sulfur recovery performance, its regeneration performance was poor due to the production of polysulfides. Calcium sulfide (CaS) was a feasible option of the desulfurizer because both its sulfur recovery performance and regeneration performance were satisfactory. CaS was prepared after the reduction of the commercial CaSO 4 (Red-Ca), the flue gas desulfurization gypsum (Red-FGD), the phosphogypsum (Red-P), and the titanogypsum (Red-Ti), respectively. The results showed that the performances of Red-Ca and Red-FGD were quite similar and both of them were distinctly better than Red-P and Red-Ti. According to XRF analysis and XRD patterns, the impurities in Red-P and Red-Ti reduced the activity of CaS. The sulfur recovery performance of both Red-FGD and Na 2 S in the presence of oxygen decreased comparing with the performance in the absence of oxygen, while the decrease for Red-FGD was less than Na 2 S. Higher reaction temperature and lower space velocity could significantly enhance the sulfur recovery performance of Red-FGD. The sulfur recovery performance was very stable in the investigated NO concentration, i.e., 400−800 ppm. SEM photos indicated that some mesopores newly occurred in the reduction of the FGD particles but then the porosity decreased to some extent after the desulfurization.

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Calcium carbide and methanol are important platform chemicals, and the reaction between them can easily produce methyl vinyl ether (MVE). This paper aims to explore the downstream products of MVE through reaction with H2. Several catalysts with different active components and supports are screened in a fixed-bed reactor, and the product distributions at different reaction conditions are disclosed. At reaction temperatures of 200–300 °C, MVE is hydrogenated to methyl ethyl ether over PtO2/Al2O3 with a carbon yield of 59%, hydrolyzed to acetaldehyde over NiMoS/Al2O3 with a carbon yield of 31%, and hydrocracked to ethanol over CuO/Al2O3 and CuO/SiO2 with carbon yields of 13%–15%. At 400–450 °C, MVE is hydrodeoxygenated to C2–C4 hydrocarbons over PtO2/Al2O3 with a carbon yield of 95%. Methylbenzene, especially hexamethylbenzene, is formed over CuO/Al2O3 at 400–450 °C, and the reaction matrix was investigated at different VH2 /VMVE ratios and space velocities and by the control experiments of acetaldehyde and methanol.