In this study, the modified activated coke (AC-Tit) was prepared from coals using titanium ore by the blending method with a one-step carbonization–activation process. The results show that the addition of titanium ore affects the physicochemical properties of AC-Tit. The AC-Tit samples have higher V mic and V mic/V tot ratios as well as oxygen and CO functional group. The metal oxides (i.e., FeTiO3, TiO2, Fe2O3, and Fe) were detected on the surface of samples, attributed to the existence of Fe and Ti in the titanium ore. The titanium ore addition improved the desulfurization performance of the AC-Tit effectively; the highest sulfur capacity was 203.3 mg/g, which was much higher than that of the blank sample (120.1 mg/g). After desulfurization, some metal sulfates, i.e., Fe2(SO4)3 and CaSO4, were detected on the AC-Tit samples. When the sample was regenerated, its surface area (S BET) and V mic did not change significantly, the relative content of CO decreased, and COOH increased evidently. In addition, metal sulfates on the AC-Tit samples were not decomposed during the regeneration process. The variation of surface chemical properties of the regenerated AC-Tit caused the reduction of the desulfurization activity after regeneration.

Novel biochar was prepared from plant-based biomass by the addition of nitrogen-containing phosphates (NCPs), including ammonia phosphate (AP), ammonia polyphosphate (APP) and urea phosphate (UP).

No abstract

In this study, five kinds of iron ores, limonite, hematite, manganese ore, magnetite and lava rock, were used as the in situ desulfurizers in the anaerobic digestion reactors to investigate their effects on controlling H2S in biogas. The results show that the addition of the five iron ores could significantly control the content of H2S in biogas, with the best performance for limonite. As limonite dosages increase (10-60 g/L), the contents of H2S in biogas were evidently decreased in the digesters with different initial sulfate concentrations (0-1000 mg/L). After the anaerobic digestion, the removed sulfur was mostly deposited on the surface of limonite. A possible mechanism of H2S control in biogas by limonite was proposed preliminarily, including adsorption, FeS precipitation, and Fe (III) oxidation. The results demonstrated that limonite was a promising in situ desulfurizer for controlling H2S in biogas with low cost and high efficiency.