Removal of hydrogen sulfide gas using coal fly ash – blast furnace cement composite

Abstract

The number of complaints regarding offensive odors from service industries, such as restaurants and garages, has recently increased. In this study, we aimed to develop an adsorbent for hydrogen sulfide gas derived from domestic wastewater and reveal the mechanisms of its removal. The adsorbent used for hydrogen sulfide gas removal was prepared by mixing coal fly ash and blast furnace cement with a mixing ratio of 87:13 by mass percentage. The optimum calcination temperature of the adsorbent was 700 °C to achieve a high removal performance for both dry and humid hydrogen sulfide gas. The X-ray absorption fine structure analysis revealed that hydrogen sulfide was removed on the adsorbent by oxidizing to sulfate. A pilot-scale experiment was conducted to evaluate the removal performance of hydrogen sulfide gas derived from domestic wastewater using the developed adsorbent. For a week, the average removal percentage of hydrogen sulfide gas derived from domestic wastewater remained at 99.1%. Therefore, the developed adsorbent for hydrogen sulfide gas is promising and cost-effective for promoting the recycling of coal fly ash.

Recent Attempts on the Removal of H2S from Various Gas Mixtures Using Zeolites and Waste-Based Adsorbents

“…Asaoka et al [64] synthesized an H 2 S adsorbent by combining coal fly ash and blast furnace cement. In the optimal conditions, adsorption capacities of 650 g-H 2 Sm −3 (62.15 mg H 2 S/g, calculated according to the density of average coal fly ash [65] and blast furnace cement [66]) under dry conditions and 730 g-H 2 Sm −3 (71,71 mg H 2 S/g) under humid conditions were achieved with a component ratio of 87:13 and a calcination temperature of 700 • C. The synthesized adsorbent can remove both dry and humid H 2 S up to 99.1%, as H 2 S oxidation into sulfate, meaning chemisorption occurred.…”

“…Coal fly ash and blast furnace cement were used in the synthesis of H 2 S adsorbent by Asaoka et al [64]. With a component ratio of 87:13 and a calcination temperature of 700 • C, it was possible to achieve adsorption capacities of 650 g-H 2 Sm −3 (62.15 mg H 2 S/g, calculated according to the density of average coal fly ash [65] and blast furnace cement [66]) under dry conditions and 730 g-H 2 Sm −3 (71,71 mg H 2 S/g) under humid conditions.…”