Valorization of Waste-Derived Inorganic Sorbents for the Removal of HCl in Syngas

Augustina Ephraim (1) , Linhdan Ngo (2, 3) , Doan Pham Minh (1) , Damien Lebonnois (4) , Carlos Peregrina (4) , Patrick Sharrock (1) , Ange Nzihou (1)

1 RAPSODEE - Centre de recherche d'Albi en génie des procédés des solides divisés, de l'énergie et de l'environnement
2 PC2A - Physicochimie des Processus de Combustion et de l’Atmosphère - UMR 8522
3 PhLAM - Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523
4 Suez Environnement

Syngas production via the pyro-gasification of waste biomass is a promising means of managing waste while producing renewable fuel. However, such waste may contain a significant level of impurities such as chlorine, which may result in hydrogen chloride (HCl) being formed in the syngas produced. The presence of HCl gas may increase the risk of corrosion and may be harmful to health and to the environment. Consequently, stricter limits on HCl concentration in syngas are being imposed by environmental regulations and syngas end-use specifications, which is driving the search and development of more efficient and cost-effective methods of eliminating HCl. One such method is dry adsorption using inorganic sorbents. In literature, the majority of sorbents studied are based on commercialised products, and thus, there lack studies on the use of waste-derived sorbents for treating HCl in syngas. Therefore, this paper presents an experimental study on the adsorption potential of the solid waste sorbent, CCW-S, which is compared to that of the commercial sorbent, Bicar. Various physico-chemical analyses were performed on the sorbents before and after the tests, including ICP, FTIR, XRD and TEM-EDX. The first set of adsorption tests were performed using a gas mixture of 500 ppm HCl in nitrogen (HCl/N2) at ambient conditions (25 °C, 1 atm). The results revealed that Bicar was the better performing sorbent with an average breakthrough time of 66 h and a HCl adsorption capacity of 27 wt%, whereas the performance of CCW-S was lower (7.8 h and 4 wt%). Furthermore, TEM-EDX images of CCW-S particles show the participation of the impurities—Al, Fe, and Mg—in HCl capture. When the second set of adsorption tests were conducted with a simulated HCl/syngas atmosphere, a significant decrease in sorbent performance was observed, which showcases inhibitory interactions occurring between syngas and the sorbents, in relation to HCl adsorption. The results of this preliminary investigation reveal a promising opportunity to valorize industrial residues as cheap and efficient sorbents for the removal of HCl in syngas. This will enable a wider market penetrating of waste-derived syngas, while meeting the quality requirements of increasingly strict environmental regulations and end-use devices.

Mots clés: Inorganic waste sorbents; Syngas; Hydrogen chloride; Dry adsorption

Domaines: Sciences de l'ingénieur [physics]

Augustina Ephraim, Linhdan Ngo, Doan Pham Minh, Damien Lebonnois, Carlos Peregrina, et al.. Valorization of Waste-Derived Inorganic Sorbents for the Removal of HCl in Syngas. Waste and Biomass Valorization, 2019, 10 (11), pp.3435-3446. ⟨10.1007/s12649-018-0355-1⟩. ⟨hal-01818380⟩