Upcycling of medical protective clothing for H2 production through catalytic steam reforming over Ni-impregnated catalysts

Abstract

Disposing medical protective clothing (MPC) presents a significant challenge due to the potential risk of virus contamination. Catalytic steam reforming using Ni-impregnated catalysts was proposed to upcycle MPC for H2-rich gas production. Parametric studies validated that an optimal steam rate of 42 mL/h and a catalytic reforming temperature of 800 ℃ were ideal for H2-rich gas production. 10 wt% Ni impregnated on diverse supports (HY, ZSM-5, MCM-41, γ-Al2O3, MgO, CaO, and activated carbon) were prepared for steam reforming of MPC to assess the impact of support type on H2 production. Of these Ni-impregnated catalysts, Ni/CaO was found to present the highest gas yield (141.4 mmol/g) with a high H2 proportion of 65.2 vol%, due to its superior catalytic cracking and reforming ability of Ni/CaO, favoring the conversion of MPC intermediates into H2-rich gas. To evaluate the recyclability and reforming activity, the optimized Ni/CaO with and without catalyst regeneration was evaluated throughout the successive tests. It was found that Ni/CaO regenerated throughout the successive tests could more effectively mitigate the decreasing tendency of gas yields, favor H2 production, and reduce tar formation than the catalyst without regeneration. That was due to the removal of carbon deposition by catalyst regeneration, thereby mitigating the catalyst deactivation. In contrast, Ni/CaO without the catalyst regeneration was more responsible for the CO2 reduction, accompanying with a more significant decrease of ƞ (4.8 – 3.5 g CO2 /g H2). Overall, this study demonstrated the feasibility of valorizing medical plastic waste into H2-rich gas using effective Ni-based catalysts.