Low-temperature H₂S removal for solid oxide fuel cell application with metal oxide adsorbents

Abstract

The desulfurization of biogas is essential for the successful operation of solid oxide fuel cells. H 2 S is one of the main components in biogas. In order to feed a solid oxide fuel cell, the contaminated gas has to be reduced to a certain degree. In this work, different parameters onto the desulfurization performance of commercially available desulfurization adsorbents were investigated. The experiments were carried out using a custom made lab-scale unit. Synthetic biogas was passed through the sorbent bed and the outlet H 2 S concentration was measured. Experimental runs in a fixed bed reactor were conducted to monitor H 2 S removal efficiency of a zinc oxide adsorbent, an adsorbent based on a mixture of manganese and copper oxide and a zeolite adsorbent. H 2 S removal efficiency was monitored under various operating conditions such as different temperatures, space velocities and inlet concentrations. This work provides useful data for adsorption tower design and process optimization.

Investigation of NH3 Influence on Adsorptive H2S Removal from Biogas for Solid Oxide Fuel Cell Application

“…The influence of H 2 S concentration on the adsorption performance of different sorbents as well as the effect of the main components of biogas on H 2 S adsorption performance have been investigated by the authors in former publications , .…”

“…The determination of higher NH 3 concentrations results from the goal of realizing a gas purification based on a modular system and, additionally, by using different energy carriers for the operation of the SOFC. The influence of H 2 S concentration on the adsorption performance of different sorbents as well as the effect of the main components of biogas on H 2 S adsorption performance have been investigated by the authors in former publications [16,24].…”

“…A great advantage of these sorbents is that they can be used at ambient temperature and pressure. In a former research the authors examined different sorbents at different operating conditions and achieved H 2 S outlet concentrations below 1 ppmv . Thus, an adsorber dimensioning with respect to H 2 S is already feasible, but the influence of NH 3 on the adsorption process has to be further investigated in order to achieve additional optimization.…”

Green Synthetic Fuels: Renewable Routes for the Conversion of Non-Fossil Feedstocks into Gaseous Fuels and Their End Uses

“…Hydrogen sulfides and halogens are adsorbed on Ni/YSZ active surface inhibiting the catalytic reactions [688]. H 2 S and HCl are removed by adsorption in materials, such as activated carbon, metal oxides (ZnO, MnO, CuO), silica gel and zeolites [689], or chemical absorption in water [690]. The hydrogen sulfide solubility is improved by alkaline compounds or by H 2 S catalytic oxidation [690].…”

Hydrogen Sulfide Adsorption by Iron Oxides and Their Polymer Composites: A Case-Study Application to Biogas Purification

“…The need for milder operative conditions in order to fulfill more restrictive protocols related to process safety and energy savings, together with economic considerations [ 23 ], led to expanding the research towards sorbents like transition metal oxides operating at the lowest temperatures compatible with satisfactory chemisorption kinetics, but this task remains an open challenge. Weinlaender et al [ 24 ] compared the performances of ZnO, a mixture of MnO-CuO and CuO-doped zeolite at different space velocities, H 2 S inlet concentrations and temperatures to test the influence of such variables on the global efficiency of H 2 S capture from synthetic biogas. Yang et al [ 25 ] used the wet impregnation technique followed by calcination to prepare a sorbent made of ZnFe 2 O 4 on activated carbon, having an H 2 S breakthrough capacity of 122.5 mg/g even at room temperature.…”