Desenvolvimento de uma tecnologia para oxidação de H2S: escalonamento e prova de conceito

Abstract

The use of e biogas obtained from different sources to generate electricity is an important opportunity for different sectors of the economy today. However, the presence of sulfide-based compounds, H2S, causes strong corrosion in generators leading to high maintenance costs. The present work reports the development of a catalyst in the laboratory and on pilot scale for the oxidation of sulfide for the treatment of biogas. In the first step of this work, the catalyst was synthesized from precipitated silica impregnated with iron by means of the Chemical Vapour Deposition (CVD) technique at 600°C with commercial ethanol and acetonitrile as carbon source. The catalysts obtained were characterized by TG, Raman, Mössbauer, MEV, MET, BET, and CHN. On a scale of 100 mg, the synthesized materials were tested for the oxidation of sulfides in an aqueous medium, reaching oxidation of 85% in 2h of reaction. A catalyst was also synthesized starting from iron mining waste, which reached 47% oxidation in 6h of reaction. The second stage of the work was to study the scale-up of the synthesis by the CVD technique. For this, a rotary tubular oven with tilt control was designed and built, initially operating at a scale of 500 g. Two catalysts were synthesized from several initial optimization studies from two supports, i.e. precipitated silica and iron mining waste. The materials were characterized by different techniques and tested for sulfide oxidation in aqueous media, reaching an oxidation rate of 85%. The reuse of materials was also tested, which showed a drop in efficiency in the first cycle, stabilizing afterward. At the end of the scaling step, an attempt was made to carry out a proof of concept in a real environment. A visit was made to a swine farm with biogas and electricity production.