REMOVAL OF HYDROGEN SULPHIDE FROM BIOGAS USING AQUEOUS ABSORBENTS
The possibilities of trace hydrogen sulphide (H2S) absorption were investigated using different aqueous absorbents. In this study, 1–15 % aqueous solutions of monoethanolamine (MEA) and 1–2 % aqueous solutions of dolomite and opoka as well as distilled water were used. Absorption using MEA solutions was carried out at 20, 30, 40 °C with solutions of dolomite and opoka at 20 °C.
Increasing the temperature above 20 °C did not lead to a better H2S absorption; thus, it is not advisable to raise the temperature of the sorption process. H2S absorption results using MEA solutions of different concentrations showed that the most effective was 5 % MEA solution. The aqueous solution of opoka (1–2 %) showed the lowest absorption ability. The experimental results revealed the advantage of aqueous solution of dolomite over other studied solutions in H2S absorption at ambient temperature. Even 1 % dolomite solution absorbed all the H2S from the studied gaseous samples; therefore, the usage of neither chemical absorbents (MEA) nor higher concentrations of dolomite solution are advisable.