Export Initiative for Environmental Protection

S-IRCLE Project

In Vietnam, there are over 500,000 small-scale biogas plants, which have a digester volume of less than 50m3. These plants primarily generate biogas for the purpose of household cooking. The expansion of biogas utilization in Vietnam is limited due to the high concentration of hydrogen sulphide (H2S) in the biogas. H2S is a toxic gas for human health even with the low concentration and it has a distinct odour of rotten eggs. Its presence in biogas can lead to corrosion and significantly reduce the lifetime of biogas appliances like biogas cooking stoves. The biogas filters currently available in the Vietnam market are ineffective in eliminating H2S, have a short lifetime and lack of warranty. Therefore, there is a high demand for a high-quality biogas filter that is effective and long-lasting.

S-IRCLE stands for Circular Biogas Technology - Smart Filter Systems for H2S-Removal and S-Recovery. The goals of S-IRCLE project are (1) to develop an innovative, automatic, regenerable external filter system to remove H2S in small-scale biogas plants and (2) to recycle sulphur in the loaded filter material as an alternative sulphur fertilizer. The filter prototype will be first improved and upgraded to include automatic regeneration. Subsequently, field tests will be conducted for a duration of 1 year at a minimum of three biogas plants in northern Vietnam with the supervision of the local partner. Simultaneously, two plant test will be conducted to (1) examine the correlation between the filter material grain size and the release of sulphur. (2) to evaluate the fertilization efficacy of the three fertilizer mixtures developed from the loaded filter material. Moreover, a survey on the Vietnamese waste disposal and recycling system will be carried out to collect data to assess the recyclability of the filter under local conditions. Ultimately, a material flow analysis will be applied to evaluate the environmental impacts of the novel biogas filter in comparison to the current scenario. A biogas workshop involving local stakeholders and an international scientific conference will be organized in Vietnam to share the project outcomes.

Read our project flyer here.

March 2023 – February 2025