This webinar series focused on commonly used substrates for biogas production including, industrial waste, and agricultural residues among others. It showcased pretreatment of feedstocks through various technologies that enhance biogas production.
Table 1: Webinar 4, agenda
| Topics | Speakers | Facilitator |
| Pretreatment of Agricultural Residues Pretreatment of Industrial and Commercial Waste Challenges, opportunities and success stories in South Africa | Josef Höckner, BioG Mathias Hartel, Fachverband Biogas e.V. (FVB) Yaseen Salie, GreenCape, SA | GIZ |