
Reply To: Semi-dry digestion
Hi Natalia, from my experience it is less a question of which AD process type is more or less popular but rather what are the characteristics of the feedstock(s) that then govern the selection of the process type.
So if you start with a feedstock that has a high TS, let’s say 30+ percent, then high-solids AD processes such as plug-flow or batch would be preferrable.
We did a study for a client back in 2016 that included a survey of all municipal organics AD installations world-wide. So for source separated organics and organic fraction of MSW. We found that the low-solids AD installations were about equal in number to high-solids AD installations. Back then High-solids batch represented about 20 percent of the all high-solids AD installations.
For ‘semi-dry’ AD -I would say between 15 and 25% TS- there are some providers that have specialized on this range, most notably for corn silage applications or an other AG-feestocks. For these applications slow-moving mixer designs are typically used for a CSTR design (e.g., offered by Agraferm, ArgiComp, among others).