HoSt and Twence started a cooperation in 2010 with the aim to develop and build a combi-digester. The combi-digester is a pilot projects and fits into the “waste to energy” objectives pursued by Twence. The concept aims to digest organic waste material in a primair and after-digester combination (wet digestion line) in combination with a parallel-connected container digester.

In the combi-digester, organic waste like flotation sludge and contaminated organic waste/ verge cuttings are processed seperately, wherein the polluted streams will be processed into the container digester. In particular, the digestion of verge cuttings in a separate parallel container digester can be classified as innovative. The pilot focusses on the container digester and integrating the system into the wet digestion line.

The advantage of the container digester is that the different streams can be digested without pre-treatment. The combination with a wet digester is interesting, because this makes it possible to  inoculate the solid digester and to startup quickly. Furthermore, it is possible to directly feed the wet digester with liquid streams. The combination of organic waste with wet input streams is also interesting because fluctuations in the organic waste quality over the season can be accommodated.


Start Construction June 2013
Startup April 2014


Capacity Wet line: 9,000 tonnes / year; solid line: 2,000 tonnes/year
Input Organic waste, roadside grass, sewage fat and other materials
Digester(s) 2 x Microferm + 1 x 1,350 m³
Container digester 140 m³
Pre-strorage/ receipt 2 x 150 m³ polyester silos


  • Pilot project combi-digestion
  • Digestion of organic waste / roadside grass without pre-treatment

More information

Do you want to receive more information about our biogas plants or do you want to know what HoSt can do for you? Don’t hesitate to contact us through [email protected] or call us on +31 (0)53 – 460 90 80.