In the forecast of the Netherlands Environmental Assessment
Agency (PBL), the volume of biogas to be generated in the
Netherlands by digestion is predicted to increase by 74% from 8.6 PJ
to 15 PJ in the time period 2010e2020; the total energy end use in
2010 was 2304 PJ, with 86 PJ from renewable sources. The main
cause for the increase is the growth of co-digestion of manure and
co-substrates. In the outlook for 2030 a further increase is foreseen
to 61 PJ because of the ability to use biogas to produce heat at a high
overall efficiency in a CHP and in the production of green gas [1].
The use of manure as a substrate is encouraged as it is one of the
targets of the Sustainable Dairy Chain Initiative. The dairy sector
organization, Nederlandse Zuivel Organisatie (NZO), wants the
production of dairy products to be energy neutral. To reach this goal