Do I need to pre-process material before feeding it to the BiogasPro?

Try to reduce the size of feed materials, (about 5cm or less all round).   This reduces your chances of blocking up the system.  Like us, your digester thrives on a varied diet.  Silage (store) large volumes of grass cuttings, leaves, crop husks etc, before feeding them little and often to the digester together with other waste. Feel free to contact AGAMA Biogas for specific advice, and refer to the product datasheet for loading information.