POTENTIAL OF BIOGAS PRODUCTION IN SUSTAINABLE BIOREFINERY CONCEPTS

ABSTRACT: Currently, biogas production is mainly based on the anaerobic digestion of single energy crops. In the future, biogas production from energy crops will increase and will have to be based on a wide range of energy crops that are grown in versatile, sustainable crop rotations. In addition, more by-products products from the agricultural, food and energy industry need to be integrated. The potential of biogas production will be larger than hitherto assumed when sustainable systems are the base of calculations. The present paper deals with the potential of biogas production using sustainable biofuels-based biorefinery concepts to optimise methane yield and economic efficiency of biogas production. The aim of this study was to find locally adapted biofuel-based biorefinery concepts based on bioethanol and biogas. Production of raw materials took place in integrated crop rotations. The crop rotation presented in this paper produces 20.5 GJ energy ha-1 a-1 in the form of ethanol and 76.1 GJ energy ha-1 a-1 the form of biogas Integrated crop rotation uses the total arable area for an integrated production of food, feed and energy crops. In this system, it is assumed that on average 96.6 GJ energy ha-1 a-1 can be produced on the whole agricultural area of EU-25. This results in a methane production of 8.983.800 TJ energy a-1 or 215 million t COE a-1. In the system 69% of the energy need of all road traffic in EU-25 can be met. With a straw pretreatment in the "steam explosion" procedure, 12,024,900 TJ energy a-1 can be produced, which amounts to 94 % of the energy demand of road traffic in EU-25