Polygeneration of bioethanol, biogas, electricity and heat through operating community Sun Power Plant Project GesbR.
The objective of this study is to analyse the economic feasibility of fuel-bioethanol production in the region Harmansdorf/Rückersdorf (NÖ), partner of the so called leader region "10 vor Wien". Contrary to common bioethanol production in large-scale plants, this project scrutinises a decentralised small-scale plant that is to be embedded into existing regional structures. Derived from a systematic analysis of the proposed location and its suitability an ethanol plant with a capacity of 5000 t/a was identified to be manageable by local resources. Therefore one of the requirements for sustainability is satisfied.
The required adaptations of the ethanol process for fuel grade ethanol production by membrane processes were proven in lab scale experiments. The most energy efficient and economic processes at given plant setup were identified by process simulation. For estimating the methane yields a comprehensive series of tests with multiple substrates was conducted. Although the ethanol process based on starch reaches near case ideal yields, an economic setup could not be developed. This is due to high steel and energy prices but foremost based on former unpredictable price hikes of the substrates wheat grain and corn.
To compensate for this development lignocellulosic matter was facilitated not only in anaerobic digestion but also for the ethanol process. By increasing the plant size greater than 2500 t/a ethanol and electric energy fed into the grid at given rates the concept is potential competitive. These plants can be regarded as full second generation plants and do not interfere with food production. Based on laboratory trials and simulation work this concept is proven to be viable but requires to be transferred in pilot and demonstration scale plants to optimize the process interplay as well was the efficiency of the critical process steps.
Ao. Univ.-Prof. Dr. Anton FRIEDL
TU Wien, Institut für Verfahrenstechnik