Christian Carl Ing. GmbH, Ziegelstraße 21, 73033 Göppingen, Germany.
Contact person: Alexander Plank, info@ChristianCarl.com;
Function of the Project Partner: Partner
Sun Power Project GesbR, Neubergstraße 13, 2100 Stetten, Austria.
Contact person: Ing. Karl Holzer, ak.holzer@a1.net;
Function of the Project Partner: Partner
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.
The sustainable development of bioethanol as a renewable source of energy requires a holistic approach to feedstock production, energy supply, and utilisation of waste materials. Therefore, several environmental aspects are considered, such as sustainable crop rotation concepts for regional feedstock production, and the thermal utilisation of biogenous residual materials. In particular, an innovative combination of bioethanol- and biogas-plants is to be set up. To close the ecological cycle, the resulting biogas residues are supposed to be reintegrated as fertilisers.
From a technical point of view, optimisation has to focus on improving heat integration, as small-scale plants still show rather poor energy efficiency. Another issue is whether the economic efficiency of the total system as well as individual process components can be improved. For example, the state of the art technology for ethanol dewatering is adsorption – in large-scale production, however. As the implementation of an adsorption unit in small bioethanol plants is comparatively expensive, membrane technology emerges as interesting and – due to the modular concept – cheaper alternative. With gas permeation and pervaporation, two membrane separation methods will be investigated theoretically, followed by laboratory experiments with the more promising method.
The main emphasis of this study is to cover the energy demand of the bioethanol plant exclusively by exploitation of residual substances of the process. By fermentation of the total amount of distillation residue (stillage) and varying amounts of other biomass (e. g. residues of feedstock harvest) biogas will be produced. Due to the fact that the plant-specific usage of biogas – CHP, biogas boiler or turbine – influences the quantity of heat produced, adequate heat supply has to be ensured by adapting the biogas feedstock for each option, e.g. by changing the ratio of stillage to co-substrates. Different feedstock compositions are to be examined in regard to biogas yield, optimal fermentation parameters, as well as the quality of residual biogas manure in terms of fertiliser. Batch and continuous experiments are conducted for this purpose.
Based on simulation data different scenarios of small-scale bioethanol production with innovative energy supplying facilities will be evaluated both energetically and economically. In conclusion a feasility study is elaborated, which points out the most valuable process combination for producing bioethanol in the region Harmansdorf/Rückersdorf – in the most sustainable way.
** Bauer, A; Bösch, P; Friedl, A; Amon, T;
Analysis of methane potentials of steam-exploded wheat straw and estimation of energy yields of combined ethanol and methane production..