Development of the Methane Energy Value Model as a tool to optimise methane yield from energy crops
- Boden und Landökosysteme
- Wasser - Atmosphäre - Umwelt
- Nachwachsende Rohstoffe und neue Technologien
Abstract
This project serves to promote biogas production from energy crops. The energy crops: sunflowers, meadow grass, wheat, triticale, rye and maize were investigated. All energy crops were harvested in the course of the vegetation period at four to six different times. At each harvest, yield measurements were carried out, as well as biomass sampled for silaging and the subsequent ingredient analyses. Following, laboratory investigations for the determination of the specific methane yield were carried. The methane hectare yield and the optimal harvest times were determined. Of all the energy crop species investigated in this project, maize showed the highest biomass yields and methane yields per hectare (up to 31 t DM ha-1 and up to 12,657 Nm3 CH4 ha-1). Sunflowers achieved approximately 30% of the methane hectare yield obtained by maize, cereals or intensively farmed meadow grass on average 26.5%. Variations of 6 to 38% in methane hectare yield appeared within the examined energy crop species depending on the variety, the place of cultivation, the management intensity or the harvest time. For an economic biogas production, the right choice of variety and the optimal harvest time has a great relevance. The effect of pretreatment measures (acidifying, heat treatment, microwave irradiation and addition of clay minerals) on the specific methane yield of energy crops was examined. Heat, microwaves and acid pretreatment aimed to induce a predigestion of the crude fiber fraction. This effect was only observed with meadow grass and sunflowers, not however for cereals. The addition of clay minerals increased the specific methane yield of all energy crops. The influence of the protein:energy ratio of mixtures of energy crops on the specific methane yield and on the biogas quality was examined with mixtures of protein-rich clover grass silage and energy-rich maize silage. A higher portion of maize silage in the mixture resulted in a higher specific methane yield. The higher the protein content and/or the portion of clover grass silage in the fermenting mixture, the lower the methane content in the produced biogas and the higher the hydrogen sulfide and ammonia content. Guidelines for (a) optimized biogas production from energy crops, (b) efficient fertilization with fermentation residues of fermented energy crops as well as (c) different uses of biogas are given. In order to achieve long-term success, the cultivation of energy crops must be organized using sustainable crop rotation principles. The results of this project show that the potentials of biogas from energy crops are larger than have been assumed so far. The present, new calculations of integrated biogas production systems show an annual total potential of 4.8 MIO t ROE or 4.8 billion m3 methane. That means if the potentials of biogas production would be used, in Austria more than 16 MIO t CO2 emissions could be saved per year. This equals exactly the current requirements of reduction in Austria to reach the Kyoto target.
- biogas production
- climate protection
- greenhouse gas emissions
Project staff
Barbara Amon
Priv.-Doz. Dr. Barbara Amon
barbara.amon@boku.ac.at
Project Staff
01.05.2004 - 30.04.2006
Bernhard Freyer
Univ.-Prof. i.R. Dipl.-Ing. Dr.Ing. Bernhard Freyer
bernhard.freyer@boku.ac.at
Project Staff
01.05.2004 - 30.04.2006
Jürgen Kurt Friedel
Ao.Univ.Prof. Dipl.-Ing. Dr. Jürgen Kurt Friedel
Tel: +43 1 47654-93317
Project Staff
01.05.2004 - 30.04.2006
Martina Fröhlich
Dipl.-Ing. Dipl.-Päd. Martina Fröhlich
martina.froehlich@boku.ac.at
Tel: +43 1 47654-31221
Project Staff
01.05.2004 - 30.04.2006
Johann Sölkner
Univ.Prof. Dipl.-Ing. Dr.nat.techn. Johann Sölkner
johann.soelkner@boku.ac.at
Tel: +43 1 47654-93201, 93231
Project Staff
01.05.2004 - 30.04.2006
Helmut Wagentristl
Ass.Prof. Dipl.-Ing. Dr.nat.techn. Helmut Wagentristl
helmut.wagentristl@boku.ac.at
Tel: +43 1 47654-95501, 95511
Project Staff
01.05.2004 - 30.04.2006
Werner Zollitsch
Univ.Prof. Dipl.-Ing. Dr. Werner Zollitsch
werner.zollitsch@boku.ac.at
Tel: +43 1 47654-93211, 99101, 99111
Project Staff
01.05.2004 - 30.04.2006
BOKU partners
External partners
_x000D_
Dr. Erich Pötsch
partner
Austrian Agency for Health and Food Safety
DI Erwin Pfundtner
partner
IPUS, Service for Industry, Production and Environmental Technology, Ltd.
Dr. Gernot Scheiflinger
partner
RWA Raiffeisen Ware Austria AG
DI. Erwin Arocker
partner
Monsanto Agrar Germany Ltd.
none
partner
Jenbacher Energy Systems
Dr. Günther Herdin
partner
Limagrain-Nickerson Ltd
none
partner
Pioneer Seeds Ltd.
Dr. Felix Rudolph
partner
Nawaros Bioenergy and Raw Material Production Ltd_x000D_
Dr. Thomas Kraßnitzer
partner
Schmack Biogas AG
Dr. Doris Schmack
partner