Reducing fossil energy consumption of a belt dryer by using biogas waste heat
- Publication Type
- Contribution to conference
- Authors
- Böhner M; Senckenberg P; Heindl A; Müller J
- Year of publication
- 2010
- Published in
- Proceedings of the XVIIth World Congress of the International Commission of Agricultural Engineering (CIGR)
- Page (from - to)
- 1-9
- Conference name
- XVIIth World Congress of the International Commission of Agricultural Engineering (CIGR) - Section VI: Postharvest Technology and Process Engineering
- Conference location
- Quebec City (Canada)
- Conference date
- 13-17 June 2010
Conventional multibelt dryers have a high energy consumption mainly supplied by fossil fuel energy resources. The goal was to harness the waste heat from a combined heat and power unit (CHP) of a biogas plant for drying curly parsley (Petroselinum crispum) on a belt dryer. After cutting the fresh material the stems and leaves were separated by air classifying. Both the stems and conventional substrates were used for the biogas fermentation. A standardised batch fermentation test (Hohenheimer biogas yield test) was carried out to measure the potential biogas yield of the parsley stems. The leaves were dried by hot air partially heated by the light fuel oil burners and waste heat from the CHP. The belt dryer consists of a single-belt predryer and a five-belt dryer including three temperature zones with a total drying area of 316 m². High temperatures were applied for drying parsley with a temperature profile of 90/80/75°C for the three zones. The energy consumption of light fuel oil and the energy from the biogas CHP was measured.