Drying Characteristics of Biogas Digestate in a Hybrid Waste-Heat/Solar Dryer
The use of biogas plants has increased sharply in recent years. A typical biogas plant of 500 kW<sub>el</sub> produces approx. 10,000 t of digestate per year, with a moisture content of more than 90%. For the purpose of reducing the transport mass and increasing the nutrient concentratio...
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MDPI AG
2019-04-01
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| Series: | Energies |
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| Online Access: | https://www.mdpi.com/1996-1073/12/7/1294 |
| _version_ | 1811301374960336896 |
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| author | Claudia Maurer Joachim Müller |
| author_facet | Claudia Maurer Joachim Müller |
| author_sort | Claudia Maurer |
| collection | DOAJ |
| description | The use of biogas plants has increased sharply in recent years. A typical biogas plant of 500 kW<sub>el</sub> produces approx. 10,000 t of digestate per year, with a moisture content of more than 90%. For the purpose of reducing the transport mass and increasing the nutrient concentration, the digestate has to be dried. Using renewable energy is a way to treat biogas digestate without any additional fossil energy requirement for drying. In this study a solar greenhouse dryer was modified to use additional waste-heat from the combined heat and power unit (variant S-CHP), as well as the exhaust gas from a micro turbine (variant S-CHP-MT). The hybrid waste-heat/solar dryer achieved a moisture content for the digestate of 10.9%, and 10.5%, after 13 d of drying for variant S-CHP-MT and S-CHP-MT, respectively. Due to the higher energy input by additional use of the micro turbine, the specific energy consumption is higher for the variant S-CHP-MT. In general, the results showed that the combination of solar energy and waste-heat from electricity generation of a biogas plant is a suitable way to reduce the moisture content of the digestate to a safe level for further handling and storage. |
| first_indexed | 2024-04-13T07:07:44Z |
| format | Article |
| id | doaj.art-75b796e7a4ff4fb28bebef89627d9e25 |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-04-13T07:07:44Z |
| publishDate | 2019-04-01 |
| publisher | MDPI AG |
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| series | Energies |
| spelling | doaj.art-75b796e7a4ff4fb28bebef89627d9e252022-12-22T02:56:57ZengMDPI AGEnergies1996-10732019-04-01127129410.3390/en12071294en12071294Drying Characteristics of Biogas Digestate in a Hybrid Waste-Heat/Solar DryerClaudia Maurer0Joachim Müller1Institute of Agricultural Engineering, Tropics and Subtropics Group (440e), University of Hohenheim, Garbenstraße 9, D-70599 Stuttgart, GermanyInstitute of Agricultural Engineering, Tropics and Subtropics Group (440e), University of Hohenheim, Garbenstraße 9, D-70599 Stuttgart, GermanyThe use of biogas plants has increased sharply in recent years. A typical biogas plant of 500 kW<sub>el</sub> produces approx. 10,000 t of digestate per year, with a moisture content of more than 90%. For the purpose of reducing the transport mass and increasing the nutrient concentration, the digestate has to be dried. Using renewable energy is a way to treat biogas digestate without any additional fossil energy requirement for drying. In this study a solar greenhouse dryer was modified to use additional waste-heat from the combined heat and power unit (variant S-CHP), as well as the exhaust gas from a micro turbine (variant S-CHP-MT). The hybrid waste-heat/solar dryer achieved a moisture content for the digestate of 10.9%, and 10.5%, after 13 d of drying for variant S-CHP-MT and S-CHP-MT, respectively. Due to the higher energy input by additional use of the micro turbine, the specific energy consumption is higher for the variant S-CHP-MT. In general, the results showed that the combination of solar energy and waste-heat from electricity generation of a biogas plant is a suitable way to reduce the moisture content of the digestate to a safe level for further handling and storage.https://www.mdpi.com/1996-1073/12/7/1294drying processwaste-heat usagebiogas digestateenergy consumption |
| spellingShingle | Claudia Maurer Joachim Müller Drying Characteristics of Biogas Digestate in a Hybrid Waste-Heat/Solar Dryer Energies drying process waste-heat usage biogas digestate energy consumption |
| title | Drying Characteristics of Biogas Digestate in a Hybrid Waste-Heat/Solar Dryer |
| title_full | Drying Characteristics of Biogas Digestate in a Hybrid Waste-Heat/Solar Dryer |
| title_fullStr | Drying Characteristics of Biogas Digestate in a Hybrid Waste-Heat/Solar Dryer |
| title_full_unstemmed | Drying Characteristics of Biogas Digestate in a Hybrid Waste-Heat/Solar Dryer |
| title_short | Drying Characteristics of Biogas Digestate in a Hybrid Waste-Heat/Solar Dryer |
| title_sort | drying characteristics of biogas digestate in a hybrid waste heat solar dryer |
| topic | drying process waste-heat usage biogas digestate energy consumption |
| url | https://www.mdpi.com/1996-1073/12/7/1294 |
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