Hohenheim Biogas Yield Test
Topic
Biogas yield tests are used as a state-of-the-art method for the design of biogas plants. Substrates and digestate are tested for their methane and biogas potential. Furthermore, the methane content and the kinetics, i.e. the degradation over time, can be considered. The German regulation VDI 4630 is used in Hohenheim as a guideline for carrying out the tests.
Goals
At the State Institute for Agricultural Engineering and Bioenergy, the so-called Hohenheim Biogas Yield Test (HBT) is used for this purpose, which was also developed in-house. The advantage of the HBT is a low required weight (400 mg TS) of the substrate combined with high accuracy.
In Hohenheim, 257 samples can be tested simultaneously in 3-fold repetition. A high reproducibility of the results is guaranteed by the use of two standards, which have been investigated since 2013. In addition, an inoculum is used that is fed in a controlled manner at a low and constant level in an adjacent 400 L laboratory reactor to enable the comparability of the results.
High quality of the results is also ensured by participation in the KTBL round robin test. So far, the certificate could be achieved in every year. Furthermore, the State Institute for Agricultural Engineering actively cooperates and leads the committee for the round robin test as well as the KTBL publication ".Gas Yield in Agricultural Biogas Plants", in which standard values for methane potentials of various conventional substrates are presented.
The HBT is used in the context of various scientific projects and contract work with very different questions and substrates.
