Legal framework of the EEG 2017 for anaerobic Digestion plants based on waste and residues
© Wasteconsult international (5/2017)
The 2017 German Renewable Energy Sources Act (EEG 2017) came into force on 1st January 2017. This revision altered the German mechanism to support the Generation of energy from renewable sources for the first time since the law originally took effect in 2000, moving from fixed feed-in tariffs to an auction model. The new requirements create completely new challenges for plant operators and public authorities involved with implementation.
European Harmonization of Methods to Quantify Methane Emissions from Biogas Plants
© Lehrstuhl für Abfallverwertungstechnik und Abfallwirtschaft der Montanuniversität Leoben (11/2016)
In the past years, attempts were undertaken to quantify single emission sources as well as overall emissions from biogas plants using on-site (direct) and remote sensing (indirect) methods. While measurements on site often focus on one type of CH4
sources, remote sensing methods cover the overall emission plume. Among the current available emission measurement techniques, none is in a position to be recognized as the best international reference. Therefore, the establishment of a scientifically based standardization and harmonization of methods would greatly contribute to the assessment of the fugitive emissions from biogas plants.
Fast methanification of swine manure as an example for substrates with low organic content
© Agrar- und Umweltwissenschaftliche Fakultät Rostock (6/2015)
A biogas reactor of 45 m³ was fed with pure swine manure. A straw layer worked as an anaerobic filter on top of the fluid. The manure was continuously circulated to irrigate the straw. Hydraulic retention time (HRT) of straw was 45 days. HRT of manure was reduced from 45 to 7.5 days within one year. Average concentration of volatile solids (VS) of manure only was 1.8 %. We varied VS concentration and temperature to simulate normal disturbances of operation. Gas production normalized within one day after each short heating interruption. Variations of VS concentration had no negative influence on the Operation as a whole. After two months, a zone with granular sludge in autonomous fluidization was observed just below the straw layer. This shows that the reactor is a hybrid biogas reactor containing a fixed bed on the top, and an UASB zone below.
Experiences with Power-to-Gas – upgrading technology for sewage treatment plants?
© Wasteconsult international (5/2015)
Methane produced in a biological process using surplus electricity from renewable sources such as wind and the sun is being fed into the natural gas grid for the first time in Allendorf (Eder), Germany. The first system of this type in the world went into Operation in early March. The MicrobEnergy (Viessmann Group) demonstration plant had been in operation at the Schwandorf sewage works until the end of December 2014.
System for mixing the contents of a biogas digester by means of cyclically drawing off the product gas
© Wasteconsult international (5/2015)
Conventional digesters fed on high solids material like manure, energy crops and/or other fibrous matter suffer from various disadvantages, among which :
- the need to use powerful agitating and mixing systems in the digester in order to avoid the formation of a floating crust on top of the contents
- the need to dilute the contents of the digester in order to be able to mix it, with as a result an increase of the size of the digester
- the high thermal needs of the digester due to ist size
- the high electricity consumption of the mixing system
- the high investment costs of the system (size and auxiliary equipment).
Biogas Utilisation in Berlin
© TK Verlag - Fachverlag für Kreislaufwirtschaft (11/2014)
Sustainable resource management and active climate protection as well as the longterm rise in energy prices determine the decision-making processes of municipal waste service providers. Optimised energy utilisation from waste is is a major priority in the strategy of BSR (Berlin City Cleaning Services). As a result BSR started up an organic waste fermentation plant in 2013. The biogas is processed and transformed into biomethane, which is fed into Berlin‘s gas distribution network and then used as fuel for BSR‘s waste collection vehicles that run on natural gas, thereby replacing about 2.5 million litres of diesel.
Greenhouse gases from composting and anaerobic digestion of biowaste in Germany
© European Compost Network ECN e.V. (6/2014)
Greenhouse gas (GHG) emissions from 12 to 120 kg CO2
äq/Mg from composting and anaerobic digestion of biowaste are important for environmental impacts and results in Life Cycle Assessment (LCA). Poor operation can cause even higher emissions up to 400 kg CO2
äq/Mg. The amount of CH4
and primary N2
O differ in a range of factor 10 between different plants and is a result of variation in substrate (feedstock) and basic process parameters like: porosity, density, temperature, moisture, C:N ratio, O2