While currently a lot about EEG novella 2012 and possible impacts for bioenergy are discussed, some plant operators develop their biogas plants further, make them more modern and add treatment plants for biomethane. Today I would like to present an interesting example of a new biogas park in Barsikow in Brandenburg with an innovative heat utilization concept.
You will find the effects of the 2012 EEG amendment on the biogas industry in this article (added on August 18.8.2011th, XNUMX)
Repowering of biogas plants
The further development of an existing technology and the adaptation to changing customer requirements is usually a prerequisite for the long-term success of a product. This principle naturally also applies to biogas plants, which have to adapt as well as possible to changing market conditions or society's requirements. Continuous improvement is also one of the central requirements of every quality management system according to ISO 9001.
Repowering is often referred to as technological adaptations to existing systems. The following is a list of possible starting points and measures for repowering biogas plants:
- Exchange of heavily used system parts (e.g. agitators, feeders)
- Increase in the energy efficiency of the biogas plant (e.g. exchange of the CHP)
- Integration of a processing and feed-in system for biomethane or bio natural gas
- Improvement of emission / exhaust gas values (e.g. formaldehyde for EEG bonus)
- Pretreatment of the substrates to improve their digestion
- Improvement of living conditions for microorganisms
- Increase the throughput of the fermenter
If the necessary investment sums are available, there are numerous ways to optimize a biogas plant. The painful “never change a running system” experience must of course be carefully weighed up at this point. A risk that is particularly well known among operators with a pronounced pioneering spirit.
Repowering is often about increasing the efficiency of the existing system. This also includes the use of the heat generated during electricity generation. The creation of the most comprehensive heat utilization concept possible - there are some examples of heat use concepts here - still one of the most difficult points when planning an economically well-running biogas plant.
Biogas park in Barsikow with a processing plant for biomethane
Im Brandenburg Barsikow an interesting way is taken to solve this "heat problem", which improves the energy balance of the system and at the same time enables the production of another bioenergy product.
The planned biogas park with 3 fermenters and 4 fermentation residues will be around 2011 m from 1.0003 Produce biogas per hour. What is currently still special about this biogas plant is the planned processing plant for biomethane. So with 480 m3/ h, about half of the biogas obtained is further processed into bio natural gas and fed into the natural gas network. The other half of the biogas is converted into electricity directly on site.
Viewed over the whole year, the production in Barsikow Park is 4,3 million m3 Biomethane reached. Generously calculated, this corresponds to approximately 0,1% of the annual production of 6 billion m targeted by the Federal Government3 Bio natural gas in 2020.
Micro gas turbine supports amine scrubbing from biogas to biomethane
The biogas park in Barsikow, financed and operated by Nordmethan GmbH, a subsidiary of Weltec Biopower GmbH, will use what is known as "amine scrubbing" as a treatment process for the raw biogas. A 200 kW micro gas turbine from the Berlin company Greenvironment GmbH is also used to generate electricity from the biogas.
Particular attention should be paid to the combination of amine scrubbing and micro gas turbine, as it is very elegant in terms of process technology and means that the heat generated during the conversion of the biogas into electricity can be used directly on site as process heat!
There are three main process steps required for biogas upgrading, some of which have a constant need for process heat:
- Biogas desulfurization
- Carbon dioxide separation
- Gas drying
With the help of amine scrubbing, the hydrogen sulfide and carbon dioxide are to be separated from the biogas. The biogas is passed through an alkaline aqueous solution of amines, the amines being the undesired gases reversible tie. The amines are then dissolved again by heating the acid gas to 140 ° C. and can be used again.
The heat generated when the biogas is converted into electricity can be used to heat the gas. Since micro gas turbines have a particularly high thermal efficiency due to their recuperator (heat exchanger), they are very well suited for use in biogas plants using treatment plants.
I have already discussed different types of combined heat and power units for generating electricity from biogas in an earlier article - see comparison of CHP - juxtaposed. The 200 kW micro gas turbine of the Greenvironment GmbH (Manufacturer Capstone), which, in addition to classic internal combustion engines, offers the possibility of converting biogas into electricity using combined heat and power technology.
Other processes for processing the biogas are pressure swing adsorption (PSA) and pressurized water washing.
Cascade use of biomass in the Arneburg industrial park
With the planning for a similar biogas park in the industrial park in Arneburg / Saxony-Anhalt, a colorful mix for the material and energetic use of biomass is created under the leadership of Nordmethan GmbH.
In Arneburg there is already a comprehensive infrastructure for the material use of biomass (wood) with one of the most modern and largest pulp mills in Central Europe (Zellstoff Stendal GmbH) and a paper mill (Delipapier GmbH). In addition, the pulp mill in Arneburg with 100 MW is also the largest biomass power plant in Germany.
The new biogas park combines traditional (pulp) and relatively young (biomethane) usage paths for renewable raw materials at the site. Perhaps there are opportunities for a comprehensive cascade concept with which various material and energetic usage paths of biomass can be combined.
Which adjustments for bioenergy should be included in the EEG amendment?
The various experts and interest groups have not yet agreed on the way in which the Renewable Energy Sources Act should be adapted. This is currently leading to hot discussions, which will hopefully ultimately lead to a coherent and accepted concept for the bioenergy industry. There is agreement on the point that an adjustment is necessary to counteract undesirable developments, such as the increasing maize monocultures in some districts.
Which technologies or input materials are to be promoted, which developments are prevented and which measures are used? What ideas or criticism do you have for the amendment to the EEG? A selection of change approaches that are currently being discussed, Is there ... here.