Biogas plants – Design, construction, and operation

Renewable energies are increasingly important. An ever growing number of businesses and private households, as well as energy companies, are backing the sustainable creation of electricity and heat from renewable raw materials. Many countries in the world support the expansion and use of renewable energy – this also includes aid and subsidies in the creation and operation of a biogas plant.

BioConstruct plans, builds, and maintains individual AD-Plants for farms and agricultural purposes as well as medium-sized communal plants and industrial waste treatment plants (waste to energy). Farmers, in particular, benefit from a biogas plant on their own farm: the gas generated from solid manure, liquid manure, grass and energy crops can be directly used for electricity generation and building heating or fed into the national grid for profit with a connected, on-site combined heat and power unit (CHP).

The installed electric capacity of biogas plants ranges from around 30 kW to several megawatts. How much electricity is generated by the plant is dependent upon the amount of biogas produced. A farmer can expect to produce 400-500 m³ of biogas per livestock unit per year. Up to 7,000 m³ of biogas can be produced from one hectare of field grass, or even more from energy-rich plants such as turnips or maize. This means that the construction of a biogas plant is not only beneficial to climate and environmental protection, but also a sustainable investment in the farm’s future efficiency and profitability.

Functionality of a biogas plant

When organic substances ferment, biogas is produced. In nature, for example, this occurs in bodies of water and in moors, but also in the stomachs of ruminants. The controlled fermentation process takes place in the fermenters of a biogas plant. In these large containers, the organic substrate is decomposed by methane bacteria. The gas mixture produced by this is around 60 % energy-rich methane biogas. The so-called digestate that remains after this metabolic process can also be completely reused as valuable natural fertilizer.

The process of biogas production takes place in four phases: in hydrolysis, or the liquefaction phase, the starting materials (fat, carbohydrate, and protein) are broken down into their chemical components (such as fatty acids, simple sugars, and amino acids). In acidogenesis, or the acidification phase, the dissolved starting materials are decomposed into organic acids. In the third phase, acetogenesis, or the creation of acetic acid, the microorganisms transform the materials into hydrogen, carbon, and acetic acid, the so-called precursor materials of biogas.

Methanogenesis, or the creation of methane, is the final phase of the process. Without access to air (anaerobically) the methane bacteria first transform the acetic acid into carbon dioxide, hydrogen, and methane. Carbon dioxide and hydrogen are then, in turn, transformed into water and methane. Before further use, the biogas is then desulphurised, cleaned, and prepared for the CHP. If you would like to find out more about modern biogas plant construction and biogas technology, we would be happy to explain all the details to you in a comprehensive information and consultation meeting.

From green field to biogas plant: Planning, permitting, and financing

A permit is required for the construction of an AD-plant and for the generation of biogas. If you would like to operate a biogas plant, you must know the legal requirements and have completed all of the necessary formalities before construction. We are happy to help our customers get biogas permits: we have over 15 years of user and developer knowledge and are therefore very well-versed in the individual steps and procedures. We will smooth the way through the red tape so that your biogas plant will be legally compliant and you can claim all possible aid and subsidies from federal and state governments.

Once the preparations are completed, the biogas plant can be built on the intended spot. Before regular commissioning, we carry out all the necessary checks and a professional inspection. Once this has taken place, you can begin with your farm's own biogas production – and enjoy clean heating and affordable electricity of your own production as soon as next winter.

Which biogas plant meets my requirements?

Four points have to be taken into account in the planning and development of a biogas plant: the availability of raw materials, the selection of the right technology, the qualification of future management, and financing options, including the use of all available subsidies. Once all such questions have been answered and sensibly integrated into an individual concept, then you can begin constructing an AD-Plant that is secure in the long term, of low maintenance, and profitable.

BioConstruct accompanies you through this entire process – from the first idea to construction, commissioning, and beyond. We support you in your profitability calculations and answer your questions on operation, energy utilisation, and biogas financing. We make facts and figures transparent for you, so that you can precisely understand the anticipated costs and profits of your individual requirements.

With our modern SCADA system, BioControl, we ensure that large and small biogas plants always give their best performance whilst working at optimum profitability. The corresponding software was developed by BioConstruct engineers and is also suitable for retrofitting older biogas plants. This allows you to adjust your plant perfectly to your needs (e.g. for summer or winter) – and get a precise overview of the individual sequence of operations at any time.

Our service, too, is all about sustainability

As leading experts in biogas engineering we undertake the monitoring and maintenance of your biogas plant following legally required maintenance intervals. Our repair and replacement parts service is always available to you as a plant operator – as is an emergency service that's available around the clock for rapid troubleshooting. Furthermore, we offer mobile feeding for the bridging of production stoppages. You can also use the BioConstruct expert and biogas services if you operate a plant by a different manufacturer.

Your contact person:

Name: Andreas Bröcker

E-Mail: a.broecker(at)

Tel.: +49 (0) 5226 5932 235