13 Good Reasons for Biogas Injection

One of the most auspicious applications of biomass is the generation of biogas. In mid-2008 roughly 4,000 plants existed in Germany alone, in which biogas was created through fermentation. Innovative technologies are available on the market, allowing biogas to be upgraded to natural gas quality – also called “biomethane” or “bio-natural gas” – and to be fed into the natural gas grid.

This process makes possible the replacement of conventional natural gas in many areas, thus representing an important contribution to climate protection. Currently, around 16 plants feed biomethane into the natural gas grid in Germany. Several other projects are currently being planned or constructed, with a very clear growth trend. 

1. Biomethane protects our climate

Biomethane (or bio-natural gas) extracted from biomass can replace fossil-based natural gas. It can in this way abate the emissions from greenhouse gases, and thus achieve an important contribution to a sustainable and environmentally friendly energy economy.

CO₂ sources are known to be a primary cause of global warming. Natural energy sources like biomethane release only as much CO₂ as is absorbed from the atmosphere by plants as they mature. Thereby, the ideal circumstances for climate-neutral energy consumption become conceivable.

The utilisation of agricultural waste through biogas generation can make a further contribution to climate protection. The fermentation of liquid manure and the subsequent output in the field reduces the potential of global warming. This positive consequence is unique to biogas production. It is for this reason that biogas and biomethane can be seen as having a more positive influence on the global climate balance than other forms of biomass currently in use. 

2. Biomethane reduces import dependency

Some 97 percent of Germany’s oil and over 80 percent of the country’s natural gas is imported. A large portion of these imports originate in countries whose future political stability remains incalculable. In light of such deterministic geopolitics, the strategic relevance of a secure energy supply has increased in Germany and the EU.

Biomethane is created from indigenous, renewable resources and organic waste products. Legitimate prognoses project a sufficient amount of resources for biomethane to supply 10 percent of Germany’s demand for natural gas by 2030. These calculations take into consideration Germany’s overall energy goals for the future. This state of affairs would allow the country to import less natural gas, and to significantly increase energy security simultaneously. 

3. Biomethane stimulates regional development

The production of biogas from regional resources creates jobs, especially in agriculture, supply logistics, engineering, and plant construction and maintenance.

In particular, this allows local farmers to profit from resulting developments in related “non-food” sectors of local economic development. These sectors provide increased planning security and create an opportunity for alternative sources of revenue.

As plant operators or partial plant owners, the commercialisation and injection of biogas allows farmers to become direct beneficiaries of overall regional economic prosperity. Technology-related occupations in Germany are created, not only to satisfy domestic demand for German biogas technology and German know-how, but also in the German export market. 

4. Biomethane is eco-friendly

A variety of organic materials can be used in biogas plants exclusively, or in combination with others, withoutsubstantial technical alternation to the facility. Typically, crops commonly used for the generation of energy are processed together with biogenic waste, thus providing site-specific adaptability of the energy mixture used.

The cultivation of energy crops is generally associated with the formation of monoculture. However, due to the diversity of resources that can be used for the production of biogas, this is no longer a necessary concern. Moreover, farmers tend to be interested in cultivating a large variety of plants in order to ensure fertility of their cropland.

Existing research projects in this area tend to focus primarily on the implementation and accelerated cultivation of various energy crops. Furthermore, new cultivation methods are being field-tested, and thereby adapted to local conditions.

The production of biomethane necessitates comprehensive understanding of the preservation of biodiversity, contextualised within a multifaceted landscape. The cultivation of fuel crops for the production of biogas is capable of being integrated into existing agro-ecosystems, and provides opportunities for the responsible use of natural resources. 

5.Biomethane secures patterns of material flow at a local level.

The generation of biogas creates a simple and ecological means of harnessing the solar energy preserved within plants, and thereby sustaining the circulation of nutrients locally.

Anaerobic digestion of biomass generates biogas, which can be converted into energy. A digestate is created as a byproduct comprised of all non-digestible substances and all mineral deposits contained within the biomass. In addition to basic nutriment composites found in plants, such as nitrogen, phosphorus and calcium, unused trace elements are also measurable.

Biogas plants are always located in close proximity to areas where biomass is cultivated. This circumvents the need for energy-intensive transportation of energy crops to the plant location, and minimises the cost of redistributing the byproduct throughout surrounding cropland. The byproduct can be used as a commercial fertiliser, thus reducing the costs associated with the regular purchase of manufactured fertiliser. The use of all biogas byproducts ensures the optimisation of the value-added chain of this resource.   

6. Biomethane comes from natural processes

The technical procedure for creating biogas reflects a natural process sequence. Naturally occurring bacteria break down the biomass in the fermenter, similar to the way nutrients are digested in the stomach of a cow. As the bacteria separate the natural fibres of the biomass, biogas emerges as long molecular strands of hydrocarbon. These strands are comprised of roughly 55 percent methane, with the remaining percentage represented in great part by carbon dioxide, as well as minimal amounts of trace gases such as ammonium and hydrogen sulphide.

However, unlike the process in the cow’s stomach, technical processes capture the biogas generated, preventing it from entering the atmosphere.

The energy source in biogas is methane. Once biogas is sufficiently processed to the quality and purity of natural gas it can be injected directly into the natural gas grid. The release of carbon dioxide resulting from the subsequent burning of biomethane is counterbalanced by the retrieval of carbon dioxide from the atmosphere during energy crop cultivation, thus neutralising the atmospheric effects of the process as a whole. 

7. Biomethane stabilizes the energy system

The supply of biogas and biomethane can be maintained all year round. Slurry, manure and organic waste resulting from food processing continue to accumulate. Similarly, harvested biomass is stored in silos designed to be large enough to maintain the necessary supply of energy from biogas throughout the year.

Thus, the production of biogas and biomethane makes an important contribution to a stable and reliable energy supply. The regularity of supply has the ability to balance the fluctuating electricity production originating from alternative renewable energy sources such as wind and photovoltaic.

This advantage is increased by the ability to inject the gas directly into the existing natural gas grid and to use it independently from its production location.  

8. Biomethane uses existing infrastructure.

Once they have been processed, no difference exists between the practical applications of biogas and biomethane and their fossil-based counterparts. That is, biomethane can be injected into the existing natural gas infrastructure, and can be used by conventional technical devices as well.

This means that many appliances used within the residential, industrial or transport sectors can be powered by environmentally friendly biomethane without having to invest substantial amounts of additional resources into the conversion of existing system technology. Thus, the financial burden placed upon the political economy by the integration of biogas and biomethane is minimal. 

9. Biomethane is versatile

Biomethane is more flexible in its application than any other renewable source of energy. Its ability to be injected directly into the existing natural gas grid allows for energy-efficient and cost-effective transport. This allows gas grid operators to enable consumers to make an easy transition to a renewable source of gas.

The diverse, flexible spectrum of applications in the areas of electricity generation, heat provision, and mobility creates a broad base of potential customers. Biomethane can be used to generate electricity and heating from within smaller decentralised, or large centrally-located combined heat and power plants. It can be used by heating systems with a highly efficient fuel value, and employed as a regenerative power source in gas-powered vehicles. The utilisation of biomethane as a source of energy is a crucial step toward a sustainable energy supply.  

10. Biomethane supports efficient combined heat and power systems

Of the estimated 4,000 biogas plants in operation in Germany in the beginning of 2009, only a small portion utilised the energy content of their biogas efficiently. In the majority of cases, biogas was only used for electricity production. The production of heat, which represents some two-thirds of biogas energy output, remained unused due to a lack of viable heat-related applications in the site area.

The upgrading and injection of biogas into the natural gas grid allows biomethane to be brought to other areas, in which the heat generated can be used alongside the electricity generated. The heat generated from biomethane can be used for all forms of household, commercial and industrial applications. These so called combined heat and power systems are, from the perspective of climate protection, the most efficient applications of biogas and biomethane.

The conversion of biogas to biomethane only makes sense in cases where the plant is of a minimum size. New and existing small-scale biogas plants have the option to transport biogas generated, by way of a micro-gas grid, to a larger, more centralised location where the biogas can be processed and fed into the central grid. 

11. Biomethane is a highly efficient biofuel

Biomethane can play a central role in the development of biofuels due to its high energy output per hectare of arable cropland. The complete utilisation of the plant generates a high output comparable to the projected future output of Biomass-to-Liquid (BtL) fuels (see graph).

The production of first generation biofuels (biodiesel, bioethanol and vegetable oil) is solely based upon the oil, sugar or starch content of plants. Biomethane production can increase the value of first generation biofuels if the remaining byproducts (mash, straw/mulch) are utilised. 

In comparison to second generation BtL-biofuels, which will only become commercially viable in the future, biomethane is an existing way to fuel gas-powered vehicles without technical modification. 

12. Biomethane brings partners together

In addition to fully developed technical conceptualisations, the success of biogas injection projects heavily depends upon the development of a practical business model. Having affiliates in the related fields of agriculture, plant construction, and areas of business, such as finance and energy economics, provides an opportunity for the consolidation of know-how and capital for purposes of project realisation. This consolidation facilitates a synergistic relationship among professional players throughout the added-value chain. These players represent the key to further optimisation and exploitation of potential for efficiency. The participating affiliates profit from a lasting return on their investment.

The early integration of external players such as local administrators, residents and environmental organisations can help subjugate conflicts of interest, establish common goals, and develop comprehensive solutions. Central to this process is the exploitation of all merits of the injection of biogas in order to ensure a lasting contribution to the development of a sustainable energy system. 

13. Biomethane is the intelligent option for the future

In addition to prevailing methods of biomethane generation currently in use involving the anaerobic digestion of biomass, research has been conducted in recent years to identify an alternative means of production. The acronym SNG stands for “Synthetic Natural Gas”. It can be created using coal, lignite, or biomass (Bio-SNG). In contrast to biogas production from anaerobic digestion, the biomass in this case is metabolised through thermo-chemical processes. Following the gasification of organic materials, the gas is converted from its raw form into a synthetic gas, methanised, and eventually processed into its final form.

Bio-SNG can also be injected directly into the natural gas grid. Although processes of anaerobic fermentation typically use forms of biomass that have high water content, and are easily metabolised by bacteria, Bio-SNG will primarily employ wood and other more solid forms of biomass such as miscanthus or straw. The type of technology used for Bio-SNG plants allows for the construction of larger plants with greater output potential than those currently in use today. Bio-SNG installations are anticipated to become marketable as early as 2015.

The parallel use of both methods for biomethane production presents an interesting option for the future. The combination of the two processes allows all possible raw organic and waste materials to be efficiently converted into a natural gas substitute which can be used within the natural gas grid. The current generation of biogas by way of anaerobic digestion, and the subsequent treatment and injection procedure, is the first step toward developing a comprehensive strategy for climate neutral gas injection. This strategy will allow biomass to be integrated into the energy system in an efficient and environmentally friendly fashion.