Biomethane Industry in Europe

Biomethane is a well-known and well-proven source of clean energy, and is witnessing increasing demand worldwide, especially in European countries. Between 2012 and 2016, more than 500 biomethane production plants were built across Europe which indicates a steep rise of 165 percent. The main reasons behind the growth of biomethane industry in Europe is increasing interest in industrial waste-derived biogas sector and public interest in biogas.  Another important reason has been the guaranteed access to gas grid for all biomethane suppliers.

Biomethane production in Europe has swiftly increased from 752 GWh in 2011 to 17,264 GWh in 2016 with Germany being the market leader with 195 biomethane production plants, followed by United Kingdom with 92 facilities. Biogas generation across Europe also witnessed a rapid growth of 59% during the year 2011 and 2016. In terms of plant capacities, the regional trend is to establish large-scale biomethane plants.

Sources of Biomethane in Europe

Landfill gas and AD plants (based on energy crops, agricultural residues, food waste, industrial waste and sewage sludge) are the major resources for biomethane production in Europe, with the predominant source being agricultural crops (such as maize) and dedicated energy crops (like miscanthus). In countries, like Germany, Austria and Denmark, energy crops, agricultural by-products, sewage sludge and animal manure are the major feedstock for biomethane production. On the other hand, France, UK, Spain and Italy rely more on landfill gas to generate biomethane.

A large number of biogas plants in Europe are located in agricultural areas having abundant availability of organic wastes, such as grass silage and green waste, which are cheaper than crops. Maize is the most cost-effective raw material for biomethane production. In many parts of Europe, the practice of co-digestion is practised whereby energy crops are used in combination with animal manure as a substrate. After agricultural biogas plants, sewage sludge is one of the most popular substrates for biomethane production in Europe.

Biomethane Utilization Trends in Europe

Biomethane has a wide range of applications in the clean energy sector. In Europe, the main uses of biomethane include the following:

  1. Production of heat and/or steam
  2. Power generation and combined heat and power production(CHP)
  3. Replacement for natural gas (gas grid injection)
  4. Replacement for compressed natural gas & diesel – (bio-CNG for use as transport fuel)
  5. Replacement for liquid natural gas – (bio-LNG for use as transport fuel)

Prior to practically all utilization options, the biogas has to be dried (usually through application of a cooling/condensation step). Furthermore, elements such as hydrogen sulphide and other harmful trace elements must be removed (usually trough application of an activated carbon filter) to prevent adverse effects on downstream processing equipment (such as compressors, piping, boilers and CHP systems).

biomethane-transport

Biomethane is getting popularity as a clean vehicle fuel in Europe. For example, Germany has more than 900 CNG filling stations, with a fleet of around 100,000 gas-powered vehicles including cars, buses and trucks. Around 170 CNG filling stations in Germany sell a blend mixture of natural gas and biomethane while about 125 filling stations sell 100% biomethane from AD plants.

Barriers to Overcome

The fact that energy crops can put extra pressure on land availability for cultivation of food crops has led many European countries to initiate measures to reduce or restrict biogas production from energy crops. As far as waste-derived biomethane is concerned, most of the EU nations are phasing out landfill-based waste management systems which may lead to rapid decline in landfill gas production thus putting the onus of biomethane production largely on anaerobic digestion of food waste, sewage sludge, industrial waste and agricultural residues.

The high costs of biogas upgradation and natural gas grid connection is a major hurdle in the development of biomethane sector in Eastern European nations. The injection of biomethane is also limited by location of suitable biomethane production facilities, which should ideally be located close to the natural gas grid.  Several European nations have introduced industry standards for injecting biogas into the natural gas grid but these standards differ considerably with each other.

Another important issue is the insufficient number of biomethane filling stations and biomethane-powered vehicles in Europe. A large section of the population is still not aware about the benefits of biomethane as a vehicle fuel. Strong political backing and infrastructural support will provide greater thrust to biomethane industry in Europe.

Feedstock for AD Plants

Anaerobic digestion is the natural biological process which stabilizes organic waste in the absence of air and transforms it into biofertilizer and biogas. Almost any organic material can be processed with anaerobic digestion.

Biogas_Plant

Anaerobic digestion is particularly suited to wet organic material and is commonly used for effluent and sewage treatment.  This includes biodegradable waste materials such as waste paper, grass clippings, leftover food, sewage and animal waste. Large quantity of waste, in both solid and liquid forms, is generated by the industrial sector like breweries, sugar mills, distilleries, food-processing industries, tanneries, and paper and pulp industries. Poultry waste has the highest per ton energy potential of electricity per ton but livestock have the greatest potential for energy generation in the agricultural sector.

Agricultural Feedstock

Community-Based Feedstock

  • Organic fraction of MSW (OFMSW)
  • MSW
  • Sewage sludge
  • Grass clippings/garden waste
  • Food wastes
  • Institutional wastes etc.

 Industrial Feedstock

  • Food/beverage processing
  • Dairy
  • Starch industry
  • Sugar industry
  • Pharmaceutical industry
  • Cosmetic industry
  • Biochemical industry
  • Pulp and paper
  • Slaughterhouse/rendering plant etc.

Anaerobic digestion is particularly suited to wet organic material and is commonly used for effluent and sewage treatment. Almost any organic material can be processed with anaerobic digestion process. This includes biodegradable waste materials such as waste paper, grass clippings, leftover food, sewage and animal waste. The exception to this is woody wastes that are largely unaffected by digestion as most anaerobic microorganisms are unable to degrade lignin.

Anaerobic digesters can also be fed with specially grown energy crops such as silage for dedicated biogas production. A wide range of crops, especially C-4 plants, demonstrate good biogas potentials. Corn is one of the most popular co-substrate in Germany while Sudan grass is grown as an energy crop for co-digestion in Austria. Crops like maize, sunflower, grass, beets etc., are finding increasing use in agricultural digesters as co-substrates as well as single substrate.

A wide range of organic substances are anaerobically easily degradable without major pretreatment. Among these are leachates, slops, sludges, oils, fats or whey. Some wastes can form inhibiting metabolites (e.g.NH3) during anaerobic digestion which require higher dilutions with substrates like manure or sewage sludge. A number of other waste materials often require pre-treatment steps (e.g. source separated municipal organic waste, food residuals, expired food, market wastes and crop residues).