Why biogas plants are important for our environment

Statutory regulations establish the maximum number of animals (livestock units) allowed in a given operation. This clear limitation of mass animal husbandry is intended to prevent the over-fertilization of the soil. Especially in mountainous areas, steep slopes make it difficult to evenly distribute agricultural nutrients. The over-fertilization of steep pastureland can also increase the danger of landslides. Studies show that the nitrate contamination of land in the vicinity of farmsteads is higher than elsewhere. This leads to elevated nitrate concentrations in the groundwater and can present a hazard to human health.

Biogas Wipptal processes only farmyard wastes and liquid manure. No plant (e.g., grains) is processed here. Furthermore, throughout the biogas installation’s service area, no preventative medicines or other substances having physiological effects are introduced into the livestock feed. Medicines are used only for therapeutic purposes and only by authorized veterinarians.

Gases from bovine manure and their utilization

Livestock waste and liquid manure generate such greenhouse gases as methane and CO2; when the wastes are deposited on pastureland, these gases are allowed to escape into the atmosphere. Biogas plants can capture and utilize these gases to generate electrical and thermal energy in so-called modular cogeneration plants. Here, too, Biogas Wipptal is a technological trailblazer. Using the latest membrane technology, it extracts the methane and CO2 from the biogas. These two highly pure gases then undergo complicated processing to produce liquefied methane (LNG) and carbon dioxide. The energy needed to do this can be obtained from the plant’s own biogas generator in a CO2-neutral fashion.

Decarbonization

In order to limit the global increase in temperature to 1.5 °C, no more than 355 gigatons of CO2 can be allowed to enter the atmosphere on a worldwide basis. That is an ambitious goal. At present rates, this CO2 budget will be exhausted in only eight years. The European Union has clearly announced its goal to promote decarbonization and supports Biogas Wipptal in its battle against CO2 released due to the burning of fossil fuels.

Ammonia is of great importance in various technical areas. Most ammonia is used for the manufacture of synthetic fertilizers. However, it is not widely known that the manufacture of ammonia is responsible for a significant portion of global CO2 emissions. Thus, for every ton of ammonia produced, approx. 1.9 tons of CO2 are released into the atmosphere. On a worldwide basis, ammonia production accounts for approx. 2% of total CO2 emissions. This corresponds to about 1,000,000,000 tons of CO2. For comparison: Global street traffic accounts for 1,200,000,000 tons.

With its organic fertilizers derived from natural sources, Biogas Wipptal can help reduce the need for synthetic fertilizers produced from ammonia. This yields a potential savings of up to 3,000,000 kg of CO2 annually.

The production of approx. 9,000 kg of organic LNG per day makes it possible to fuel about 100 trucks in a CO2-neutral fashion. The average truck is responsible for emissions of about 900 grams per km. Given a mean mileage of 100,000 km per year, this means that roughly 90,000 kg/year of CO2 are released into the atmosphere by each truck fuelled with fossil energy sources. Thus, one hundred trucks which switch to the use of organic LNG can avoid about 9,000,000 kg of CO2 emissions.

The regional production of natural carbon dioxide can also make a considerable contribution towards reducing CO2 emissions. Part of the carbon dioxide produced is converted into dry ice with a temperature of -79 °C. This makes it possible to use a new form of refrigerator trucks on a wholly natural basis. Especially in light of the introduction of new propulsion systems for trucks based on LNG and hydrogen, diesel refrigeration equipment is losing appeal. Dry ice guarantees an unbroken cooling chain on a natural basis, and is – in contrast to conventional refrigeration equipment – silent. The use of dry ice can help avoid CO2 emissions averaging about 6.5 kg per hour.

Given a fleet of 50 trucks employing dry ice refrigeration, this would yield approx. 40,000 kg lower CO2 emissions per year.

All in all, Biogas Wipptal has the capacity to reduce CO2 emissions by about 12,000,000 kg per year – chiefly in the agricultural sector and in transport.