Biogas is the cleanest fuel on the market
In Sweden, we lead the world in the use of biogas as a vehicle fuel
Biogas is the renewable alternative to fossil gas
Industrial production is normally carried out in large digesters where an active bacterial flora breaks down the organic material, converting it into so called raw gas. In parallel, a digestate is generated, which in many cases can be used as a nutritive bio-fertilizer. Spread over arable land, it replenishes the earth with important nutrients such as nitrogen, phosphorus, potassium and magnesium.
Biogas production is a natural process, in which organic material is broken down by microorganisms in an oxygen-deficient environment
Between 0.5 and 1.0 cubic meter of biogas can typically be extracted from one kilo of dry organic material. However, the amount of biogas actually produced depends on the type of organic material used, the type of pretreatment and the digestion system as well as the know-how behind operating an efficient biogas production process. Using Scandinavian Biogas’ qualified expertise the biogas production can increase up to four times compared to conventional processes.
The main component of biogas is methane (CH4). Methane is a high-quality, energy-rich energy carrying gas generated by the anaerobic, decomposition of organic matter. During anaerobic digestion biogas is formed from fresh organic material and recycled in the biosphere, which means that no additional fossil carbon dioxide is being produced.
Improved resource efficiency
Many businesses that handle organic material have a resource that they are not using to its full potential
Cities, municipalities, food manufacturers as well as producers of ethanol and companies in the paper and forestry industries could potentially convert their organic waste and residues into a valuable resource that can be used as vehicle fuel or converted to electricity and heat. The biogas generated from the waste can become a locally produced renewable energy carrier that can be converted into electricity or can be purified and used as vehicle fuel. For many industries and countries alike, biogas production is a way of increasing access to renewable energy and reducing dependence on imported fuel, often fossil fuel.
Biogas production means that organic waste is reused and converted into a resource
Biogas is a product of the anaerobic decomposition of organic matter through digestion and can be generated from waste, residual products, energy crops and forestry materials. Sewage sludge from wastewater plants is often used, as is food waste from restaurants and households as well as residual products from ethanol production, farming and the food industry. In addition to biogas, the process generates a nutritive residue, which in many cases can be used as fertilizer.
The environmental benefits of the production of biogas are quite simply dependent on the type of substrate used, along with the type of pretreatment applied, as well as how well the organic material is digested in the process. The digestion of waste for biogas production entails better utilization of already used resources, while residues, waste products, energy crops and forestry material can be transformed into renewable fuel under the right conditions. In many cases, the anaerobic digestion of biogas also means less emissions of flue gases and other pollutants.
Renewable fuels are strategically important
Today, over thirty cities in Sweden power their municipal buses with biogas, which is also used by taxis and sanitation companies. Many industries also use renewable fuel, which like biogas, has become strategically important and at times even a prerequisite for doing business.
Light vehicles – Compressed biogas (CBG) for light vehicles is currently the main segment for biogas in Sweden, although this market is currently dependent on policy instruments. The market is also limited by the supply of gas cars and filling stations. In Sweden, filling stations are mainly concentrated in metropolitan areas, along the natural gas pipeline on the country’s west coast, and in Bergslagen. It is today possible to drive a gas vehicle throughout Göta- and Svealand and along the entire Norrland coast.
Buses – Public transport is a strong market for biogas and will remain a key driver in the industry. In 2017, approximately 20 per cent of Sweden’s buses ran on biogas, a year-on-year increase of 10 per cent when calculated by number of vehicle kilometres. Municipalities often oversee treatment plants as well as public transport, which has provided opportunities for local cycles that utilise waste. Stockholm Public Transport (SL) and its operators are the players in Sweden that use the most biogas.
Heavy transport – An increasing number of heavy vehicles are powered by alternative fuels such as biogas. This also applies to long-haul traffic. Volvo, Scania, MAN, Mercedes and Iveco are some of the companies that have invested heavily in developing efficient, sustainable fuel solutions. The Euro 6 gas engine is essentially as effective as a diesel engine. Meanwhile, interest in gas trucks and lorries is on the rise in several European countries. Since freight transport is normally done across national borders, this affects conditions for biogas use also in Sweden and Norway. Renewable alternatives such as biogas also benefit from the expected rise in oil prices in the long term. Liquid biogas production and access to filling stations are factors that are currently limiting the use of biogas as a fuel for heavy transport.
Shipping – The shipping sector has increased its use of gas as fuel in recent years. A 2017 review of newly ordered vessels with links to Sweden showed that half of all new vessels were built to run on gas. Although mainly liquid natural gas is being used, biogas can easily be blended with natural gas, or can replace it entirely. This trend has its origin in the sector’s environmental ambitions and tough new sulphur emissions standards for the Baltic Sea. Neither natural gas nor biogas give rise to sulphur emissions. Carbon dioxide emissions can be reduced by around 30 per cent using natural gas instead of heavy oil, and by a full 120 per cent using biogas. Supplying the shipping sector’s needs, however, requires large quantities of gas. As the supply of LBG increases, several shipping companies are ordering gas-powered vessels. And as more and more vessels are powered by gas, the need for biogas (LBG) also increases dramatically.
Industry – Approximately 9 TWh of gas is used annually by Swedish industry, with biogas representing only a small share of this amount. Most of the industries that use gas are located along the gas grid on Sweden’s west coast. In addition to reducing climate impact, the transition to gas from oil and other fossil fuels enables more precise process control. The food industry is therefore particularly interested in gas as a fuel. Estrella, for example, has been using biogas in its production of crisps and snacks since 2017, reducing its carbon emissions by 92 per cent. Stronger financial incentives and increased LBG production would enable biogas to achieve a real impact in industry.
Enormous growth potential in Europe
According to estimates, the market for methane-fuelled vehicles in Europe has enormous potential. European trade association NGVA expects the vehicle fleet to be 13 million strong by 2030, distributed between passenger cars, light vehicles, buses, heavy vehicles, and ships. This represents a ten-fold increase from current levels. The development potential for gas-fuelled lorries is deemed particularly significant – from the current 2,500 vehicles to 280,000 in 2030. The supply of renewable gas is expected to increase in parallel with this development.
Biogas is the result of a biological process
The term digestate is commonly used as a general name for “digested sludge” and “biofertilizer”. Digested sludge is the residue that comes from the anaerobic digestion process at wastewater treatment plants, while biofertilizer is the residue from co-digestion plants. Digestate contains all nutrients that initially in the substrates and it is often rich in nitrogen, potassium and phosphorus. It also contains calcium, sulfur, magnesium, micronutrients and humus. Hence, it is a perfect alternative to chemical based fertilizers. To reuse nutrients helps us to recicle them and avoid a possible future shortage of, for example, phosphorus, which is a central nutrient in today’s intensive agriculture.
At Södertörn we have three different digestate fractions: liquid, dewatered and concentrated and all three are sold to agriculture
Liquid digestate is sold in the proximity of the plant, while dewatered digestate (rich in mainly phosphorus and humus) has a larger geographic market because it is easier to be transported. The concentrate is the remaining fraction after evaporation of reject water obtaibed during the dewatering step. This fraction mainly contains nitrogen and potassium.
The Liquid digestate at Södertörn is certified according to “Certified recycling” (SPCR120). The certification is voluntary and is based on openness towards the customer providing quality documentation and free transparency regarding the product’s quality.
Increasing demand to reach renewable energy targets
A growing world population, hand in hand with better living standards for many, means that global energy consumption is increasing and will continue to increase. Based on 2017 data provided by the Swedish Energy Agency, 81% of the global energy supply is made up of fossil fuels, while renewable energy including hydropower constitutes around 14%, with nuclear power comprising 5%. Indeed, the current energy situation contributes to an increase in carbon emissions.
Sweden leads development
In Sweden, the share of renewable energy amounted to 41% t in 2017. We are also a leading nation in the use of eco-friendly fuels in the transport sector. Despite this, the availability of renewable energy at competitive prices poses an enormous challenge for Sweden too.
National Biogas strategy 2.0
Politicians in Sweden continue to push for development towards a more sustainable society and have set up a target for a fossil fuel free transport sector by 2030, as well as to be an emissions neutral country by 2050. According to the Swedish Transport Administration, in order to achieve these goals, the share of fossil fuels used in road transport needs to decline by 80% and that the availability of biofuel must reach levels of between 15-20 TWh by 2030.
In 2018, the Swedish Gas Association louched the National Biogas strategy 2.0. The purpose of the strategy is to contribute to achieve Sweden’s established goals within the majority of prioritised policy areas through increased use of biogas within the transportation, industrial and co-generation sectors. The goal is to achieve at least 15 TWh use of biogas in Sweden by 2030. Based on Scandinavian Biogas’s calculations show that about 15 TWh of biogas could be produced from residual products from agriculture and from various waste streams in society, which corresponds to roughly the same percentage of Sweden’s total fuel consumption. Additional gas is expected to be recovered in the future by thermal gasification of forest raw materials.
Figure – Biofuel consumption in the swedish transport sector. Out of 88 TWh total usage, 19 TWh (22%) comes from biofuels, 3 TWh from electricity and the remaining part from fossil based fuels (Swedish Energy Agency, 2018). Whitin the biofuels, the share of biogas is 7% (1.3 TWh). In Sweden, the overall biogas production during 2017 was ca. 1.6 TWh: +20% compared to 2016 and +60% compared to 2010.