BIOGAS AS AN ALTERNATIVE TO NATURAL GAS
Anaerobic digestion technology, which is used in biogas plants, has successfully proven its ability to process biogenic waste. The biogas complex is a solution to the issue of recycling organic waste in a variety of areas:
- in agriculture;
- during wastewater treatment;
- in the processing of food industry waste;
- at garbage processing enterprises, etc.
Today, more than 1000 anaerobic plants are operating in the world that are involved in the treatment of industrial wastewater. In agriculture, this figure is even higher. Hundreds of enterprises using oxygen-free fermentation use organic residues from municipal solid waste, composting them or turning them into an inactive state suitable for safe disposal.
Anaerobic digestion is a mixed gas, mainly consisting of methane CH₄ and carbon dioxide, commonly called biogas. Biogas is used in heating systems, for the production of electricity, as an alternative fuel in transport.
Agricultural waste processing
Agriculture produces a huge amount of plant and animal residues, the storage and disposal of which takes a lot of money and effort. Partially, we already talked about waste disposal. Now recall that from 1 kg of cattle manure, about 40-50 liters of biogas are obtained, from pig manure – 55-65 liters, from chicken manure – 70-90 liters.
The amount of manure (litter) received from animals per year is determined by the formula: Q year. = D (q + P) m,
where Q is the annual output of manure (litter), kg; D is the number of days of accumulation; q – average daily excretion, kg; P – daily rate of litter per animal, kg; m is the number of animals. If we take into account that only one cow receives from 55 to 70 kg of excrement per day, then in a year this amount will be at least 20 tons, from which at least 800 cubic meters of biogas will come out. And if the farm has 250 goals? The biogas complex successfully solves the problem of processing such quantities of manure, simultaneously receiving valuable energy raw materials for their needs or for sale.
The same situation is in crop production. Straw, silage, sugar beet pulp and other plant residues can be used to produce biogas. So, for example, Ukraine launched the largest biogas plant with a capacity of 7.5 MW on sugar beet processing waste.
According to the Bioenergy Association of Ukraine, the production of biogas from agricultural waste has a potential of up to 18 billion cubic meters in terms of natural gas.
Why is recycling necessary?
The volumes of garbage accumulation in Ukraine are simply amazing: per inhabitant there are about 300 tons! And only 5.93% of them are subjected to varying degrees of processing, mainly burned. We are talking about municipal solid waste, which includes 85% of organic matter.
In Europe, the separation of garbage by type and their corresponding processing has long been adopted. For example, in Germany, about 90% of municipal solid waste is recycled. Our country is very, very far from these indicators. And the potential for profit and, most importantly, the improvement of the environmental situation is huge.
At the moment, only food waste makes up at least 30% of the total amount of garbage. This is a huge array of raw materials for producing alternative fuel, which can then be used in thermal power plants for heating or for generating electricity.
Some changes for the better still occur, but these are isolated examples.
So, in 2019, a new biogas plant at the solid waste landfill was launched in Mariupol. It will produce more than 10 million kWh of electricity per year.
According to the press service of the State Agency for Energy Efficiency and Energy Saving, a total of 24 biogas plants with a total capacity of 22 MW produce landfill gas at solid waste landfills. Nationwide, this is a drop in the bucket, and the prospects for landfill gas production are very impressive.
How does biogas production affect the environment?
The product obtained at the exit from the biogas station contains 50-70% methane. To use it in the fuel systems of transport or transfer to gas transmission systems, it is necessary to carry out the so-called modernization, or the most complete cleaning of impurities. First of all, they include hydrogen sulfide and carbon dioxide. The methane content must be brought to the level of natural gas, which is 95-99%. Only then can biomethane be transferred to a common gas distribution network. There it is mixed with natural gas and used:
- to receive electricity;
- for heating purposes;
- at gas stations for cars.
In addition, alternative fuel from waste is cheaper than purchased natural gas, which saves significant money.
It should be emphasized that the production of biogas from household, industrial or agricultural organic waste reduces the burden on the ecosystem, improves the local environmental situation and allows you to save resources, including land, for other purposes.
Can biomethane be used instead of natural gas?
Long before the biogas production reaches the planned targets and the biogas complex reaches its design capacity, we need to talk about the use of gas. Already at the design stage, it should be foreseen how much and how much biogas will be consumed for the company’s own needs, and how much can be processed into electricity or sold.
Article 19 of the Law of Ukraine “On the Natural Gas Market” as amended on December 29, 2019 gives business entities the right to access gas transmission networks. For this, gas produced from any type of organic raw material using anaerobic fermentation technology must comply with the physical and technical characteristics of natural gas in accordance with the industry standard.
What does this give the owner of a biogas plant? This means that biogas, which has passed all stages of purification and is identical in its properties to natural gas, can be supplied to a common network, from where it will be supplied to enterprises and consumer organizations. Such gas – biomethane – is produced by a modern high-tech biogas plant with several stages of purification, from condensation of water vapor to membrane impurity absorption devices. Ecodevelop company selects equipment from leading European manufacturers for its projects.
Alternative Fuel Prospects
As we saw in the above examples, the construction of a biogas station and the production of biogas can solve several problems:
- recycle production waste;
- heat premises with own biogas;
- generate electricity and sell it at a green tariff;
- to sell biomethane to enterprises in exchange for natural gas.
The latter aspect is very important due to the decrease in dependence on the fossil, and therefore the final source of energy. The more biomethane will be produced, the less procurement will be needed on foreign markets. This creates the energy independence of the enterprise in particular and the country as a whole, and gives freedom of maneuver when solving social and other problems.
The biomethane market is in its infancy, but has excellent prospects. Ecodevelop invites interested parties to join together in this field.