BIOGAS AND ITS POSSIBILITY OF USE IN KAZAKHSTAN

Due to the constantly growing demand for energy and increasing of their cost, environmental degradation, reduction of oil reserves, coal, gas and other fossil fuels, the issues of energy saving, as well as the search for new alternative energy sources for both our state and the global community are becoming urgent.

For life, a person needs energy that is used daily and everywhere. Traditional sources of energy, such as: oil, coal, natural gas, have limited reserves. With the development of technology, the degree of energy consumption is growing at an enormous pace. In order to meet the ever-increasing energy needs, it is necessary to use local renewable energy resources, for example, wind and solar energy, hydropower, bioenergy [1].

Biogas is a combustible gas mixture produced during the fermentation of biomass (organic waste) by exposing it to various types of bacteria. Microorganisms metabolize carbon from organic substrates under anoxic conditions (anaerobic). As a result of the digestion of biowaste, biogas is produced [2].

Biogas has great potential to meet sustainable energy demand, especially for countries and regions with low availability of fossil fuels and nuclear facilities. In fact, biogas energy comes from biomass, which is a biodegradable fraction of products, waste and agricultural residues (including plant and animal matter), forestry and related industries, as well as a biodegradable fraction of industrial and household waste.

In world practice, we can observe a large number of examples of the use of biogas. In recent years, biogas production in Europe significantly increased, both in terms of the number of plants and in terms of installed capacity. Germany, the United Kingdom (Great Britain), Italy, Spain and France are the leaders in biogas production in Europe. In Germany, most biogas is produced from agricultural waste and energy crops. Denmark and the Netherlands also produce a significant proportion of their biogas from agricultural substrates, approximately 70% and 59%, respectively [4, 5].

It can be assumed that there is a great potential for further increasing the production of biogas from agricultural waste and energy crops. For example, according to the European Biomass Association (EBA), the real potential for biogas production in the European Union (EU) countries is about 465 TW-h, which is equivalent to 40 million tons of fossil oil. Today, total biogas production in Sweden is 1.8 TW-h, which is produced at 277 biogas plants, including 37 farm biogas plants with a capacity of 44 GW-h each.

Kazakhstan is an agro-industrial country where about forty-three percent of the population lives in a rural areas, ranks ninth place in the world by its territory, with an average population density of only 6.3 people / m². Therefore, to warm the living quarters in winter, to introduce to civilization, connecting all the settlements to the electrical networks, for our country it is not easy and quite expensive. Many territories are far from oil and gas pipes, coal mines and woodlands, as well as high-voltage power lines. In order for electricity to enter the outlet, you need to extract coal or oil, take them to the power station, burn it, get steam, pass it through a steam turbine that will transfer energy to electric generators, feed it through a transformer to a high-voltage power line to consumption areas, reduce it through transformers voltage up to 220V household power, send to homes by wire or cable, pass through the energy meter and only then bring to the sockets and switches. On this long journey, up to half of the electricity generated by the power plant is lost, which, in turn, due to the characteristics of the technology, loses more than half of its fuel energy. As a result, the final consumer receives no more than 20-25 % of the energy of the fuel, the remaining 75-80 % heat the atmosphere, accelerating its global warming.

In the Republic of Kazakhstan, in which territory agriculture is actively developing, there are many livestock and poultry farming enterprises. As a result of such enterprises, a large amount of organic waste is generated, the disposal of which will ensure environmental safety of the atmosphere.

Agrarian complexes have invaluable energy sources, such as: manure, droppings, brewer's grains, beet pulp, fecal sediments and a huge amount of other organic waste, from which, after a certain technological process, biogas is obtained. This type of fuel is economical, since 1 m3 of biogas is equivalent in terms of heat of combustion: 0.8 m3 of natural gas, 0.7 kg of fuel oil or 1.5 kg of firewood [6].

In addition, if biogas is used to produce electricity, its prime cost is only $ 0.025–0.075 kW per hour, while electricity from traditional sources costs between $ 0.1–0.15 kW per hour. Thus, biogas is 2-4 times more economical.

Such conclusions were made by the staff of the SPA (Scientific Production Association) Ecomuseum in Karaganda, who successfully implemented a project to obtain biogas from organic waste. Also in Kazakhstan, the Kazakh Scientific Research Institute of Agricultural Mechanization and Electrification (KazSRIAME) is developing biogas plants, which developed the bioreactor BI-5(bioreactor installation) with a working volume of 5 m³. The technological scheme also includes: a gas tank with a volume of 5 m³, a loading ladle-dosing unit, a heat exchanger, a fuel boiler with an automatic gas burner. They are engaged in the installation of plants in the farms of Aktobe and Almaty regions.

A biogas plant that produces biogas (biomethane) based on anaerobic bioconversion (digestion) of organic waste is an integral part of waste-free, more modern production.

By processing agricultural waste in biogas plants, it is possible to ensure the management of biogas and use it in any household gas appliances, and as highly efficient organic bio-fertilizers, the use of which contributes to an increase in soil productivity by 10–30 % [1].

Biogas production from organic waste is based on their ability to release combustible gas, due to the so-called "methane fermentation" in anaerobic (without air access) conditions. In turn, “methane digestion” occurs during the decomposition of organic substances due to the vital activity of microorganisms. Biogas is a mixture consisting of 50–80 % methane gas, 50–20 % carbon dioxide, and about 1 % hydrogen sulfide, and may also contain some other gases, such as nitrogen, oxygen, hydrogen, ammonia, etc. [1].

In modern conditions, the advantage of biogas, compared with other types of renewable energy sources (VEI) and traditional energy sources, is the availability of raw materials, as well as the complete absence of fuel costs. The availability of raw materials is determined geographically, so biogas plants can be located in any area and do not require the construction of expensive gas pipelines and network infrastructure.

As a source of raw materials can be used any liquid fast-decomposing organic waste from farms, poultry farms, oil mills, meat processing plants, etc. In the balance of raw materials the largest part is manure of cattle, pigs, bird droppings. In EU countries, manure accounts for 89% of biomass processed in bioenergy plants. Raw materials for the production of biogas is estimated by the biogas yield (m³) per unit of organic mass (OM) and unit of biomass (BM).

One of the important factors that affect the production of biogas is temperature. With its increase, there is an increase in the speed and degree of fermentation of raw materials.

The second important factor is the quality of organic raw materials. It must be available for decomposition by methane-forming bacteria, with a neutral pH value, without the content of compounds that prevent the growth of bacteria, for example, soap, powders, antibiotics, etc.

Table 1 presents data on the output of biogas from various organic waste.

Table 1.

Biogas yield from organic matter

Conclusions:

Biogas production has become a promising technology for converting agricultural waste of animal and vegetable origin, as well as industrial and municipal waste into thermal and electrical energy.

The use of biomass for energy production is one of the alternatives that has recently become attractive worldwide as a clean and sustainable source of energy.

The Republic of Kazakhstan has a sufficient amount of necessary raw materials for the successful implementation of technologies for the production of biogas in various sectors of the economy.

Bibliography:

1. Малофеев В.М. Биотехнология и охрана окружающей среды. М.: Арктос, 2012. - 432с.
2. B. Linke, Country Report, Germany, 2015. Available from, http://www.ieabiogas.net/country-reports.html. IEA Bioenergy Task 37.
3. T. Al Seadi, IEA Country Report Denmark, 2015. Available from, http://www.iea-biogas.net/country-reports.html. IEA Bioenergy Task 37.
4. T. Persson, D. Baxter, IEA Bioenergy Task 37 - Country Reports Summary 2014, 2015. Available from, http://www.iea-biogas.net/country-reports.html. IEA Bioenergy Task 37.
5. AEBIOM, A biogas road map for Europe, AEBIOM, European biomass assiciation, 2009. Available from, http://www.seai.ie/Renewables/AD_In_Ireland_22nd_October/A_Biogas_Roadmap_for_Europe.pdf.
6. Интернет-портал сообщества ТЭК [электронный ресурс] // www.Energyland.info