Regional Biogas Development Strategy and Action Plan - Tartu

More documents

Recommendations

Info

4.2. Environmental aspects and impacts of biogas The structure describing the environmental impact caused by commissioning a biogas plant is similar to the description of impact caused by its construction. Environmental impact caused by the commissioning of a plant is divided as follows: 1) impact on living nature; 2) impact on the soil and landscape; 3) impact on the air environment; 4) impact on the water environment; 5) impact on the visual environment and cultural heritage; 6) noise and vibration 36 . 4.2.1. Impact on living nature Impact on vegetation There will be no impact on vegetation during the biogas production process itself. Yet biogas production has an indirect impact on plant production via the use of fermentation waste as fertiliser. In addition to fertilising properties, the use of fermentation waste reduces the spread of weeds on fields, since the majority of such seeds are destroyed during the production process. Yet it has to be considered that in the event that the digestate used as fertiliser contains pieces of plastic (for instance plastic bags), the value of it is much lower than that of a clean digestate 37 . As a rule, the ratio of carbon and nitrogen is smaller in fermentation waste than in biomass itself. Thus the binding capacity of nitrogen with the soil is lower and the availability of nitrogen contained in fermentation waste for plants improved. To reduce ammoniac losses, fermentation waste should enter the soil as soon as possible (Biogas production and use. Manual 2009). Impact on animals Biogas production has no critical impact on animals 38 . 4.2.2. Impact on the soil and landscape Operating a biogas plant involves the use of grease in small quantities and maintenance chemicals required for the operation of machines. Impact on the soil is related to emergency cases and accidents, the probability of which is very low 39 . 36 Feasibility and profitability study - Construction of a biogas plant to produce fuel for Tartu city buses .ERKAS, Valduse OÜ, 2011. 37 Ibid. 38 Ibid. 39 Feasibility and profitability study - Construction of a biogas plant to produce fuel for Tartu city buses 24
4.2.3. Impact on the air environment The closed system of biogas production is not influenced by weather conditions. Also, smell is kept under control, since gas is directed into tanks where it is used for consumption: nothing is emitted into the outside air 40 . Smells Although the production process of biogas takes place is in a closed system, unpleasant smells may still be produced. This is mainly during the storing of substrate before production of biogas starts. Spread mostly depends on the direction of the wind. According to data from 2005 received from Tartu-Tõravere meteorological station, the prevailing winds in the Tartu area are southwest and west (Tartu Biogaas OÜ Ilmatsalu biogas and co-generation plant. Pre-assessment of strategic evaluation of environmental impact. 2010). It is estimated that in the fermentation process, the smell of manure and other biodegradable waste will be reduced by up to 80% (according to Tuomisto Mattila, 2005). In order to reduce smell pollution, the substrate must be stored according to requirements (for as short a period as possible, with good ventilation in the room) and emission of gases collected in the fermentation process and smells into the outside air should be avoided 41 . Emission of greenhouse gases On average, biogas contains 60-70% methane, 30-40% carbon dioxide, less than 1% hydrogen sulphide and to a lesser extent other gases. In high temperature conditions the fermentation process is shorter, methane production is greater and the substrate is sanitised more efficiently (Tuomisto 2005). A biogas plant emits relatively few greenhouse gases, but emission of ammonia is relatively high due to the fact that fermentation waste and digestates generated after gas production are spread on the surface. To reduce ammoniac losses, the digestate should enter the soil as quickly as possible (Biogas production and use. Manual 2009). In the process of biogas production, nitrogen is bound in the digestate, reducing the emission of nitrogen oxide (a strong greenhouse gas) compared to the composting of biodegradable matter or storing in landfill. At the same time, fermentation waste must meet certain quality requirements (to be probably stipulated in future) so that it can be used as a fertiliser on fields 42 . Methane generated in biogas production is used for energy production. This reduces the total emission of methane as a greenhouse gas. In general, the use of fossil fuels is reduced as is the emission of greenhouse gases caused by it 43 . .ERKAS, Valduse OÜ, 2011. 40 Ibid. 41 Ibid. 42 Feasibility and profitability study - Construction of a biogas plant to produce fuel for Tartu city buses 43 Ibid. .ERKAS, Valduse OÜ, 2011. 25
Page 1 and 2: Regional Biogas Development Strateg
Page 3 and 4: Definitions and Abbreviations Bioen
Page 5 and 6: It is important for each state's en
Page 7 and 8: 1.2 The biogas sector in relation t
Page 9 and 10: Figure 1. Technologial scheme of bi
Page 11 and 12: V. Marketing and sales - Economical
Page 13 and 14: finances from other side creates a
Page 15 and 16: In 2011, thus consumption of petrol
Page 17 and 18: maximum use of the European Union
Page 19 and 20: The Bases of the Security Policy of
Page 21 and 22: Environment and the Ministry of Agr
Page 23: 2) social issues, and 3) waste mana
Page 27 and 28: 4.2.5. Impact on the visual environ
Page 29 and 30: I.8 To use 80% of landfill gas for
Page 31 and 32: V.6 To introduce the obligation to
Page 33 and 34: 6. Implementation of biogas product
Page 35 and 36: VI fertilizer. It must cover the wh
Page 37 and 38: I II III IV V VI VII VIII natural g
Page 39 and 40: II III IV V biomethane. To collect
Page 41 and 42: enewable energy production, namely
Page 43 and 44: transported to a central location w

Regional Biogas Development Strategy and Action Plan - Tartu

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?