Preface by Magnus
This Master’s thesis covers a wide range of topics, from biogas and renewable energy to wine and agriculture. It has been made in a Swedish-Moldovan multicultural context and includes aspects of Moldovan society and politics and how these aspects relate to the engineering perspective of biogas. An experience in itself is often greater than the report of it, however I will try to make clear the understanding I got during my stay in Moldova on how a biogas project can be realized.
I first got the idea of producing biogas from wine production residues during my initial meeting with Borlänge Energi and Sida, the Swedish development cooperation agency, at BNG communications in Stockholm, February 2011. There was a presentation of a country called Moldova, of which I knew very little. In the presentation it was mentioned that Moldova is a wine producing country that uses Russian natural gas. I therefore came up with the idea of producing biogas from the wine production residues and feeding it to the gas grid. I thought that would increase the income for the Moldovan people and at the same time decrease the environmental impact. At this point all I had was questions; I knew nothing of anaerobic digestion, wine production or its residues. As they often do, answers came with time; and as usual, they were not the expected ones.
Before beginning the report I want to stress an important matter. There are five biogas plants in Moldova today. None of them work. Four of them were operational, but not anymore. In all cases the reason for the failure was not in the biogas plants; technically they all worked fine. So why did they fail? The answer of that question will be given in the report and is a key for successfully implementing biogas at wineries in Moldova. Implementing biogas in Moldova will not be huge technical challenge. The problem lies instead in adapting the technology to the situation and context in which it will be used in. It does not matter if one finds the perfect technical solution for a problem if that solution does not work in its context.
The prestudy was made during the spring and summer in Sweden. A way of transport with low environmental impact was chosen to get to Moldova, the bicycle. The trip was 2000 km and was made in three weeks through Sweden, Poland, Ukraine and Moldova.The autumn was spent in Chisinau, Moldova, at the Department for Foreign Relations in the Chisinau City Hall. The finishing work took place at the Division of Energy Technology at Chalmers.
Biogas produced by anaerobic digestion is a proven and renewable energy technology that has a role to play reaching towards a sustainable development. It is a process where microorganisms feed on organic matter. Moldova is wine producing country where the energy-rich waste from the wine production, pomace, is mostly landfilled today. It is therefore both free and readily available for biogas production.
The aim of this thesis is to investigate if biogas produced at wineries in Moldova can be economic, it also evaluates its environmental and social benefits. The technical aspects investigated include plant scale, preferred technology, substrate and gas offset.
The thesis was carried out in three steps. First a pre study, then field work during a three months stay in Moldova and finally plant calculations and dimensioning. Five wineries were included in the case study. The waste streams at the wineries and their properties and potential for biogas production were identified. The data was analyzed to get understanding of how biogas from wine production residues can be implemented in Moldova. The amount of grapes harvested at the studied wineries determined the size of the biogas plants, at each winery. Flows of energy, substrate, fertilizer and money were calculated which served as a basis for investment proposals and recommendations for the wineries.
The proposed biogas plant is a tank reactor, fed with stored pomace from the local winery. It produces combined heat and power and organic fertilizer. A Moldovan winery that processes 3800 tons of grapes annually can with this technology produce over 500 GWh of electricity and 260 GWh of useful heat. The reduction in climate impact is 1100 ton of CO2-equivalents per year. The annual income of such a plant is 60 000 euro. On top of this comes the economic benefit from the organic fertilizer. This plant has an investment cost of 260 000 euro which gives a payback time of less than five years. The export potential for biogas companies to deliver these solutions is 6.4 million euro for the 20 largest wineries in Moldova. Moldovan wineries are interested but need assistance with planning and implementation.
The conclusion is that a biogas plant at a Moldovan winery is profitable and also reduces climate impact and contributes to energy independency and security. Investment is therefore recommended. It can also be an interesting possibility for other wine producing countries.
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