Browsing by Subject "bioenergia"

Hevosia on Suomessa noin 74 200 yksilöä, ne tuottavat lantaa laskennallisesti noin 1 187 200 m³ vuodessa. Lannasta suurin osa menee pelloille lannoitteeksi tai maanparannusaineeksi. Hevosenlannan käsittelymenetelmiä ovat passiivinen ja aktiivinen kompostointi, mädätys (biokaasutus), terminen käsittely ja poltto. Hevosenlantaa pidetään talleilla usein ongelmana ja monilla talleilla sen lantalasta pois saaminen tuottaa haasteita. Tässä tutkimuksessa tutkitaan mitkä tekijät vaikuttavat siihen, että hevosenlanta koetaan ongelmana. Sen lisäksi tutkitaan millä kuivikkeella kuivitettua hevosenlantaa eri toimijat ovat valmiita vastaanottamaan ja mitä eri menetelmiä he käyttävät tai olisivat valmiita käyttämään hevosenlannan käsittelemiseen. Maanviljelijöiden vastauksista tutkittiin lisäksi kiinnostus prosessoimattoman hevosenlannan vastaanottamiseen. Hevosenlanta koettiin ongelmana niillä talleilla, joilla oli käytössä tilapäinen lantavarasto. Lisäksi hevosalaan liittyvä toimintamuoto vaikutti ongelman kokemiseen. Kuivikkeella, laidunnusajalla ja hevosten määrällä ei todettu olevan merkitystä ongelman kokemiseen. Ympärivuotisesta lantaongelmasta kärsivät tämän tutkimuksen mukaan Uudellamaalla ja Keski-Suomessa sijaitsevat pienet alle kymmenen hevosen tallit, jotka käyttivät toiminnassaan useampaa kuin yhtä kuivikemateriaalia ja varastoivat lannan tilapäisessä lantavarastossa, tai joilla oli käytössä useampi eri varastointitapa. Kaikki toimijat olivat valmiita vastaanottamaan hevosenlantaa, mutta eri kuivikkeiden vastaanottohalukkuus vaihteli. Mieluiten maanviljelijät vastaanottivat turvetta ja olkea. Energiayhtiöitä kiinnostivat sekä puupohjaiset kuivikkeet että turve. Puupohjainen kuivike oli suosittua etenkin niillä energiatuottajilla, joiden hyödyntämismenetelmänä oli poltto. Jätehuollon toimijoista jokainen oli valmis ottamaan vastaan turvetta. Muut suositut kuivikkeet olivat kutterin- ja sahanpuru sekä olki. Ongelman kokemiseen vaikuttavat monet eri tekijät. Tilapäisten lantavarastojen korvaaminen kiinteillä lantaloilla on yksi ratkaisu lantaongelman vähentämiseen. Kuivikkeella ja lantaongelman kokemisella ei ollut suoraa yhteyttä, mutta kuiviketta vaihtamalla tallinpitäjä voi vaikuttaa lannan pois saamiseen. Kuivikkeiden vaihtaminen alueella toimivalle vastaanottavalle taholle mieluisammaksi voi olla yksi ratkaisu lantaongelman helpottumiseen. Tärkeää on keskusteluyhteyden avaaminen lähialueen toimijoiden välille.

This research is for UPM Kymmene Oyj. They are very interested in this topic because they are Finlands biggest users of the stumps and also big stump dealer for the other companies. The research is included to the big research project which is coordinated by FIBIC. Projects name is BEST, which means Sustainable Bioenergy Solutions for Tomorrow. The European Union has set the obligations for the renewable energy source usage in their climate and energy policy. This means that the use of forest biomass needs to grow from year 2006 to year 2020 from 3,6 million cubic meters to 13,5 million cubic meters in year 2020. In the year 2012 usage of forest biomass was 8,3 million cubic meters. The share of the stumps from that amount was 1,1 million cubic meters. The share of the stumps can grow even more. If we are going to use stumps even more we should increase the quality of stump wood. Most harmful things in stump wood quality is the soil particles. They comes up from the ground with stumps when the stumps are lifted. These particles increases stumps ash contents which is very harmful in the combustion process. But still stumps are energy rich fuel which keeps low moisture content during the winter and that is the time when we most need energy. The goal of the research is to find ways to rise energy thickness of the stump by different handling methods. First method is to precrush stumps with Arjes Raptor XL crusher. That special method should decrease moisture content and this has founded out earlier in practical tests because this crusher has special crushing unit. Second method is to take unwanted particles away by sieving. In the research we use two different sieving machines: Neuenhauser 2F StarScreen starscreen and Keestrack Frontier screen. Crushing and sieving together increased heating values 7,5–16,6 % and average was 11,1 %. Different handling methods effects most by decreasing moisture and ash content.

Spruce stumps have been harvested in large scale for combustion in heat and power plants since the beginning of the 21th century. Normally the stump harvesting operations are done by excavators. On stump harvesting areas the risk to serious soil damage is greater because there are more driving tracks on the ground than in original logging operations. In stump harvesting areas machines cannot get benefit from frozen soil or coarse roots to increase bearing capacity. Compacted soil can reduce tree root penetration, increase nutrient leaching and affect soil water properties. The aim of this study was to clarify if the stump harvesting compacts the forest soil and if it possibly recovers in the long run. I also studied how much the soil surface will be disturbed after stump harvesting operations. In this study there were three stump harvesting sites which varied in the time passed since harvesting. Comparable reference sites were chosen from nearby areas where the stumps were not harvested. All sites were located in Southern and Central Finland. Every site had three 5 x 5 meter study plots in which soil strength was measured by a cone penetrometer. Soil core samples were also taken from every study plot. The soil surface disturbance proportions were estimated visually and using a soil sampling probe. Measurements were carried out under summer of 2014. The results indicate that the soil has been compacted by stump harvesting in the 4-year-old site but differences were statistically significant (p<0.05) only in 2 of 6 depth classes. In the middle aged (7 years) site the impacts were the opposite. In the oldest (13 years) site there were no differences between the treatments. The soil surface in stump harvesting sites has been disturbed most in the youngest site (50 %), and at the other sites the disturbed soil surface proportion was about 40 %. About 25 % of soil surface was disturbed in all reference sites. The soil disturbance results in this study were minor compared to other studies in the literature. In the upper depth classes soils were not too compacted for tree growth, root penetration and nutrient uptake. This indicates that the changes in soil structural properties caused by stump harvesting are not harmful for forest growth but more long-term studies are needed.

Availability of raw material is a key issue for the future of the wood pellet industry. Wood pellet production primarily uses dry by-products of the mechanical wood processing industry, but increasing demand forces to use even more wet sawdust of the sawmill industry. This study examined the procurement of wet sawdust as a raw material for four pellet mills. As a research method, a model based on linear optimization was created about the Finnish sawdust market. To form a market model, the research compiled a database of demand and supply of sawdust. The demand database was collected on 7 expert interviews, and the ability to pay of each actor was determined by reference fuel. The supply database was composed by gathering the industrial size sawmills in Finland. The production capacity of sawmills determined an estimate of the by-product sawdust. With this model, three different raw material procurement scenarios were created for the year 2021, based on the different production volumes of the sawmill industry, compared with the year 2017. In the base scenario, the utilization rate will remain at the 2017 level, the minimum scenario will decrease by 10% and in the maximum scenario will increase by 10%. In each scenario, raw material procurement of factories was examined at 50%, 75% and 100% of the maximum capacity of factories. In the first step of optimization, the profit margin of sawmills was maximized, by delivering items to the most profitable user. In the second step, the raw material costs of pellet mills were minimized by utilizing the results of the first stage optimization. The results show that the production volume of the sawmill industry has a significant impact on the raw material costs of pellet mills due to changes in supply. In the minimum scenario, the raw material costs of four factories were 10,1 to 10,4 percent higher, in the base scenario, 6,0 to 7,6 percent higher and in the maximum scenario, costs fell 0,7 to 0,8 percent compared with the year 2017. According to the results, the price of the sawdust may rise due to increased demand. Increasing raw material costs will affect the profitability of the pellet industry and the demand for the end-product negatively.

Tämä maisteritutkielma luo katseen Suomen metsäohjelmien lähihistoriaan, tarkas-tellen Kansallinen metsäohjelma 2010, Kansallinen metsäohjelma 2015 sekä Kansallinen metsä-strategia 2025 valmistelutyötä. Tarkoituksena on vastata siihen kysymykseen, mitkä olivat ne toimijat, diskurssit sekä uskomukset jotka dominoivat suomalaisen metsäpoliittisten ohjelmien valmistelutyötä. Tätä kysymystä tutkin koalitiopohjaisen tutkimusmetodi Advocacy Coalition Frameworkin lävitse jakamalla toimijat uskomuspohjaisiin fiktiivisiin koalitioihin. Työssä tunnistan viisi erillistä koalitiota, näiden ollessa metsiensuojelu-, markkina-, työvoima-, tutkimus- sekä muut-koalitio. Näiden kautta kuva erilaisten toimijoiden valta-suhteista, ristiriidoista sekä muutoksista yhteiskunnallisessa keskustelussa sekä uskomuksissa piirtyy kulloisenkin tarkastelujakson vertautuessa toisiinsa. Analyysini keskiöön nousevatkin ennen kaikkea ristiriidat sekä niiden mahdolliset puuttumiset koalitioiden välisessä vaikuttamis-työssä ja esiin herää kysymys siitä, onko onnistunut vaikuttaminen lopulta kiinni koalitioiden resursseista, uskomusten liittolaisista vai kenties puhtaasta koosta? Entä missä määrin hallitus-vastuu tai yleisesti eduskuntapuolueiden rooli korostuu koalitioiden menestyksessä. Vaikka politiikasta puhutaan usein pelinä ja tässäkin työssä käsittelen onnistumisia usein voittoina, on kyse lopulta myös aina ruohonjuuritason tekemisestä. Tässä nousee metodologiavalintani vahvuus, sillä sen avulla kykenen rakentamaan analyysini osaksi myös sellaisia toimijoita jotka tavallisesti jäisivät huomiotta perinteisen politiikan määritelmissä. Tämän työn perimmäinen tarkoitus onkin luoda katsanto yhteiskuntaamme monin tavoin määriteleviin metsiin. Se, miten käsittelemme metsiämme ei ole yhdentekevää kotimaisessa eikä globaalissa mittakaavassa, taloutta ja ihmisten hyvinvointia unohtamatta. Raottamalla verhoa metsäohjelmien ja -strategian valmistelutyön suhteen, toivon samalla rakentavani myös ymmärrystä siitä politiikan jatkumosta jonka keskiössä metsäinen maamme seisoo.

Climate change has been found to be one of the most serious challenges humankind has to face in the future. The link between climate change and forests is based on trees’ ability to use carbon dioxide as a raw material for growth. The growing stock sequesters carbon dioxide from the air to itself and ultimately as the forest is harvested the carbon stored is released and it moves from carbon pool of forests to another carbon pool. As the concept of emissions’ trading is applied to the investigation, a price for sequestered and released carbon can be determined. With the market price for carbon dioxide known, a net present value for the revenues and costs during the forest’s rotation period can be calculated. Using wood for different purposes, however, can result in various climatic benefits. These climatic benefits are described in this study by carbon displacement factors which can be used in determining how much the costs of releasing carbon from forests can be deducted. This study investigates the significance of forest management in a stand level from the climate change mitigation point of view in three Norway spruce (Picea abies, L.) and three Scots pine (Pinus Sylvestris, L.) stands as the previous carbon accounting aspects are taken into consideration. Stand Management Assistant (SMA) software is used in the optimization and simulation calculations. The SMA software is used for calculating the carbon accounting net present values and average carbon storages during the rotation periods of the stands included in the study with different intensities of bioenergy biomass harvesting. This way the level of biomass harvesting for bioenergy that returns with the highest net present value for carbon accounting and/or the highest average carbon storage can be calculated. The calculations are made with two interest rates, two carbon dioxide prices and with climatic benefits from bioenergy or with climatic benefits from bioenergy and forest products included. According to the results it can be stated that the intensification of forest biomass recovery for bioenergy production does not always result in the optimal climate change mitigation. The use of Norway spruce is considered of being the most potential forest-based bioenergy source in Finland. As the climatic benefits from bioenergy use were only taken into consideration, the intensification of recovery of Norway spruce biomass for bioenergy seemed to be most profitable. If, however, the climatic benefits from forest products are included in the investigation as well, the bioenergy use of Norway spruce is no longer optimal for the climate change mitigation. The climatic benefits from Norway spruce material use exceed the benefits from bioenergy use. This means that biomass recovery for bioenergy production does not necessarily result in optimal climate change mitigation.