916 resultados para greenhouse gas intensity


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The soils of the world contain more carbon than the combined total amounts occurring in vegetation and the atmosphere. Hence soils are a major reservoir of carbon in terrestrial ecosystems and an important sink. Recently, emphasis has been placed on the need to sequester carbon from atmospheric carbon dioxide into soil organic matter because of international concerns about greenhouse gas emissions and global climate change. The best strategies to built-up carbon stocks in the soil are basically those that increase the input of organic matter to the soil, and/or decrease the rate of soil organic matter decomposition. Grain crop systems based on soil ploughing and harrowing lead to CO2 emissions combined with tremendous soil losses. In Brazil, no-tillage system was introduced to combat soil erosion by water and this soil management led to the build-up of soil carbon stocks with simultaneous high crop yields. However, the present procedure used to quantify carbon stocks in soils is laborious and of high cost. The use of infrared spectroscopy is very promising as an alternative low-cost method of soil carbon determination.

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Emission trading with greenhouse gases and green certificates are part if the climate policy the main target of which is reduce greenhouse gas emissions. The carbon dioxide and fine particle emissions of energy production in Helsinki Metropolitan area are calculated in this study. The analysis is made mainly by district heating point of view and the changes of the district heating network are assessed. Carbon dioxide emissions would be a bit higher, if the district heating network is expanded, but then the fine particle emissions would be much lower. Carbon dioxide emissions are roughly 10 % higher, if the district heating network is expanded at same rate as it has in past five years in the year 2030. The expansion of district heating network would decrease the fine particle emissions about 40 %. The cost of the expansion is allocated to be reduction cost of the fine particle emissions, which is considerably higher than the traditional reduction methods costs. The possible new nuclear plant would reduce the emissions considerably and the costs of the nuclear plant would be relatively low comparing the other energy production methods.

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Chemical-looping combustion (CLC) is a novel combustion technology with inherent separation of the greenhouse gas CO2. The technique typically employs a dual fluidized bed system where a metal oxide is used as a solid oxygen carrier that transfers the oxygen from combustion air to the fuel. The oxygen carrier is looping between the air reactor, where it is oxidized by the air, and the fuel reactor, where it is reduced by the fuel. Hence, air is not mixed with the fuel, and outgoing CO2 does not become diluted by the nitrogen, which gives a possibility to collect the CO2 from the flue gases after the water vapor is condensed. CLC is being proposed as a promising and energy efficient carbon capture technology, since it can achieve both an increase in power station efficiency simultaneously with low energy penalty from the carbon capture. The outcome of a comprehensive literature study concerning the current status of CLC development is presented in this thesis. Also, a steady state model of the CLC process, based on the conservation equations of mass and energy, was developed. The model was used to determine the process conditions and to calculate the reactor dimensions of a 100 MWth CLC system with bunsenite (NiO) as oxygen carrier and methane (CH4) as fuel. This study has been made in Oxygen Carriers and Their Industrial Applications research project (2008 – 2011), funded by the Tekes – Functional Material program. I would like to acknowledge Tekes and participating companies for funding and all project partners for good and comfortable cooperation.

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Climate innovations, that cover both technological applications and process and service innovations, play a key role in climate change mitigation. The purpose of this study was to examine how the Finnish innovation system could be enhanced with governmental measures so that the diffusion of climate innovations could be speeded up. During the study, it became evident that the governmental measures need to support the whole innovation chain, which comprises of research, development, demonstration and deployment. Only this can lead to the successful birth and diffusion of low carbon innovations. The study found that the strengths of the Finnish innovation system are research and development, and the current national innovation policies strongly support these activities. However, these have been emphasised at the expense of the demonstration and deployment. Consequently, the biggest bottlenecks in the Finnish innovation landscape are the lack of pilot and demonstration projects and slow commercialisation, thus the high price of the innovation. To meet with the challenge, the government should firstly promote strict greenhouse gas emission reduction targets. This would boost up the innovation activities, which would also lower the prices of the innovations. To speed up the commercialisation process, measures that stimulate the domestic market, such as feed-in-tariffs and public procurements, are needed. Special attention should also be paid to the measures that could shift the traditional closed innovation chain towards open innovation. This means that the product development should involve experts from several fields such as the user and marketing experts to speed up the commercialisation. In addition, efficient innovation co-operation between both private and public sector is essential. Finally, as the domestic resources are not adequate for producing all the innovations needed, the domestic innovation activities should be focused on a few sectors, and at the same time promote efficient import policies.

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The cycle of fossil fuels as an energy source for mankind is approaching its end. Finite resources, coupled with greenhouse gas, have led to an increased effort in the search for alternative renewable energy sources. Brazil has a leading position, due to a 46% participation of renewable sources in its primary energy supply, compared to the global average of 12%. The expansion of the renewable sources in Brazil depends on medium and long term planning, and a large volume of investments. The present financial crisis will have major effects in the energy market. Despite a negative initial impact, it is expected that the rearrangement of the financial system will ultimately lead to an expansion in the use of renewable energy sources. Brazil is a tropical country, with the largest biodiversity in our planet and excellent conditions to expand the use of all forms of renewable sources.

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Coal, natural gas and petroleum-based liquid fuels are still the most widely used energy sources in modern society. The current scenario contrasts with the foreseen shortage of petroleum that was spread out in the beginning of the XXI century, when the concept of "energy security" emerged as an urgent agenda to ensure a good balance between energy supply and demand. Much beyond protecting refineries and oil ducts from terrorist attacks, these issues soon developed to a portfolio of measures related to process sustainability, involving at least three fundamental dimensions: (a) the need for technological breakthroughs to improve energy production worldwide; (b) the improvement of energy efficiency in all sectors of modern society; and (c) the increase of the social perception that education is a key-word towards a better use of our energy resources. Together with these technological, economic or social issues, "energy security" is also strongly influenced by environmental issues involving greenhouse gas emissions, loss of biodiversity in environmentally sensitive areas, pollution and poor solid waste management. For these and other reasons, the implementation of more sustainable practices in our currently available industrial facilities and the search for alternative energy sources that could partly replace the fossil fuels became a major priority throughout the world. Regarding fossil fuels, the main technological bottlenecks are related to the exploitation of less accessible petroleum resources such as those in the pre-salt layer, ranging from the proper characterization of these deep-water oil reservoirs, the development of lighter and more efficient equipment for both exploration and exploitation, the optimization of the drilling techniques, the achievement of further improvements in production yields and the establishment of specialized training programs for the technical staff. The production of natural gas from shale is also emerging in several countries but its production in large scale has several problems ranging from the unavoidable environmental impact of shale mining as well as to the bad consequences of its large scale exploitation in the past. The large scale use of coal has similar environmental problems, which are aggravated by difficulties in its proper characterization. Also, the mitigation of harmful gases and particulate matter that are released as a result of combustion is still depending on the development of new gas cleaning technologies including more efficient catalysts to improve its emission profile. On the other hand, biofuels are still struggling to fulfill their role in reducing our high dependence on fossil fuels. Fatty acid alkyl esters (biodiesel) from vegetable oils and ethanol from cane sucrose and corn starch are mature technologies whose market share is partially limited by the availability of their raw materials. For this reason, there has been a great effort to develop "second-generation" technologies to produce methanol, ethanol, butanol, biodiesel, biogas (methane), bio-oils, syngas and synthetic fuels from lower grade renewable feedstocks such as lignocellulosic materials whose consumption would not interfere with the rather sensitive issues of food security. Advanced fermentation processes are envisaged as "third generation" technologies and these are primarily linked to the use of algae feedstocks as well as other organisms that could produce biofuels or simply provide microbial biomass for the processes listed above. Due to the complexity and cost of their production chain, "third generation" technologies usually aim at high value added biofuels such as biojet fuel, biohydrogen and hydrocarbons with a fuel performance similar to diesel or gasoline, situations in which the use of genetically modified organisms is usually required. In general, the main challenges in this field could be summarized as follows: (a) the need for prospecting alternative sources of biomass that are not linked to the food chain; (b) the intensive use of green chemistry principles in our current industrial activities; (c) the development of mature technologies for the production of second and third generation biofuels; (d) the development of safe bioprocesses that are based on environmentally benign microorganisms; (e) the scale-up of potential technologies to a suitable demonstration scale; and (f) the full understanding of the technological and environmental implications of the food vs. fuel debate. On the basis of these, the main objective of this article is to stimulate the discussion and help the decision making regarding "energy security" issues and their challenges for modern society, in such a way to encourage the participation of the Brazilian Chemistry community in the design of a road map for a safer, sustainable and prosper future for our nation.

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Tässä työssä arvioidaan kotitalouksien energiansäästöpotentiaalia valaistuksen osalta Suomessa. Euroopan Unioni on ratifioinut päästövähennystavoitteen 20 % koskien kaikkia primäärienergiantuotantomuotoja. Päästövähennystavoite on tarkoitus toteuttaa vuoteen 2020 mennessä. Tässä kandidaatintyössä arvioidaan saavutettavissa olevaa energiansäästöpotentiaalia Suomessa kotitalouksissa laitesähkön osalta. Energiansäästöpotentiaalin arviointi perustuu hehkulampun korvaamismahdollisuuksien vertailuun. Valaistuksessa voidaan saavuttaa jopa 75 % sähkönsäästö, kun korvataan yksi 60 W hehkulamppu vastaavan valomäärän tuottavalla energiansäästölampulla. Kokonaisuudessa kotitalouksien valaistuksessa on tehostamispotentiaalia noin 60 %. Valaistuksen tehostamisella saavutetaan noin 1,5 TWh säästö Suomen kokonaissähkökulutuksessa. Saavutettavat säästöt voivat olla jopa suuremmatkin, jos käytetään lisäksi älykästä valonohjausta. Johtopäätöksenä voidaan todeta, että tehostamispotentiaalia on merkittävästi ja tehostaminen on yksittäiselle kotitaloudelle taloudellisesti kannattavaa. Energiansäästöpotentiaalin toteuttamisen vaikutuksia kansantalouteen ei ole arvioitu.

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Päästöjen rajoittaminen ja seuranta on tullut yhä ajankohtaisemmaksi 2000-luvulla ilmastonmuutoksen edetessä. Varsinkin kasvihuonekaasupäästöihin kiinnitetään suurta huomiota, joista yleisimmin tarkastelun kohteena on hiilidioksidi. Tuotteen tai palvelun aiheuttamaa ympäristökuormaa kuvaamaan on kehitetty käsitteet ekologinen jalanjälki ja hiilijalanjälki. Ensimmäinen kuvaa koko ympäristökuormituksen määrää, ja jälkimmäinen hiilidioksidipäästöjen määrää. Ajatus tähän työhön kehittyi mietittäessä ajankohtaista, uutta sovellusta paikkatietotekniikalle. Paikkatietojärjestelmien käyttöä liikenteen päästöjen seurantaan ei tiettävästi ole aikaisemmin laajemmalti tutkittu. Sen sijaan niitä käytetään kokeiluluontoisesti esimerkiksi ajoneuvojen vakuutusmaksujen suuruuden määräämiseen. Teknisesti käyttö kyseiseen tarkoitukseen on melko samantyyppistä kuin tässä työssä tutkittavaan päästöjen seurantaan. Tässä työssä tutkittiin yleisluontoisesti paikkatietotekniikan soveltuvuutta päästöjen seurantaan. Tarkoituksena ei ollut rakentaa täysin toimiva järjestelmää, vaan tehdä kokeita prototyypin avulla.

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Tämä diplomityö on tehty Aalto yliopiston Teknillisen korkeakoulun Lahden keskuksen IMMU-hankkeeseen. Teoriaosassa tarkastellaan kaukolämmityksen nykytilannetta ja sen tulevai-suuteen vaikuttavia tekijöitä. Työssä on tarkasteltu Lahti Energia Oy:n Kymijärven voimalaitosalueen kehittämismahdollisuuksia vuosina 2012 ja 2016. Vertailukohtana käytetään nykytilannetta vuoden 2009 tiedoilla. Työssä on selvitetty voimalaitosalueen elinkaaren aikaisia kasvihuonekaasupäästöjä ja niiden muutoksia mahdollisten uusien voimalaitosinvestointien myötä. Vuonna 2012 alueelle rakennetaan kiinteää polttoainetta käyttävä kaasutusvoimalaitos jolloin nykyisen laitoksen käyttö ja samalla kivihiilen käyttö vähenee huomattavasti. Tässä työssä vuoden 2016 skenaariossa alueelle ajatellaan rakennettavan kolmas voimalaitos, maakaasukäyttöinen kaasukombiturbiini. Tarkasteluissa energiantuotantomäärien oletetaan pysyvän nykytilanteen suuruisina. Työssä tarkasteltujen skenaarioiden perusteella alueen yhdistetyn kaukolämmön- ja sähköntuotannon (CHP) päästöjä voitaisiin vähentää vuonna 2012 noin 20 % ja vuonna 2016 noin 30 % nykytilanteesta. Esitettyjen investointien riskinä on sopivan polttoaineen saatavuus ja riittävyys. Lisäksi työssä tarkasteltiin kaasutusvoimalaitoksen ja kaasukombiturbiinin takaisinmaksuaikoja. Kierrätyspolttoaineen hinnan kallistuminen hinnasta 5 €/MWh hintaan 15 €/MWh vaikutti kaasutusvoimalaitoksen takaisinmaksuaikaan yhdeksällä vuodella. Kaasukombiturbiinin takaisinmaksuaika piteni tämän hetkiseen maakaasun hintaan 27 €/MWh verrattuna päästöoikeuden lisäkustannus 6 €/MWh huomioiden kahdeksan vuotta. Takaisinmaksuaikaan vaikuttaa muun muassa polttoaineen hinta ja laitoksen huipunkäyttöaika.

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Tämä diplomityö on tehty IMMU-hankkeeseen, jossa selvitetään konkreettisia keinoja ilmastonmuutoksen hillintään Lahden seudulla. Diplomityössä tarkastellaan mahdollisuuksia lisätä biopolttoaineita pienen kokoluokan kaukolämmön tuotantolaitoksissa. Teoria osuuden pohjalta luodaan skenaariot Nastolaan ja Vääksyyn (Asikkala). Skenaarioissa tarkastellaan biopolttoaineiden lisäämisen vaikutuksia kasvihuonekaasu- ja hiukkaspäästöihin käyttämällä elinkaariarviointimenetelmää. Taloudellisia seikkoja tarkastellaan laskemalla takaisinmaksuaikoja eri biolaitosratkaisuille nettonykyarvomenetelmällä. Tutkimuksen tuloksena saatiin, että kasvihuonekaasupäästöt tuotannon elinkaaren ajalta vähenevät eniten tuottamalla kaukolämmön perustuotanto Nastolassa ja Vääksyssä bio-CHP-laitoksella haketta polttamalla. Kiinteitä biopolttoaineita poltettaessa tulevat kuitenkin suurimmat hiukkaspäästöt, mikä vaikuttaa asuinympäristön viihtyvyyteen tuotantolaitoksen läheisyydessä. Bio-CHP-laitoksen investointikustannukset ovat suurimmat ja takaisinmaksuaika pisin. Nastolan kulutusperusteisiä päästöjä pystytään vähentämään eniten investoimalla biolämpölaitokseen tai bio-CHP-laitokseen. Päästöjä Nastolassa pystyttäisiin kyseisillä investoinneilla vähentämään enimmillään 6,4 %. Lahti energian kokonaispäästöjä pystyttäisiin enimmillään vähentämään noin 1,6 %. Johtopäätöksenä tutkimuksesta voidaan sanoa, että kasvihuonekaasupäästöjä pystytään vähentämään investointien avulla. Toiset ratkaisut ovat vain kalliimpia kuin toiset. Lisäksi kiinteitä biopolttoaineita käytettäessä jotkut poltto-ominaisuudet voivat heiketä esim. verrattuna maakaasun polttoon. Biopolttoaineiden lisäämisellä kuitenkin päästään irti riippuvuudesta fossiilisiin polttoaineisiin kuten öljyyn ja maakaasuun. Investointeja tehdessä on vaikea sanoa suoraan, mikä vaihtoehto on paras tapa tuottaa kaukolämpöä. Investointipäätöksiä tehdessä päätökseen vaikuttaa se, mitä tuotannon ominaispiirteitä painotetaan eniten.

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International energy and climate strategies also set Finland’s commitments to increasing the use of renewable energy sources and reducing greenhouse gas emissions. The target can be achieved by, for example, increasing the use of energy wood. Finland’s forest biomass potential is significant compared with current use. Increased use will change forest management and wood harvesting methods however. The thesis examined the potential for integrated pulp and paper mills to increase bioenergy production. The effects of two bioenergy production technologies on the carbon footprint of an integrated LWC mill were studied at mill level and from the cradle-to-customer approach. The LignoBoost process and FT diesel production were chosen as bioenergy cases. The data for the LignoBoost process were obtained from Metso and for the FT diesel process from Neste Oil. The rest of the information is based on the literature and databases of the KCL-ECO life-cycle computer program and Ecoinvent. In both case studies, the carbon footprint was reduced. From the results, it can be concluded that it is possible to achieve a fossil-fuel-free pulp mill with the LignoBoost process. By using steam from the FT diesel process, the amount of auxiliary fuel can be reduced considerably and the bark boiler can be replaced. With a choice of auxiliary fuels for use in heat production in the paper mill and the production methods for purchased electricity, it is possible to affect the carbon footprints even more in both cases.

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The condition of Baltic Sea has weakened considerably because of eutrophication which has caused massive increase of devalued fish. The condition of Baltic Sea can be helped by fishing these fish. This study handles three different ways to approach those fish utilizations and counts carbon footprint for those three chains. Environmental point of views are also examined. There are three different fish processing chains. Every processing chain begins with fishing the fish in Baltic Sea. After that the fishes are prepared by crushing and some formic acid is added to ensure preservation. In the first processing chain the fishes are processed as biodiesel. The waste from the biodiesel process is taken to the anaerobic digestion and the forming methane is used as energy. In the second chain the fishes are taken straight to the anaerobic digestion after preparing. In the third chain, the fish will be first prepared and then taken to fur farms as forage. The carbon footprint has been calculated for 1000 kg fish. The carbon footprint in the first chain is 164-178 kg CO2e, in the second chain 313 – 333 kg CO2e and in the third chain 363 kg CO2e. In the processing chains the bioenergy is produced from the biodiesel, anaerobic digestion and from the glycerol, which is by-product of the biodiesel. The energy produced from the biodiesel is so-called emission neutral, which is not taken into account when calculating emissions. The energy is used to compensate the emissions caused by fossil fuels. The PAS 2050 was used to calculate the carbon footprint. Only carbon dioxide and methane were used when calculating the carbon footprint.

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The environmental challenges of plastic packaging industry have increased remarkably along with climate change debate. The interest to study carbon footprints of packaging has increased in packaging industry to find out the real climate change impacts of packaging. In this thesis the greenhouse gas discharges of plastic packaging during their life cycle is examined. The carbon footprint is calculated for food packaging manufactured from plastic laminate. The structure of the laminate is low density polyethylene (PE-LD) and oriented polypropylene (OPP), which have been joined together with laminating adhesive. The purpose is to find out the possibilities to create a carbon footprint calculating tool for plastic packaging and its usability in a plastic packaging manufacturing company. As a carbon footprint calculating method PAS 2050 standard has been used. In the calculations direct and indirect greenhouse gas discharges as well as avoided discharges are considered. Avoided discharges are born for example in packaging waste utilization as energy. The results of the calculations have been used to create a simple calculating tool to be used for similar laminate structures. Although the utilization of the calculating tool is limited to one manufacturing plant because the primary activity data is dependent of geographical location and for example the discharges of used energy in the plant. The results give an approximation of the climate change potential caused by the laminate. It is although noticed that calculations do not include all environmental impacts of plastic packaging´s life cycle.

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Lappeenrannassa kerätään ja hyödynnetään tällä hetkellä kaatopaikkakaasua 0,3 milj.m3 vuodessa. Biokaasua voitaisiin tuottaa Lappeenrannassa mädättämällä bioperäisiä jätteitä ja biokaasuntuotantoa varten kasvatettuja energiakasveja. Biokaasuntuotantoon soveltuvia jätteitä ovat erilliskerätty biojäte, jätevedenpuhdistamon jätevesiliete, puutarhajäte, lietelannat ja oljet. Kesannolla olevilla peltoaloilla voitaisiin kasvattaa ruokohelpeä. Biokaasun tuotantoon soveltuvia materiaaleja voitaisiin kerätä 143 000 t/a ja kasvattaa 68 000 t/a. Työssä tarkastellaan vaihtoehtoa, jossa mädätetään vain puhdistamoliete, sekä useita materiaaleja mädättävää yhteismädättämöä, johon liittyen tutkitaan kolmea eri vaihtoehtoa: kunnallisen jätteen mädätystä, kaiken jätteen mädätystä ja jätteen sekä energiakasvien mädätystä. Paras sijoituspaikka mädättämölle olisi jätevedenpuhdistamon läheisyydessä. Jätemateriaalista saataisiin kaasua enintään 12 milj. m3 ja energiakasveista enintään 16 milj. m3. Kaasusta voitaisiin tuottaa energiaa CHP-laitoksessa enintään 184 GWh. Mikäli biokaasun tuotannolla halutaan ensisijaisesti vähentää kasvi-huonekaasupäästöjä, kannattaa kaasu jalostaa ajoneuvopolttoaineeksi. Jalostettu kaasu on mahdollista myös syöttää maakaasuverkostoon. Suurimmat tulot on mahdollista saavuttaa yhdistetyssä sähkön- ja lämmöntuotannossa, mikäli biokaasulle suunniteltu syöttötariffi toteutuu. Muussa tapauksessa suurimmat tulot saadaan jalostamalla biokaasua ajoneuvojen polttoaineeksi.