Since the 19th century the concentration of CO2 in the atmosphere hasincreased by 40 percent as an effect of the use of fossil energy sources.Increased concentration of CO2 will likely lead to increased temperature,changes in precipitation, rising sea level and increased frequency of extremeweather like storm events. A step to reduce emissions of CO2 and mitigateclimate change, for the property of Tagel, can be to adopt new silviculturalstrategies and analyse which is the most effective. As a result of that, threescenarios was produced, business-as-usual (BAU), increased set aside landand energy. An introduction of windpower at Tagels estate (property) andeffects on carbon balance was also examined. By using the Heureka systemand LCA-analysis in this study, it showed that the scenario of increased setaside land was the most efficient way to reduce carbon dioxide (CO2)emissions for the analysed period of 100 years. The effect of substitution(replacing for example fossil fuel or energy consuming building materials,with renewable raw material such as biomass) didn’t give the result that waspredicted. It appears that the use of pulpwood is very important, if it goes tothe pulp industry no substitution effect occurs, but if all pulp will be used forbioenergy purposes, the energy scenario will be the best in terms of overallcarbon balance. The stored carbon in tree biomass over and in roots wasaffected by all scenarios. The soil carbon was almost the same for allscenarios. In the future the property of Tagel can still use the alternativeBAU as an effective way to mitigate climate change but then explore thepossibilities to use the pulp for bioenergy purposes instead and to set asidemore land at the property. This study considered to have high credibilitybecause the Heureka-analyses, LCA and the substitution model were carriedout by experts in area of research.

The threat of global warming is bringing a new pro-environmental paradigm all over the world under the Kyoto Protocol. Addressing climate change is beneficial to all countries because environment is global public good. However, because global warming is also closely related to each country’s specific condition such as industrial development and political situation, prudent approaches considering different situations of each country are required in order prevent unintended negative consequences. This study focuses on the weakness of the current CDM (Clean Development Mechanism) in terms of impeding sustainable development in LDCs (Least Development Countries). As a case study, the Grameen Shakti Program in Bangladesh demonstrates the potential scenario of sustainable development in LDCs through CDM markets and a new financial model of CERs (Certified Emissions Reductions) is suggested to support and replicate the Grameen Shakti Program other LDCs. / text

Transportation and energy play an essential role in modern society. Since the Industrial Revolution, fossil fuels have enabled great advancements in human society. Within this process, Internal Combustion Engines Vehicles (ICEVs) played a significant role in guaranteeing reliable and affordable long-distance transportation. However, the subsequent increase of the Motorized Private Transport resulted in undesired effects such as pollution. One instrument in reducing the Greenhouse Gas (GHG) emissions of the transport sector is to shift from the conventional ICEVs toward zero local emission vehicles. Electric Vehicles (EVs) are being promoted worldwide as a suitable powertrain technology that could replace the ICEVs. However, unless combined with electricity from renewable generation technologies the EVs will not effectively reduce GHG emissions. Through the simulation of future transport and energy sector scenarios in Germany, the GHG emission reductions have been analyzed. Techno-economic and environmental characteristics for several powertrain technologies under several vehicles charging strategies are evaluated. The thesis explores the impact of charging EVs on the electrical grid. The result show that EVs using smart charging strategies that support Vehicle-to-grid (V2G) are capable of fulfilling mobility needs of users while providing substantial flexibility to the electrical grid. Such flexibility can facilitate the future expansion of non-dispatchable Renewable Energy Sources (RES).

This thesis focuses on a technology called cylinder deactivation. The technology helps reducing emissions and fuel consumption. The first part summarizes the possibilities of application of the cylinder deactivation technology as well as advantages resulting from combination with other technologies. The thesis also consists of two design options for valvetrain in inline four-cylinder engine and the results of simulations of dynamics of its cranktrain.

Master's Thesis is focused on production of CO2 from fossil fuels combustion and the methods of CO2 emission from fossil fuels combustion reduction, resp. pre-combustion and post-combustion separation of CO2. Recapitulation of world consumption of primary energetic resources and carbon dioxide production as a result of theirs combustion in years 1971 - 2006 was made using a number of information sources. Whilst combustion o fossil fuel is related with production of CO2, calculation of emission rate of CO2 from fossil fuels (natural gas, crude oil and coal) was demonstrated. The Case Study of energy and material balances of gas turbine cycle with synthesis of methane from CO2 and from hydrogen which is produced in water splitting was made, using CHEMCAD software.

Pendling in till stadens centrum orsakar trafikköer och dålig luft samtidigt som fordonstrafik står för en av de största utsläppskällorna av växthusgaser i Sverige. Pendelparkeringar representerar ett mer miljövänligt alternativ men det utnyttjas inte till fullo. Detta examensarbete har som syfte att undersöka hur användandet av pendlarparkeringar kan främjas, som ett led i ett mer hållbart resande inom Gävle kommun. Studiens mål är att skapa ett kunskapsunderlag som kan guida kommunen att främja utvecklingen i praktiken. Examensarbetet utgick från aspekter kopplat till pendlarparkeringar, framtagna i förstudien till detta arbete. Studien syftar till att svara på forskningsfrågorna Hur har de sex slumpmässigt utvalda svenska kommunerna arbetat med (de sedan tidigare utpekade) aspekterna kostnad, beteende, tid och tillgänglighet för att främja användandet av pendlarparkeringar? och Hur ser potentiella användare av pendlarparkeringar i Gävle kommun på vikten av kostnad, beteende, tid och tillgänglighet för att motivera deras användande? Examensarbetet består av två olika metoder, en enkätundersökning för potentiella användare och en intervjustudie med de sex slumpmässigt utvalda svenska kommunerna. Två kommuner deltog via videosamtal och resterande fyra deltog via mail. Både kommunerna och respondenterna av enkäten ansåg att billig parkeringsavgift och bra biljettsystem var viktigt för att bilburna skall välja att använda pendlarparkeringar. Samtliga kommuner tryckte även på vikten av god tillgänglighet till kollektivtrafik samtidigt som respondenterna i enkätundersökningen tyckte att turtätheten i kollektivtrafiken var viktig. Aspekter som kostnad, tid och bekvämlighet är val som prioriteras högt medan miljö inte får lika stort fokus. Studien visar på att individer gör val efter det som gynnar dem själv. / Commuting into the city center causes traffic jams and bad air at the same time as vehicle traffic accounts for one of the largest sources of greenhouse gas emissions in Sweden. Shuttle parking represents a more environmentally friendly alternative but it is not fully utilized. The purpose of this thesis is to investigate how the use of commuter parking can be promoted, as part of a more sustainable travel within Gävle municipality. The aim of the study is to create a knowledge base that can guide the municipality to promote development in practice. The degree project was based on aspects linked to commuter parking, developed in the feasibility study for this project. The study aims to answer the research questions How have the six randomly selected Swedish municipalities worked with (the previously designated) aspects cost, behavior, time and accessibility to promote the use of commuter parking? and How do potential users of commuter car parks in Gävle municipality view the importance of cost, behavior, time and accessibility to justify their use? The degree project consists of two different methods, a survey for potential users and an interview study with the six randomly selected Swedish municipalities. Two municipalities participated via video calls and the remaining four participated via email. Both the municipalities and the respondents of the survey considered that cheap parking fees and a good ticket system were important for car users to choose to use commuter parking. All municipalities also emphasized the importance of good accessibility to public transport, while the respondents in the survey thought that the frequency of public transport was important. Aspects such as cost, time and convenience are choices that are given high priority, while the environment does not receive as much focus. The study shows that individuals make choices based on what benefits them.

This research project represents a collaborative effort between E&C Consultants, an international energy procurement consultancy, and aims to address the increasing demand for guidance on scope 1 emissions reduction strategies expressed by their clients. From a procurement perspective, companies are actively seeking alternative commodities, such as biomethane or hydrogen, to substitute their natural gas consumption. In response to this growing trend, multinational corporations are displaying an increased interest in voluntary emission reduction initiatives, including the Science Based Targets initiative and the Greenhouse Gas Protocol. Subsequently, the research project encompasses an investigation into the sustainability plans adopted by companies. Furthermore, an analysis of the European biomethane and hydrogen markets is made. Most of the information is derived from interviews conducted with diverse stakeholders, including multinational companies, energy traders, an energy supplier, a gas market expert, and a carbon removal expert. The findings of this research project indicate that multinational corporations have established robust short-term sustainability plans, yet encounter challenges in formulating long-term strategies, primarily due to legislative ambiguities and limited resources and expertise. The implementation of REPowerEU [1] is expected to significantly augment the production levels of both biomethane and hydrogen by 2030. The biomethane market is predominantly characterised by supply constraints, owing to the high demand it experiences, resulting in elevated prices. Conversely, the hydrogen market is less mature and exhibits comparatively lower demand as companies have to implement alternative technologies that are required for hydrogen adoption. Eventually, both biomethane and hydrogen possess the potential to emerge as cost-competitive alternatives to natural gas, depending upon the maturation and development of their respective markets. / Detta forskningsprojekt representerar ett samarbete mellan E&C Consultants, en internationell energiupphandling, och syftar till att möta den ökande efterfrågan på vägledning om scope 1-strategier för minskning av utsläppen uttryckt av deras kunder. Ur ett upphandlingsperspektiv söker företag aktivt alternativa råvaror, såsom biometan eller väte, för att ersätta deras naturgas konsumtion. Som svar på denna växande trend visar multinationella företag ett ökat intresse för frivilliga initiativ för att minska utsläppen, inklusive initiativet Science Based Targets och Greenhouse Gas Protocol. Därtill omfattar forskningsprojektet en utredning av antagna hållbarhetsplaner av företag. Dessutom görs en analys av den europeiska biometan- och vätemarknaderna. Merparten av informationen kommer från intervjuer med olika intressenter, inklusive multinationella företag, energimäklare, en energileverantör, en gasmarknadsexpert och en expert på koldioxidinfångning. Av denna studie indikerar att multinationella företag har etablerat robusta kortsiktiga hållbarhetsplaner, men stöter på utmaningar i att formulera långsiktiga strategier, främst på grund av oklarheter i lagstiftningen och begränsade resurser och expertis. Implementeringen av REPowerEU [1] förväntas avsevärt förstärka produktionsnivåer av både biometan och väte till 2030. Biometanmarknaden kännetecknas övervägande av utbudsbegränsningar på grund av den höga efterfrågan, vilket resulterar i förhöjda priser. Omvänt är vätgasmarknaden mindre mogen och uppvisar jämförelsevis lägre efterfrågan eftersom företag måste implementera alternativa tekniker som krävs för att använda väte. Så småningom kan båda biometan och väte ha potential att vara konkurrenskraftiga alternativ till naturgas, beroende på deras mognad och utveckling de respektive marknaderna.

[ES] Históricamente, el sector del transporte de servicio mediano y pesado ha sido desafiado por las regulaciones de emisiones que se han impuesto a lo largo de los años, lo que requirió intensificar el esfuerzo de investigación con el objetivo de avanzar en el desarrollo tecnológico para ofrecer una opción que cumpla con las normas a un precio similar para el propietario. No obstante, la reciente introducción de la normativa EUVI ha requerido la adición de un complejo sistema de postratamiento, agregando nuevos costes fijos al producto, así como costes operativos con el consumo de urea. Este avance fue necesario debido a la limitación de la combustión diésel convencional que no puede desacoplar las altas emisiones de NOx y la eficiencia. Esta limitación tecnológica ha impulsado la investigación sobre diferentes conceptos de combustión que podrían mantener niveles de eficiencia similares a los de la combustión diésel controlando la formación de emisiones durante el proceso de combustión. Entre las diferentes soluciones que han ido apareciendo a lo largo de los años, se demostró que la Ignición por Compresión Controlada por Reactividad (RCCI por sus siglas en inglés) tiene una ventaja competitiva debido a su mejor controlabilidad, alta eficiencia y bajas emisiones de hollín y NOx. A pesar de sus beneficios, la extensión de RCCI a la operación de mapa completo ha indicado limitaciones importantes como gradientes de presión excesivos a alta carga, o alta inestabilidad de combustión y productos no quemados a baja carga del motor. Recientemente, se introdujo el concepto de combustión Dual-Mode Dual-Fuel (DMDF) como un intento de resolver los inconvenientes de la combustión RCCI manteniendo sus ventajas. Los resultados preliminares obtenidos en un motor mono cilíndrico (SCE por sus siglas en inglés) han demostrado que el DMDF puede alcanzar niveles de eficiencia similares a los de la combustión diésel convencional al mismo tiempo que favorece niveles ultra bajos de hollín y NOx. Si bien, los requisitos de la condición límite son difíciles de encajar en el rango operativo de sistema de gestión de aire, así como inconvenientes como el exceso de HC y CO que aún persiste en la zona de baja y media carga, lo que puede ser un desafío para el sistema de postratamiento. Además, las futuras regulaciones a corto plazo exigirán una reducción del 15 % de las emisiones de CO2 en 2025, reto que la literatura sugiere que no se logrará fácilmente solo mediante la optimización del proceso de combustión. En este sentido, esta tesis tiene como objetivo general la implementación del concepto de combustión DMDF en un motor multicilindro (MCE por sus siglas en inglés) bajo las restricciones de las aplicaciones reales para realizar una combustión limpia y eficiente en el mapa completo a la vez que brinda alternativas para reducir la concentración de HC y CO y lograr un ahorro de CO2. Este objetivo se logra mediante un primer extenso procedimiento de calibración experimental que tiene como objetivo trasladar las pautas de la combustión DMDF del SCE al MCE respetando los límites operativos del hardware original, evaluando su impacto en los resultados de combustión, rendimiento y emisiones en condiciones estacionarias y condiciones de ciclo de conducción. A continuación, se realizan estudios específicos para abordar el problema relacionado con la concentración excesiva de productos no quemados mediante investigaciones experimentales y simulaciones numéricas para comprender las consecuencias del uso de combustibles con diferente reactividad en la eficiencia de conversión del catalizador de oxidación original y su capacidad para lograr emisiones en el escape menores que el límite EUVI. Finalmente, se busca la reducción de CO2 a través de la modificación del combustible, investigando tanto la mejora del proceso de combustión como el equilibrio entre el ciclo de vida del combustible. / [CA] Històricament, el sector del transport de servei mitjà i pesat ha sigut desafiat per les regulacions d'emissions que s'han imposat al llarg dels anys, la qual cosa va requerir intensificar l'esforç d'investigació amb l'objectiu d'avançar en el desenvolupament tecnològic per a oferir una opció que complisca amb les normes a un preu similar per al propietari. No obstant això, la recent introducció de la normativa EUVI ha requerit l'addició d'un complex sistema de postractament, agregant nous costos fixos al producte, així com costos operatius amb el consum d'urea. Aquest avanç va ser necessari a causa de la limitació de la combustió dièsel convencional que no pot desacoblar les altes emissions de NOx i l'eficiència. Aquesta limitació tecnològica ha impulsat la investigació sobre diferents conceptes de combustió que podrien mantindre nivells d'eficiència similars als de la combustió dièsel controlant la formació d'emissions durant el procés de combustió. Entre les diferents solucions que han anat apareixent al llarg dels anys, es va demostrar que la Ignició per Compressió Controlada per Reactivitat (RCCI per les seues sigles en anglés) té un avantatge competitiu a causa de la seua millor controlabilitat, alta eficiència i baixes emissions de sutge i NOx. Malgrat els seus beneficis, l'extensió del RCCI a l'operació de mapa complet ha indicat limitacions importants com a gradients de pressió excessius a alta càrrega, o alta inestabilitat de combustió i productes no cremats a baixa càrrega del motor. Recentment, es va introduir el concepte de combustió Dual-Mode Dual-Fuel (DMDF) com un intent de resoldre els inconvenients de la combustió RCCI mantenint els seus avantatges. Els resultats preliminars obtinguts en un motor mono-cilíndric (SCE per les seues sigles en anglés) han demostrat que el DMDF pot aconseguir nivells d'eficiència similars als de la combustió dièsel convencional al mateix temps que afavoreix nivells ultra baixos de sutge i NOx. Si bé, els requisits de la condició límit són difícils d'encaixar en el rang operatiu de sistema de gestió d'aire, així com inconvenients com l'excés de HC i CO que encara persisteix en la zona de baixa i mitja càrrega, la qual cosa pot ser un desafiament per al sistema de postractament. A més, les futures regulacions a curt termini exigiran una reducció del 15% de les emissions de CO¿ en 2025, repte que la literatura suggereix que no s'aconseguirà fàcilment només mitjançant l'optimització del procés de combustió. En aquest sentit, aquesta tesi té com a objectiu general la implementació del concepte de combustió DMDF en un motor multi-cilindre (MCE per les seues sigles en anglés) sota les restriccions de les aplicacions reals per a realitzar una combustió neta i eficient en el mapa complet alhora que brinda alternatives per a reduir la concentració de HC i CO i aconseguir un estalvi de CO¿. Aquest objectiu s'aconsegueix mitjançant un primer extens procediment de calibratge experimental que té com a objectiu traslladar les pautes de la combustió DMDF del SCE al MCE respectant els límits operatius del motor original, avaluant el seu impacte en els resultats de combustió, rendiment i emissions en condicions estacionàries i condicions de cicle de conducció. A continuació, es realitzen estudis específics per a abordar el problema relacionat amb la concentració excessiva de productes no cremats mitjançant investigacions experimentals i simulacions numèriques per a comprendre les conseqüències de l'ús de combustibles amb diferent reactivitat en l'eficiència de conversió del catalitzador d'oxidació original i la seua capacitat per a aconseguir emissions al tub d'escapament menors que el límit EUVI. Finalment, es busca la reducció de CO2 a través de la modificació del combustible, investigant tant la millora del procés de combustió com l'equilibri entre el cicle de vida del combustible. / [EN] The medium and heavy-duty transport sector was historically challenged by the emissions regulations that were imposed along the years, requiring to step up the research effort aiming at advancing the product development to deliver a normative compliant option at similar price to the owner. Nonetheless, the recent introduction of EUVI normative have required the addition of a complex aftertreatment system, adding new fixed costs to the product as well as operational costs with the urea consumption. This breakthrough was required due to the limitation of the conventional diesel combustion which cannot decouple high NOx emissions and efficiency. This technological limitation has boosted the investigation on different combustion concepts that could maintain similar efficiency levels than the diesel combustion while controlling the emission formation during the combustion process. Among the different solutions that have appeared along the years, Reactivity Controlled Compression Ignition (RCCI) was demonstrated to have a competitive edge due to its better controllability, high efficiency and low soot and NOx emissions. Despite the benefits, the extension of RCCI to full map operation has presented significant limitations, as excessive pressure gradients at high load and high combustion instability and unburned products at low engine load. Recently, Dual-Mode Dual-Fuel (DMDF) combustion concept was introduced as an attempt of solving the drawbacks of the RCCI combustion while maintaining its advantages. The preliminary results obtained in single cylinder engine (SCE) have evidenced that DMDF can achieves similar efficiency levels than those from conventional diesel combustion while promoting ultra-low levels of soot and NOx. Albeit, the boundary condition requirements are hard to fit in the operating range of commercial air management system as well as drawbacks like excessive HC and CO that still persists from low to medium load, which can be a challenge for the aftertreatment system. Moreover, short-term future regulations will demand a 15 % reduction of CO2 emissions in 2025 which was proven in the literature to not be easily achieved only by combustion process optimization. In this sense, this thesis has as general objective the implementation of the DMDF combustion concept in a multi-cylinder engine (MCE) under the restrictions of real applications to realize clean and efficient combustion in the complete map while providing alternatives to reduce the HC and CO concentration and accomplish CO2 savings. This objective is accomplished by means of a first extensive experimental calibration procedure aiming to translate the guidelines of the DMDF combustion from the SCE to the MCE while respecting the operating limits of the stock hardware, assessing its impacts on combustion, performance, and emission results under steady and driving cycle conditions. Next, dedicated studies are performed to address the issue related with the excessive concentration of unburned products by means of experimental investigations and numerical simulations, to understand the consequences of using fuels with different reactivity in the stock oxidation catalyst conversion efficiency and its ability in achieving EUVI tailpipe emissions. Finally, CO2 reduction is explored through fuel modification, investigating both combustion process improvement and well-to-wheel balance as paths to realize CO2 abatement. / This doctoral thesis has been partially supported by the Spanish Ministry of Science Innovation and Universities under the grant:"Ayudas para contratos predoctorales para la formación de doctores" (PRE2018-085043) / Lago Sari, R. (2021). Dual Mode Dual Fuel Combustion: Implementation on a Real Medium Duty Engine Platform [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/165366 / TESIS

<p>Diesel engines emit toxic gases like NOx and hydrocarbons. These gases need to be treated before they are released out the tailpipe. Thus, an aftertreatment system is installed which comprises of DOC, DPF and SCR. The DOC oxidizes the hydrocarbons and NO, the DPF traps the particulate matter and SCR reduces the NOx by reacting with NH3 at high temperatures. However, since NH3 is also a toxic gas, it cannot be released out the tailpipe in excess. It is important to inject an appropriate amount of NH3 so that it does not slip out the tailpipe. With increasingly stringent regulations on the emission limits of these toxic gases, control of SCR has become more necessary than before.</p> <p>In this thesis, the work done by previous members of the lab research group was improved upon. The objective remained the same, namely, keeping the NH3 slip under 50 ppm while maximizing NOx reduction. On initial inspection, it was realized that the entire controller had been designed and implemented in continuous time. Since the controller would be implemented digitally, with limited hardware sampling time, a discrete-time implementation as done via a DCU was created. The controller switched between two controllers – slip-based and storage-based. The slip-based controller was modified to include a feedforward term in the system so that the response time could be improved along with a feedback controller to eliminate any disturbances and steady-state error, using ammonia slip feedback as measured by an NH3 sensor. It aims at keeping the maximum ammonia slip under 50 ppm. The storage controller is a feedback controller which tries to limit the ammonia storage based on the values fed by a lookup table. This lookup table is a simplified table that determines the maximum ammonia storage at any given instant based on the catalyst bed temperature. The feedback controller gains for both controllers were determined based on a linearized plant model since the initial gains were ineffective with the discretized model. The initial switching mode controller that switches between slip control and storage control switched too frequently between the controllers, thereby affecting controller performance. A switching logic was implemented to limit the number of switches. A switch will be permitted only if the previous switch occurred over a certain time. By implementing all the subparts together in the controller, incremental improvements were prominent. In the end, the performance by implementing the proposed idea was distinctly better. The metrics considered for performance comparison are the number of switches and the ability to maximize slip up to 50 ppm. Parameter error was also studied as well and its effect on the controller performance was analyzed. The data when tested against sets of underestimated, overestimated and mixed estimates for the plant parameters resulted in the underestimated parameters to work within the scope of the objective. The controller was able to compensate for the underdosing. Overestimation caused overdosing in the system which led to spikes in the NH3 slip. Thus, it is better to underestimate the plant parameters than overestimate them.</p>

Made available in DSpace on 2016-04-26T20:48:35Z (GMT). No. of bitstreams: 1 SaraGodoy.pdf: 5804152 bytes, checksum: baeceffd1a1f8912ffc807d85cb63398 (MD5) Previous issue date: 2005-10-18 / The purpose of this work is to present the limits and benefits of Clean Development Mechanism (CDM) Projects implementation. The supplemental objectives are the limits and potentialities evaluation of the Kyoto Protocol and the Tools for the Demonstration and Assessment of Additionality analysis, that is an tool proposed by CDM Executive Committee enabling the companies who propose the CDM projects to prove the additionality of its projects. The Protocol firmed in 1997 during COP 3 (3rd Conference of Parts) of United Nations Framework Convention on Climate Change (UNFCCC), in Kyoto, determined emissions ceiling for some developed countries, considering an institucional apparatus to provide support to the process implementation. In order to make flexible the goals fullfilment, the Protocol creates mechanisms (the Mechanism of Clean Development, the Joint Implementation and the Emissions Trade) that also allow the fullfilment of the reduction objectives. The countries can reach its reduction goals, purchasing emission reduction from other countries. Therefore, these tools enable and improve the carbon market. As relevant part of this work, the CDM appears as a great tool that if well used, can bring benefits for development countries, bringing up economic and enviromental advantages once these projects are implemented in its territories, promoting the sustainable development. There are still plenty of challenges ahead for the CDM and the Protocol development, as reduce the uncertainties of regulatory framework, minors transaction costs and institutional improvements that can be reached. Related to the Tools for the Demonstration and Assessment of Additionality, it fullfils with its function to demonstrate adittionnality, not limiting or promoting new CDM projects / O trabalho objetiva apresentar os limites e benefícios da implantação do Mecanismo de Desenvolvimento Limpo (MDL). Os objetivos subsidiários ao principal são a avaliação mais ampla dos limites e potencialidades do Protocolo de Kyoto e a análise mais específica do Teste de Adicionalidade, que é um instrumento proposto pelo Comitê Executivo do MDL com o intuito de que os proponentes de projetos de MDL possam comprovar se seus projetos são adicionais. O Protocolo firmado em 1997 durante a COP 3 (3º Conferência das Partes) da Convenção-Quadro das Nações Unidas sobre Mudanças do Clima (CQNUMC), em Kyoto, determinou um teto de emissões para vários países desenvolvidos e propôs um aparato institucional para dar sustentação à implantação desse processo. Buscando uma maior flexibilidade no cumprimento das metas, o Protocolo cria mecanismos de flexibilização (o MDL, a Implementação Conjunta e o Comércio de Emissões) que procuram assegurar o cumprimento dos objetivos de redução. Os países podem alcançar suas metas de redução por intermédio de compras de reduções de emissão de outros países. A criação dessas ferramentas possibilita, portanto, o surgimento de um mercado de certificados de carbono. Como parte relevante desse trabalho, o MDL aparece como uma grande ferramenta, que se bem utilizada, pode ser muito benéfica aos países em desenvolvimento, pois pode trazer vantagens econômicas e ambientais com a implantação dos projetos em seus territórios, promovendo assim o desenvolvimento sustentável. Há vários obstáculos a serem transpostos para o maior desenvolvimento do MDL e do Protocolo, como maior regulação, menores custos de transação e melhorias institucionais que podem ser obtidas. Quanto ao Teste de Adicionalidade ele cumpre com sua função de demonstrativo de adicionalidade, não sendo nem limitador nem promotor de novos projetos.