Förbränning av traditionellt fartygsbränsle medför utsläpp av ämnen som har negativa effekter på miljön. Uppkomsten av strängare internationella regler gällande utsläpp från sjöfartstrafiken kräver ett skifte från det konventionella marina bränslet tjockolja till alternativ med lägre utsläpp. Vågkraft och metanol är två möjliga alternativ inom sjöfarten som kan uppfylla de internationella regleringarna för utsläpp, och har i denna studie jämförts med tjockolja. Beräkningar av emissioner, kostnad och den möjliga producerade effekten utfördes med hjälp av referensfartyget M/V Fidelio som underlag. Studien visar att metanol och vågkraft bidrar med signifikant lägre utsläpp, vilket tyder på stora möjligheter att uppfylla de uppsatta internationella utsläppskraven. Däremot uppfyller de inte referensfartygets effektbehov och är kostsamma i relation till deras möjliga effektuttag. För att minska fartygens miljöpåverkan, lämpar det sig i dagsläget bättre att använda metanol och vågkraft som komplement till andra drivmedel. / Combustion of traditional ship fuels causes emissions of substances that have negative impacts on the environment. Adoption of stricter international regulations regarding emissions from the maritime traffic requires possible substitution of the widely used conventional heavy fluid oil, with lower emissions. Wave power and methanol are two possible substitutions in the maritime traffic that could fulfill the adopted international regulations regarding emissions, and have in this study been compared to heavy fluid oil. Calculations regarding emissions, costs and the possible power generation were performed using the ship M/V Fidelio as a basis. The study presents that wave power and methanol have significant lower emissions, which increases their opportunity to fulfill the international emission regulations. However, these options fail to fulfill the ship’s power demand. Furtheremore, these alternative solutions are costly in relation to their power generation. Currently it is more suitable to use methanol and wave power as a supplement to other fuels, in order to reduce the maritime traffic’s impact on the environment.

Carbon emissions are one of the primary drivers of climate change and the transport sector accounts for 24% of the global carbon emissions. A shift within the automobile industry towards more eco-friendly modes of transportation is hence needed. Vehicles powered by hydrogen are a carbon emissions-free mode of transportation and have been identified as a viable approach to de-carbonize the transport sector, yet, the number of hydrogen-powered vehicles on the roads in Sweden as of 2022 is relatively low compared to the rest of the world. The aim of this study was both to identify factors that are important for actors to invest in hydrogen technology within the transport sector, and to identify how the collaboration between different actors was formed during the adoption process. The study uses a multiple-case study research design where the five cases of Storuman, Mariestad, Sandviken, Trelleborg and Ljungby were selected. Data was collected through eleven semi-structured interviews over video calls. The study has examined the diffusion process of hydrogen technology within the transport sector of each case according to the diffusion of innovations theory. An analysis of the diffusion of hydrogen technology has not, to the best of my knowledge, been conducted in the examined cases. Gaining an understanding of these processes can provide guidance for other municipalities or actors who aims to reduce their emissions and can play an important role in achieving Sweden´s objective of becoming the world´s first fossil-free welfare nation. The findings of the study were that investments in hydrogen technology within the transport sector are currently not economically profitable. However, investments in the innovation were still motivated in terms of a relative environmental advantage, reception of financial funding, the will to take a leading role in the energy transition, geographical location, long-term economic benefits and indirect economic benefits which mainly include that the municipality can market themselves as green and progressive in order to attract competent workforce and business opportunities. The study also concluded that local political support is an important pre-condition for a successful adoption of the innovation.

<p>A variety of methods have been developed to enhance solid propellant burning rates, including adjusting oxidizer particle size, modifying metal additives, tailoring the propellant core geometry, and adding catalysts or wires. Fully consumable reactive wires embedded in propellant have been used to increase the burning rate by increasing the surface area; however, the manufacture of propellant grains and the observation of geometric effects with reactive components has been restricted by traditional manufacturing and viewing methods. In this work, a printable reactive filament was developed that is tailorable to a number of use cases spanning reactive fibers to photosensitive igniters. The filament employs aluminum fuel within a printable polyvinylidene fluoride matrix that can be tailored to a desired burning rate through stoichiometry or aluminum fuel configuration such as particle size and modified aluminum composites. The material is printable with fused filament fabrication, enabling access to more complex geometries such as spirals and branches that are inaccessible to traditionally cast reactive materials. However, additively manufacturing the reactive fluoropolymer and propellant together comes attendant with many challenges given the significantly different physical properties, particularly regarding adhesion. To circumvent the challenges posed by multiple printing techniques required for such dissimilar materials, the reactive fluoropolymer was included within a solid propellant carrier matrix as small fibers. The fibers were varied in aspect ratio (AR) and orientation, with aspect ratios greater than one exhibiting a self-alignment behavior in concordance with the prescribed extrusion direction. The effective burning rate of the propellant was improved nearly twofold with 10 wt.% reactive fibers with an AR of 7 and vertical orientation. </p> <p>The reactive wires and fibers in propellant proved difficult to image in realistic sample designs, given that traditional visible imaging techniques restrict the location and dimensions of the reactive wire due to the necessity of an intrusive window next to the wire, a single-view dynamic X-ray imaging technique was employed to analyze the evolution of the internal burning profile of propellant cast with embedded additively manufacture reactive components. To image complex branching geometries and propellant with multiple reactive components stacked within the same line of sight, the dynamic X-ray imaging technique was expanded to two views. Topographic reconstructions of propellants with multiple reactive fibers showed the evolution of the burning surface enhanced by the geometric effects caused by the faster burning fibers. These dual-view reconstructions provide a method for accurate quantitative analysis of volumetric burning rates that can improve the accessibility and viability of novel propellant grain designs.</p>

>Magister Scientiae - MSc / Chemical speciation and the evaluation of species distribution is the key to understanding the potential of brines to form scale or corrode the water circuit as well as the potential of mobility and release trends of the pollutants into the environment. It is important to identify highly soluble free ions in water chemistry because toxicity of ions is related to mobility and consequently bioavailability. The chemical composition, character and chemical speciation modelling of saline effluents (brines) at Tutuka Power Station and Sasol Synthetic Fuels Complex in Secunda were studied. The form in which chemical species exist (chemical speciation) and the physical and chemical interactions of species in saline effluents at these two study sites is not fully understood. This study investigated how pH, temperature, alkalinity and chemical composition influenced chemical speciation, species distribution, scale forming and corrosion potentials of the different saline effluent streams at the two sites using computer programs PHREEQC and Aq.QA. Characterizations of the results were presented in Stiff and Piper diagrams generated by the Aq.QA computer software. Chemical speciation modelling of the brines showed that scale-forming minerals aragonite, calcite, hematite, anhydrite and gypsum have positive saturation indices between 0 and 20 in mine water, RO brine at Tutuka and Sasol Secunda, EDR brine at Sasol Secunda and VC brine at Tutuka Power Station. The water types at Tutuka Power Station were found to be mainly Na-S04 water types and those at Sasol Secunda were a mixture of Na-Cl and Na-S04 water types. Water treatment chemicals playa major role in increase were absent in the intake water. It was found that Sasol Secunda water streams are much more heavily contaminated than Tutuka water streams. The study also found that the mine water utilised at Sasol Secunda is two-fold more polluted than the mine water utilised at Tutuka although these sites are a mere 40 km apart. The sodium adsorption ratios showed that all the saline effluent streams at Tutuka and Sasol Secunda were unsuitable for irrigation, except for desalination product waters. Chemical speciation showed that the predominant species in the most concentrated saline effluent (VC brine) at Tutuka were the free cr ion at approximately 100 % with very minute quantities of FeCI+ and ZnCI+ and the predominant sodium species were the free Na+ ion which existed at 85 %. Magnesium species had the predominant form as the ionic compound MgS04 at 73 % and the carbonates were mainly in the form of NaC03- (53 %), HC03- (28 %) and CO{(7 %). The most concentrated brine analysed at Sasol Secunda was the TRO brine. PHREEQC did not predict the precipitation of CaC03 from the TRO brine at Sasol Secunda. The most abundant calcium species were Ca2+(59 %) ions and CaS04 (40 %). The brine was at a pH of 5.76 with dissolved CO2 at 73 % of the carbonate species. Trace elements were evaluated and the toxic trace elements varied from 0.07 mg/L (As) to 26.75 mg/L (Sr) at Sasol Secunda. At Tutuka Power Station the toxic trace elements in brines varied from 0.02 mg/L (As/Se) to 16.85 mg/L (Sr). Sr and B were found to be the most highly concentrated toxic elements. The major and trace ion chemistry, alkalinity, pH, sodium adsorption ratios, change in concentration of the water streams and the brine chemical composition after contact with ash was also evaluated. When saline effluents at Tutuka Power Station and Sasol Secunda are combined with ash, pH, Ca content and alkalinity of the resulting solution increased. The chemical composition of saline effluents can be influenced by the ingress of CO2 from the atmosphere. The study shows conclusively that brine composition and concentration is highly variable at these South African power utilities and processes such as RO, contact with ash and C02 ingress can have an impact upon the overall brine quality. Aq.QA was found to be a more accurate tool for classifying waters according to dominant ions than Stiff diagrams but Stiff diagrams still have the superior advantage of being a mapping tool to easily identify samples of similar composition as well as quickly identify what has been added or what has been removed from a water stream. Chemical speciation could identify effluent streams where C02 dissolution had taken place.

Today’s society is adapting to reduce the climate footprint which is why the Swedish Armed Forces is expected to revise its use of fossil fuel. The choice of fuel is not obvious, and this report aims to examine the possibilities and limitations for a few renewable fuel’simplementation in the Swedish Armed Forces. Based on Moche Kress logistics concept an analyzing tool were created. The analyzing tool is based on the category’s economy, industry/engine technology, technology/characteristics, inventory, storage facilities and transports. Methods used is a mixture of document collection and interviews with an expert in the area of alternative fuels and combustion engines. The renewable fuels analyzed are FAME, HVO, biogas and DME. Results of the analysis show that FAME has a relative low cost for production, only requires small-scale modifications in engines, the domestic production is expected to expand and is interoperable with the current supply chain. The biggest limitations are the bad qualities regarding cold temperatures and can’t be stored longer periods of time. HVO has a bit higher production cost but has good qualities even in colder temperatures, high energy density, can beused in all diesel engines after an approval from the manufacturer and can be implemented incurrent infrastructure as well as supply chain. Raw materials consist on the other hand largely from palm oil production. Biogas has a relatively high production cost, low energy density, requires extensive renovations/installations of engines/fuel systems and can neither be implemented in current infrastructure nor supply chain. Positive features are its good qualities in cold temperatures and big part domestic production. DME also has good qualities in cold temperatures but requires a new injection system and a new tank, can’t be implemented in neither current infrastructure nor supply chain and is not produced anywhere globally today. Based on the results from the analysis HVO were concluded as the most realistic alternative for the Swedish Armed Forces. Further conclusions were that FAME is not the best alternative and neither biogas nor DME were estimated as a realistic choice today. The last conclusion of the analysis is that none of the alternatives had possible self-sufficiency in Sweden as of now. / Mot bakgrund av att samhället ställer om till att bli mer klimatpolitiskt hållbart förväntas ett drivmedelsbyte vara aktuellt för Försvarsmakten. Vilket drivmedel som är aktuellt för detta är inte självklart och detta arbete syftar till att undersöka vilka förutsättningar ett antal förnybara drivmedelsalternativ har för implementering i Försvarsmakten. Utifrån Moche Kress logistikkoncept togs ett analysverktyg fram som utgår från kategorierna ekonomi, industri/motorteknik, teknologi/egenskaper, lagerhållning/tillgänglighet, infrastruktur för lagerhållning och transporter. Empiri samlades därefter in via en dokumentinsamling samt intervjuer med en expert inom alternativa drivmedel och förbränningsmotorer. Alternativen som analyserats är FAME, HVO, biogas och DME. Resultat av analysen var att FAME har en relativt låg produktionskostnad, enbart kräver mindre anpassningar i motorer, har inhemsk produktion som förväntas expandera och kan implementeras i befintlig försörjningskedja. Största begränsningarna är att det har begränsade köldegenskaper samt låg lagringsbeständighet. HVO har en något högre produktionskostnad men goda köldegenskaper, högt energiinnehåll, kan nyttjas i samtliga dieselmotorer efter tillverkarens godkännande och kan implementeras i befintlig försörjningskedja respektive infrastruktur. Råvaror kommer dock till stor del från palmoljeproduktion. Biogas har en relativt hög produktionskostnad, lågt energiinnehåll, kräver omfattande renoveringar/installationer av motorer/bränslesystem och kan inte implementeras i varken befintlig försörjningskedja eller infrastruktur. Det har dock bra köldegenskaper och hög andel inhemsk produktion. DME har bra köldegenskaper, men kräver nytt insprutningssystem och ny tank, kan inte implementeras i dagens försörjningskedja eller infrastruktur och produceras ingenstans i världen idag. Utifrån analysens resultat bedömdes HVO som det mest realistiska alternativet för Försvarsmakten. Utöver det bedöms inte FAME som mindre fördelaktigt, och biogas respektive DME som orealistiska alternativ i dagsläget. Den sista slutsatsen av analysen var att inget alternativ medger självförsörjning i Sverige idag.

Le secteur du transport joue un rôle majeur dans le changement climatique et la pollution atmosphérique. Parmi les secteurs d'origine anthropique, le transport routier est considéré comme le premier contributeur au réchauffement climatique, due notamment aux émissions de CO2, de précurseurs d'ozone, et d'aérosols carbonés (carbone noir). De plus, les émissions liées au transport routier telles que les oxydes d'azote (NOx), l'ammoniac (NH3), les carbonyles volatiles, les hydrocarbures gazeux, et les aérosols, contribuent à la dégradation de la qualité de l'air.Le but de cette étude était d'approfondir l'état des connaissances en termes de facteurs d'émissions associés au transport, pour les polluants en phases gazeuse et solide. Un intérêt particulier a été apporté sur l'influence des systèmes de post-traitement des gaz d'échappement, et de la qualité du carburant, sur les émissions d'espèces réglementées et non-réglementées. Des campagnes de mesure ont été menées sur différentes catégories de véhicules dans le laboratoire d'étude des émissions (VELA) du centre commun de recherche de la commission Européenne (JRC-EC) à Ispra, en Italie. La flotte de véhicules choisie comprenait des camions (moyens et poids lourds), des voitures et des deux-roues formant un ensemble représentatif des véhicules circulant en Europe. En plus des carburants classiques, essence et diesel, les véhicules ont été alimentés avec des carburants alternatifs tels que le bioéthanol, et le gaz de pétrole liquéfié. Les émissions en phase gazeuse ont été mesurées par spectroscopie infra-rouge à transformé de Fourier (FT-IR; pour les composés azotés, les carbonyles volatiles et les petits hydrocarbures), par spectrométrie de masse à temps de vol après ionisation multi-photonique résonnante (REMPI-ToF-MS; pour les hydrocarbures aromatiques mono et polycycliques), par spectromètrie de masse haute résolution à temps de vol dédié à l'analyse des aérosols atmosphériques (HR-TOF-AMS; pour les aérosols organiques), et par photométrie d'absorption multi-angle (MAAP; pour le carbone élémentaire).Parmi les véhicules étudiés, les scooters ont été les plus gros émetteurs d'aérosols organiques primaires et d'hydrocarbures mono et polycycliques. De plus, le système de post-traitement des gaz d'échappement étudié pour le scooter le plus récent (conforme à la réglementation Euro 2) pourrait être responsable d'émissions importantes d'aérosols organiques. Concernant les voitures, et en particulier celles équipées de moteurs à allumage par étincelle, la plupart de leurs émissions intervenaient en début de cycle, avant que la température d'amorçage du pot catalytique soit atteinte. Ces émissions liées au démarrage à froid du véhicule pouvaient masquer les effets bénéfiques des carburants alternatifs en terme d'émissions de précurseurs d'ozone. Finalement, les camions étaient les plus gros émetteurs de suie (carbone élémentaire) et de NOx. Malgré le fait que plusieurs systèmes de retrofit se sont montrés particulièrement efficaces pour réduire les émissions des polluants réglementés (particules et NOx) de ces véhicules, certains d'entre eux produisaient des quantités significatives de NH3. Ce projet a permis de collecter des informations précieuses pour l'élaboration de la législation relative au développement d'un transport durable en Europe. / Transport sector plays a key role in global warming and air pollution. Among the anthropogenic sectors, on-road transport is recognized as the first contributor to global warming, mainly due to its emission of carbon dioxide, ozone precursors and carbonaceous aerosols. In addition, on-road transport contributes to the deterioration of air quality by releasing nitrogen oxides, ammonia, carbonyls, hydrocarbons and aerosols. However, the current European legislation of vehicles emissions focusses on a limited number of pollutants, namely hydrocarbons, carbon monoxide, nitrogen oxides, and particulate matter.The aim of this work was to improve the knowledge about the emission factors of gas phase and particle-associated emissions from vehicle exhaust. The impacts of aftertreatment devices and fuel quality on regulated and unregulated species were studied. Several sampling campaigns with different types of vehicles were conducted in the vehicle emission laboratory (VELA) at the European Commission Joint Research Centre (EC-JRC) Ispra, Italy. The vehicles chosen were representative of some categories circulating in Europe (heavy duty vehicles, light duty vehicles, two-stroke mopeds), and either standard fuel or some alternative fuels (ethanol and liquefied petroleum gas) were used. The gas phase was monitored by a Fourier transform infrared spectrometer (carbonyls, nitrogen-containing species, small hydrocarbons), and a resonance-enhanced multiphoton ionization time-of-flight mass spectrometer (mono and polycyclic aromatic hydrocarbons). The particulate phase was analyzed by a high-resolution time-of-flight aerosol mass spectrometer (organic aerosol, chloride, nitrate), and a multiangle absorption photometer (black carbon). The mopeds were found to have the higher emission factors of primary organic aerosol and polycyclic aromatic hydrocarbons. While efficient to reduce the regulated emissions, the after-treatment used to comply with the moped Euro 2 emission standard might be responsible of large emission of unregulated organic aerosols. Most of the emission linked to the gasoline light duty vehicles were released before the light-off of the catalyst. Whereas alternative fuels studied helped to reduce ozone precursor emissions, the emissions associated to the cold start of the vehicle reduced this beneficial effect. Finally, the heavy duty diesel vehicle featured the highest NOx and black carbon emissions. Despite efficient retrofit and after-treatment systems (for particles and NOx), these vehicles could release significant amount of NH3. These results provided valuable insights for the drafting of legislation related to the achievement of sustainable transport in Europe.

The Bush administration's decision to abandon the Kyoto Protocol can be explained by prospect theory. The change in federal climate policy between the Clinton and Bush administrations was due to the difference in domain that each president operated under. President Clinton operated under a domain of losses as he associated continued fossil fuel use with future socio-economic and environmental damages from climate change. This domain of losses increased President Clinton's risk tolerances and explains his pursuit of the Kyoto Protocol, an international agreement to limit greenhouse gas emissions. Conversely, President Bush operated under a domain of gains where he did not connect fossil fuel use with future damages, rather with continued economic growth. President Bush's domain of gains reduced his risk tolerance and resulted in his pursuit of fossil fuel intensive economic development policies. This paper defines the domain that Presidents Clinton and Bush operated under regarding climate change, the independent variable of this analysis. A total of 26 speeches on climate change by these presidents were coded to explicate domain according to two categories of beliefs. The single most salient variable is the decision makers beliefs about the perceived robustness of the current state of scientific knowledge on climate change. The second most important aspect of these decision makers beliefs revolve around the role of fossil fuels in economic growth. Once domain has been defined through the cognitive maps and each decision makers corresponding risk tolerance explicated, the dependent variable of policy preferences are analyzed. Two policy options are analyzed; the business as usual (BAU) option associated with the status quo, as well as a climate protection policy that is reflective of the emissions reductions associated with US compliance with Kyoto. These two policy options are evaluated in three case studies; the economy wide costs of compliance with Kyoto targets for greenhouse gas emissions, the public health impacts of greenhouse gas reductions, and finally against a component of the Kyoto Protocol that allows for international trading of permits to emit greenhouse gases.

No description available.

Denna studie har kartlagt vilka drivmedel som användes av svenska handelsflottans fartyg från 2016 och hur stor andel som inte var petroleumbaserad. Fokus riktades mot Linnéuniversitetets sjöingenjörsprogram där en analys av kursplaners mål samt innehåll belyste om alternativa drivmedel fanns inkluderat i utbildningen. Respondenterna på sjöingenjörsprogrammet var delaktiga i en intervjustudie som klargjorde om framtidsutsikter för realisering av alternativa drivmedel var möjlig. Resultaten visade att det fanns tre alternativa drivmedel inom svenska sjöfarten, där inga kurser hade direkt koppling men genom ledord fanns tre kurser med relevans till alternativa drivmedel. Det fanns ett gemensamt mål inom respondenterna på Linnéuniversitetet om alternativa drivmedel men vägen till förverkligande var inte klarsynt. / A few years ago, marine diesel and heavy fuel oil were the fuels that drove shipsforward. But with new legal requirements and climate goals, other potential fuelshave seen the light of day. These alternative fuels have resulted in an increase in thesystems you need knowledge of on board. The purpose of the study is to focus onhow the education to become a marine engineer keeps up with the rapidtechnological development that is taking place today.The study was carried out in several stages where document studies were compiledand became the basis for an interview study. The first document study resulted inwhat fuel the Swedish merchant fleet's newer ships use. In addition to marine dieseland heavy oil, alternative fuels such as liquid natural gas, methanol and batteryoperation are also used. These alternative fuels are used or can be used on about athird of the surveyed ships today.The second document study was done against the marine engineering program tosee if there was any connection to alternative fuels in the education's syllabuses. Nodirect connection was found, but by using key words for alternative fuels, threecourses were found with content that could be associated with the alternative fuels.The results of the document studies formed the basis for an interview study in whichpersonnel linked to the marine engineering education at the Linnaeus Universitywere interviewed. The result of the interview study was that all respondents agreedthat education is needed in the alternative fuels that have arrived. However, therespondents did not agree on what the training should look like, as there were manydifferent education proposals. Since there were also expressions from respondentsabout time, knowledge, and resource shortages, they need to reach an agreementwith a way forward to be able to secure the educational efforts towards a commongoal.

<div>The commercial vehicle sector is an important enabler of the economy and is heavily dependent on fossil fuels. In the fight against climate change, reduction of emissions by improving fuel economy is a key step for the commercial vehicle sector. Improving fuel economy deals with reducing energy losses from fuel to the wheels. This study aims to analyze efficiency improvements for two systems that are important in reducing CO2 emissions - hybrid powertrains and natural gas engines. At first, a prototype series hybrid powertrain was analyzed based on on-highway data collected from its powertrain components. Work done per mile by the electrical components of the powertrain showed inefficient battery operation. The net energy delivery of the battery was close to zero at the end of the runs. This indicated battery was majorly used as an energy storage device. Roughly 15% of losses were observed in the power electronics to supply power from battery and generator to the motor. Ability of the hybrid system to capture regenerative energy and utilize it to propel the vehicle is a primary cause for fuel savings. The ability of this system to capture the regenerative energy was studied by modeling the system. The vehicle model demonstrated that the system was capturing most of the theoretically available regenerative energy. The thesis also demonstrates the possibility of reduction of vehicular level losses for the prototype truck. Drag and rolling resistance coefficients were estimated based on two coast down tests conducted. The ratio of captured regenerative to the drive energy energy for estimated drag and rolling resistant coefficients showed that the current system utilizes 4%-9% of its drive energy from the captured regenerative energy. Whereas a low mileage Peterbilt 579 truck could increase the energy capture ratio to 8%-18% for the same drive profile and route. Decrease in the truck’s aerodynamic drag and rolling resistance can potentially improve the fuel benefits.</div><div>The second study aimed to reduce the engine level pumping losses for a natural gas spark ignition engine by cylinder deactivation (CDA). Spark ignited stoichiometric engines with an intake throttle valve encounter pumping/throttling losses at low speed, low loads due to the restriction of intake air by the throttle body. A simulation study for CDA on a six cylinder natural gas engine model was performed in GT- Power. The simulations were ran for steady state operating points with a torque range 25-560 ftlbs and 1600 rpm. Two , three and four cylinders were deactivated in the simulation study. CDA showed significant fuel benefits with increase in brake thermal efficiency and reduction in brake specific fuel consumption depending on the number of deactivated cylinders. The fuel benefits tend to decrease with increase in torque. Engine cycle efficiencies were analyzed to investigate the efficiency improvements. The open cycle efficiency is the main contributor to the overall increase in the brake thermal efficiency. The work done by the engine to overcome the gas exchange during the intake and exhaust stroke is referred to the pumping losses. The reduction in pumping losses cause an improvement in the open cycle efficiency. By deactivating cylinders, the engine meets its low torque requirements by increase in the intake manifold pressure. Increased intake manifold pressure also resulted in reduction of the pumping loop indicating reduced pumping losses. A major limitation of the CDA strategy was ability to meet EGR fraction requirements. The increase in intake manifold pressure also caused a reduction in the delta pressure across the EGR valve. At higher torques with high EGR requirements CDA strategy was unable to meet the required EGR fraction targets. This limited the benefits of CDA to a specific torque range based on the number of deactivated cylinders. Some variable valve actuation strategies were suggested to overcome this challenge and extend the benefits of CDA for a greater torque range.</div><div><br></div>