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Electrofuels produced from renewable hydrogen (H2) and captured carbon dioxide (CO2) can be sustainable and carbon-neutral. Paraffinic electrodiesel (e-diesel) can be produced via Fischer-Tropsch synthesis with fuel properties resembling hydrotreated vegetable oils. Electrofuels can be also oxygenated compounds, such as oxymethylene dimethyl ethers (OMEn), having different chain lengths. We studied emissions using paraffinic diesel mimicking e-diesel and its blend with 10% of OME3-5, which has diesel-type fuel properties, in comparison with normal EN590 diesel fuel. An intensive measurement campaign was performed with a modern diesel engine without exhaust aftertreatment to study the effect of fuel on the engine-out emissions. Measurements with the RMC-C1 cycle included detailed characterization of gaseous, particle and polyaromatic hydrocarbon (PAH) emissions having adverse effects on health and the environment.

The implementation of emission standards has brought significant reductions in vehicle emissions in the EU, but road transport is still a major source of air pollution. Future emission standards will aim at making road vehicles as clean as possible under a wide range of driving conditions and throughout their complete lifetime. The current paper presents the methodology followed by the Consortium for ultra LOw Vehicle Emissions (CLOVE) to support the preparation of the Euro 7 proposal. As a first step, the emission performance of the latest-technology vehicles under various driving conditions was evaluated. Towards this direction, an emissions database was developed, containing data from a wide range of tests, both within and beyond the current RDE boundaries.

The Finnish pulp and paper company, UPM, will start a biorefinery in Finland in 2014 to produce advanced renewable diesel in commercial scale. The fuel production is based on using crude tall oil (CTO), a wood-based residue of pulping process, as a raw material. The end product, CTO based renewable diesel called UPM BioVerno, is a novel high quality drop-in diesel fuel resembling fossil diesel. It reduces greenhouse gas emissions by up to 80 % when compared to fossil fuels. In this study, the CTO renewable diesel was studied as a blending component in regular mineral-oil based fossil diesel fuel in field testing. The functionality and performance of four (4) passenger cars was evaluated by comparing e.g. fuel consumption and exhaust emissions of CTO renewable diesel blend (R20UPM) with fossil reference fuel. The field test included 20.000 km on-road driving with each car by experienced drivers from VTT Technical Research Centre of Finland.

VTT (Technical Research Centre of Finland) has together with the Finnish energy company St1 tested different high-volume ethanol fuel (E85) samples in order to find the optimum composition for this fuel to perform satisfactorily in low ambient temperature driving conditions encountered in Finland quite frequently during the winter season. Altogether six different fuel compositions were evaluated, with 70 to 85 % of anhydrous bioethanol, and various different mixes of regular petrol components and some specific species like ETBE, butane, etc. As a reference, new Euro-quality 95 RON petrol with 10% ethanol was used. Volatility of each sample was adjusted according to test temperatures to match summer or winter condition and to ensure effortless start-up. Test results showed that the composition of the fuel had marked influence on emissions. The lower the test temperature was, the more distinctive were the differences.

Over the past decade significant research and development activities have been invested in alternative fuels in order to reduce our dependency on fossil fuel sources and reduce CO₂ and local emissions from traffic. One result of these R&D efforts is paraffinic diesel fuels, which can be used with existing vehicle fleets and infrastructures. Paraffinic diesels also have other benefits compared to conventional diesels, for example, a very high cetane number and the lack of sulfur and aromatic compounds. These characteristics are beneficial in terms of exhaust gas emissions, something which has been demonstrated in numerous studies. The objective of this study was to develop low-emission combustion technologies for paraffinic renewable diesel in a compression ignition engine, and to study the possible benefits of oxygenated paraffinic diesel.

In this study, vehicle exhaust emissions and performance were studied using various renewable components with the aim of achieving a high bio-share in gasoline and compatibility with conventional cars. Several biogasoline components were included in the fuel matrix: ethanol, ETBE, isobutanol, n-butanol and renewable hydrocarbon gasoline produced from hydrotreated oils and fats. The share of bioenergy in the test fuel blends varied from 7 to 28 Eeqv%, and the oxygen content from 0 to 11 m/m%. Fossil gasoline was used as the reference fuel for emissions performance, and E85 fuel as an example of a typical market fuel for FFV cars. Experimental work was carried out at −7 °C with two conventional gasoline cars and one FFV car. The measurements included regulated and unregulated exhaust emissions.

This study presents emission results measured with renewable and synthetic diesel fuels. Three engines and five city buses were studied. The efficiency of diesel oxidation catalyst combined to particle oxidation catalyst (POC®) was measured with two engines. The studied diesel fuels were EN590, FAME, HVO and GTL. In most cases all regulated emissions decreased with HVO and GTL fuels compared to conventional EN590 diesel fuel. With FAME, the NOx emissions were higher compared to EN590, but other emissions were reduced. Alternative fuels had a positive effect on emissions, which are considered harmful to human health.

Hydrotreated vegetable oil (HVO) named NExBTL is a 2nd generation renewable diesel fuel made by a refinery-based process converting vegetable oils to paraffins. Also animal fats are suitable for feedstocks. Properties of this non-ester type biobased fuel are very similar to GTL. It contains no sulfur, oxygen, nitrogen or aromatics. Cetane number is very high (∼90). Cloud point can be adjusted by severity of the process from -5 to -30°C, heating value is similar to diesel fuel, storage stability is good, and water solubility is low. Emissions of two heavy duty engines and two city buses are presented with HVO and sulfur free EN 590 diesel fuel. The effect of HVO on regulated emissions compared to EN 590 fuel was: NOx -7 % … -14 % PM -28 % … -46 % CO -5 % … -78 % HC 0 % … -48 % Aldehydes, PAHs, mutagenicity and particulate size were also measured.

Biodiesel can be processed by esterification or by biomass-to-liquid (BTL) process. Neste Oil has developed a BTL diesel component NExBTL utilizing a proprietary conversion process for vegetable oils and animal fats. NExBTL biodiesel properties are similar to the best existing diesels such as GTL or Swedish Environmental Class 1 fuels. NExBTL is sulfur-, oxygen-, nitrogen- and aromatic free and has very high cetane number. Product meets the requirements set by EN590 and WWFC category 4 except for density. Cold properties (cloud point) of NExBTL can be adjusted in the production from -5 … -30°C to meet the needs of various climatic conditions. Heating value is similar to the EN590 hydrocarbon fuel, storage stability is good and water solubility low. NExBTL biodiesel is compatible with the existing vehicle fleet as well as diesel fuel logistic system and is technically easy to blend in conventional diesels in all ratios.

The effect of total olefin content on ozone forming potential has been widely studied. As a result a stringent limit for olefins is already given in California Specification for “Phase 2” gasoline and the 18 vol% limitation of olefins is expected to tighten also in Europe. However, it is not clear how determining the light olefins are and what is the role of heavy olefins regarding ozone forming potential. Ethanol is widely used as gasoline component in many countries, but not extensively in Europe. The biofuels have the potential to provide a renewable source of energy and contribute to lower global CO2 emissions. The unregulated emissions, especially particulates and their quality have not been studied extensively with ethanol containing gasoline using European test fleet. The objective was to study the applicability of heavy olefins in non-oxygenated and ethanol oxygenated gasolines. Alkylates in gasoline were replaced by isooctene.

This paper presents an overview of the results on heavy duty engines collected in the “PARTICULATES” project, which aimed at the characterization of exhaust particle emissions from road vehicles. The same exhaust gas sampling and measurement system as employed for the measurements on light duty vehicles [1] was used. Measurements were made in three labs to evaluate a wide range of particulate properties with a range of heavy duty engines and fuels. The measured properties included particle number, with focus separately on nucleation mode and solid particles, particle active surface and total mass. The sample consisted of 10 engines, ranging from Euro-I to prototype Euro-V technologies. The same core diesel fuels were used as in the light duty programme, mainly differentiated with respect to their sulphur content. Additional fuels were tested by some partners to extend the knowledge base.

Major part of the research work on particulate emissions has been carried out at normal ambient temperature (about +23 °C). In real life, the average day temperatures, especially in the winter season, are far below the “normal” temperature of the exhaust emission test procedures. For many years, it has been obvious that the knowledge of the total particulate mass emissions is not enough. Quality of these particles, e.g. polyaromatic hydrocarbon content and mutagenicity, has been studied. Now there is also a need to gain more information on fine particles, which can penetrate lungs more easily. International Energy Agency's Committee on Advanced Motor Fuels sponsored this study of the possible effect of ambient temperature on particle emissions. Also aldehydes and speciated hydrocarbons were studied. Several different engine and fuel technologies were covered, including gaseous fuels and biodiesel. Research work focused on light-duty technologies.

Effect of lubricant on particle emissions was studied using two heavy-duty diesel engines. Both particulate mass and particle number distribution were measured. Differences between lubricants were studied by dosing two percent of each lubricant (diesel engine oil) to diesel fuel. This arrangement was seen necessary to get clear differences between lubricants. The lubricant had a clear effect on particulate mass emissions. Two of the lubricants gave about the same emission as pure diesel fuel. The worst result was more than two times higher than without oil added to the fuel. The lubricants were all diesel engine oils with different base oils/additive package. Lubricant ash content presumably affects particulate mass. However, the difference in ash content between lubricants was no higher than 30%. Therefore, ash content can only partly explain the differences. The combustion characteristics and the sulphur content of the base oil are essential, too.

Plans to ban MTBE (Methyl tertiary-Butyl Ether) have led to discussions on how the gasoline in California will be formulated without any backsliding in air quality. One possibility is to replace MTBE with isooctane. Exhaust emissions using California Phase II gasoline with MTBE, were compared to a gasoline where MTBE had been replaced with isooctane. Regulated, particulate, carbon dioxide, and PAH (polyaromatic hydrocarbons) emissions were measured at 22 °C temperature for 8 vehicles using the European cycle for year 2000 (ECE+EUDC). One of the vehicles was a GDI (Gasoline Direct Injection), one was a carbureted model without a catalytic converter, and the others were equipped with multi point fuel injection and catalytic converters. Results indicate that no major backsliding in air quality can be expected when replacing MTBE with isooctane. NOx (nitrogen oxides) emissions were reduced in all vehicle types. CO emissions increased in the vehicle without a catalytic converter.

Many standardized tests for evaluating fuel properties have originally been designed for screening straight-run hydrocarbon products. In the case of fuels blended with new components or treated with additives, the traditional test methods may give misleading results. The objective of the work was to evaluate the correlation between the results of standardized testing and of the real-life serviceability of new diesel fuel qualities. Combustion properties, properties affecting exhaust emissions, low-temperature performance and diesel fuel lubricity were studied. The test fuel matrix comprised of typical conventional hydrocarbon diesel fuels, low-emission hydrocarbon fuels, rapeseed and tall oil esters and ethanol-blended diesel fuels. The base fuels were blended with a cetane improver additive and some fuels also with a cold flow improver additive. Combustion and emission tests were carried out with a heavy-duty bus engine and a diesel passenger car.

Exhaust emissions from cars using reformulated gasoline (RFG) that meets European 2005 regulations for gasoline quality were compared to the emissions from cars using gasoline that meets European 2000 regulations (EU2000). Methyl Tertiary Butyl Ether (MTBE) and Tertiary Amyl Methyl Ether (TAME) were used as oxygenates in the reformulated gasoline. The EU2000 gasoline contained no oxygen. Regulated, particulate and PAH exhaust emissions were measured at 22°C for 7 cars and at -7°C for 5 cars using the European MVEG cycle for year 2000 (ECE+EUDC). One of the cars was equipped with a lean burn engine, one with a direct injection engine and one was a carburetor equipped car without a catalytic converter. All other cars were equipped with multi point port fuel injection and a catalytic converter. Mutagenic activity of particulate mass was evaluated using the Ames test.