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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.

Over the years, natural gas has been promoted as a clean-burning fuel, especially for transit buses. A decade ago one could claim that natural gas buses deliver significant emission benefits over diesel buses, especially regarding particulate emissions. The spread in nitrogen oxide emissions has always been significant for natural gas engines, high for lean-burn engines and low for three-way catalyst equipped stoichiometric engines. With the introduction of US 2010 and Euro VI (effective as of 2014) exhaust emission regulations, independent of the fuel, the regulated emissions of all engines have been brought close to zero level. This means that the advantage of natural gas as a clean fuel is diminishing, especially in a situation in which electric transit buses are also entering the market. The motivation to use natural gas could still be diesel fuel substitution and to some extent, also reduction of greenhouse gas emissions.

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.

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.

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.