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A method of cleaning diesel engine lubricating oil on-line was investigated using a bypass fine particulate filter followed by an infra-red heater to remove water vapour and light diesel fractions in the oil. The impact of this oil recycler on the gaseous and particulate emissions was investigated over a 300 hour oil age period. A Ford 1.8 litre IDI passenger car diesel engine was used with engine out emission sampled every 15-20 hours. The tests were carried out at 2500rpm (52% of the maximum speed) and 12.3 kW with 47 Nm load (43% of the maximum load and 29% of the maximum power). The EGR level at this condition was 15%. A stop start test cycle was used with a cold start each time and a typical test period of 2-3 hours. The results showed that the recycler had its greatest influence on emissions for fresh oil when there was a large reduction in particulate emissions due mainly to large reductions in the ash, carbon and unburned lubricating oil fractions.

Two Ford IDI passenger car diesel engines, 1.6 and 1.8 litres, were tested over a 100 hour lube oil ageing period with engine out emission samples every 15 hours. The 1.6 litre engine was tested with 5% EGR and the 1.8 litre engine with 15% EGR. Comparison was also made with previous work using an older Petter AA1 engine. The three engines had different dependencies of particulate emissions on the lube oil age. The 1.6 litre engine increased the particulates from 1 to 2.5 g/kg of fuel, whereas the 1.8 litre engine first decreased the particulate emissions from 3 to 1 g/kg over 50 hours of oil age and then they increased to 2 g/kg at 100 hours. This was similar to the previous work on the Petter AA1 engine, where the emissions first decreased and then increased as the oil aged. For the 1.8 litre engine the lube oil fraction of the VOF was high with fresh oil and decreased with time for the first 50 hours and then remained steady.

The influence of ambient temperature on exhaust emissions for an instrumented Euro 1 SI car was determined. A real world test cycle was used, based on an urban drive cycle that was similar to the ECE urban drive cycle. It was based on four laps of a street circuit and an emissions sample bag was taken for each lap. The bag for the first lap was for the cold start emissions. An in-vehicle direct exhaust dual bag sampling technique was used to simultaneously collect exhaust samples upstream and downstream of the three-way catalyst (TWC). The cold start tests were conducted over a year, with ambient temperatures ranging from - 2°C to 32°C. The exhaust system was instrumented with thermocouples so that the catalyst light off temperature could be determined. The results showed that CO emissions for the cold start were reduced by a factor of 8 downstream of catalyst when ambient temperature rose from -2°C to 32°C, the corresponding hydrocarbon emissions were reduced by a factor of 4.

A rapeseed methyl ester biodiesel RMEB100 was tested on a heavy duty DI diesel engine under steady state conditions. The combustion performance and exhaust emissions were measured and compared to a standard petroleum derived diesel fuel. The engine used was a 6 cylinder, turbocharged, intercooled Perkins Phaser Engine, with emission compliance of EURO 2, fitted with an oxidation catalyst. The exhaust samples were taken both upstream and downstream of the catalyst. Particulates were collected and analysed for VOF, carbon and ash. A MEXA7100 gas analysis system was used for legislated gas analysis such as CO, CO2, NOx and total hydrocarbons. A FTIR analysis system was deployed for gaseous hydrocarbon speciation, which is capable of speciating up to 65 species. The results showed a significant reduction in total particulate mass, particulate VOF, CO, THC and aldehydes when using RMEB100.

A 10W-50 G4 synthetic lubricating oil (EULUBE oil) was tested on a heavy duty DI diesel engine under two steady state conditions. The exhaust emissions were measured and compared to a 10W-30 CF semi-synthetic lubricating oil. The EULUBE oil contained the friction reduction additive to improve the fuel economy. The engine used was a 6 cylinder, turbocharged, intercooled Perkins Phaser Engine, with emission compliance of EURO 2, fitted with an oxidation catalyst. The exhaust samples were taken both upstream and downstream of the catalyst. Gaseous and particulates emissions were measured. Particulate size distribution was measured using ELPI and SMPS. The particulate samples were analysed for VOF, carbon and ash. A MEXA7100 gas analysis system was used for legislated gas analysis such as CO, CO2, NOx and total hydrocarbons. The results showed a significant reduction by synthetic lubricating oil in gaseous hydrocarbon emissions, total particulate mass, particulate carbon and ash.

The transport sector is one of the major contributors to greenhouse gas emissions. This study investigated three greenhouse gases emitted from road transport using a probe vehicle: CO₂, N₂O and CH₄ emissions as a function temperature. It should be highlighted that methane is a greenhouse gas that similarly to carbon dioxide contributes to global warming and climate change. An oxidation catalyst was used to investigate CO₂, N₂O and CH₄ GHG emissions over a real-world driving cycle that included urban congested traffic and extra-urban driving conditions. The results were determined under hot start conditions, but in congested traffic the catalyst cooled below its light-off temperature and this resulted in considerable N₂O emissions as the oxidation catalyst temperature was in the N₂O formation band. This showed higher N₂O during hot start than for diesel fuel and B100 were compared. The B100 fuel was Fatty Acid Methyl Ester (FAME), derived from waste cooking oil, which was mainly RME.

This study uses on-board measurement systems to analyze emissions from a diesel engine vehicle during the cold start period. An in-vehicle FTIR (Fourier Transform Inferred) spectrometer and a Horiba on-board measurement system (OBS-1300) were installed on a EURO3 emission-compliant 1.8 TDCi diesel van, in order to measure the emissions. Both regulated and non-regulated emissions were measured, along with an analysis of the NO/NO₂ split. A VBOX GPS system was used to log coordinates and road speed for driving parameters and emission analysis. Thermal couples were installed along the exhaust system to measure the temperatures of exhaust gases during cold start. The real-time fuel consumption was measured. The study also looks at the influence of velocity on emissions of hydrocarbons (HCs) and NOx. The cold start period of an SI-engine-powered vehicle, was typically around 200 seconds in urban driving conditions.

Pure rape seed oil (RSO), as coded BO100 (BO: Bio-Oil) to distinguish from biodiesel was investigated for a range of intake oxygen levels from 21 to 24%. RSO can have deposit problems in both the fuel injector and piston crown and elevated intake oxygen levels potentially could control these by promoting their oxidation. Increased intake oxygen elevates the peak temperature and this promotes the oxidation of soot and volatile organic compounds. The effect of this on particle mass and on the particle size distribution was investigated using a 6-cylinder 6-liter Perkins Phaser Euro 2 DI diesel engine. The tests were conducted at 47 kW brake power output at 1500 rpm. The particle size distribution was determined from the engine-out exhaust sample using a Dekati microdilution system and nano-SMPS analyzer. The results showed that for air RSO had higher particle mass than diesel and that this mass decreased as the oxygen level was increased.

Light-duty China-6, which is among the most stringent vehicle exhaust emission standards globally, mandates the monitoring and reporting of real driving emissions (RDE) from July, 2023. In the process of regulation promulgation and verification, more than 300 RDE tests have been performed on over 50 China-5 and China-6 certified models. This technical paper endeavors to summarize the experience of RDE practice in China, and discuss the impacts of some boundary conditions (including vehicle dynamic parameters, data processing methods, hybrid propulsion and testing altitude) on the result of RDE measurement. In general, gasoline passenger cars confront few challenges to meet the upcoming RDE NOx requirement, but some China-5 certified samples, even powered by naturally-aspirated engines may have PN issues. PN emissions from some GDI-hybrid powertrain systems also need further reduction to meet China-6 RDE requirements.

A Gas to liquid (GTL) fuel was investigated for its combustion and emission performance in an IVECO EURO5 DI diesel engine with a DOC (Diesel Oxidation Catalyst) and DPF (Diesel Particle Filter) installed. The composition of the GTL fuel was analyzed by GC-MS (gas chromatography-mass spectrometry) and showed the carbon distribution of 8-20. Selected physical properties such as density and distillation were measured. The GTL fuel was blended with standard fossil diesel fuel by ratios of diesel/GTL: 100/0, 70/30, 50/50, 30/70 and 0/100. The engine was equipped with a pressure transducer and crank angle encoder in one of its cylinders. The properties of ignition delay and maximum in-cylinder pressure were studied as a function of fraction of the GTL fuel. Particle emissions were measured using DMS500 particle size instrument at both upstream (engine out) and downstream of the DPF (DPF out) for particle number concentrations and size distribution from 5 nm to 1000 nm.

SYNOPSIS A method of cleaning the oil on line was investigated using a bypass fine particulate filter followed by an infra red heater to remove water and light diesel fractions in the oil. This was tested on a range of on road vehicles and a Ford 1.8 litre IDI passenger car engine on a test bed. Comparison was made with the oil quality on the same vehicles and engines without the on-line recycler. Test times were from 200 to 1500 hours of oil ageing and some of the tests showed that the oil quality was still good after 4 times the normal oil life. The results showed that the on line oil recycler cleaning system reduced the rate of fall of the TBN and rate of increase of the TAN. There was a very significant reduction in the soot in oil and the fuel dilution. There was also a consistent reduction in all the wear metals apart from copper and a decrease in the rate of reduction of oil additives. There was also measured on the Ford IDI engine a 5% reduced fuel consumption.

Hydrogenated Vegetable Oil (HVO) diesel fuels have the potential to provide a reduced carbon footprint for diesel engines and reduce exhaust emissions. Therefore, it is a strong candidate for transport and diesel powered machines including electricity generators and other off-road machines. In this research, a waste cooking oil derived HVO diesel was investigated for its combustion and emission performance including ignition delays, size segregated particulate number emissions and gaseous emissions. The results were compared to the standard petroleum diesel. A EURO5 emission compliant three litre, direct injection, intercooled IVECO diesel engine equipped with EGR was used which has a maximum power output of 96kW. The engine was equipped with an integrated DOC and DPF aftertreatment system. Both the upstream and downstream of the aftertreatment emissions were measured. The tests were conducted at different RPM and loads at steady state conditions.

Aldehydes and other Volatile Organic compounds (VOC) are assessed under cold start and steady state conditions using a Perkins Phaser 6 litre diesel engine. A comparison is made between petroleum diesel fuel (PD), 100% biodiesel (WME) and 100% rapeseed oil (RSO). A Temet FTIR was used to determine aldehydes including formaldehyde, acetaldehyde and acrolein. The diesel engine was cold started at room temperature using a step start up procedure that kept the power output constant at two steady state conditions: 23kW and 47kW. Very little difference was observed between petroleum diesel and biodiesel aldehyde emissions at either steady state conditions or during cold start. There was, however, an increase in aldehydes at steady state for rapeseed oil, particularly at low load, but only for from ∼10ppm to 25 ppm for formaldehyde (i.e. 0.12g/kWh to 0.37g/kWh). During cold start conditions, the emissions were significantly higher for rapeseed oil than for petroleum diesel.

New EU environmental law requires 31 ozone precursor VOCs (Volatile Organic Compounds) to be measured for urban air quality control. In this study, 23 out of the 31 ozone precursor VOCs were measured at a rate of 0.5 HZ by an in-vehicle FTIR (Fourier Transform InfraRed) emission measurement system along with 15 other VOCs. The vehicle used was a EURO2 emission compliant SI car. The test vehicle was driven under real world urban driving conditions on the same route by the same driver on different days at different ambient temperatures. All the journeys were started from cold. The VOC emissions and OFP (Ozone Formation Potential) as a function of engine warm up and ambient temperatures during cold start were investigated. The exhaust temperatures were measured along with the exhaust emissions. The temperature and duration of light off of the catalyst for VOCs was monitored.

Direct use of straight vegetable oil based biofuels in diesel engines without trans-esterification can deliver more carbon reductions compared to its counterpart biodiesel. However, the use of high blends of straight vegetable oils especially used cooking oil based fuels in diesel engines needs to ensure compatible fuel economy with PD (Petroleum Diesel) and satisfactory operational performance. There are two ways to use high blends of SVO (Straight Vegetable Oil) in diesel engines: fixed blending ratio feeding to the engine and variable blending ratio feeding to the engine. This paper employed the latter using an on-board blending system-Bioltec system, which is capable of heating the vegetable oils and feeding the engine with neat PD or different blends of vegetable oils depending on engine load and temperature.

The Carbon Dioxide (CO₂) emission from a EURO 3 diesel van over a real-world driving cycle were investigated utilizing part of the Leeds University - Headingly Ring Road (LU-HR) driving cycle, which comprises both an urban (congested) and extra-urban (high speed) driving section. The vehicle used in this research was a 1.8-liter Ford Connect TDCi diesel van. Emissions were monitored by a Portable Emissions Measurement System (PEMS) incorporating an on-board FTIR (Fourier Transform Infrared) exhaust emission measurement system, a Horiba On Board emissions measuring System (OBS 1300) which measured the exhaust flow rate and air/fuel ratio, and a RaceLogic VBOX II differential GPS system provided geographical position, speed and acceleration data. Route topography is known to have substantial influence on vehicle emission.

To maximize CO2 reduction, refined straight used cooking oils were used as a fuel in Heavy Goods Vehicles (HGVs) in this research. The fuel is called C2G Ultra Biofuel (C2G: Convert to Green Ltd) and is a fully renewable fuel made as a diesel replacement from processed used cooking oil, used directly in diesel engines specifically modified for this purpose. This is part of a large demonstration project involving ten 44-tonne trucks using C2G Ultra Biofuel as a fuel to partially replace standard diesel fuels. A dual fuel tank containing both diesel and C2G Ultra Biofuel and an on-board fuel blending system-Bioltec system was installed on each vehicle, which is able to heat the C2G Ultra Biofuel and automatically determine the required blending ratio of diesel and C2G Ultra Biofuel according to fuel temperature and engine load. The engine was started with diesel and then switched to C2G Ultra Biofuel under appropriate conditions.

This work investigates the effect of a multifunctional diesel fuel additive package used with RapeSeed Oil (RSO) as a fuel in a DI heavy duty diesel engine. The effects on fuel injectors’ cleanliness were assessed. The aim was to maintain combustion performance and preventing the deterioration of exhaust emissions associated with injector deposit build up. Two scenarios were investigated: the effect of deposit clean-up by a high dose of the additive package; and the effect of deposit prevention using a moderate dose of the additive package. Engine combustion performance and emissions were compared for each case against use of RSO without any additive. The engine used was a 6 cylinder, turbocharged, intercooled Perkins Phaser Engine, fitted with an oxidation catalyst and meeting the Euro II emissions limits. The tests were conducted under steady state conditions of 23kW and 47kW power output at an engine speed of 1500 rpm.

EU environmental law requires 30 ozone precursor volatile organic compounds (VOCs) to be measured for urban air quality control. In this study, 28 ozone precursor VOCs were measured at a rate of 0.5 Hz by an in-vehicle FTIR emission measurement system along with other VOCs. The vehicle used was a Euro 3 emission compliant diesel van. The test vehicle was started from a cold ambient temperature soak and driven under real world urban driving conditions. Diesel and B100 (100% Biodiesel) were compared using the same repeat journeys. The VOC emissions and OFP (ozone formation potential) were investigated as a function of engine warm up and ambient temperatures during cold start. The exhaust temperatures were measured along with the exhaust emissions. The temperature and duration of light off of the catalyst for VOC were monitored and showed a cold start period to catalyst light off that was considerably longer than would occur on the NEDC (New European Driving Cycle).

In order to improve energy supply diversity and reduce carbon dioxide emissions, sustainable bio-fuels are strongly supported by EU and other governments in the world. While the feedstock of biofuels has caused a debate on the issue of sustainability, the used cooking oil (UCO) has become a preferred feedstock for biodiesel manufacturers. However, intensive energy consumption in the trans-esterification process during the UCO biodiesel production has significantly compromised the carbon reduction potentials and increased the cost of the UCO biodiesel. Moreover, the yield of biodiesel is only ∼90% and the remaining ∼10% feedstock is wasted as by-product glycerol. Direct use of UCO in diesel engines is a way to maximize its carbon saving potentials.