The main incentives towards biofuel technology were provided by the need to reduce the western world's dependence on fossil fuels, the demand of the agricultural sector to be opened towards new products and markets, and the environmental need to face the increasing greenhouse effect. For these reasons biofuels represent an attractive alternative to conventional oil-derived energy sources as they can fuel the well-proven internal combustion (IC) engines. Their extensive introduction on the market will be principally driven by the results of further studies on their technical performances, and by their cost competitiveness, sustainability and related legislation, regulation and standards.
This project mainly addresses two of these issues:
- the planned research activities evaluate and optimise the effect of the combined usage of biofuels and biolubes in current IC engine performances in terms of efficiency and emissions;
- the environmental impact of renewable fuel and lube production and usage phases with the so-called 'well-to-wheel' analysis.
According to car manufacturer EUCAR consortium beyond the year 2010, the share of engines would depend mainly on:
- availability of mature new technologies,
- infrastructure of alternative fuels,
- availability of modified / synthetic fuels and lubricants,
- costs and customer acceptance.
CLEANENGINE addressed two of these main aspects. Research activities were focused on evaluation of impacts on modern engines of:
- liquid biofuels derived from biomass (like biodiesel and bioethanol),
- environmentally friendly and ash-free lubes and/or lubrication concepts.
Effects of biofuels and biolubes usage on small (ship), medium (car) and large (ship) diesel and/or gasoline engine configurations are evaluated and compatible optimised solutions in materials, geometry and after-treatment are developed considering lifecycle assessment methodologies.
Main expected effects are:
- increase in engine efficiency (by reducing internal friction and improving combustion);
- reduce emissions at the source,
- reductions in NOx, CO and PM when using mixtures of oxygenated biofuels as bioethanol,
- improve the technological and industrial practice related to the use of alternative fuels in combination with environmentally friendly lubricants,
- increase the utilisation share of biofuels, and
- reduction of the wear originated by the accumulation of biofuels in engine oils.
The advantage that can be gained in this project will:
- help in consolidating strategic knowledge for the European large industrial partners (Fuchs, Fiat, Arizona Chemicals, Guascor, Ecocat) and the SME's (Firad, Abamotor),and
- guide politics for environmental legislations.
The CLEANENGINE project was organised into seven technical work packages (WPs): first two were 'input' work packages in which fuel, lubricant and additives developers focused their activities on designing and producing the engine alternative fluids according to end-users requirements. WP3 and WP4 were devoted at the evaluation of the compatibility of engine materials and sub-systems with the alternative fluids. In WP5, development and/or optimisation of post-treatment systems to reach emissions targets was performed for the three engine applications. In WP6, the developed alternative fluids performances were finally assessed in engines. In WP7, a LCA study was carried out to study the environmental impacts in the production and usage phases of the alternative fluids.
The activities by WPs were:
- WP1 research activities were focused on the development of bio-fuels blends according to engine manufactures specifications.
- The aim of WP2 was the development of 'compatible' lubricants with the abovementioned bio-fuels combining non-toxicity, bio-degradability characteristics and renewable resources with increased efficiency, reduced emissions and wear control.
- In WP3 tribological performances of alternatives lubes developed in WP2 and the effect of bio-fuels dilution on friction and wear of mating engine components were evaluated; alternative coatings were tested to counteract the negative effect of bio-fuel dilution. Also the corrosion effect of biofuels and alternative lubes on some engine components materials was evaluated.
- In WP4, the impact of usage of bio fuels in comparison with standard fuels on injection and combustion phases was evaluated by a numerical and experimental point of view.
- WP5 activities were devoted to develop/optimise opportune after-treatment systems for engines working with bio-fuels;
- An assessment of the developed technologies (fuels, lubricants, modified injection and combustion parameters and post-treatment systems) was carried out by engine / vehicle tests in WP6.
- The LCA study performed in WP7 had the aim to evaluate by an environmental point of view the so called 'CLEANENGINE system' combining the application of biofuels and alternative lubes.
The Project results by WPs were:
- WP1 - developed bio-fuels blends were: biodiesel + gasoil (diesel), gasoil (diesel) + bio-ethanol, petrol + bio-ethanol, bio-ethanol + biodiesel and mixtures of gasoil (diesel), biodiesel and bioethanol were considered in the project; to fulfil specifications multifunctional additive packages were formulated for all of the biofuel types.
- WP2 - to achieve the aims the bio-lubricants were based either on ester- or vegetable oils or on polyglycols, with a high amount of renewable resources. The different CLENANENGINE engine technologies required the formulation of three different oils esterbased oil families: four-stroke oil for small and medium engines, four-stroke oil for large engines, two-stroke oil for small engines. The candidate base oils from the category of the polyglycols aimed at significantly reduce the viscosities at low temperatures in order to improve the fuel economy in city driving cycles. This was achieved by means of a high, intrinsic viscosity index of the base oils, eventually improved by VI improvers. To study the solubility of alcohol and biodiesels as well as to address the different oxidation and degradation reactions, polyglycols with three different backbone compositions, were considered. The newly developed alternative oils were characterised by biodegradability and toxicity tests proposed by OECD international organisation. The viscosity characteristics and the ageing stability in presence of bio-fuel dilution were also evaluated: results showed that the behaviour of the alternative engine oils is better than the conventional reference oils.
- WP3 - different tests applied both to simple geometry specimens and real parts revealed a very good behaviour of the developed alternative oils and of the considered innovative coatings, especially in presence of fuel dilution, both in terms of friction and wear results.
- WP4 - in general, it can be stated that adding biodiesel to fossil diesel does not principally change the behaviour of the engines. In some cases, emissions become better in some cases worse, depending on the configuration. In case of large engines various fuel blend, studies were tested and, based on the results, NOx removal was seen necessary to reach EPA 2007 in future applications.
- WP5 - based on emission tests results coming from small, medium and large engines, different components were developed:
- for diesel passenger car application dedicated DOC+DPF solutions were prepare
The project brought together many and different aspects of three complementary subjects — engines, biofuels and biolubes— with the objective to identify their interactions in view of defining those common factors allowing the achievement of the EU strategic CO2 and pollutants targets in a high competitive environment at worldwide level.
More specifically the following points were considered:
- engine sizes both for displacement and power output [small (less than 19 kW), medium for car application and large size (higher than 560 kW) for genset and maritime];
- biofuels (ethanol, FAME) blended with diesel fuel;and
- alternative oils (ester based oil and polyglycol oils) with suitable additive packages.
A substantial effort was put in by the project to identify and synthesize that fuel— engine parameters really affecting exhaust emissions of engines running on biofuels and using biolubes. In establishing the most significant parameters, the project has set up the basis for future development of engines, running on conventional and alternative fuels, in front of the evolution of the non-road regulations at worldwide level as testified by a number of International regulations recently introduced under development.