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QLK5-1999-01284
DEAR: Environmentally Adapted Mixed Diesel Fuel Systems Containing Diesel, Ethanol and RME |
| Contract No: | QLK5-1999-01284 |
| Source: | Second Periodic Report, December 2001 |
| Third Periodic Report, December 2002 | |
| Final Report, December 2003 |
Final Summary Report
Period Ending
December 2003
Summary
Introduction
The transportation sector is responsible for a disproportionately high portion of the net emissions of greenhouse gases (GHG), as C02. It is necessary to reduce these emissions. This can be done in several ways. For instance, the energy efficiency of the engine can he increased by replacing gasoline vehicles by diesel vehicles, by introducing modifications to the engines, or by introducing completely new concepts such as fuel cells. These measures may have temporary effect but in the long run the effect of increasing transportation volumes will cause an increase in green house gas (GHG) emissions. Thus, more powerful action is called for.
It is generally agreed that a contribution to this can be achieved by replacing petroleum fuels by fuels derived from renewables. Experience has shown that the one way to significantly decrease the net GHG emissions is to use a low-blend concept, in which the biocomponent is blended at 5-15 % into the petroleum fuel. This approach has the advantage that no specialised vehicle fleet is needed; the existing fleet can be run on the new low-blend fuel.
The biocomponent candidates to consider today are primarily fatty acid methyl esters (FAME), such as RME (rapeseed methyl ester); biogas or bioethanol (from cereals). Within 5 -10 years the following may become candidates: bio-methanol, bio-dimethylether (bio-DME), bioethanol (from Forestry by-products or straw). However, each of these biofuel candidates has significant drawbacks. RME in itself has excellent technical properties, but the volume potential is limited. Biogas and DME, which are both gases at room temperature, suffer from the lack of distribution infrastructure and in addition require the engines to be modified. Further, these two gases cannot be blended with liquid fuels, while biogas can only be produced in small volumes, unless biomass is specifically grown for its production.
Ethanol and methanol can potentially provide large volumes and may be used directly in gasoline engines. Hence, these alcohols have a large potential as gasoline replacers, but are not well suited for diesel engines. In diesel engines they require emulsifiers as well as equipment and energy for emulsification, in addition to ignition improving additives (costly) or spark plugs (turning the engine into a gasoline engine, thus reducing overall efficiency).
Thus, there is a need for a fuel blend, with a novel type of biocomponent, without the drawbacks of the ones presented above, and with engine performance and emissions at least as good as the base fuel. This project addressed that need.
General Objectives
Problems addressed by the project:
Scientific and technical objectives :
This project aimed to provide the scientific and technical basis for the formulation of a new environmentally adapted diesel fuel. The goal of this project is to replace 15 % of ordinary fossil diesel fuel with fuel from renewable resources (alcohols, RME and others). The new diesel fuels will be in the form of a stable solution, not an emulsion. The target is to replace the existing diesel fuel for vehicles in Europe. These new diesel fuel formulations are intended to be used in today's vehicles, without any rebuilding or adjustments to the engines or the fuel systems in the vehicles.
It is also necessary to be able to use the established distribution infrastructure, which will make it possible for the fuel to have an immediate effect on emissions. These renewable fuel additions stem from production on set-aside farming land, in accordance with CAP and Agenda 2000.
The technical objectives of these new diesel fuel mixtures are
Results and Milestones
A fuel concept that fulfills the objectives for the project was developed. This results in the ability to blend a fuel formulation containing 15 % of renewable material, with excellent physical, handling, performance, and emission properties without the need for engine modification. The biocomponent of the agrodiesel blend can be regarded as having the advantages of ethanol (biologically produced: production possible from a variety of raw materials; potentially low production cost) but without its drawbacks (non-miscibility with petroleum diesel; low flashpoint; poor diesel engine ignition properties).
The suitability of the concept has been proven in minor emission and performance tests, as well as long-term tests, on test-bench engines in a specialised engine laboratory. A minor field test, involving forestry machines during winter conditions, has been successfully performed, and a small-scale bus fleet test is in progress. These field tests have not been financed by the European Commission.
An indicative life cycle analysis (LCA) has been assembled. The results show the advantage of the Agrodiesel 15 concept concerning greenhouse gas emissions and use of petroleum.
The economy of production of Agrodiesel 15 has been studied. When the fuel is produced in large volumes, some of the sub-components that make up the biocomponent will be purchased on the world market, while others for economic reasons may have to be produced in plants owned by the industrial contractor of the project, Agro Oil. A preliminary economic analysis indicates that the cost of fuel production will he market competitive.
Benefits and Beneficiaries
The main benefits of the project results will be evident when the fuel has been launched on the market and is beginning to be used on a larger scale. Then, the environmental advantages, including low general emissions, and especially a significantly lower contribution to net greenhouse gas emissions, will come into force. The benificiaries of this type of environmental properties are obviously the people of the Community. and, regarding the greenhouse gas reduction, it is actually of worldwide benefit.
Further, the Community's petroleum dependence will decrease, which is also a public benefit. It should be noted that the fuel concept of this project will provide a significant contribution to the biofuel introduction that will he required by the Biothels Directive, which was published during 2003.
The growing of biomass for the biocomponent of the project is beneficial for farmers and farming, and well within the lines of the Community Agricultural Policy. Job opportunities within rural areas will increase as will those of the biomass processing industry. This will also give opportunities to diversify crop production. Also, this will lead to a competitive agriculture sector that can gradually face up to the world market without being over-subsidised.
The fuel trading industry within the community wiIl be strengthened, selling an environmentally and economically sustainable fuel resulting from this project while not having to depend on specialised engines.
Third Progress Report Summary
Period Ending
December 2002
Summary
The objective of this project is to provide the scientific and technological basis for the formulation of a new environmentally adapted diesel fuel for the European market. The goal is to replace 15 % or more of the ordinary fossil diesel fuel with fuel from renewable resources. In order to achieve an economically realistic basis for the fuel, less costly ingredients are preferred.
During the first year of the project, a number of interesting fuel candidates were found, but as the most promising ones had poor compatibility with copper, as demonstrated by corrosion tests, this type of formulations were abandoned.
During the second year, studies of a new and very promising fuel system was initiated. These studies have been taken further during the third year and a number of fuel candidates have been subject to engine tests. In addition, there has been significant progress in the part of the project that focuses on formulation of water tolerant fuel candidates.
During the third year of the DEAR project several significant results were obtained. The new type of fuel system that the project turned its focus to during the second year has now been thoroughly investigated and a number of promising fuel candidates has successfully gone through engine tests. In addition, a substantial amount of chemical knowledge about the stability and storage properties of the new system has been gained from experiments in laboratory scale.
Another goal of the project has been to formulate a more water tolerant fuel to be able to demonstrate potentially beneficial combustion effects obtained by added water. Several candidate fuels with high water tolerance have been developed and a new surfactant with very interesting properties has been synthesised. The new surfactant can be made fully from renewable sources and it has given fuel formulations with high water tolerance combined with stability at low temperatures.
In addition to the above, systematic studies of fuel formulations containing alcohols were performed. In a laboratory study, one such formulation was found to perform almost as well as the surfactant formulation mentioned above, and it is currently being evaluated as a candidate for future engine tests. The alcohol in question can be produced from renewable sources.
Second Progress Report
Summary
December 2001
Summary
During the second year of the DEAR project, studies on a new class of fuel blend systems has been initiated. Indications from results obtained from previous tests are that these fuel formulations are likely to be good candidates for the final fuel. Although certain properties of these fuels are known, there are some important points, regarding the formulation, that still need to be investigated. Another line of work has also on identification of highly water-tolerant fuel blends, in order to test the effect of water content on engine emissions. Fuel blends have been obtained that have a high water tolerance; these will be used in test runs of an engine.
Introduction
The aim of this project is to provide the scientific and technological basis for the formulation of a new environmentally friendly diesel fuel. The goal for this project is to replace 15 % or more of the ordinary fossil diesel fuel with fuel derived from renewable resources. The target is to replace existing diesel fuel for vehicles in Europe. In order to achieve an economically realistic basis for the fuel, less costly ingredients are preferred and need to be identified.
Activities
A number of interesting fuel formulations were found during the first year of the project. The most promising of these contained organic amines as one of the components. Probably due to the presence of amines, the fuel blends were found to be too corrosive for use in engines, as shown by a copper corrosion test. Hence, this approach has been abandoned.
During the second year of the project, as reported here, studies on a new class of fuel blend systems has been initiated. Through previous tests, performed within other projects, indications have been obtained that these fuel formulations are likely to be good candidates for our final fuel. However, although certain properties of these fuels are known, there are some important points, regarding the formulation, that need to be further investigated.
An important aspect that has to be studied is the influence of water on the fuel. This requires attention for two reasons:
Another important point of study concerns optimisation of the fuel blend, taking into consideration not only the technical, but also the economic aspects, that depend on the components of the fuel formulation
Currently the most interesting candidate fuel formulation (known as "Formulation 4") has the following components:
[Note: a polar substance has molecules that are hydrophilic ("water-loving"), and possibly water soluble, but with very limited solubility in diesel; these molecules normally contain a relatively large portion of oxygen. A non-polar substance has the opposite properties. A typical surfactant has both a polar and a non-polar part]
Component 1 is the base of the fuel, and make up 85 % of the fuel volume, with the rest made up of the four oxygenates, which can be produced from biomass. The project is currently investigating how this may be done most efficiently.
The water content of a diesel fuel is believed to significantly affect both the combustion properties and the exhaust emissions. A hypothesis that is often mentioned, but less often tested, is that a high water content in the fuel should give lower combustion temperatures, which in turn would result in a lower amount of NOx in the exhaust gases. This is an important point, that will be tested.
Formulation 4 has a measured water tolerance of about 1000 ppm. It is necessary to increase this figure, in order to be able to test the hypothesis above for a fuel of the Formulation 4 type - comparing the emissions from one fuel with and one fuel without added water. To achieve this, two strategies have been tried:
The idea behind the second strategy is as follows. It has been found that the formulation role of Component 3 in Formulation 4 is mainly to increase the water tolerance. We believe that a "real" surfactant would be more effective in doing this, and it is possible that the presence of such a surfactant may result in a higher water tolerance. Results have been obtained from tests of water tolerance and stability with a lower limit for acceptable water tolerance arbitrarily set at 2100 ppm, with a low temperature stability set to minus 17 degrees C.
Through solution studies, it was found that components 3 and 4 affect the water tolerance of the fuel, so that if their concentrations are increased the water tolerance also increases. Since component 4 was shown to be the most potent of the two substances in this respect, the effects of increasing its amount in the Formulation 4 recipe were investigated and found to give an increase in water tolerance. However, such water addition resulted in samples which were not stable to minus 17 degrees C. This fuel contained 20 vol % renewables as compared to the 15 % found in standard Formulation 4. In an attempt to keep the amount of renewables constant at 15 vol % and still increase the water tolerance the ratios of component 3 to component 4 were varied. It was found that the water tolerance again increased with increasing component 4 content, but at the same time the stability of the formulation at low temperatures decreased as above.
Since no low-temperature-stable formulation with water content at or above the 2100 ppm limit could be produced by the strategy indicated above an alternative approach was adopted. This depended on the replacement of component 3 by a surfactant.
Since the objective is to produce a water in oil (w/o) emulsion it was necessary to find a surfactant that is soluble in the continuous phase (the diesel phase). Many types of surfactants are possible, these include:
Relatively pure surfactants of the first two types are available in a wide range of molecular forms, but are manufactured from non-renewable sources. Thus they are suitable for the initial model studies, but not for the final fuel formulations. Surfactant types 3-6 are partly derived from renewable sources. This makes them more interesting candidates for a final fuel formulation.
From the above list, a first screening, involving a few surfactants (at least one from each group), has been completed. Of the formulations produced so far only one possible candidatefulfilling the water tolerance and stability requirements, has been obtained (Formulation 4-B). This candidate fuel has a water tolerance of 3200-3400 ppm and was produced by replacing Component 3 in the Formulation 4 recipe by an equal amount of a nonylphenol surfactant. A fuel of this composition (without added water) was successfully tested in a research engine. It combusted well and had a satisfactory cetane number of 51.2. The flashpoint was found to be 60.5 ºC. Both of these properties are well within the limits of the Mkl diesel standard.
Replacing Component 3 in the original Formulation 4 recipe with a corresponding amount of a polyoxyethylene ether gave a fuel with an extraordinarily high water tolerance, above 10000 ppm. Attempts are currently being made to modify the recipe so as to increase the low-temperature stability of this type of formulation.
Progress
This work has resulted in a good candidate fuel formulation. This fuel can be used as is, or it can be modified in order to test fundamental fuel concepts within the frame of the project (e. g., the influence of water, as indicated above), or in order to use less costly components. The project is now well in line with the aims and objectives.
Future activities
Based on Formulation 4, and in accordance with the iterative, feed-back process of formulation delineated in the Technical Annex for the DEAR project, the work will proceed in parallel along the following two lines:
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Updated
by CPL Press:
03/07/2007
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