FBHVC has written regularly on biofuels since 2008 when our members first expressed concern about the introduction of ethanol in petrol and vegetable oils in diesel fuel. There are two key EU Directives relating to targets for biofuel uptake: firstly, the Renewable Energy Directive (RED) which requires 10% of energy used in transport to be from renewable sources by 2020 and secondly, the Fuel Quality Directive (FQD) requires fuel suppliers to reduce the greenhouse gas intensity of energy supplied for road transport by 6% by 2020. In practice the supply of biofuels is the primary means by which both targets will be met. Both Directives specify sustainability criteria that must be met by biofuels if they are to count towards either target.
The Federation has responded robustly to all government consultations on biofuels bringing forward members concerns and we have been listened to sympathetically in the main. As a result of our input the DfT commissioned a major report from QintetiQ in 2010 on compatibility issues and carburettor icing and invited our representative to attend regular Stakeholder meetings held at the DfT. DfT also invited representatives of FBHVC member clubs to one of the recent meetings. The Federation commissioned an independent expert to report on combustion problems and undertook a lengthy and expensive testing regime for additives marketed to overcome the corrosion problem. In addition the website provides detailed information about (typically plastics) compatibility issues, for which there is no cure other than vigilance and replacement of non-compatible items.
The problems likely to be encountered have been summarised as corrosion, compatibility and combustion. The 2011 Conference was on just this subject and the conclusions are summarised below:
Combustion and driveability effects: ethanol has a leaning effect and so carburettors need to be adjusted or the air/fuel ratio changes may cause driveability problems and increase exhaust temperature. Adopt measures to restrict heat transfer to carburettors by baffles, pipe routing, thermal blocks and breaks.
• Materials compatibility: replace problem materials with compatible products (FBHVC newsletter 5-2010 listed materials as does the website).
• Corrosion: ideally an aftermarket treatment should be used – added during refuelling to protect the fuel system.
The results of the test programme for suitable stability additives were received just after the last newsletter was published and is dealt with in detail below.
ADDITIVES FOR USE WITH BIOFUELS
Additives are available to protect against the main problems likely to be encountered for petrol and diesel fuelled vehicles (corrosion inhibitors, stability improvers and biocidal products).
A product for use with petrol has been designed to be added to the tank when re-fuelling to prevent degradation in storage in the fuel tank. It provides excellent protection against the possible corrosion through increased acidity which can occur when petrol containing ethanol is stored for any length of time. One bottle should provide a season’s protection – although this is obviously dependent on the vehicle and amount of usage.
A similar product for bio-diesel fuel (e.g. containing rapeseed methyl ester) has also been developed. There is no corrosion issue here but one of fuel filter blockage, injector fouling etc. It is also designed to be dispensed from a plastic bottle (with graduated optic) at refuelling time.
These products existed in 2010 but did not have a commercial outlet and so through the Federation’s trade supporter scheme, seven companies were introduced to a manufacturer of a corrosion inhibitor additive for petrol. At the end of April 2011 the Federation contacted all known suppliers inviting them to take part in the FBHVC test programme. The products that passed the test were entitled to carry the FBHVC logo on the packaging. This endorsement is similar to that given to the lead replacement additives that protect against valve seat recession and the products submitted were either given a ‘pass’ or a ‘fail’; we will not grade them for effectiveness.
The biofuel test regime was different to the programme used for the lead replacement additives in that it was purely a laboratory test for corrosion.
The tests were for additives intended to provide protection for metallic components frequently encountered in the fuel systems of historic vehicles. A table was published by FBHVC showing lists of materials incompatible with ethanol in petrol. The materials listed included coated steels such as those extensively used to make petrol tanks, plus copper, zinc, and brass, together with a number of plastics (seals and gaskets) and fibreglass composite materials. The metallic materials listed were judged to be incompatible because of potential corrosion by degraded ethanol in the fuel. The additives tested are designed to protect metals only, by preventing corrosion.
There are no known additive solutions for incompatibility between ethanol in petrol and plastic or composite materials. As has been previously stated, where compatibility problems occur with gasket and seal materials, or with fibreglass petrol tanks, as used on some motor cycles, the only realistic course of action is to replace incompatible materials with suitable alternatives. A list of these was given in the table published by the Federation. At least one carburettor supplier can now supply components which incorporate materials compatible with ethanol in petrol.
The tests carried out used an accelerated aging process (details can be found in ASTM D4625 Appendix 11) in which ethanol degrades to become increasingly acidic. One week of the aging process is equivalent to one month in normal storage, so the 13 week accelerated aging process used in the test method is equivalent to one year in normal storage. This procedure increased test severity, and was felt to offer a good margin of protection to those, for example, who may lay up their cars in the autumn, and take them out on the road again in the spring, having stored fuel in the tank over the winter. Corrosion tests were carried out every two weeks to assess the effects of the aging process on the corrosiveness of the fuel. The tests compared corrosion experienced with untreated fuel against corrosion using fuel treated with corrosion inhibitor additives. Rating of corrosion was carried out visually by trained operators, there being five performance categories, from ‘A’ to ‘E’. To achieve an ‘A’ rating, the test sample must show absolutely no rust at the end of the corrosion test, whereas an ‘E’ rating corresponds to extensive surface rust.
The results of the tests showed worsening corrosion as the ethanol aged for the test sample where no corrosion inhibitor was employed (test sample dropped from ‘D’ rating to ‘E’), whereas additive treated fuels continued to provide a very high standard of protection right to the end of the test (‘A’ rating throughout). These results should instill a high level of confidence that additives evaluated in the test programme, and endorsed by the FBHVC, will provide excellent protection from potential corrosion in fuel systems of historic vehicles, including those stored for long periods (up to and including 12 months).
The tests used highly polished mild steel probes in accordance with oil industry practice, in a procedure developed by the National Association of Corrosion Engineers (NACE) of America. This method has been used for decades and is a recognised and widely used technique for establishing the performance of corrosion inhibitor additives. The use of mild steel as a medium in the corrosion testing is valid, on the basis that other metals in the fuel system (eg copper, brass) are less susceptible to acid-corrosion than mild steel. In addition, the widespread use of steel in fuel tanks in historic vehicles, creates a significant potential for corrosion damage where tanks may be up to 100 years old.
The corrosion inhibitors used within the oil industry are non-metallic surfactant products, which have been proven to be a cost effective solution to the problem of metallic corrosion in the oil industry. Some candidate additive suppliers wished to be able to combine the ethanol-protection corrosion inhibitor additive with one already proven for protection against valve seat recession. This was permitted as long as the combined additive package was tested in the ethanol corrosion testing procedure. Some, but not all, additives used for valve seat protection may contain metallic components, so it is therefore possible that some dual-function additives offered for sale will contain metals. Additives sold entirely on the basis of corrosion inhibition alone will not contain metals. Some concerns have been raised about the use of metals in fuel, but it is still permitted to sell leaded petrol in the UK for historic vehicle owners, and although the volume of sales is low, this concession to owners of historic vehicles has not been revoked by the EU, and indeed was recently endorsed for the future. In addition, at least one manufacturer sells a product containing lead alkyl additive for historic vehicle owners to dose into fuel themselves.
A limit has been placed on the permitted use of manganese in petrol by the EU, but this material has not been banned. Manganese is one metal which has been used in additive packages to prevent valve seat recession, and at least one dual-function package for use to prevent valve seat recession and ethanol corrosion was tested. The original use of the manganese containing additive to provide protection against valve seat recession was endorsed by the FBHVC in the 1999-2000 time frame after engine testing. There is no conflict in the view of the FBHVC with the renewed endorsement of dual-function additives which have been shown to perform well in both valve seat recession tests and corrosion inhibition tests, on the basis that metal may be used in the preparation. As indicated above, there is no EU ban on the use of manganese, iron or lead in fuel additives. Those who do not wish to use additive preparations containing metals can choose FBHVC-endorsed corrosion-only packages (which are non-metallic), and if desired, use a separate valve seat recession product which does not contain metal (one effective FBHVC-endorsed product uses phosphorus).
Questions have also been raised about bacterial growth in fuels containing renewable fuel components. The additives tested do not offer any protection against bacterial growth, which generally requires water to flourish. The main risk of bacterial growth lies in diesel storage tanks where water is present, and fuel is stored for long periods. The solution recommended by the oil industry is to improve ‘housekeeping’, i.e. to ensure tanks are clean and dry internally and therefore do not contain free water. Use of biocides is not recommended, except for ‘spot’ treatment of severe bacterial growth. Regular use of biocides runs the risk of the bacteria involved developing immunity to the biocide employed. Furthermore, where free water has encouraged bacterial growth, and a biocide is used, the water must be treated as hazardous waste when it is disposed of. This may have significant cost implications.
The stability additives that passed the test are:
VSPe Power Plus, VSPe and EPS from Millers Oils email: email@example.com; website: www.millersoils.co.uk
Ethomix from Frost A R T Ltd email: firstname.lastname@example.org; website: www.frost.co.uk
Ethanolmate from Flexolite email: email@example.com; website: www.flexolite.co.uk
These all received an ‘A’ rating in the research which enables all these products to carry an endorsement from the FBHVC. The endorsement is in the form of the FBHVC logo and the words: ‘endorsed by the FBHVC as a fuel additive for protection against corrosion in metals’.
USE OF KEROSENE
It should be noted that the FBHVC does not advise the use of kerosene as an additive – more details are given on the website.
Kerosene (mainly for heating oil, but also with agricultural uses) is being considered for the inclusion of 30% bio-fuel component. While this has implications mainly for domestic heating, especially Aga cooking stoves, this aspect is not covered by the Federation remit. However, historic tractor owners, who use Tractor Vaporising Oil (TVO) as a fuel, may be impacted.
The current Biofuel (Labelling) Regulations require pumps dispensing any petrol containing more than 5% ethanol or any diesel containing more than 7% fatty acid methyl ester biodiesel to be labelled. DfT consulted in the autumn of 2011 on how to implement the RED requirement that biofuel content of greater than 10% be explicitly indicated and once again the FBHVC responded. At a meeting of the British Standards Institute in March 2012 the future of fuel and its labelling in the UK was discussed. Labelling for petrol containing 10% ethanol was discussed in some detail. The chairman, Bob Saunders, had received a letter from the Government requesting the BSI PTI/2 committee to formulate the strategy for pump labelling. Two principal conclusions emerged from the discussion: the labelling format should be harmonised with EU practice; a simple form of words should accompany the indication of ethanol content.
It seems likely that the designation ‘E10’ will be used on the label, in line with French and German proposals (and in some cases current practice). It was agreed to approach the wording of the warning by listing only those vehicles which can use the fuel, rather than giving a lengthy list of those which might not be able to use the product safely. It emerged from the discussion that few pre-2006 vehicles were likely to be guaranteed by their manufacturers as suitable for 10% ethanol petrol, and that only by 2010 were all cars manufactured as compatible with this fuel. Clearly, unless historic vehicles have been proofed against 10% ethanol petrol it would be wiser not to use it. The ‘defence’ grade, super premium unleaded petrol, will always contain less ethanol, and after the introduction of 10% ethanol into normal unleaded petrol, will be limited to 5% ethanol, so this could be a fall-back for the historic vehicle owner, albeit at higher cost.
The European standards committee has agreed on volatility limits for petrol containing 10% ethanol. The upshot is that the specification is eased slightly, with wider acceptable volatility limits when petrol is blended with 10% ethanol. The implications of this for Federation members are slightly negative, as in practice when 10% ethanol is blended into petrol, more volatile fuels will be permitted. This further emphasises the need for members to take the simple measures already proposed to reduce the incidence of vapour-lock type symptoms in historic vehicles. The timetable of these changes suggests that British standards will be brought into line with Europe during 2012, with introduction of 10% ethanol fuels in Britain expected during 2015.
DISTRIBUTION OF FUEL IN THE UK
The way that fuel is distributed in the UK makes it very difficult to give an accurate and up to date picture in the newsletter about actual ethanol content in petrol at any time.
The DfT have suggested that the FBHVC be a clearing house for data from the fuel distributors so that members can have some idea of how much ethanol is in petrol in their local area. In general the premium fuel grades from all suppliers will have a lower ethanol content, and this will continue to be the case for the foreseeable future.
There are around 40 terminals distributing petrol in the UK and it should be remembered that there is not a direct link between the retail brand and the operator of the terminal so the information below does not mean that all Super retailed under Esso, Total, Conoco, Murco etc brands is ethanol free.
As at the end of April the situation was as follows:
Exxonmobil – operate 5 fuel distribution terminals, ethanol is not blended into Super Unleaded at any of these
Total – operate 4 distribution terminals (one jointly with Conoco), ethanol is not blended into Super at any of these
ConocoPhilips – operate 3 (further) terminals, 2 don’t supply Super, the third doesn’t blend ethanol into Super
Murco – operate 3 fuel distribution terminals, ethanol is not blended into Super Unleaded at any of these
Valero – operate 6 fuel distribution terminals, ethanol is not blended into Super Unleaded at any of these
Ineos – operate 2 fuel distribution terminals, 5% ethanol is blended into Super at these
Posted On: 16/06/2012 02:10:38
Posted By: john saunders