RSSBe Prepared, Biofuels are Coming
10 August 2010, source Adler & Allan Ltd
The forum covered both national and European legislative changes and the recent and projected amendments to fuel specifications whilst exploring the impact that these changes have on fuel management and housekeeping requirements.
As a result of environmental directives from the EU which will see the percentage of bio components in diesel increase to over 20% by 2020, the key focus was on how to manage the transition from conventional hydrocarbon based fuels to next generation biofuels with minimal business disruption.
Over three consecutive days from June 22-24 Mark Calvert, Managing Director of Adler and Allan chaired each day's forum. Robin Lloyd, Biofuels Technical Manager for Mabanaft UK who jointly hosted the event, covered changes in legislation, regulation and fuel specification that are currently taking place within the industry.
Dr Philip Nathan, Adler and Allan's expert on petrochemicals and a Professor of Microbiology presented the technical issues and solutions for the storage and distribution of gasoil and biodiesel.
The forum was aimed at a wide cross-section of organisations who distribute, maintain, use or store fuel. The event also included live fuel polishing demonstrations on the college grounds. This was to show attendees there are solutions that can bring back highly contaminated fuel product to well within specification.
Biofuels
The incorporation of biofuels into mineral fuel is not new: the first Model T ran on bio ethanol and the original diesel engine ran on peanut oil. However, their widespread use (apart from Brazil) is only something that has happened in the last couple of decades.
The reasons for blending include: concerns over greenhouse gas emissions, energy security and alternative opportunities for agriculture. The challenge with them has been cost and, in order to mitigate this, a number of governments have provided fiscal incentives through lower fuel duty rates. Now, particularly in Europe, mandates have replaced incentives with financial penalties for not achieving minimum percentages of biofuel inclusion.
The main biofuels currently blended are bio ethanol into gasoline and biodiesel into diesel. Whilst bio ethanol is chemically identical (C2H5OH) regardless of feedstock, biodiesel varies significantly. The main feedstocks for biodiesel are: rapeseed, soy, palm, animal fats and used cooking oil. Most biodiesel is sold as a blend of these components as each one has strengths and weaknesses. Currently standard petrol can contain up to 5% ethanol (E5) and diesel can contain up to 7% biodiesel (B7).
The initial problem with blending biodiesel was waxing and resultant filter blocking, due to it having poorer low temperature properties than mineral diesel. It was noted that a B5 (5% biodiesel) could be blended that was fully specification compliant in the laboratory but after a few days in the field it started to wax. The main way of avoiding waxing was to restrict the levels of certain feedstocks; particularly those with long saturated hydrocarbon chains.
The next issue was microbiological contamination that also resulted in filter blocking. The microbiological activity generally resulted in two main forms of contamination: in the short term live bacteria growing on filters or longer term - biofilm. Biofilm is a hard, gritty deposit, a polysaccharide in structure.
Biodiesel in gas oil is seen as a concern by some but if the learnings from blending diesel into road fuel are adopted, particularly housekeeping, then problems should be minimised.
Legislative & Regulatory Influences. What do they mean?
Legislation
There are two main drivers behind the changes in fuel specifications that are currently taking place within the industry. The RTFO (Renewable Transport Fuels Obligation) is a legal requirement established under the EU Bio-Fuels Directive and placed upon all UK refiners and importers of road fuels to ensure that a specified percentage of all such fuels are made up of a renewable component.
The EU Directive, 2009/30/EC effective from 1st January 2011, stipulates that all gas oil for non road mobile machinery (NRMM) will be required to contain no more than 10 parts per million of sulphur. This will bring it into line with the current specification for ULSD (Ultra Low Sulphur Diesel). NRMM usage will encompass Agricultural Machinery, Portable/Mobile Generators, Construction Equipment and Inland Waterway Vessels.
In reality, refining and storage limitations will mean that the majority of gas oil supplies are likely to contain up to 7% bio-diesel from the 1st of January 2011.
Regulatory
There are other regulatory influences affecting the biofuels market such as EN 14214, the European (EU) standard for bio-diesel containing in excess of 5% bio. Up to 5% bio (and shortly up to 7%) is covered by the existing BS EN590 standard. Most major engine and vehicle manufacturers endorse the use of bio-diesel in excess of 5%, all the way up to pure 100%, but most also provide caveats on the type/source of the bio feedstock.
Given that EN14214 does not stipulate any particular feedstock, and given that the end user is unlikely to know what bio feedstock his fuel will contain, it will be very difficult for a vehicle operator to maintain the validity of his warranties.
All operators choosing to go down the route of higher bio blends are therefore going to have to be extremely vigilant in maintaining fuel quality through more regular inspection and testing.
Bio-diesel will require a more frequent and higher standard of maintenance than standard diesel. Microbial growth and water may exacerbate localised corrosion. It may also result in the blocking of dispenser filters and fuel lines.
Biofuels Issues and Effects
What are biofuels
The term biofuel refers to ethanol for use in petrol and FAME (bio-diesel) for diesel. These products are made from living things, or from the waste they produce. In principle, biofuels are a way of reducing greenhouse gas emissions compared to conventional fuels.
In recent years, the term "biofuel" has come to mean ethanol and diesel, made from globally-sourced crops including corn, sugarcane and rapeseed. Production of ethanol doubled globally between 2000 and 2005, with biodiesel output quadrupling.
Bio-ethanol, an alcohol, is usually mixed with petrol, while biodiesel is either used on its own or in a mixture. Ethanol for fuel is made through fermentation, the same process which produces it in wine and beer. Biodiesel is made through a variety of chemical processes.
Implications of using biofuels
Biodiesel will require a more frequent and higher standard of maintenance than standard diesel. It brings with it a new set of maintenance rules. Using biofuels means we're now introducing living components into the fuel mixture which can lead to microbial contamination.
Microbial growth and water may exacerbate localised corrosion of tanks and fittings which will not be noticeable without thorough checks. It may also result in the blocking of dispenser filters and fuel lines causing severe disruption to fuel supply and operations.
Summary of some of the major issues that can arise when biofuels are introduced to our supply chain:
Contamination
Microbial contamination or infection will occur when in contact with water or even when moist air is drawn through into a system, be it through download or dispensing, water leaking into any element of a fuel system or transfer from piping or from fuel delivery. As microorganisms reproduce they form a biomass which accumulates at a fuel-water interface, on tank surfaces, filters or any place within a system where micro droplets of water exist.
Bacterial contamination is not a new phenomenon, the problem has been known since the early days of fuel production. What has changed is the fuel chemistry of today's products and additives which have made them ever-increasingly susceptible to microbial attack.
Entrained Water
Fuels, such as diesels, normally shed water and do not form a fuel-water emulsion. With newer formulated fuels and especially with bio-diesels, they show a tendency to both hold and absorb considerable quantities of water forming emulsions.
The consequences of this are in the effectiveness of fuel-water separators and allow microbial activity within the body of the fuel and rapidly clog fuel filters.
Ethanol becoming suspended in water makes spills very difficult to contain or remediate. Oil/water separators are unable to function correctly.
Free Water or Free Phase Water
Water sitting on the bottom of a storage system can enter a tank in many ways:
Water has three adverse effects in fuel systems. It does not burn in the engine, can potentially freeze at low temperatures and it provides an environment in which microorganisms can grow.
As a consequence, if the fuel water interface reaches the fuel draw level, water will be dispensed into vehicles. Water promotes micro-organic growth, the formation of emulsions, rust and corrosion. Maintaining low fill volumes will increase the percentage of free water and bring about the problems mentioned above.
Corrosion
Corrosion is an electrochemical reaction caused by a flow of electrons from one metal to another and for corrosion to occur, the reaction needs an electrolytic environment which can be ethanol, FAME (biodiesel) and/or water.
All metalwork within the fuel system can become susceptible to corrosion. Microbial corrosion occurs as a result of micro-organism activity and commonly damages tanks, fuel lines and filters.
Micro-organism contamination
Bacteria, Moulds, Yeasts, Fungi and Algae can all have a significant effect on the quality of fuel. Deterioration of components also occurs due to the micro-organisms feeding on rubber seals, tank linings, hoses and coatings with obvious consequences to fuel supply.
Biofilm
Biofilm grows on tank bottoms and walls and eventually breaks off blocking filters. The key method of avoiding both live bacterial growth and biofilm is to remove water from tanks and the supply chain.
Biocide
Biocide is a poisonous substance designed to kill living organisms and get rid of microbial contamination. Using an incorrect biocide, or wrong dosage can leave you with the same problem you started with or even worse, exacerbate the condition.
Particulates
Common particulates are rust, dirt and sludge. Additionally in diesel fuels, and especially in the biodiesels, solid particulate debris due to oxidation, polymerization and dead micro-organisms are now also common.
The consequences are clogged filters, which are also caused by thermally unstable fuel degradation, and as very small particulates are not trapped by filters they may cause wear or damage to the dispensing system.
Environmental Concerns
Spills of ethanol blends may result in more persistent plumes in groundwater. There are certain properties of properties of ethanol blends that make other petroleum constituents more soluble in groundwater, and deplete groundwater of oxygen and other nutrients. Studies suggested that ethanol blends can cause the toxic compounds of petrol to travel up to 2.5 times farther than in absence of ethanol. This could have severe ramifications for those involved in a spill.
The Solution - Best Practice for Biofuels Tank Storage and Distribution
Regular maintenance will keep your fuel in good, operational condition. To prevent the build up of microbial growth and the discolouration and degradation of bio-diesel, a preventative maintenance programme should be implemented.
Adler and Allan proposes a 10-point checklist of measures that will help maintain good supply levels and avoid operational issues that affect your business. Some of these are covered below.
Storage Tank Housekeeping
Dispenser filters and cut-off systems should be checked regularly to ensure that dispenser filters remain clean enough to retain line pressure and cut-off function. Where there is sufficient degradation of the filter it should be changed immediately. If microbial contamination is suspected, we can assist by treating and polishing fuel.
Fuel Maintenance
Regular sampling and testing of fuel should be undertaken to ascertain water content, microbial growth, discolouration or the presence of sediment. Subject to the results the solutions are - a full system integrity test, dewater/desludge or a complete fuel polish.
Fuel Polishing & Tank Cleaning Solutions
Whenever a change is to be made, say from traditional fuel to E5 petrol/ethanol or diesel to biodiesel, always check your tank and overall system for leaks. The system should be clean and dry before a new fuel is delivered. Dr Nathan of Adler and Allan has experience gained on three continents, developing a highly effective mobile fuel polishing and filtration unit that is safe, reliable and highly efficient. Its primary function is to remove water and in-organic matter.
Adler and Allan's range of unique mobile tank cleaning and fuel polishing systems can treat fuel volumes ranging from as little as 3,000 litres up to large-scale works requiring 100,000 litres per hour treatment.
Summary Recommendations
Adler and Allan has over 30 years experience in fuel quality and has become a market leader in advanced fuel polishing solutions. We can help you with your fuel quality programme, for advice contact A+A Specialist Fuel Services on 01993 852419.
For further information please email Adler & Allan Ltd
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