Bio oils go on trial

Anybody providing tracked excavators on contracts for organisations such as the Environment Agency (EA) and British Waterways, will have to use a biodegradable and non-toxic hydraulic oil in their machines. The Forestry Commission is also insisting on bio oil in harvesters operating on its land, and others are likely to follow suit.
Back in 1997 the EA announced that from June 2005 hydraulic systems on all tracked excavators used on its work would have to be filled with a biodegradable and non-toxic fluid, which it calls an ECL (Environmentally Considerate Lubricant).
Frank Jackson, procurement manager (contracts) with the EA sums up the reason why: "Almost all of our work is in or near water. If a hose bursts and oil spills into a river or lake, it will cause a film which reduces the level of oxygen. This makes it difficult for fish to feed and breathe. One litre of oil can cover an area the size of a football pitch and contaminate one million litres of water. Contamination can also make water unfit for irrigation and render sewage works inoperable. Oil has the potential to coat any micro organism, plant or animal with which it comes into contact."
Putting its money where its mouth is since 1997, the EA has progressively switched its fleet of more than 200 tracked excavators to ECLs and, to date, has not encountered any lubricant-related problems.
The first difficulty facing anybody considering the use of biodegradable oils for the first time is that there are several different types on the market. Some of these, despite being biodegradable, are still toxic. The EA's three-man ECL team, Jackson, John Mitchell (principal officer, data quality) and Peter Kite (now retired) selected the worldwide standards laid down by the Organisation for Economic Co-operation and Development (OECD). In the case of biodegradability the standard is OECD 301B and for toxicity they are OECD 201, 202 and 203. These standards specify all the criteria which the oil companies have to meet to get approval. In addition, the EA stipulates that the ECL used in its own machines must be a saturated synthetic ester and approved by the original equipment manufacturer (OEM). Where subcontracted plant is used, the EA still requires the above environmental criteria to be met.
One hire company looking to start using ECLs ahead of the deadline is Land & Water. Richard Maclean, general manager of Land & Water Plant outlines the reasons: "We have the country's largest fleet of long-reach excavators and our plant is constantly working on environmentally sensitive sites and near watercourses. As part of our commitment to the environment, we have decided our excavators (in the UK) will comply with Environment Agency guidelines prior to their introduction." The company has set up a trial to allow it to fully understand what is involved in replacing the mineral oil in its current machines with an ECL, and the long-term implications of operating a completely "green" fleet.
The trial involves four of Land & Water's excavators (all JCB JS220LRs), three of which will be retrofitted with a biodegradable hydraulic oil while the fourth remains on the standard mineral oil to use as a baseline. All the bio lubricants are being supplied directly by the oil company or distributor and each will monitor the machine using its product.
The companies involved are Panolin (with its HLP Synth46), Shell (Naturelle FH-E46) and Q8 Holbine 46 packaged by Falcon Lubricants as Hawk Bio SE46 and supplied through Pirtek. The fourth machine remains on JCB's own HP46 mineral oil.
The first hurdle is getting the oil into the machines and achieving the required level of purity as contamination with traditional mineral oil erodes and destroys the environmental advantages of the ECLs. Two cross-contamination limit figures are commonly quoted for mixing biodegradable with non-biodegradable oils in the hydraulic system: 5% and 8%. While Jackson recommends the lower figure, he does not set a hard and fast rule saying: "It is a matter for the oil supplier and end user to decide at what point the contamination with conventional oil starts to negate the environmental benefits." At a certain point the increasingly contaminated hydraulic oil will no longer fulfil the OECD standards and that will determine the limit. For the purposes of this trial, Land & Water is initially aiming at the 8% mark.
There is no getting away from the fact that biodegradable hydraulic oils are expensive and Panolin's sales and marketing manager, Derrick Simpkin says there are big differences in the types on the market depending on the base oils.
Pure rapes are the cheapest (ranging from two to five times the cost of a mineral equivalent) but generally these are unsuitable for closed systems as they degrade very quickly. Unsaturated esters are more expensive (around five to six times the cost of a mineral) and have improved durability but remain suspect in terms of handling heat.
As many hydraulic systems run at around 80×C (or even 90×C when running a breaker) these types of oils are not usually recommended for extended oil drain periods. At around seven times the cost of a mineral oil are saturated esters, they can handle the heat and have the durability for extended drain periods. While these may seem expensive, Simpkin points out that mineral hydraulic oils are also becoming more expensive as the plant manufacturers increase the required cleanliness levels.
Before converting the machines, oil samples were taken for analysis to assess the original state of the machine's hydraulic system and ensure there were no existing problems and allow any subsequent problem to be identified and quantified. These figures will be compared right across the trial machines including the one running on the standard mineral oil.
After conversion the machines were to be suitably liveried to denote their new eco-friendly status and with stickers to warn operators of the need to top up with the correct bio oil. Regular oil samples will keep track of contamination levels, wear rates and whether the oil remains suitable for further use.
To convert an in-service machine to an ECL with an acceptable level of contamination requires flushing the system through - that means two fills. In the case of the JS220LRs the hydraulic system holds 200 litres while the tank itself holds 120 litres. When fitted with Land & Water's own design of long boom, capacity is much larger as an even greater proportion of the oil is in the boom's long hydraulic pipes. The changeover process was to drain the mineral oil, fill with a bio-lube, cycle all the hydraulic cylinders, the slew and track motors to flush out the mineral oil before draining off the highly contaminated oil. Then the filters are changed and the machine refilled with fresh biodegradable oil.
Panolin's HLP synth46 was put into a machine that had clocked up 1,293 hours prior to the conversion. The lubricant is an ISO 46 viscosity saturated ester that complies to OECD 301B and for toxicity it is OECD 201, 202 and 203. An oil sample immediately after conversion showed a contamination level of 9% but by the time the running hours had risen to 1,421, the contamination level had risen to 15%. Simpkin says this is quite normal as the last remnants of mineral oil are displaced from all the cylinders, pumps, motors and hoses. To rectify the situation and bring the contaminant below the 8% target, 46% (15-8/15) of the oil will have to be dropped and replaced with fresh ECL. That means a further 138 litres had to be removed and replaced bringing the total to just under 400 litres.
Shell put its Naturelle HF-E46 forward for the trial. It is a combination of saturated and unsaturated synthetic esters with about 52% being from renewable resource and it conforms to all the OECD requirements. This oil is currently supplied under contract to the EA and costs between three and four times the price of a premium mineral equivalent. The initial flush and fill on Land & Water's machine took place with 1,240 hours and required 260 litres of oil. A subsequent oil sample taken in operation showed that the contamination by mineral oil had risen to around the 15% level. Shell decided it wanted to get to 5% and the only way was to drop the complete charge, flush the system again and refill the machine. In doing so the volume of oil used in the conversion rose to 400 litres but the contamination is now well below. With a straight double flush it could have been done with just 360 litres, says Shell.  
The third machine is filled with Q8 Holbine 46/ Hawk Bio SE46 supplied through Falcon Lubricants and Pirtek. This is a fully saturated synthetic ester with full OECD 301B, 201, 202 and 203 approvals and was put into one of the JS220s when there were 2,889 hours on the clock. Refill was done through a filter unit that has a computerised particle counter giving readout of cleanliness (to meet ISO 1411). During this process, oil is drawn from the tank, filtered and returned until the required cleanliness level has been achieved. Having used a total of 416 litres of fluid in the flush and refill, an oil sample at changeover indicated well below 8% mineral contamination.
At list prices the cost of oil used in the conversion ranges from just over £1,000 to almost £2,000. A straight replacement of the mineral oil (without flushing) would cost in the region of £250 depending on the brand and quality selected.
While it did not appear so at the time, getting to 8% contamination may be the easy part of the trial. PMJ will carry regular updates on how the trial is progressing and all information will be available through our sister magazine Contract Journal's web site contractjournal.com. Search the archive under biodegradable oil.