The global shipping industry, comprising vessels over 400 gross tonnes (approx. 60 000 vessels), consumes 410 million tonnes/yr of fuel oil. Some 0.5% of this fuel is lost during the process of separating the oil from dust particles. During this process the discarded oil is mixed with water and stored in sludge tanks for further treatment. This waste oil is usually incinerated on board the vessel or on shore.
The overall objective of the ‘Pure Energy Separator’ project was to demonstrate and evaluate a new, innovative continuous ejection technology, based on a new method of expelling sludge from a separator. The system was not expected to require any process water and therefore the sludge was to be concentrated and dry, with the result that more than 90% of the waste oil could be reused. The volume of oil going for incineration should then have been reduced, which was in line with the objectives of the Directive for the Disposal of Waste Oils (75/439/EEC).
The Pure Energy Separator project developed, constructed and tested a total of 12 oil separator devices, which were installed and tested in marine vessels (12 pcs), at the mechanical workshops of metal industry companies (3 pcs) and at the beneficiary's test laboratory (1 pcs). All marine industry devices were found to work well, producing purified and recycled spill and engine oils that represented approximately 2% of the annual fuel consumption (in the region of 200-250 m3/yr) for large container/passenger vessels. Such results also reduced corresponding amounts of CO2 emissions. The beneficiary has actively disseminated the results and is developing them into a service package that is being marketed worldwide to the shipping industry.
Direct environmental benefits flow from using the recycled spill oils (waste mainly from the ships’ own fuel and machinery) as ship fuel instead of virgin hydrocarbon fuel. Some 2 % of the annual fuel consumption in an average (larger) vessel can be replaced with recycled oil. This presents CO2 reductions and reduces amounts of waste oil that is currently incinerated. Such an outcome is in line with the objectives of the Directive for the Disposal of Waste Oils (75/439/EEC).
Devices for the mechanical industry functioned basically in the same way as in the marine industry. Interim results for this part of the project indicated similarly promising environmental benefits as the system developed for marine industry. However, handling waste oils (which possess much more varying characteristics than oil in vessels) proved not fully feasible during the project period and still requires further fine-tuning. Separation and purification results were good but wear-and-tear problems existed and these required regular changing of parts, which made the operation uneconomic. The beneficiary explains that there is a keen demand for these separation devices and is therefore actively continuing the development work after the LIFE supported stage. Also, the project’s experiences produced a lot of practical and useful new information for the beneficiary to use in future.
Innovative elements were noted throughout the project. For example, mobile oil purification systems installed in the test ships worked ‘on-line’, thereby avoiding waste oil transportation and disposal (except for tiny amounts of almost solid residues which are logistically easy to handle).
A purification/separation system developed for the mechanical industry relies closely on the same principles as in the shipping industry (i.e. trying to avoid unnecessary transportation of oil and its incineration). The working principles of the developed system are simple and transparent which aids demonstration purposes.
Overall project achievements are based on the beneficiary's very long experience with these types of technical solutions, and especially their ability to closely cooperate with new clients and markets (in this case with the shipping and mechanical industry).