Inray’s continuous fuel quality control method, FUELCONTROL, has been verified under the ETV programme of the European Commission. The tests were carried out in actual environment at the Naantali power plant of Turun Seudun Energiantuotanto Ltd. Danish Technological Institute (DTI) was in charge of the verification, and ETA-Danmark of the facility tests. We are unaware of any other supplier whose biofuel online measurement or automatic sampling element would have been verified in actual conditions.
The operations of ETA-Danmark are accredited by The Danish Accreditation Fund (DANAK), and they have carried out several verifications in the field of environmental technology. In the winter of 2018-2019, researchers of the Danish DTI arrived in Naantali to carry out tests. The test matrix included the testing of both moisture and contaminant detections. The tests were carried out by selecting random fuel shipments to test from those arriving to the Naantali facility, which makes this the first biofuel quality control method test carried out in actual power plant conditions in wintertime.
There exist many national instructions and related standards for the quality control of biofuels, but these do not really address continuous online measurements. Since the matter is of interest to the operators in this field, we began to look into how the functioning of a control method could be tested. The EU has its own verification process for technologies in the field of environmental technology. In this ETV programme, a company can suggest their own technology to be verified. First, experts at ETV investigate whether the technology fits into the programme; then third party independent, EU-validated operators are selected for the work, and they compose a test programme, carry out the testing, and report the results to ETV. ETV supervises the test carried out by the third party, for instance, in the case of our tests, by visiting the site at the facility to check that ETA-Danmark satisfied the requirements of the standards and the test programme in their execution, sample handling, and reporting.
An interesting side product of the verification process was a comparison made by the Danes on oven drying results between themselves and a Finnish accredited laboratory. In the test, a ca. 5 litre sample was divided according to standard instructions into two samples, which were oven-dried in two different places using calibrated ovens. The results were as expected. One does not get the exact same results; the differences were 0.5-2.2 w-%. In this light, one may wonder at the great accuracy demands presented in various connections. The oven drying result of an individual collective sample can’t be taken as an average of the whole shipment, either, but it is an individual result from some part of one of the lots in the shipment.
What did we learn from the verification process? The process is long and requires a careful plan with descriptions of what will be tested and how. For example, the test on contaminants using steel nuts would have been wasted, if the original idea of collecting them from the sifting space magnet would have remained as the method of determination of the validity of detection. Now the majority of the nuts passed the magnet without getting caught, but that was alright, since we determined the success of the detection from the contaminant images automatically saved by the FUELCONTROL system. Likewise, it is worth paying attention to fuel quality determinations already during planning, especially if the terms used and their meanings vary from country to country and facility to facility. For instance, “an industry side product” is too vague from the point of view of verification testing. When the testing was initiated, we mostly had reports of verifications carried out in a laboratory setting to work with, so we had to act as pioneers in many respects and to invent new concepts together with the verification testers. We look forward to seeing corresponding tests by other companies in the field as well as their results.