No stabilizers pass no-harm test for bio heating oil

None of the stabilizers examined in AGQM's first-round of no-harm tests for biodiesel-blended heating oil passed
By Ron Kotrba | July 13, 2016

The German biodiesel quality management association AGQM announced it has completed its first no-harm test round of oxidation stabilizers for fatty acid methyl esters (FAME) intended for blending with heating oil. None of the products tested passed, according to the organization.

The sophisticated tests are meant to rule out probable harmful effects of the fuel itself as well as undesired interactions with other fuel components.

Last year, when AGQM prepared to start the testing, Andrea Seifert with AGQM explained that, “In order to assure the quality of fuels and FAME, additives such as flow improvers, metal deactivators, odor-covering agents and stabilizers are used. Due to unwanted interactions, such substances may lead to incomplete combustion, corrosion, increased emissions and the plugging of filters and nozzles. In the interest of a safe use of those additives—from the blending process to their use and combustion in the burner—possible problems must thus be detected beforehand. Suitable test methods, so-called ‘no-harm tests,’ were developed for that purpose.”

AGQM has offered a no-harm test for oxidation stabilizers since 2008, developed in cooperation with DGMK, used for biodiesel blended with diesel fuel used in compression-ignition engines. Successfully tested products are published in its publicly available no-harm list.

The new no-harm test program for stabilizers used in biodiesel for blending with heating oil includes assessment of compliance with the stipulated minimum requirements; DGMK filtration test 663; interaction test; and determination of the relative efficiency of oxidation stabilizers.

Some of the other differences between the no-harm test for FAME blended in fuels for compression-ignition engines and FAME comingled with heating oil for use in oilheat burners include the use of B20 as a test fuel for the latter, whereas B10 is used for the former. “B20 is a common bio heating oil in the German Market,” Seifert told me last year. “For the use as engine fuel, a B10 covers the reality of B7 in practice better.” The concentration of additive is limited to 1200 mg/kg in both tests. In addition, AGQM ran tests on total acid number, sulfur content, alkali metal and alkaline earth metal content, because of specific requirements in the DIN SPEC 51603-6. Due to long storage times, high values for these parameters in heating systems can lead to more serious problems than in the fuel sector.

“In contrast to our established no-harm test for fuels, we run the no-harm test for bio heating oil without the expensive XUD9 engine test because of a higher tolerance of heating systems concerning nozzle fouling,” Seifert said. “In our no harm test for FAME for diesel fuel we are using a reference diesel fuel without any additives. We do use the same fuel for our no harm test for FAME in heating oil due to the fact that it is impossible to get a comparable batch of heating oil in each test period.”

Regarding all of the products failing this first no-harm test round for bio heating oil, AGQM stated, “The problems could be verified and therefore it can be assumed that the additives will pass the no-harm test successfully at a reexamination. This clearly indicates that no-harm testing is essential to ensure quality and secure use of additives.”

The new test program was developed in cooperation with the German petroleum industry since the application of biodiesel as a heating oil blend component must be safely handled at all times, and negative interactions with additives is unacceptable. In addition, tests are carried out concerning the relative effectiveness to also be able to adapt the use of additives to the individual application from an economical point to view.

The second round of no-harm testing is expected to begin this fall.