Long-term protection for sustainable HVO through conservation

In contrast to fossil fuels, HVO (hydrogenated vegetable oil) is enjoying a growing demand in the industrial sector and as an additive in diesel fuel for everyday use. Biocide specialist Vink Chemicals has now investigated whether the effective fuel biocides grotamar® 71 and grotamar® 82 can also protect this sustainable fuel from harmful microorganisms.

HVO is produced by treating used vegetable oils, animal fats or food waste with hydrogen (hydrogenation). In its pure form it is defined in the EN 15940 standard (paraffinic diesel fuels) and can be used directly in existing diesel engines. In Europe, blends of HVO with diesel fuel are fully permitted under the current EN 590 standard.

grotamar® 71 and grotamar® 82 - Biocides for the preservation of HVO and blends 
As HVO is readily biodegradable, there is a risk that the fuel may be susceptible to microbial contamination by the micro-organisms typically found in fuels. HVO and B0 diesel were used for the tests. HVO was tested on its own and as a 30% (V/V) blend with B0. The samples were contaminated according to ASTM E1259-18 with the bacterium Pseudomonas aeruginosa (ATCC 33988), the yeast Candida viswanathii (ATCC 48138) and the mould fungus Hormoconis resinae (ATCC 20495). It was investigated whether grotamar® 71 and grotamar® 82 are suitable biocides for the protection of HVO and its mixtures.

A fuel/water ratio of 500:1 and a total contact time of 336 hours (14 days) were chosen for the tests. Part of the samples were treated with 50 ppmv grotamar® 71 or 250 ppmv grotamar® 82. This is the lowest concentration recommended for the particular biocide.

Full success for Vink Chemicals' biocides
As a result of the laboratory tests, it was found that both HVO and blends are susceptible to microbial contamination. Under real conditions (field test), the results are easy to reproduce, as the growth conditions (free water phase, nutrients, heat) are also present in nature.

In the tests, grotamar® 71 and grotamar® 82 proved to be efficient broad-spectrum biocides for HVO. Already the lowest concentration (50 ppmv of grotamar® 71 or 250 ppmv of grotamar® 82) is sufficient to preserve HVO and blends of 30% HVO in mineral diesel oil. Both biocides were also able to reduce bacterial contamination of the samples within 24 hours.