TOMSK, November 2. /TASS/. Scientists have found a way to optimize the properties of biodiesel by blending rapeseed, linseed, and safflower oils in a ratio of 90%, 5%, and 5%, respectively, making it possible to produce fuel with target characteristics without chemical additives and reduces logistics costs by 10-15% compared to imported raw materials, the Russian Ministry of Education and Science told TASS.
One of the main obstacles to the commercial application of biodiesel is the influence of the raw material fatty acid composition on its properties: low-temperature performance, oxidative stability, specific heat of combustion, and viscosity. Scientists consider the pre-blending of vegetable oils prior to transesterification to be a promising approach as combining raw materials with complementary fatty acid profiles helps neutralize limitations and improve properties. However, the choice of oils is often dictated by regional availability and cost rather than properties optimization.
"Scientists from Tomsk Polytechnic University, together with colleagues, have proposed an approach that allows optimizing the physicochemical properties of oil-based biodiesel fuel and, in the long term, creating a cost-effective strategy for producing biodiesel with specified characteristics without chemical additives," the ministry noted.
The comprehensive predictive model proposed by the scientists is adapted to raw materials common in regions with a temperate continental climate, specifically rapeseed, flax, and safflower, said Vladlena Chobotova, a research engineer at the Heat and Mass Transfer Laboratory,. This approach transforms the pre-blending of oils from a simple logistical measure into a precise tool for tailoring biofuel properties to the EN 14214 standard without chemical additives.
The scientists selected unrefined rapeseed, linseed, and safflower oils as raw materials due to their inherent properties, regional availability, and lower cost compared to refined counterparts. The properties of rapeseed oil allow for obtaining biodiesel with a high cetane number and oxidation capacity, linseed oil helps reduce viscosity, and safflower oil yields fuel with properties intermediate between rapeseed and linseed. Methanol and potassium hydroxide were used as the alcohol and alkaline catalysts, respectively.
In the course of their research, the scientists developed eight predictive models that link raw material composition to fuel properties. Their accuracy was confirmed by statistical verification. It was also established that blending rapeseed, linseed, and safflower oils before transesterification alters the fatty acid composition almost linearly. The yield of methyl esters was 96.8-99.2%, which complies with the EN 14214 standard. Minor fatty acids significantly affect viscosity and low-temperature properties. The optimal ratio is 90% rapeseed, 5% linseed, and 5% safflower. The algorithm can be integrated into automated raw material management systems to adjust the formulation during price and quality fluctuations. The results obtained showed that using regionally available oils reduces logistics costs by 10-15% compared to imported raw materials. At the same time, the proposed optimization model can be easily adapted to other regional oil combinations, making it promising for localized and cost-effective biodiesel production.