Siberian Federal University

Due to global warming and depletion of non-renewable natural resources, the task of developing technologies for the capture, processing and disposal of industrial waste is becoming increasingly important for the sustainable development of energy and ensuring environmental safety, the authors of the work say.

One of the ways of waste processing is the decomposition of organic and many inorganic compounds into molecules of simpler substances under the influence of high temperature — pyrolysis. Pyrolysis, for example, can produce hydrogen from hydrocarbons.

The scientists of Siberian Federal University, together with Russian and German colleagues, have modeled and experimentally proved that the efficiency of the production of hydrogen and hydrogen-containing mixtures in a pyrolysis reactor can be enhanced by increasing the contact area of the coolant with raw materials — organic industrial waste. The area was increased by applying hemispherical projections to the inner surface of the channel through which the coolant passes.

“A similar effect in everyday life can be observed when tea is cooled. When we pour tea from a cup into a saucer, the contact area increases, and there is a more intense heat exchange,” said Oleg Kolenchukov, junior researcher at the Laboratory of Biofuel Compositions of SibFU.

According to him, the use of projections contributes to an increase in heat transfer up to 11.5% and increases heat transfer by an average of 2.23 times. In addition, the protrusions create vortex formations inside the channel, which further enhances the heat exchange between the coolant and the raw material. By comparing the heat transfer and hydraulic resistance indicators, the scientists determined the optimal combination of the flow velocity and the height of the protrusions.

Increasing the efficiency of heat exchange has a positive effect on the quality of the obtained hydrogen-containing mixtures and the volume of produced hydrogen, helps to reduce the size of reactors, and minimizes secondary decomposition reactions, thereby reducing the amount of pollutants formed during pyrolysis, according to SibFU.

The research was carried out in the laboratory of biofuel compositions of SibFU on the state assignment of the Ministry of Science and Higher Education of Russia. The laboratory was created as part of the activities of the Research and Educational Center Yenisey Siberia.

The activities of the Research and Educational Center Yenisey Siberia, established on the basis of Siberian Federal University on the initiative of Krasnoyarsk Territory, the Republics of Khakassia and Tyva, are aimed at improving the environmental situation in Russia and decarbonizing industry. The REC consists of 9 universities, 5 research institutes and 14 industrial enterprises.