The photo is sourced from rscf.ru
Processing low-grade oil featuring high density and high sulfur content is very complicated from the technical standpoint: it requires high temperature maintained by fossil fuel combustion, and at the same time it requires big volumes of hydrogen. It is possible to decrease the costs of such processing by using plasma reactors, where chemical reactions go on with low-temperature plasma. Such reactors do not require using hydrogen or expensive catalysts, and at the same time allow for receiving valuable substances as by-products.
For example, during plasma-based oil pyrolysis radicals and ions evolve by the action of electrical discharge activating the organic compounds molecules. This launches some special reactions resulting in breaking up bigger molecules into smaller ones, which may be used in various chemical processes.
To evaluate all these advantages, the scientists from Nizhny Novgorod State Technical University assembled the plasma-based pyrolysis plant comprising the reactor, the system for registering electrical charges and the unit for collecting the generated gases. The size of the reactor was 300 cm3 – more than 7 times bigger than all the other models available today.
The authors performed an experiment, when fuel oil was poured between two electrodes under 500 V. The following substances were received: hydrogen, ethylene, acetylene, methane and hydrocarbons containing from 3 to 5 carbon items – all of them are widely used in chemical industry. The yield of valuable gaseous hydrocarbons during this experiment was 46.5% (of the aggregate weight), and the yield of gaseous solids – from 53.5% to 70.1%. The scientists found disordered graphite and multiwalled carbon nanotubes among them, which may be used in electronics, as well as sulfur, vanadium, oxygen and nickel atoms capable of serving as catalysts for the industry.
“In our further studies we will be trying to increase the depth of fuel oil processing, to maximise the productivity and profitability of plasma-chemical pyrolysis. We also plan to study carbon nano-structures for using them as catalysts and adsorbents”, says Evgeniy Titov, Ph.D. in Engineering, lead researcher of R.E. Alexeev Nizhny Novgorod State Technical University (courtesy of Russian Science Foundation).
