Advances in Artificial Intelligence for Renewable Energy Systems and Energy Autonomy by Unknown

Author:Unknown
Language: eng
Format: epub
ISBN: 9783031264962
Publisher: Springer International Publishing

The charge prepared in advance consisted of finely dispersed wastes of petroleum coke and microsilica. The ratio of the mixed components of the charge was deliberately reduced to 50% the amount of solid carbonaceous reducing agent – petroleum coke, determined by stoichiometric ratio of the reaction of silicon with carbon. The missing part of the carbonaceous reducing agent was replenished with natural gas containing the reducing agent in the form of carbon and hydrogen, since natural gas is 94% CH4. The mixture, consisting of waste petroleum coke and microsilica, was poured without any compaction on the tiers of a multi-tiered boat 15 made of refractory ceramics and then, using a rod 16, was pushed inside the tubular flow system 2 of the resistance furnace 1, namely, into the heating zone “A.” Then the front flange 3 was installed, equipped with a prechamber 7, the system was purged with an inert gas – nitrogen, the heating was turned on, and upon reaching the set temperature in zone “A,” methane was let into the tubular flow system 2. The consumption of methane was chosen taking into account the missing part of the carbonaceous reducing agent, according to the stoichiometric ratio between silica and carbon, and it was monitored by the position of the rotameter float.

The silicon carbide synthesis was carried out, as it was already noted above, with the preliminary dissociation of methane supplied through pipe 5 to flow system 2. To do this, methane was passed through prechamber 7, which is a flow container with built-in catalyst 8. The catalyst 8 was a hollow body made of nickel with fine mesh partitions 9 installed inside. Nickel was chosen due to its experimentally proven catalytic properties with respect to methane. The outer walls of the catalyst 8 are in contact with the inner walls of the prechamber to provide thermal contact. Outside, prechamber 7 was heated to ~600–800 °C using two heaters – burner 11 and adjustable electric heater 13. As a result of methane contact with the heated catalyst surface, it dissociates into hydrogen and carbon, which contributes to an increase in the reactivity of methane in silica reduction reactions.

To determine the optimal synthesis conditions and achieve the maximum yield of SiC, experiments were carried out by varying the proportion of methane in the composition of the total carbonaceous reducing agent: petroleum coke, Сpc(s), and gaseous methane, CH4(g). While maintaining the total amount of carbonaceous reducing agent required by the stoichiometric ratio to reduce silicon with carbon, the proportion of CH4(g) varied from 0.15 to 0.60 of the total amounts of carbon, and Сpc(s) decreased from 0.85 to 0.40, respectively.

The test results of the proposed method and the developed device for its implementation have shown the operability, efficiency, and usefulness of the proposed technology. SiC powders with a predominant particle size of less than 100 nanometers were synthesized. The analysis of the powder X-ray indicates the production of SiC cubic 3C and hexagonal 4H and 6H polytypes of interest for use in modern technology.

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