The production of needle coke due to precise control of parameters such as chemical composition, temperature, time, an‎d pressure of thermal decomposition process for Special hydrocarbon materials is monopolized by the few advanced countries in the world. Also, hydrocarbon materials with unique characteristics have the potential to synthesize needle coke. This study aimed to investigate coal tar pitches an‎d heavy oil coal in terms of process variables of mesophase synthesis such as temperature, time an‎d pressure, an‎d feasibility of needle coke production. Hereupon, four coal tar pitches (with a low, medium, an‎d high softening point, quinoline insoluble 4, 5, 6, an‎d 7%, ash content of 0.2%, 0.3%, an‎d 0.5%), heavy oil coal (with zero percent quinoline insoluble an‎d 0.02 percent ash), an‎d naphthalene as an additive were prepared. The thermal decomposition process was designed an‎d constructed in a tube reactor with an effective capacity of 100 ml, made of 304 low carbon austenitic stainless steel, with the ability to withstan‎d temperatures of 600 °C at 10 atmospheres pressure. Due to the high importance of carbon an‎d sulfur elements in preparing needle coke, carbon, an‎d sulfur, samples were measured by the Leco device. Fourier transform infrared spectroscopy was also performed to determine the samplesʹ parts an‎d components an‎d determine the aromaticity quality. Green cokes produced from samples were treated with a calcination process after the thermal decomposition process at 1050 °C for 60 minutes. Then, the microstructure an‎d morphology of green cokes produced after thermal decomposition an‎d calcination processes were studied using polarized optical microscopy. Also, the X-ray diffraction test obtained crystalline properties such as interplanar spacing, length an‎d crystal width. The results showed that coal tar pitch with a lower softening point, quinoline insoluble in less an‎d lower ash content, qualitatively has higher aromaticity an‎d the relatively high atomic ratio of carbon to sulfur, from which the prepared green coke has crystalline an‎d microscopic structural properties closer to commercial needle cokes. Heavy oil coal seemed to be a good option due to the high quality of aromaticity an‎d minimum quinoline insoluble, but due to its low coking value, it did not provide suitable results. Naphthalene additive provided favorable results an‎d effectively modified the structure of coal tar pitch. Therefore, it is recommended to produce desirable needle coke from coal pitch with a low softening point at 550 °C, a pressure of 10 atmospheres, an‎d a time of 90 minutes.

مسعود پنجه پور , محمود مرآتيان اصفهاني

رحمت اله عمادي , مهدي احمديان