Production of needle cokes via mild condition co-pyrolysis of FCC-DO and PFPE

[Display omitted] •We suggest a novel mild co-pyrolysis of FCC-DO and PFPE for needle cokes production.•Needle coke is successfully obtained at 440 °C and 1 bar with addition of 10 wt% PFPE.•Characteristics of green cokes confirm the efficacy of PFPE assisted co-pyrolysis.•The proposed reaction mechanisms involve radical reactions during PFPE decomposition.•Electrical and thermal properties underscore superior qualities of resulting cokes. The conventional needle coke production process suffers from high reaction temperature and pressure, and therefore, alternative approaches for needle coke production with low energy consumption should be developed. The co-pyrolysis process of FCC decant oil (FCC-DO) and perfluoropolyether (PFPE) was suggested to prepare needle cokes under mild reaction conditions in this work. The characteristics of green pitches and cokes from the co-pyrolysis process were evaluated with XRD, FT-IR, TGA, EA and polarized images to prove the effectiveness of the PFPE-aided reaction in accelerating polymerization. The mixture of FCC-DO and 10 wt% of PFPE was heated to 420, 430, 440, and 450 °C and 1 bar in continuous nitrogen flow, and needle cokes could be successfully derived at a temperature of 440 °C and atmospheric pressure with the addition of PFPE, which are significantly milder conditions compared with prior studies on needle coke production. The reaction mechanism of co-pyrolysis was suggested with radical-based reactions that emerged during the thermal decomposition of PFPE. Furthermore, the electrical and thermal properties of the carbonized needle cokes indicated the superior structural, thermal, and chemical characteristics of PFPE-assisted reaction-derived needle cokes; the needle cokes obtained from PFPE co-pyrolysis showed a 23.5 % reduced CTE value and 7.2 times higher electrical conductivity compared with cokes from pure FCC-DO. Effective needle coke production at a low temperature and pressure could be achieved with a PFPE-assisted co-pyrolysis reaction, and we believe that this study could contribute to a novel method for preparing needle cokes with low energy consumption and extending the applicability of needle cokes by supplying high-quality and low-price needle cokes.