The influence of the carbon precursor, carbon feed rate and helium gas flow rate on the synthesis of fullerenes from carbon powder in an entrained flow 3-phase AG plasma reactor operating at atmospheric pressure

摘要

We studied an entrained flow 3-phase AC plasma reactor operating at atmospheric pressure with helium for the synthesis of fullerenes from different carbon powder precursors through an evaporation-condensation process. A parametric study focusing on gas flow rate and carbon powder feed rate was carried out using three commercial carbon materials: Y50A acetylene black from SN2A, E 250 carbon black from TIMCAL, and KS 4 graphite powder from TIMCAL. This study revealed a strong dependence of these parameters with fullerene yield and rate of fullerene production. It also revealed the key role of the carbon black purity. The best results were obtained using acetylene black Y50 A, for which a rate of ful-lerene production of the order of 17 g h~(_1) corresponding to a 480 g h~(_1) carbon feed rate at 3.6% fullerene content (C60 + C70) were obtained. The specific energy input defined as the plasma power related to carbon precursor feed rate and rate of fullerene production were estimated to 0.039 kWh g~(_1) and 1.11 kWh g~(_1) respectively.