Table 1 Technical requirements for ethylene cracking mixed carbon eight Item indicators Appearance transparent liquid, no free water Density (20℃), kg/m3≤ 940 Toluene, w%≤ 2.5 Ethylbenzene, w% actual measured value Xylene, w% actual measured value Styrene, w% ≥ 12 C8 sum a, w% ≥ 30 C8 and above C8 components b, w% ≥ 80 aC8 sum refers to the sum of ethylbenzene, xylene, and styrene components. bC8 and above components refer to the sum of all components after ethylbenzene (including ethylbenzene) in the order of chromatographic peaks.