Table 1 Technical requirements for extraction of C8 aromatics Project indicators Clear and transparent appearance, no mechanical impurities Styrene, w% ≤ 3.0 C 8 aromatics a, w% ≥ 80 C9 and C9 and above components b, w% ≤ 0.85 Sulfolane, mg /kg≤ 10.0 moisture, mg/kg≤ 600 aC8-aromatic hydrocarbons refer to ethylbenzene, xylene, and styrene. bC9 and above components refer to the sum of all components after ethylbenzene (excluding xylene and styrene) in the order of chromatographic peaks.