1. In the High-temperature tar in the 1.0-2.0%. By cutting 290-310 ℃ from the wash oil distillate, the distillation column equivalent to 115 theoretical trays was used for precision fractionation, reflux ratio was 15:1, and 292-302 ℃ narrow fractions were cut. By cooling, crystallization, centrifugal separation, get coarse, and then with 1:25 benzene or xylene recrystallization, then the industrial. The industrial solution is dissolved in benzene, washed with 40% sulfuric acid, then washed and dissolved by neutralization, and then distilled, the distillate is crystallized with gasoline and ethanol, and purity is 95% pure.
2. With the catalysis of ferric chloride, the reaction of biphenyl with two chloro methane was made.