Table 3: Analysis of L9(3)4 orthogonal test results.

Number( ) Ethanediol concentration ( ) Ratio of residue 1 to ethanediol ( ) Time( ) TemperatureThe yield of lignin

1111110.64
2122216.01
3133324.01
4212326.78
5223118.86
6231228.27
7313233.60
8321334.47
9332118.09
K116.8923.6724.4615.86
K224.6423.1120.2925.96
K328.7223.4625.4928.42
11.830.565.2012.56