Consecutively Preparing D-Xylose, Organosolv Lignin, and Amorphous Ultrafine Silica from Rice Husk

Table 2

Factors and levels for L₉(3)⁴ orthogonal test.

Variable	Levels
	1	2	3
Ethanediol’s concentration (v/v)	70	80	90
Ratio of residue to ethanediol (g : mL)	1 : 4	1 : 6	1 : 8
Time (hour)	4	5	6
Temperature (K)	473	483	493