Bioresource Technology, Vol.263, 289-296, 2018
Effect of oxidation processing on the preparation of post-hydrothermolysis acid from cotton stalk
The typical properties and yield of the refined hydrothermolytic acid (RHTA) and refined hydrothermolytic oxidation acid (RHOA) respectively prepared from cotton stalk by the hydrothermolysis process with and without hydrogen peroxide at 180-280 degrees C were investigated. The pH of RHOA at 180-260 degrees C is lower than that of RHTA. The yield of RHOA prepared at 180-280 degrees C is higher than that of RHTA except 230 degrees C. Besides, the variation trend of RHOA yield at 180-260 degrees C is in accordance with that of RHTA yield at 200-280 degrees C. The composition of RHTA and RHOA were determined using gas chromatography and mass spectrometry. The acids content of RHOA at 200 degrees C reaches the maximum. The phenols of RHOA at 200-230 degrees C is significantly higher than that of RHTA. Under oxidation atmosphere, the formation of ketones is inhibited and the secondary reactions of furan derivatives is promoted. Overall, the oxidation processing can alleviate the severe hydrothermolysis conditions for preparing post-hydrothermolysis acid.
Keywords:Wood vinegar;Hydrothermolysis;Hydrothermolysis oxidation;Hydrothermolytic acid;Hydrothermolytic oxidation acid