2.1. Materials
The refined WCO was obtained from Shanghai Zhongqi Environment Technology Co., Ltd. DDCL was obtained from Shanghai Institute of China SH Coal to Liquid and Chemical Co., Ltd. Ethanol (ET) and 1-butanol (BT) with purity of ≥99.7% was purchased from Shanghai Titan Technology Co., Ltd. (China). All other chemicals and reagents were analytical grade and obtained from Adamas-beta® Reagent Co., Ltd. (Shanghai).
In addition, BWCO used in this paper was produced by the alkali-catalyzed transesterification of WCO with methanol in our laboratory [12].