Preparation, application, and optimization of Zn/Al complex oxides for biodiesel production under sub-critical conditions.
Biodiesel produced by transesterification is a promising green fuel in the future. A new heterogeneous catalyst, Zn/Al complex oxide, was prepared for biodiesel production. The results showed that the catalyst derived from a hydrotalcite-like precursor with a zinc/aluminum atom ratio of 3.74:1 and calcined at 450 degrees C gave the highest conversion of 84.25%. Analysis of XRD, XPS, FI-IF, TG-DTA, BET and alkalinity tests demonstrated that it is the unique structure of hydrotalcite-like compound precursor that gave the catalyst a high alkalinity greater than 11.1. The optimal reaction condition for Zn/Al complex oxide was under methanol sub-critical condition: 200 degrees C, 2.5MPa, 1.4% (wt) catalyst dosage, and 24:1 methanol to oil ratio. Under these conditions, the conversion reached 84.25% after 90min, which was better than Mg/Al complex oxides. The excellent tolerance to water and free fatty acid was exhibited when the oil feed had fewer than 6% FFA or 10% water content with a conversion greater than 80%.
Jiang
Wei
W
Multi-phases Mass Transfer and Reaction Engineering Laboratory, College of Chemical Engineering, Sichuan University, Chengdu, 610065, China.
Lu
Hou-Fang
HF
Qi
Tao
T
Yan
Shu-Li
SL
Liang
Bin
B
D000536:Aluminum Hydroxide / Q000737:chemistry; D000537:Aluminum Oxide / Q000138:chemical synthesis / Q000737:chemistry*; D056804:Biofuels; D001709:Biotechnology / Q000379:methods*; D004951:Esterification; D005229:Fatty Acids, Monounsaturated; D008276:Magnesium Hydroxide / Q000737:chemistry; D000432:Methanol / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D010316:Particle Size; D010938:Plant Oils / Q000737:chemistry; D000074262:Rapeseed Oil; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D014961:X-Ray Diffraction; D015034:Zinc Oxide / Q000138:chemical synthesis / Q000737:chemistry*
D056804:Biofuels; D005229:Fatty Acids, Monounsaturated; D010938:Plant Oils; D000074262:Rapeseed Oil; C010467:hydrotalcite; D000536:Aluminum Hydroxide; D000537:Aluminum Oxide; D008276:Magnesium Hydroxide; D015034:Zinc Oxide; D000432:Methanol