(745e) Znla Catalyst Durability and Regeneration Method in the Process of Converting DDGS Oil and Yellow Grease Into Biodiesel

This research focuses on using heterogeneous catalyst for biodiesel production. Currently biodiesel producer suffer from high oil feedstock cost. Development of catalytic technologies using some crude and inexpensive oil as feedstocks becomes attractive to all biodiesel producers. However, these cheap oil feedstocks generally contains a high content of impurities, such as free fatty acids, moisture, phosphor lipid,  steroidal, some lipid soluble protein and polysaccharide. These impurities not only poison the catalysts but also complicate the whole biodiesel production process. Therefore, investigate the catalyst tolerance to poisons, the regenerate method for the foiled catalysts and the structure of the regenerated catalyst become important. In last decades, there are multiple studies on the effect of FFA and water to homogeneous biodiesel catalysts. However, few focus on heterogeneous catalysts.  In our previous studies, a series of Zn based catalysts were developed with high activity and long life in refined soybean oil system. In this study, crude extracted corn oil from DDGS and yellow grease from several restaurants were used as raw materials. The compositions of oil feedstocks were tested by HPLC, GC-MS, ICP, UV-VIS etc.  Surface coverage of catalyst active site by long carbon chain species are considered as the reason for catalyst deactivation. A deactivation mechanism is proposed here. The foiled catalyst was regenerated by simple calcination method and hydrothermal calcination method. The regenerated catalysts were characterized by XRD, XPS, EDS, HRTEM etc. and evaluated in batch and continuous reactors. It was found that the regenerated catalyst particles have the same structure and activity as fresh catalyst.