687a Transesterification of Poultry Lipids Using Mg-Al Hydrotalcite Derived Catalysts

Yijun Liu1, Edgar Lotero2, James G. Goodwin2, and David Bruce2. (1) Department of Chemical and Biochemical Engineering, Clemson University, Clemson, SC 29634, (2) Department of Chemical and Biomolecular Engineering, Clemson University, 127 Earle Hall, Clemson, SC 29634-0909

Currently, the United States with an average slaughter and processing of eight billion chickens each year ranks first in the world in poultry production and derived products. Concurrently with the production of meat, egg and animal fibers, vast amounts of by-products such as fat and soluble protein are generated representing approximately 40% of the weight of each slaughtered chicken. These by-products are mainly used to produce low value feedstuffs, underutilizing their energy content. The synthesis of biodiesel from poultry lipids provides a way to convert the by-product of a renewable resource to a very important value-added biofuel.

In this work, the use of heterogeneous base catalysts derived from Mg-Al hydrotalcite was investigated for the conversion of poultry lipid to biodiesel. This solid base showed high activity for triglyceride transesterification with methanol without signs of catalyst leaching. Catalytic performance was significantly affected by pretreatment and operating conditions. Calcination in N2 was key in obtaining the highest catalyst activities. Also, methanol had to be contacted with the catalyst before reaction; otherwise, catalyst activity was seriously impaired. Rehydration of the calcined catalyst before reaction using wet nitrogen, however, decreased catalytic activity for the transesterification of poultry fat, in contrast to its positive impact on catalyst reported in condensation reactions1. The catalyst underwent significant deactivation during the first reaction cycle probably due to deactivation of the strongest base sites. However, after the first reaction cycle, it was stable for subsequent cycles. Procedures for catalyst regeneration were also investigated and will be discussed.