(576d) The Conversion of Lipids Derived From Activated Sludge Into Biofuels

The lipidic materials associated with the microbial consortium of the activated sludge were converted to biofuels utilizing both the biodiesel and green diesel pathways. For the biodiesel pathway, in situ transesterification with and without drying was employed. Optimization of process parameters was conducted using sulfuric acid as catalyst. For the in situ transesterification with drying, results indicated that an optimum biodiesel yield of 4.79 ± 0.02% (wt) can be obtained at temperature of 55^oC, methanol loading of 25 mL/g and 4% (vol.) catalyst concentration. On the other hand, the results of the in situ transesterification without drying showed that a maximum biodiesel yield of 3.93 ± 0.15% (wt.) can be obtained at temperature of 75^oC, methanol loading of 30 mL/g and 10% (vol.) catalyst concentration. For the green diesel pathway, the lipidic materials from activated sludge were extracted using Bligh and Dyer extraction procedure. Then, the extract was characterized to determine the major lipid species present. Based on the characterization, a synthetic mixture lipid mixture was prepared and was subjected to catalytic cracking using ZSM5 as catalyst. The lipidic materials from the extract were isolated using a modified Soxhlet extraction procedure using silica gel as matrix. The isolated lipids were subjected to catalytic cracking using the same conditions as the synthetic mixture. This was done to determine if the synthetic and the isolated lipids will yield the same products upon cracking. Furthermore, this was done to asses the effect of other minor components present in the isolated lipids on the products formed.