Biomedical Engineering Reference
In-Depth Information
Pre-treatment is necessary to reduce free fatty acid content in feedstock [20]. This is
because FFAs react with the base catalyst to produce soaps and water [20]. The typical
method for pretreatment is esterification of the FFA with methanol in the presence of sulfuric
acid [20].
(a)
(b)
Figure 16. Batch process design for biodiesel production.
Batch reactor systems are beneficial for small scale production. This can be scaled up
however by running multiple batch reactors in a cycle that simulates continuous processing to
the downstream steps. Mixing is very important in the batch reactor process. Early mixing is
important to enhance reaction between the immiscible reagents, and can be decreased as the
reaction progresses. Figure 16(a) displays the typical batch reaction process The triglyceride
is charged first; then alcohol and catalyst are added with thorough mixing during the reaction
as detailed in Table 14. After the reaction, the mixture can be allowed to settle to separate
