PHE has developed a heterogeneous (solid) catalyst that can produce biodiesel from waste and recycled oils and fats (with any mix of free fatty acids and triglycerides) in a single process operation in the presence of water and at relatively low temperatures. This biodiesel process technology is the result of a focused effort to develop a catalyst with the following characteristics:
- Heterogeneous. A solid form allows the catalyst to be contained in the reactor and reused. (As opposed to liquid biodiesel catalysts which are used once and then end up in a waste or reprocessing stream.)
- Safe. The catalyst should not require complex handling procedures in order to be used safely. (As opposed to current liquid catalysts which are acids or bases and require special handling.)
- Flexible. The catalyst must be capable of converting pure oils, recycled oils, and waste oils simultaneously in a single reactor. Chemically this means that the catalyst must be capable of facilitating both esterification and transesterification reactions. (As opposed to alternative catalyst technology which requires separate energy-intensive reactions and/or separate capital-intensive process equipment for each reaction.)
- Robust. The catalyst must not fail in the presence of small quantities of common contaminants or reaction products, such as water. (As opposed to liquid base catalyst technology which fails in the presence of even small quantities of water or free fatty acids.)
- Efficient. The catalyst must drive the reactions close to full conversion at reasonably low temperatures. Higher temperatures require more energy and more expensive process equipment in order to contain the higher pressures necessary to keep the reactants in the liquid state. (As opposed to alternative heterogeneous catalysts that require very high temperatures.)
- Green. The catalyst must be capable of facilitating the reaction with multiple alcohols, including ethanol which can be made from renewable sources. Further, the catalyst must possess environmentally friendly disposal characteristics.
- Stable. The catalyst must have sufficient lifetime to be cost-effective in commercial production.