Selective hydrolysis, liquid-liquid extraction as an approach to feedstock pretreatment

The centrifuges and leaf filters employed by conventional pretreatment processes are expensive, labor intensive, wasteful and not well suited to petro-scale, high-volume fuel production.  While conventional pretreatment processes can be feedstock flexible, additive and powder formulations must be optimized for each feedstock to maximize effectiveness and minimize cost.  Despite careful optimization, feedstock specification targets (e.g. < 5ppm impurities) can still be difficult to achieve for all feedstocks.  This research explores the feasibility of a high temperature, selective hydrolysis, liquid-liquid extraction process as a truly feedstock-flexible pretreatment method.  Such a process eliminates the need for centrifuges and leaf filters, while maximizing yield and minimizing water usage.  A series of benchtop batch reactions was performed to explore the design space as defined by reaction conditions such as temperature, pressure, and residence time.  Additionally, feedstock selection, water content, and catalyst were also varied in these benchtop trials.  Upon discovering a range of conditions and reaction constituents that provided favorable results, a fully continuous pilot system was constructed to further explore the concept feasibility in a more commercially relevant environment.  Starting feedstocks and pretreated samples were analyzed via ICP-OES with the target of achieving less than 2 ppm phosphorus and less than 5 ppm total metals in treated samples.  This target was met and exceeded with a wide variety of feedstocks in the continuous pilot system. This research demonstrates the feasibility of a selective hydrolysis, liquid-liquid extraction process as a successful approach to feedstock pretreatment applicable to fuel production.  The process is also well suited for the purification of edible oils and industrial fats & oils. This approach eliminates the headaches and yield loss associated with centrifuges and leaf filters while providing system hardware that is more familiar to the fuel industry and better suited to high-volume fuel production.