Piedmont Biofuels R&A Novel Biodiesel Processing Technologies Hydrodynamic Cavitation and Enzyme Catalyzed Biodiesel Production - descriptions and small-scale applications Greg Austic Research and Analytics Division Piedmont Biofuels 1
Overview Motivation for second gen. processing How processing helps feedstocks High quality products, minimize waste streams Improve energy and resource efficiency Gen 1.5 Hydrodynamic Cavitation Theory and process Experiences Design for small scale Gen 2.0 Theory and process Advantages Roadblocks and roadmap Vision of small scale application
Motivation and, as Bob Armantrout would say: incomplete product separation Soap overuse of methanol It's all about the feedstocks, dummy! Hazardous Chemicals emulsions Wash Water low quality complex, highly Glycerin variable process 3
Process technology can help: Motivation Simplify process, especially esterification Reduce/remove hazardous chemicals Reduce use of methanol Eliminate soap formation Improve glycerin quality and value Eliminate water wash Improve separations Simple, consistent biodiesel production method from low quality feedstocks Small or Large Scale 4
Theory and Practice Cavitational Mixing Hydrodynamic cavitation is most energy efficient form to optimize biodiesel production (Kelkar et al 2008) The phenomenon of formation of vapor bubbles of a flowing liquid in a region where the pressure of the liquid falls below its vapor pressure Used to increase interface between methanol and feedstock oil Decreases process time by 40% and lowers the temperature required by 50% Incoming feedstock parameters up to 1% moisture and free fatty acid content to 7% Developed model scalable for flexible production capacity Good book to start: Cavitation Reaction Engineering, Shah, Pandit, Moholkar 5
Cavitational Mixing Advantages: Continuous processing Good conversion Low temperature Eliminates need for methoxide tank, reactor tank Seems less affected by water Problems: Requires precise metering Viscosity, temperature affect orifice size Separation may be more difficult Generally should be automated 6
Effectiveness and Conversion Conversion after cavitation 24% MeOH, 8 g/l KOH Conversion wt% 105 100 95 WVO 90 85 80 75 0 5 10 15 20 25 30 35 40 45 Time (min) 7
Effectiveness and Conversion 8
Development Started here... 9
Development Now we're here! 10
Development 11
Development 12
Batch Process Small Scale Design 13
Small Scale Batch Process Design Cutting Costs: Slower speed: 0 1gpm No automation, no metering Could use totes, large batches Retained Benefits: Consistent, complete conversion Low temperature Esterify and transesterify 14
Small Scale Design Continuous Process Cutting Costs: Slower speed: 0 1gpm Fixed metering using pipe size Retained Benefits: Complete conversion Low temperature Eliminate reactor tank 15
What are enzymes? Enzymatic Processing Proteins which can catalyze reactions used in detergent industry, beer making, cheese making, wood processing, ethanol, chemical processing, etc. Generally requires less energy, reaction specific For Biodiesel: Novozymes 435, aka Candida Antarctica Lipase B (CALB) TL Thermomyces Lanuginosa Can transesterify and esterify 16
Enzymatic Processing Advantages: Low temperature: 30 50C No soap formation, no catalyst in coproducts Continuous processing Esterify and transesterify Can easily use higher chained alcohols (ethanol, etc) Uses less alcohol than traditional process Problems: Currently very expensive Enzymes degrade in the presence of alcohol Long reaction time needed 17
Past/Present Work: Enzymatic Processing Deactivation of enzyme by alcohol Use a cosolvent Add alcohol in multiple stages Enzyme too expensive Reduce production costs Reduce component costs Reaction time too long, enzyme life too short Use support media (like amberlite beads) 18
Current Work Enzymatic Processing Novozymes: 3 million, 3.5 years with European universities Improve enzyme life Engineer and optimize system Produce a pilot scale plant Piedmont Biofuels: 150 thousand, 10 months, collaboration with Novozymes Develop a lab scale process which is commercially viable Design and build a pilot Test pilot, acquire data for future work at Piedmont and Novozymes 19
Speculative... but probably something like this: Small Scale Design 20
Small Scale Design Column reactor system (think amberlite/purolite) 2 4 columns, no pressure, 30 50C. 1 2 water/glycerin removal steps. 1 2 alcohol removal steps. Processing method more feedstock independent Must always reduce chance of killing column Key steps: Well filtered feedstocks, low metals, low peroxides Large excess alcohol can kill enzymes High T can kill enzymes 21
Future of small scale tech Remember!!!! Large scale works because engineers and scientists are paid to make it work. Small scale works if WE make it work! Process feedstocks process feedstocks Even 8 years after the appleseed small scale biodiesel is far from perfect (oh, large scale too). 22