Progress 07/01/18 to 02/28/19

Outputs
Target Audience:One target audience is the biomass suppliers. In particular, ones with used vegetable oil and yellow and brown greases. Another target audience is the fuel suppliers that need to meet mandates for biofuel sales or biofuel incorporation into petroleum blends. This includes the airlines industry who are looking to include moresustainable aviation fuels.A large target audience is the "fuel-using" public. It will be beneficial for them to know there is potential for use of more sustainable biofuels in the future. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Training activities: Individual technicians and interns were trained by key personnel (PhD chemists) to use high-temperature, high-pressure, continuous flow equipment. Knowledge of HPLC pumps and their maintenance was gained and used to continue the research efficiently. Techniques to collect gaseous and liquid bioproducts in a continuous, catalytic system were learned. These technicians and interns were taught how to prepare samples for GCMS, FTIR, and NMR measurements as well as acid numbers and sulfur values of the samples. Distillation techniques to separate out the biofuels, and then to wash, rinse, and dry the biofuels were developed and made more efficient for the resulting biocrude. Professional development: Nothing to Report How have the results been disseminated to communities of interest? Airlines Airports were called to see if they would have interest in using the alternative aviation fuels that we are creating. They stated that, "we have customers interested in having us make renewable aviation fuels available for them", as they are available in a just a few other airports. Thus, some airports have knowledge of our activities to produce biojet and they are also interested in alternative UL94 and LL100 avgas options if we could make those fuels available. The higher minimum octane values (of 94 and 100) have been difficult to attain from non-petroleum sources or processes. Politicians: MN Senator Tina Smith and Isanti (MN) Mayor George Wimmar We met with Politicians (MN Senator Tina Smith and Isanti Mayor George Wimmer) at the Ever Cat Fuels Refinery in Isanti, MN where they toured the 3 million gal/yr biodiesel refinery facility and we were able to discuss our research quest to manufacture renewable biogasoline, biojet, and bio-based diesel (different than biodiesel). Both Politicians were very excited about the news and mentioned their support for this effort, especially if it can result in the creation of another refinery such as the Ever Cat Fuels facility that they had just toured as it was "clean and fits right in with the business community in the area". Biomass suppliers We have discussed our research quest to turn waste grease materials into viable "drop-in" fuels with the Sanimax representative who provided us with some gratis samples in great hopes of having us establish a fuel facility that would use many thousands of gallons of their waste grease feedstock on a continuous basis. The folks at the St. Paul (MN) wastewater treatment plant provided us with a sample of the waste floatable material from which we extracted waste brown grease that we processed into biofuels. The St. Paul facility workers told us, "Please come back and take as much as you want, we produce two to four manure spreaders full per day." Biomass Interns The University of Minnesota has a program for Bioproduct Engineering and we have hired two interns from that program to come and help work during the Phase I project. From this outreach these students have gained valuable insight into biomass processing into higher value materials. They have assisted with the acquiring, the quality measurements, and the pre-treatment of the biomass feedstocks. They have assisted with the processing of the feedstocks and collection of the resulting biocrude and bioproducts, as well as obtaining, measuring, and analyzing the product samples. They have also attended meetings and helped present the data and analysis of the materials. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? In 2017, ~17 billion gallons of renewable fuel were used in the United States. The Congressionally mandated RFS2 calls for 36 billion gallons of renewable fuel to be used by 2022. Hence, novel technology to convert a wider variety of non-food waste greases into renewable fuel is needed. Our Phase I project demonstrated the physical and economic feasibility of producing biofuels from waste greases using a novel hydrothermal, continuous-flow catalytic process operating with supercritical water. Mixtures of brown and yellow greases were continuously flow-processed and converted into 77% biocrude liquid and 23% combustible gaseous products, by mass. The biocrude was distilled into 27% biogasoline, 40% biojet, 30% bio-based diesel, and 3% biobunker fuels. The gas, jet, and diesel biofuels were blended at 5% and 20% levels with petroleum fuels (91-octane, Jet A, and diesel #2). The blends were tested in spark ignition, jet, and diesel engines and ran them at 98 - 101% performance levels compared to the pure petroleum fuels and passed all the ASTM fuel specifications. These results demonstrated that the biofuels were true drop-in fuels blended up to 20% and would fit seamlessly into the existing petroleum infrastructure and economy. Scale-up requirements for a Phase II pilot model were determined to allow for greater volumes of biofuels to be produced and tested in larger engines. A conservative estimation model shows a strong economic opportunity to commercialize this carbon-neutral, sustainable technology to create more renewable fuels for the energy market while adding employment opportunities and improving the environmental future. 1. Demonstrate continuous conversion of waste oil feedstocks into biofuels. a. Catalyst and feedstocks (distiller's corn oil, DCO, yellow grease, YG, brown grease, BG) were obtained. A continuous flow catalytic hydrothermal system was set up for supercritical water (SCW) operations. b. Pump rates of feedstocks (FS) and water were calibrated for input and output amounts. Masses and samples of the top phase liquid layer and solvent extracts of the separated bottom water phase products were prepared for NMR, and FTIR analysis. Gas phase outputs were collected for GCMS and FTIR analyses. c. Conditions were systematically varied towards maximum conversion into liquid biocrude. d. DCO, YG, or BG could be used individually or mixed to produce bioproducts. 2. Explore the effects of T, P, and catalyst contact time upon prod. rate and bioproduct composition from feedstocks and model compounds. a. System temperatures, pressures, and catalyst contact times were systematically varied (350-590 °C, 2500-5000 psi, 30-90 seconds). Model compounds (methyl octanoate, octanoic acid, oleic acid, 2-octanone, octane, hexadecane, octadecene, octanethiol) were run (350-550°C, 3300 psi, constant flow). b. GCMS chromatograms and NMR/FTIR spectra were collected from liquid bioproduct samples. c. Above 500°C showed increasing fuel and decreased ketone compounds. 550°C gave the highest percentage fuel compounds with the least gases. Pressure had little effect. Slower flow or higher temperature created more gases. Faster flows carbonized and plugged catalyst beds more quickly. d. Conditions of 550°C, 3300 psi, 60-second catalyst contact, and a 1:3 FS:water ratio established maximum catalyst efficiency. 3. Determine the chem. compounds produced and their amounts with different processing conditions. a. Resulting bioproduct liquid and gas samples were collected for analyses. b. GCMS and FTIR spectra were obtained from the gaseous samples and these along with NMR for the liquid samples. GCMS peak analyses gave specific compounds and percentages. c. There were several hundred compounds. The top five compounds (550 °C) were: toluene (6.1%), p-xylene (4.5%), ethylbenzene (3.2%), 1-ethyl-2-methyl-benzene (3.1%), and 1-methyl-indene (2.2%). Compounds were sorted into functional classes and the biocrude was: 47.8% alkenes, 14.9% aromatics, 14.6% alkanes, 12.3% ketones, 8.6% alcohols, and 1.7% aldehydes. d. The main compounds in the biocrude are also found in petroleum gasoline. 4. Theorize reaction kinetics for the conv. of non-food biomass into bioproducts. a. Literature was searched for mechanisms of ketone and hydrocarbon formations as well as supercritical water, hydrothermal, and cracking processes. b. GCMS chromatograms of the model compounds were studied. c. GCMS analysis showed abundant compounds, patterns, and degradations. One observation was the formation of dimer ketones from fatty acids (450°C) which degraded into smaller alkanes, alkenes, and aromatics at temperatures over 500°C. d. Model compound studies identified three main conversion mechanisms: hydrolysis of esters, ketonization of free fatty acids, and fragmentation of aliphatic side chains. 5. Optimize, maximize biocrude prod. and distillation parameters for drop-in biofuels. a. FS was continuously processed into biocrude, then distilled into biofuels that were washed, filtered, dried, and blended at 5% and 20% with their respective pure petroleum fuel. They were tested in respective engines and ASTM tests were performed. b. About 15L of biocrude resulted from processing 20L of 25:75, BG:YG (550°C, 3500 psi, 60-sec.contact). Input and output masses were taken. GCMS chromatograms of the distilled fractions and the petroleum fuels were taken and analyzed. Fuel engine performance and emissions for biofuel blends at two engine modes were measured and ASTM specifications were obtained (D4814, D7566, D975). c. The biocrude liquid was 76.5% of input mass. It distilled into 27% biogasoline, 40% biojet, 30% biojet, and 3% biobunker fuels. GCMS analyses allowed fractions to be mixed into a biofuel comparable to a petroleum fuel (91-octane, Jet A, and diesel #2). Engine tests for the 5% blend of biogasoline showed 99.5% and 100.7% performance levels (2400, 3000 rpm rates) and 20% biogasoline showed 100.0% and 99.7%. The 5% biojet showed the same 100.0% performances with both engine loads (15kW, 20kW) while the 20% blend showed 100.0% and 97.7%. The 5% bio-based diesel showed 100.9% and 102.6% performances (2000, 2500 rpm) and the 20% blend showed 100.3% and 101.0%. All 5% and 20 % biofuel blends passed all ASTM specifications tests. d. The feedstock processing conditions were optimized for biocrude liquid production, while maximizing the biojet fraction. The engine performance and ASTM results show these are true drop-in fuels for biofuel blends up to 20%. 6. Study the reactor material stability and demonstrate catalyst regeneration to orig. activity. a. Zirconia catalyst was massed and employed to create biocrude, then regenerated, re-massed and re-employed. Masses were taken of Stainless steel, Hastelloy, Inconel, and Titanium metal reactors before and after making biocrude. b. Masses and borescope pictures of the reactors were obtained. c. The zirconia catalyst had the same mass fresh and after regeneration (± 0.2%) and chromatograms showed the same resulting biocrude. Different metal reactors showed the same mass before and after processing at least 2 liters of FS. Pictures showed the same clean interior surfaces of all metals before and after long-term use. d. Sustainability of the various metal reactors and the indefinite regeneration of the zirconia catalyst was established. 7. Determine process economics based on the mass balance for the pilot scale and comm. scale prod. of drop-in biofuels. a. An economic model was developed for a 3 million gallon per year facility with Phase I process mass balances and current FS and petroleum pricing. b. Nothing to report c. A conservative economic model showed a gross cost of $9.05 million and revenues of $10.89 million that gave a net annual profit of $1.84 million. d. This technology is deemed economically feasible to scale-up to a 3 million gallons per year facility that creates biofuels from waste greases.

Publications