Grantee Research Project Results
Final Report: Continuous Fermentation Bioprocess Resolving Food Waste Issues from Greek Yogurt Production
EPA Contract Number: 68HERC21C0050Title: Continuous Fermentation Bioprocess Resolving Food Waste Issues from Greek Yogurt Production
Investigators: Guzman, Juan J
Small Business: Capro-X Inc.
EPA Contact: Richards, April
Phase: II
Project Period: April 1, 2021 through March 31, 2023
Project Amount: $400,000
RFA: Small Business Innovation Research (SBIR) - Phase II (2021) Recipients Lists
Research Category: Small Business Innovation Research (SBIR)
Description:
Capro-X is a sustainable ag-biotech startup bringing greater sustainability to the food and agriculture industry by upcycling problematic waste streams at the production-plant level into treated water and valuable sustainable biochemicals. The company’s solution, called the WheyAway, has been focused on upcycling lactose-containing wastes and byproducts from dairy production (strained yogurts, cheese, milk), yielding biochemicals that are direct alternatives to those sourced from palm oil. Capro-X has been focused on delivering the WheyAway to the Greek yogurt industry, and has additionally evaluated opportunities to upcycle waste streams from cheese and milk processing, and has identified general food waste from candy, ice cream, fruit juice, etc. as significant growth opportunities. For dairy processors, concentrated byproducts from yogurt, cheese, and whey protein are largely trucked hours off-site to be disposed of; Capro-X will install WheyAway systems on-site at these facilities through a biorefinery project finance model, which will eliminate customers’ painpoint of disposing of the waste while potentially turning their waste streams into revenue streams. To date, the company has operated a year-long on-site project demonstrating viability at the pilot scale, and plans to scale 10x in the following year to a production pilot based on learnings from this Phase 2 project. Product-wise, Capro-X’s goal is to deliver competitively-priced sustainable food-grade biochemicals as direct replacements to palm chemicals today, and to scale to produce sustainable aviation fuel within 5 years.
Graphic illustration of Capro-X's novel process.
Summary/Accomplishments (Outputs/Outcomes):
In this project, Capro-X focused on optimizations at the lab scale through three aims. For the first aim, the company operated a number of bench-scale (~1-gallon) bioprocesses comparing the conversion performance of feedstocks including dairy waste, cane sugar sweetened waste, fruit juice waste, and ice cream waste; we also evaluated optimizations to lower the capital cost for a number of process units. In our second aim, we evaluated novel chemistries for the proprietary chemical extraction process unit. The final, and largest, aim of the project, was to evaluate the impact of different bioreactor architectures on overall performance at the prototype scale (~10-gallons), altering parameters such as height, diameter, and recirculation rate.
Conclusions:
Capro-X’s efforts in this project focused on evaluating potential future market opportunities for feedstocks to upcycle, along with derisking scale-up economics by optimizing process unit design and operation.
Capro-X began by upcycling acid whey waste from Greek yogurt, then transitioned to milk processing waste with a new dairy partner; this new feedstock for our bioprocess was able to be upcycled with similar costs
and performance to the original acid whey. We then began converting cane sugar mixed into dairy waste at gradually increasing concentrations, ultimately proceeding to a feedstock containing only cane sugar as the carbon source; we successfully converted this waste into our biochemicals. We then began feeding ice cream waste, and successfully converted organics in ice cream to our biochemicals. Finally, we transitioned to treating apple juice waste, and achieved successful conversion to our biochemicals. From our efforts in this first activity, we found that the WheyAway bioprocess is flexible to common sugars outside of dairy wastes; we expect we can confidently begin proposing scale-up projects with processors of foods outside of the dairy space. For all evaluation performed in this project, we observed similar conversion performance for all feedstocks, and expect to be able to tackle any simple carbohydrate-containing feedstock in the near future.
We additionally evaluated scaling impacts for a number of process units (membranes, extraction system, pumping requirements, bioreactor architecture) at the 1- and 10-gallon scales. We operated bioreactors with limiting quantities of membranes for filtration and the extraction capability, and identified mass transfer limiting scaling factors. We also evaluated lowering mixing rates by 90% to decrease pumping costs, and observed limited impact through the operating ranges evaluated. At the 10-gallon scale, we also evaluated multiple bioreactor architectures (different height and diameter ratios, internal surface area materials), and identified an optimal bioreactor design for future scale-ups.
Finally, our evaluations optimizing our biochemical extraction system demonstrated opportunities to increase extraction rates nearly 5x by altering solvent and extractant chemicals; this finding will ultimately yield lower capital costs due to the need to install smaller, yet more intensified, extraction units.
Capro-X integrated all of our findings into a technoeconomic analysis model that was built using collected data by a third-party engineering firm; the model calculates operating costs for each process unit of the WheyAway (each bioreactor step, extraction system, downstream processing, effluent treatment to sewer, labor), as well as capital cost for all equipment. At the start of this project, Capro-X’s most recent findings indicated a 5.8 year payback period operating on a 59% margin. By reducing pumping costs and filtration requirements, increasing biochemical extraction efficiency, and increasing extraction rate, we calculate a 2.3 year payback period operating with a margin of 75% when selling our biochemicals to the specialty chemicals market. In total, our optimizations throughout this project increased our net operating margin by 89%, and lowered our capital costs by 25%.
Graph of biochemical sales, operating cost, and capital cost pre- and post-project.
Based on Capro-X’s efforts completed in this project, we have significantly derisked the WheyAway fermentation to yield biochemicals that can meet current commodity pricing for our biochemicals. We have encountered a number of opportunities to optimize the WheyAway in the future, and expect to continue expanding the production operating margin to be able to produce biofuel and bioplastic precursors economically. Today, Capro-X can enter the specialty chemicals market with our biochemicals, meeting the $2/lb market price with our current performance. We are currently securing investors to support our next scale-up system: a production pilot yielding 5 ton/yr of biochemicals, where we expect to demonstrate opex/capex to deliver <$0.50/lb to enter the biofuels market. We further expect to reevaluate our technoeconomic model as well as greenhouse gas impact analysis at this larger scale to determine if our current -2 tonGHG/tonproduct metric still translates at the larger scale.
SBIR Phase I:
Continuous Fermentation Bioprocess Resolving Food Waste Issues From Greek Yogurt Production | Final ReportThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.