Progress 09/01/21 to 08/31/23

Outputs
Target Audience:Research activities for this Phase II project were conducted largely in-house with outcomes being observed and utilized by the researchers themselves. Four primary outcomes of the research were transferred to factory operations throughout the projectwith technical learning opportunities for factory leadership and operations personnel. Additionally work led by Ph.D. researchers provided opportunity for learning and career development accross the team of research technicians and associate laboratory personnel. Changes/Problems:Stony Creek experienced no significant problems during the Phase II project. One of the research areas related to the isolation and immobiliaztion of enzymes for a process improvement embodiment yielded no positive results, but this was not a gating item, and the alternate proposed research area yielded very positive results. The other notable deviation from plan was the accelerated adoption of the membrane filtration technology at the factory level including construction and integration of a factory-sized skid based on the interim Phase II work.. Ultimately this resulted in demonstrable improvements to Stony Creek's production process. What opportunities for training and professional development has the project provided?The work performed provided opportunities to train factory and production personnel on new processes and rationale, and provided opportunities for researchers todevelop and transfer technology products to the factory floor. How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? As a result of research and development performed under the Phase II project, Stony Creek Colors evaluated a wide range of membrane filtration media and configurations, ultimately settling on a two-part system consisting of an ultrafiltration stage followed by a nanofiltration stage which together allowed for the concentration of dye precursor extract to roughly 6 times its original state. This arrangement allowed for roughly 90% recylce of water, and an 80% reduction in water processed in the dye conversion step. This technology was piloted and ultimately transferred to the factory floor through the design and construction of a factory-scale nanofiltration skid which was utilized during the 2022/23 season. A conversion process for this concentrate was also developed under this project which utilized an acid hydrolysis reaction with chemical oxidation to yield what would be the highest prutiy, highest conversion yield natural indigo product generated at Stony Creek Colors' facility. This process will be transferred to a toll processor for final conversion of concentrate, as Stony Creek does not have that equipment or safety infrastructure to perform the reaction at industrial scale, and the extraction and concentration process has already formed the basis for future expansion plans. Ultimately these improvements from Phase II work have enabled the scale and purity of natural indigo dye production to expand into previously unservable markets include pre-reduced natural indigo dye for textiles and high-purity natural indigo dye for food colorant applications.

Publications

Progress 09/01/21 to 08/31/22

Outputs
Target Audience:During this reporting period, research activities were conducted largely in-house with outcomes being observed and utilized by the researchers themselves. Two primary outcomes of the research were transferred to factory operations near the end of the reporting period with technical learning opportunities for factory leadership and operations personnel. Additionally work led by Ph.D. researchers provided opportunity for learning and career development accross the team of research technicians and associate laboratory personnel. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Introduction of two non-traditional technologies and unit operations(nanofiltration and bacterial fermentation)into an established chemical production line has allowed opportunities to train factory operators and process engineers on the function and benefits of the processes. Additionally work performed by senior scientists within the research and development department has allowed opportunities for laboratory technicians and associate personnel to learn new techniques and build skillsets that will help within the progression of their careers.Introduction of two non-traditional technologies and unit operations(nanofiltration and bacterial fermentation)into an established chemical production line has allowed opportunities to train factory operators and process engineers on the function and benefits of the processes. Additionally work performed by senior scientists within the research and development department has allowed opportunities for laboratory technicians and associate personnel to learn new techniques and build skillsets that will help within the progression of their careers. How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals?During the second half of this Phase II project, researchers will finalize implementation of the membrane filtration technology including downstream processing and a potential continuous flow arrangement. This will include optimization of the microbial fermentation step to minimize impurities in the final crude, as well as potential segregation and capture of target impurities for re-use or sale. The final continuous flow process design will be transferred to a working pilot line with a final outcome of being ready for factory-scale technology transfer.

Impacts
What was accomplished under these goals? Within Technical Objective 1, researchers executed a broad design of experiments to understand the boundaries operational conditions for processing indigo plant soak water with various nanofiltration and ultrafiltration membranes. Initial pilot operation data across multiple membrane sizes aided in the selection of an appropriate membrane specification which would allow for concentration of the soluble indican molecule with the least amount of energy and highest segregation of other soak water constituents. Upon selection of the membrane, tests were run across full arrays of flow rate, concentration, and pressure to model the potential working environments at various points along the multi-stage membrane array proposed for the industrial system. The model was utilized in the final design of the filter array, and the technology was transferred to the factory floor with technical and operational success. Within Technical Objective 2, experiments were conducted to establish optimal propagation and conversion conditions for the company's bacteria used in the fermentation step. Multiple nutrient regimens, temperatures, and conditions were evaluated resulting in an augmented nutrient solution that increased growth rates and cell density over standard conditions. Monitoring rates of doubling and hydrolyzing activity, an improved procedure was developed for optimizing the scale-up and addition of the bacteria so that a maximum rate of conversion occurred with less opportunity for side reactions. Within Technical Objective 3, third party assays were conducted to demonstrate the effectiveness of the nanofiltration system to not only concentrate indican but also to pre-treat wastewater for both re-use and discharge to municipal sources. Previous wastewater concerns of BOD and COD were reduced by 150X and 250X, respectively. Phenols were reduced to and undetectable level. Within Technical Objective 5, the primary membrane filtration skid has been designed, built, and implemented and the factory, having resulted in successful concentration of indigo soak water to 4x with a corresponding improvement in dye yield per batch; and the permeate side has been successfully used in soaks of subsequent batches.

Publications