Progress 07/01/23 to 08/31/24
Outputs
Target Audience:Worldwide, cereal grains, led in large part by corn and wheat, account for greater than 50% of the daily caloric intake. This over $322 billion marketcan only meet global needs with the proper drying, conditioning, and storage of harvested material. When grain crops are initially harvested, their moisture content is too high, producing a favorable environment for pathogen growth. The drying process effectively reduces the moisture content and allows the grain to be stored for months without fear of contamination. Farmers rely on drying technology to operate against the volatile demands of the grain market, but high operating costs, energy inefficiency, and drying time often depresses profit, placing an inordinate strain on small and mid-sized farms. USDA data from 2021 shows that 89% of farms in the U.S. are small family farms. Despite their necessity, these farms are facing greater financial hardship than their larger, industrial counterparts. Since 2017, the number of farms with sales over $500,000 has increased, while the number of farms producing less than that has decreased. Much of this can be attributed to the often-prohibitive costs associated with many integral on-farm processes like drying. The development and introduction of a highly efficient, low-cost, and reliable integrated drying system, especially one operable with renewable energy, can significantly cut costs and support the persistence of these farms. Grain drying takes place locally at the farm, regionally at small facilities, and industrially at large commercial facilities. Although our dryer can be applied to any of these levels, our current focus is at the regional scale and smaller. Conversation and data sharing with a local seed company that dries product from across the county has offered elucidation on the issues farms face and the technologies currently in use. Standard drying technology is powered by relatively costly liquid petroleum gas that, when coupled with the imprecise moisture measurement capacity of traditional bin drying, drives operating costs up and profit margins down. Thus, it has been communicated that drying outfits of this size are in search of systems that can both lower cost and dry harvested material faster. Current drying techniques are quite rudimentary, and the drying space has great room for improvement particularly regarding energy efficiency. Test data demonstrates that our energy agnostic system will address this area, significantly lowering operating costs for its users. The money saved through the adoption of the dryer can swiftly be incorporated to bolster profits, increase scale, and improve efficiency in other processes. The other area of concern, drying time, is currently being investigated. Communication with the USDA Healthy Processed Foods Research Lab in Albany, California and the Kent Feed Mill and Grain Science Complex at Iowa State University is ongoing on the ways to optimize drying time without damaging the crop. At present, the sale of grain dryers is carried out via direct sales from original equipment manufacturers (OEMs) to farms and elevators. Private and public pressure in the form of legislation, subsidies, and tax breaks create a favorable environment for the adoption of energy efficient technology such as ours that has been developed, tested, and can be easily incorporated. It is our belief this will make us an attractive partner for companies seeking to capitalize on these benefits. We are currently seeking out well-connected partners who can integrate our technology into their existing dryer designs for two reasons. Firstly, this will allow for rapid establishment of our technology in the grain drying market beyond what could be accomplished independently. Secondly, corn production in the United States is heavily centralized in the Midwest - 90% of the corn and soybean production for the country comes from just 13 states in this area.Therefore, to reach the bulk of the potential customer base, it is important to find sales partners located in the region. Our focus at this time remains on small and intermediate drying operations in need of cost-reducing measures. The savings potential of this system should appeal to entities working with small profit margins, creating a robust market for our product. At the same time, we have the capacity to scale our system up if an opportunity presents itself. Large farms and grain elevators seeking to lower costs and receive government benefits can utilize our system just as effectively if we wish to market towards them in the future. Changes/Problems:No major issues were experienced during the execution of this Phase I SBIR program. There were, however, some unexpected issues which caused changes in the planned effort. At the start of this program, MNT engaged SES to understand their economics,issues, and desires. The clear response was the desire to reduce the cost and time of the seed drying process. Further research indicated that the energy usage required for a single batch of seed dried was not known. Additionally, no data was/is provided by the manufacturer of the drying equipment to establish the efficiency of the process. Discussions with others indicated that this lack of detailed information is typical. In lieu of using monthly data to estimate the per batch cost, the decision was made to instrument the current seed drying process to measure its energy efficiency throughout the entire batch process. This decision, due to the seasonal nature of the seed drying business, resulted in the extension of this Phase I effort. The resulting detailed efficiency data provides the baseline data necessary to establish the energy savings of the proposed technology. The ability to reduce the time associated with drying a batch of seed was the second desire. Typically, the speed at which a product can be dried is limited by its ability to release moisture. Drying faster than a product's ability to release moisture, damages the product. To prevent this, in other industries such as lumber, drying schedules have been established for each type of product. A literature review, and discussions with people in the industry, indicate that these types of drying schedules do not exist for seed and grain. The result is that while the proposed technology is not dependent on the ambient environment, and can control the batch inlet air conditions (make the inlet air dryer than ambient), which has the potential to increase the drying speed, it is not known if this is beneficial. Based on this it is recommended that testing to establish drying speed be performed as part of the proposed Phase II effort. What opportunities for training and professional development has the project provided?This Phase I effort funded training and professional development of the program manager, engineers, graduate students and undergraduate students at Micro Nano Technologies (MNT) and its subcontractor the University of Florida (UF). As part of this effort a graduate student at UF's Nanostructured Energy Systems Laboratories (NESLabs) was funded to perform the numerical simulation of the proposed absorption technology in the seed and grain drying application. As absorption technology is typically not taught in detail at the undergraduate or graduate level, this funding enabled the graduate student to understand the absorption cycle in general, our implementation of the absorption cycle, and then apply this understanding to the operational characteristics and conditions of the seed drying application. This effort funded a portion of the third year of a mechanical engineering doctoral student. An undergraduate intern was hired by MNT to assist the program team in the research and development of the techno-economic analysis of seed/grain drying and the impact of implementing the proposed technology. This effort involved the research of the seed/grain drying market, manufacturers, the techno-economic analysis process, and economics of the current and proposed technologies. This effort was largely conducted as one-on-one work with the MNT program manager, with participation in meetings with the program TABApartner, prospective partners such as the USDA Western Regional Research Center and the Iowa State University Feed Mill and Grain Science Complex, and visits/discussions with the local seed drying partner SES. Additionally, as part of UF's Innovate Hub, MNT provided and encouraged the participation in a wide variety of lunch and learn, virtual webinars, and on-site presentations/ learning opportunities focused on the innovation and start-up ecosystem. As a sustainability major, this opportunity, has helped to deepen the intern'sunderstanding of how sustainable technologies are developed, implemented, and enter the market. To gain a user prospective MNT worked with SES, a local small seed drying company. This interface provided the program management and engineering team with invaluable information regarding the process of seed drying. This information including, the drying technology, drying process, energy use, maintenance issues, and economics helped to form the basis of our effort. This support, accompanied by inputs from the TABA mentor, was instrumental in elevating the knowledge of the MNT program team in the understanding of the seed/grain drying market, its economics, and the potential implementation of the proposed technology. The result was an order of magnitude increase in the team's understanding of this complex and promising market. How have the results been disseminated to communities of interest?The data collected as a part of this Phase I effort consists of techno-economic data, seed drying experimental data using existing technology, and performance data of the proposed technology when operating under the seed drying conditions. This data has been shared with a local community of interest (local seed drying company), and is in the process of being prepared for distribution to more general communities of interest. The program team worked closely with SES, a small local seed drying company,developing a comprehensive understanding of their seed drying process and associated economics. As part of these efforts, MNT instrumented and tested the SES equipment across the entire seed drying process. This was done to establish the efficiency of the existing process as a function of time throughout the entire process. As SES currently measures the economics of their operations on a monthly average basis, this data has been shared with SES to provide them with a more detailed understanding of their existing process. Based on this experimentally established performance data, the energy savings/associated economics of the proposed technology have been communicated to SES. This data has encouraged their participation as a field test site in the proposed Phase II effort. Additionally, this experimental data is being prepared for its dissemination to our contacts at the USDA Western Regional Research Center and the Iowa State University Feed Mill and Grain Science Complex, and is being prepared for publication in an academic journal. Locally, we are using this data and the economics of the proposed technology, to engage the Florida F-300 AgriFoodTech Regional Tech Hub consortium and the members of the Florida Feed Association. MNT will further use UF's Institute of Food and Agricultural Science (IFAS) infrastructure to disseminate the resulting information to its entities in each of the sixty-seven counties in Florida. Additionally, as part of our Phase II proposal efforts, we are sharing the potential of this technology as we engage existing manufacturers in the drying sector. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
The proposed Phase I effort was segregated into four tasks; the establishment of the operational environment necessary for crop drying, the design of a small lab-scale system based on the, or a selected subset, of the defined crop drying operational environment, the fabrication of a small-lab scale system for the testing of the system at the operational conditions needed for crop drying, and the experimental characterization of the system performance when operating at these conditions to establish the viability and efficiency of the proposed technology. Operational Conditions: The technology currently used in crop drying, is a single pass technology. As such ambient air ispulled into the dryer, heated to the desired temperature, blown past/through the crop, and then exhausted back to the environment. In some instances, heat recovery is performed using the heat in the exhaust air to preheat the incoming air to improve efficiency. The crop drying (moisture release process)is driven by temperature (heat) and water vapor pressure differential between the crop and the drying air, and the crop's internal water release rate. As such, dryer, hotter air increases the drying rate (speed) until it reaches a rate at which the crop cannot release water faster. Attempting to dry the crop faster than its ability to release moisture results in the damaging (i.e. discoloration, surface damage, etc.)of the crop in the drying process. As a single pass technology, the operational environment of the drying process involves the ambient and the desired drying chamber air conditions. Based on a survey of literature, discussions with people in the seed/grain drying industry, our technical and business assistance (TABA) mentors, and the data measured at our local seed drying partner, the drying chamber temperature should be kept below 60 °C, with the exception of corn which can be dried up to temperatures of 115 °C. Based on this data, the operational environment for seed/grain drying ranges from ambient conditions (location, season dependent) to 60 °C. To be conservative, the proposed system has been designed to provide an operational drying temperature up to 71 °C. As the proposed technology is recirculatory, it is not dependent on ambient conditions, enabling the potential to achieve faster drying times at lower temperatures. Lab Scale Design/Fabrication: A heat driven lab scale proof-of-concept drying system was designed and fabricated to support testing to demonstrate the technology's ability remove the moisture released during the drying process and to achieve the desired drying chamber temperatures. The resulting single effect proof-of-concept system was designed to operate at air flow rates up to 400 cfm, configured with a condenser heat recovery system, and instrumented with thermocouples, air temperature and relative humidity sensors, and flow meters to provide the ability to experimentally measure its performance. The system was designed to be indirectly heated through the use of a heat transfer fluid. This provides the ability to fuel-switch without impacting the internal system configuration. As such, the system can be driven by natural gas/propane, biomass, solar thermal or a combination of multiple fuel sources. The system was designed to operate using one of two ionic (IL) liquid desiccants, our legacy IL and our new hybrid IL. Both of these ILs are stable and inert across the drying operational range, with the new hybrid IL having a greater dehumidification potential and a slightly lower regeneration temperature. However, due to the availability (amount on hand) the proof-of-concept system has only been operated to date with the legacy IL. The thought process is that if the system can operate with the legacy IL, its performance characteristics will only improve when operating with the new hybrid IL. The completed system has been operated to support its characterization across the dryingoperating envelope. System Characterization: The system characterization effort involved two distinct efforts, the establishment of the performance characteristic of existing technology to establish a baseline, and the establishment of the performance of the proposed technology. To obtain a complete understanding of the operational requirements and performance characteristics of seed/grain drying, a relationship with a local small seed drying company (Southeast Seed) was established. Southeast Seed (SES) batch dries a variety of grass seed (Pensacola and Argentine Bahia; Brown Top, Clay, Dove Proso, and Japanese Millet, among others) from small local growers (including themselves), using drying trailers in which heated air is blown into an undercarriage plenum and exhausted out the open trailer top. Given the simplicity and widespread use of this technology in the southeast, it is this technology which has been used to establish a drying baseline. As SES does not meter the energy consumption of each individual dryer, only monthly average specific moisture extraction rate (SMER) performance data (kgs water removed/energy consumed) was readily available. To obtain performance data throughout the drying process, an experimental test setup was designed and implemented. This test setup used sensors to measure the ambient air conditions, the air conditions in the drying cart undercarriage plenum, the air conditions just above the wet seed, and air flow rate. Using the air flow rate, the fan power consumption was established based on the fan power curve. Using the air flow rate, the change in air temperature, and assuming a 90% burner efficiency the amount of propane used in the drying process was established. To date we have been able to test two batches of the same type of seed (Bahia). As expected, the experimentally measured SMER performance of the system indicates that it is most efficient (~ 0.7 kg H20/kWh) at the beginning of the drying process, when the seed is wet, and it is inefficient (0.2 kg H20/kWh) at the end of the drying process when the seed is almost dry. This data has been used as the baseline for the comparison with the proposed technology. The test setup remains at SES and will be used to increase the data set (number of test runs and seed types) to support our Phase II proposal effort and the release of an academic publication. To establish the performance characteristics of the proposed technology, a combination of proof-of-concept drying system test data and numerical analysis using validated system thermodynamic models was used. The several test runs of the proof-of-concept drying system were conducted in the lab at several conditions within the established drying envelope. As this system is fully instrumented with sensors its performance is easily measured/established. The data from these test runs were compared with the theoretical model results to ensure close correlation. Based on this close correlation, the balance of the desired performance data was numerically derived. This data indicated that the SMER performance of the system should remain essentially constant across the drying process with a SMER of ~1.4 kg H20/kWh. The ability to maintain a constant system performance is due to the fact that this technology is recirculatory and demand driven. Heat is used to remove the moisture from the air. As the moisture is removed from the air, the air temperature is increased. If no, or little moisture, is in the air, little heat will be used by the system (with the exception of small heat losses). Thus, the system self-adjusts its energy usage based on the amount of moisture being removed. The accomplishments of this Phase I effort, indicate that this technology can significantly reduce operational costs, significantly reducing carbon emissions when using current fossil fuels, or virtually eliminating them when implemented using solar thermal.
Publications
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