Location: Cotton Ginning Research
2018 Annual Report
Objectives
1: Determine the expected impact of new cultivars, agronomic practices, and harvesting/storage practices on profitability and risks in ginning of Western and long-staple cotton in collaboration with private-sector partners, ARS-SRRC-CSQ, and other ARS laboratories.
1A: Improve or enhance cotton fiber ginnability, textile utility, and cottonseed end use value of new germplasm releases of both Upland and Pima cottons.
1B: Reduce fiber damage during harvesting.
1C: Improve and reduce environmental risk of cotton harvest preparation.
2: Enable, from a technological standpoint, new commercial technologies, methods and processes to (1) improve process efficiencies, (2) reduce uncertainties and risk, and (3) increase end-product and co-product value in the ginning of Western and other long-staple cottons.
2A: Improve seed-cotton drying and foreign matter extraction.
2B: Develop improved saw ginning technologies to increase efficiency and productivity, and enhance fiber quality.
2C: Enhance high speed roller-ginning technologies to increase capacity and improve textile processing efficiency and yarn quality.
2D: Enhance understanding and knowledge of ginning techniques and processes for better decision making tools at the gin and textile mill.
2E: Improve foreign matter extraction and fiber quality of ginned lint.
2F: Develop methods and systems to reduce energy consumption during ginning.
2G: Assist the ginning industry in complying with regulatory standards.
3: Enable the commercial processing of cotton companion crops, such as chile peppers and tree nuts.
3A: Assist tree nut industries in improving process efficiency and reducing environmental risk.
3B: Optimize field machinery for chile harvest mechanization.
Approach
To address critical production, processing and regulatory compliance issues pertaining to Western irrigated cottons and companion crops, this project focuses on three main research areas. The first area advances knowledge of and improves cotton cultivars and production and harvesting practices by 1) collaborating with cotton breeders to determine the ginned fiber quality, textile processing characteristics, and cottonseed quality of newly developed cotton cultivars; 2) investigating cotton picker spindle designs to reduce quality degradation during harvesting; and 3) developing a technology to thermally treat cotton plant stalks for whole-plant desiccation and defoliation. The second improves processing, reduces risk, and increases value by 1) building on earlier work to advance the use of microwave energy to effectively dry seed cotton; 2) improving a device developed to accurately measure seed cotton moisture content for better system management; 3) developing an infrared based sensor to detect plastics contamination in seed cotton at the gin and an electrostatic based device to separate plastics from seed cotton by exploiting static charge affinity differences; 4) evaluating current and, then, developing improved gin saw designs that maintain capacity and reduce fiber damage; 5) cooperating with industry partners in further evaluating and refining a prototype seed cotton reclaimer and lint cleaner feed works capable of processing seed cotton carryover and ginned lint from high speed roller gin stands; 6) evaluating roller ginned upland cotton textile utilization without combing to reduce processing cost; 7) studying in depth the cost of roller ginning upland cottons; 8) exploring improvements in lint cleaner saw wire configuration and grid bar design, and developing new air knife and rotary brush technologies to reduce seed coat fragments in ginned lint; 9) developing continuous air system monitoring and control systems and performing cyclone flow sensitivity analyses to reduce gin energy consumption; and 10) updating particulate emission factors, evaluating regulatory dispersion models, documenting federal reference method particulate samplers for more equitable industry regulation. The third area enhances the viability of cotton companion crops by 1) modifying current walnut drying technologies to reduce energy usage and drying time; 2) building on previous testing and utilizing an experimental approach to improve a retrofit particulate abatement technology for mobile agricultural equipment; and 3) optimizing a prototype to mechanize succulent chili harvest.
Progress Report
Progress on the three objectives of this project focused on cotton ginning, textile utility, and agricultural regulatory and processing issues. Under Objective 1, progress was made in enabling new germplasm releases of Pima and other extra-long-staple cottons. Cooperating with cotton breeders from different parts of the U.S., this laboratory roller ginned breeder samples and provided lint and seed samples with turnout calculations for three groups: 1) Pima cotton for Texas Agrilife Extension in El Paso County; 2) Hazera for a farmer/breeder attempting to grow the high yielding, low water usage, long staple, hybrid variety in West Texas; and 3) Sea Island cotton for a hobbyist breeder from South Carolina growing and reviving the historical, extra-long-staple cotton and sharing the lint and seed with university researchers in the area.
Under Objective 2, progress was made to improve gin process efficiency, maintain fiber quality, and reduce waste and energy consumption. Analysis continued on data from an online cotton moisture measurement system that could improve cotton dryer control. Results showed that real time seed cotton mass flow still varied considerably. A calculated moving average of seed cotton mass flow did slightly improve the performance of the model, but not to an acceptable level. A more reliable mass flow measurement is needed to accurately predict cotton moisture. Further testing of the moisture measurement system is planned.
At the request of industry partners, testing was done on a prototype lint cleaner coupled directly to a roller gin stand. Ginned fiber is usually transported by air ducts to a separate lint cleaner condenser which forms the fiber into a batt (blanket) before feeding it to the cleaning cylinder of the lint cleaner. Instead of forming a batt, the coupled lint cleaner delivers individual tufts of ginned fiber to the lint cleaner. Cleaning individual tufts of fibers should be more efficient than a batt of fibers which does not have as much surface area exposed. The coupling arrangement also eliminates the need to transport ginned fiber thru air ducts to a separate lint cleaner, thereby reducing energy, particulate emissions, and auxiliary gin equipment.
Studies that modify components of the saw-type lint cleaner to remove seed coat fragments were expanded to also include improving fiber length uniformity with the lint cleaner. Testing began on four different types of lint cleaners that eliminated and/or modified the harmful feed works assembly found on the conventional saw-type lint cleaner. Testing was completed at the New Mexico Ginning Lab on saw-type lint cleaners that were coupled directly to a saw gin and a roller gin, which eliminated the feed works assembly altogether. Testing is planned at the ARS Ginning Lab in Mississippi and the University of Georgia Micro Gin on lint cleaners that have modified feed works assemblies for placing the ginned fiber on the cleaning saw.
A 2-year Non-Assistance Cooperative Agreement (NACA) was established with New Mexico State University to collect and interpret economic data to determine the ginning costs of saw ginning and high-speed roller ginning of Upland and Pima cotton in the Far West (California, Arizona, New Mexico, and Far West Texas). Cost categories include direct, indirect, and administrative expenses; and the operational structure, processing capacity, and ginning volume of each gin.
In conjunction with ARS researchers in Lubbock, Texas, a system to detect colored plastics that contaminate seed cotton at the gin, a major problem for U.S. cotton, and eject it from the cotton stream was developed. The detection components and software were refined by the scientists in Lubbock, while the pneumatic ejection device was devised and manufactured at this laboratory in Las Cruces. Testing under simulated ginning conditions was conducted in Las Cruces. Large pieces of plastic were detected nearly 100 percent of the time, but smaller pieces had mixed results. In ejection tests, larger pieces were detected and ejected with the prototype system about 85 percent of the time. Further testing on actual ginning equipment was planned.
Work was continued with a CRADA partner to reduce lint and cottonseed loss by developing a high-capacity roller gin reclaimer. Several modifications to two experimental cleaners were tested. It was determined that the experimental reclaimers lost less cotton fiber than the conventional reclaimer, but the conventional reclaimer lost less seed. Further analysis showed that the cost of the lost fiber was more than the cost of the less valuable seed. So, the new reclaimers may be more beneficial to the producers, resulting in better economic returns. Further testing and analyses were planned with the CRADA partner.
Although based on a 45 year old standard method, there are differences in how the ARS ginning laboratories determine cotton moisture content. Testing and analysis to compare the methods was completed. Differences between historic and present methodologies were presented and discussed in a journal manuscript. The modern procedures have reduced variability and increased statistical power, but there is a systemic difference that needs to be considered when comparing results from antecedent research. Confidence in current methods was justified, minimum number of samples updated and a reference publication was drafted for current procedures.
Cryogenically treated gin saws that were previously installed in a commercial cotton gin were tested for a third season, comparing saw-life with conventional saws in terms of number of bales ginned. The saws that had ginned about 30,000 bales through the 2nd season continued to function properly. Fiber quality data showed no differences between the two types of saws. The conventional saw became worn and was replaced after only a few thousand bales in this third season. The cryogenic saws continued to gin cotton properly, but were damaged near the end of the season and removed. Unfortunately, the ARS scientists involved left the ARS and the original cooperating gin manager left the gin before the third season. The new gin manager was not able to track the exact number bales ginned when the saws were removed and the saws were not recovered for analysis. Another test with new cooperating gins is being planned.
The third and final year of sampling for a comprehensive fuel energy audit campaign aimed at reducing energy consumption during ginning was conducted during the 2017-18 ginning season with cooperation from ARS researchers at Stoneville, Mississippi. Temperature and air flow measurement equipment was installed and sampling campaigns conducted at 30 gins across the Cotton Belt to quantify fuel use and drying effectiveness, and identify plant layouts, devices, and operating strategies that use less fuel. Preliminary results were presented to the industry at a technical conference.
Working with researchers from Oklahoma State University, 264 cotton gin particulate matter emissions sampling reports were updated. The reports are very important to the U.S. cotton ginning industry, in that they contain cotton gin particulate emissions data based on scientifically collected data instead of conjecture. These reports were submitted to EPA in 2015 for quality rating and incorporation into EPAs Compilation of Emission Factors, but there were questions that needed clarification. All 264 reports were updated and are under review. The reports will be resubmitted to EPA later this year.
Work continued on updating the Cotton Ginners Handbook, an invaluable information source for the ginning industry and text for university courses teaching ginning technology. Revision of 13 chapters is directly overseen by scientists from this lab as lead authors. Two chapters with scientists from this lab as authors or co-authors were submitted this FY. The new Handbook will be published in the Journal of Cotton Science, an industry supported, open-access, online peer-reviewed journal.
Under Objective 3, significant progress was made to aid processing and mechanization of cotton companion crops. In cooperative research with New Mexico State University on improving mechanized chile production (especially harvesting), a scientist from this lab participated in field experiments using a modified commercially available chile harvester; comparing the impact of cultivars and plant populations on machine harvest. Continued assistance to plant breeding efforts by providing agricultural engineering expertise is planned.
Responding to stakeholders requests, energy audits in commercial walnut drying and almond hulling facilities in California were planned with cooperation from the Western Agricultural Processors Association. Candidate facilities were selected for site visits. Sensors and equipment recently used for similar work at cotton gins was repaired, prepared, and purchased for a 2018 campaign.
A test stand was prepared for evaluating two model experimental devices designed to retrofit existing tree nut harvesting equipment and reduce harvest dust emissions. Preliminary runs were conducted. It was found that the particulate feeding system was inadequate for testing the nut harvesting devices. A new loss-in-weight screw feeder was sourced and ordered, and will be incorporated into the test stand. Then, evaluation of the dust abatement devices will resume.
Accomplishments
1. Improving fuel stewardship in cotton gins. Fuel cost increases and consumption volatility threaten the profitability of cotton post-harvest processing facilities. Fuel use effectiveness varies widely, indicating significant opportunity for improvement. Over three years, ARS scientists from Las Cruces, New Mexico and Stoneville, Mississippi audited the drying systems at twenty-three commercial gins across the U.S. to quantify fuel use effectiveness and identify patterns in fuel use efficiency that correlate to the various facility designs, equipment selections, or operation strategies and that resulted in more efficient use of natural gas and propane fuels. Fuel use efficiency was highly variable, ranging from 3 to 38 percent, and it was not possible to separate fuel use efficiency differences by specific dryer types. However, gins with insulated drying ducts and burners located closer to the point where the heated air and cotton mixed made better use of dryer fuel. These results were shared with stakeholders at industry technical meetings and via an online cotton industry educational webcast (http://www.plantmanagementnetwork.org/edcenter/seminars/cotton/SavingEnergy/). Identifying industry best practices is a first step to recommending best practices, and an opportunity to inform wise use of resources for future research projects addressing fuel energy conservation. In addition, reducing fuel use improves environmental stewardship and sustainability as well as industry economic viability.
Review Publications
Armijo, C.B., Whitelock, D.P., Thomas, J.W., Hughs, S.E., Gillum, M.N. 2017. Roller ginning. Journal of Cotton Science. 21:199-209.
Whitelock, D.P., Armijo, C.B., Delhom, C.D. 2018. Seed cotton and lint moisture addition at a Western cotton gin. Applied Engineering in Agriculture. 34(3):623-632. https://doi.org/10.13031/aea.12618.
Joukhadar, I.C., Walker, S.J., Funk, P.A. 2018. Comparative mechanical harvest efficiency of six New Mexico Pod-type green chile pepper cultivars. HortTechnology. 28(3):310-318. https://doi.org/10.21273/HORTTECH03999-18.
