Greg A. Holt

CHARACTERIZATION OF COTTON GIN BYPRODUCTS PRODUCED BY VARIOUS MACHINERY GROUPS USED IN THE GINNING OPERATION

Byproducts produced from cotton gins have commonly been referred to as trash since they were deemed to have little value. However in some areas of the cotton belt, the byproducts have been utilized successfully. Cotton gin byproducts (CGB) have been fed to livestock, used to make compost, bedding for dairy cattle, or applied back on the land to add humus to the soil. Over the years, extensive research has been performed in evaluating and creating uses for CGB. Almost without exception, all research pertaining to utilization of CGB has evaluated or measured some aspect of the product to determine a desired or needed characteristic pertaining to a specific research objective or goal. Currently, cotton gins produce various streams of byproducts due to the design and layout of the equipment used in the ginning process. In most every case, the byproducts are combined into a single waste stream and sent to a central location. The objective of this research was to characterize the various parameters of the individual waste streams prior to their being combined, to ascertain if the ginning equipment was sorting the byproducts into components that had more desirable characteristics to potential end users. Our results showed that the extractors, lower gin motes, gin stand feeder, overflow separator and lint cleaners produced a product with more desirable characteristics for livestock feeding and fuel utilization than those byproducts from the inclined cleaners and unloading system.

Soil Moisture Sensing via Swept Frequency Based Microwave Sensors

There is a need for low-cost, high-accuracy measurement of water content in various materials. This study assesses the performance of a new microwave swept frequency domain instrument (SFI) that has promise to provide a low-cost, high-accuracy alternative to the traditional and more expensive time domain reflectometry (TDR). The technique obtains permittivity measurements of soils in the frequency domain utilizing a through transmission configuration, transmissometry, which provides a frequency domain transmissometry measurement (FDT). The measurement is comparable to time domain transmissometry (TDT) with the added advantage of also being able to separately quantify the real and imaginary portions of the complex permittivity so that the measured bulk permittivity is more accurate that the measurement TDR provides where the apparent permittivity is impacted by the signal loss, which can be significant in heavier soils. The experimental SFI was compared with a high-end 12 GHz TDR/TDT system across a range of soils at varying soil water contents and densities. As propagation delay is the fundamental measurement of interest to the well-established TDR or TDT technique; the first set of tests utilized precision propagation delay lines to test the accuracy of the SFI instrument’s ability to resolve propagation delays across the expected range of delays that a soil probe would present when subjected to the expected range of soil types and soil moisture typical to an agronomic cropping system. The results of the precision-delay line testing suggests the instrument is capable of predicting propagation delays with a RMSE of +/−105 ps across the range of delays ranging from 0 to 12,000 ps with a coefficient of determination of r2 = 0.998. The second phase of tests noted the rich history of TDR for prediction of soil moisture and leveraged this history by utilizing TDT measured with a high-end Hewlett Packard TDR/TDT instrument to directly benchmark the SFI instrument over a range of soil types, at varying levels of moisture. This testing protocol was developed to provide the best possible comparison between SFI to TDT than would otherwise be possible by using soil moisture as the bench mark, due to variations in soil density between soil water content levels which are known to impact the calibration between TDR’s estimate of soil water content from the measured propagation delay which is converted to an apparent permittivity measurement. This experimental decision, to compare propagation delay of TDT to FDT, effectively removes the errors due to variations in packing density from the evaluation and provides a direct comparison between the SFI instrument and the time domain technique of TDT. The tests utilized three soils (a sand, an Acuff loam and an Olton clay-loam) that were packed to varying bulk densities and prepared to provide a range of water contents and electrical conductivities by which to compare the performance of the SFI technology to TDT measurements of propagation delay. For each sample tested, the SFI instrument and the TDT both performed the measurements on the exact same probe, thereby both instruments were measuring the exact same soil/soil-probe response to ensure the most accurate means to compare the SFI instrument to a high-end TDT instrument. Test results provided an estimated instrumental accuracy for the SFI of +/−0.98% of full scale, RMSE basis, for the precision delay lines and +/−1.32% when the SFI was evaluated on loam and clay loam soils, in comparison to TDT as the bench-mark. Results from both experiments provide evidence that the low-cost SFI approach is a viable alternative to conventional TDR/TDT for high accuracy applications.

Fringe capacitance correction for a coaxial soil cell.

Accurate measurement of moisture content is a prime requirement in hydrological, geophysical and biogeochemical research as well as for material characterization and process control. Within these areas, accurate measurements of the surface area and bound water content is becoming increasingly important for providing answers to many fundamental questions ranging from characterization of cotton fiber maturity, to accurate characterization of soil water content in soil water conservation research to bio-plant water utilization to chemical reactions and diffusions of ionic species across membranes in cells as well as in the dense suspensions that occur in surface films. One promising technique to address the increasing demands for higher accuracy water content measurements is utilization of electrical permittivity characterization of materials. This technique has enjoyed a strong following in the soil-science and geological community through measurements of apparent permittivity via time-domain-reflectometry (TDR) as well in many process control applications. Recent research however, is indicating a need to increase the accuracy beyond that available from traditional TDR. The most logical pathway then becomes a transition from TDR based measurements to network analyzer measurements of absolute permittivity that will remove the adverse effects that high surface area soils and conductivity impart onto the measurements of apparent permittivity in traditional TDR applications. This research examines an observed experimental error for the coaxial probe, from which the modern TDR probe originated, which is hypothesized to be due to fringe capacitance. The research provides an experimental and theoretical basis for the cause of the error and provides a technique by which to correct the system to remove this source of error. To test this theory, a Poisson model of a coaxial cell was formulated to calculate the effective theoretical extra length caused by the fringe capacitance which is then used to correct the experimental results such that experimental measurements utilizing differing coaxial cell diameters and probe lengths, upon correction with the Poisson model derived correction factor, all produce the same results thereby lending support and for an augmented measurement technique for measurement of absolute permittivity.

Accurate Permittivity Measurements for Microwave Imaging via Ultra-Wideband Removal of Spurious Reflectors

The use of microwave imaging is becoming more prevalent for detection of interior hidden defects in manufactured and packaged materials. In applications for detection of hidden moisture, microwave tomography can be used to image the material and then perform an inverse calculation to derive an estimate of the variability of the hidden material, such internal moisture, thereby alerting personnel to damaging levels of the hidden moisture before material degradation occurs. One impediment to this type of imaging occurs with nearby objects create strong reflections that create destructive and constructive interference, at the receiver, as the material is conveyed past the imaging antenna array. In an effort to remove the influence of the reflectors, such as metal bale ties, research was conducted to develop an algorithm for removal of the influence of the local proximity reflectors from the microwave images. This research effort produced a technique, based upon the use of ultra-wideband signals, for the removal of spurious reflections created by local proximity reflectors. This improvement enables accurate microwave measurements of moisture in such products as cotton bales, as well as other physical properties such as density or material composition. The proposed algorithm was shown to reduce errors by a 4:1 ratio and is an enabling technology for imaging applications in the presence of metal bale ties.

Feasibility Study for Constructing and Operating a Facility to Manufacture Fuel Pellets from Cotton By-Products

The objective of this study was to explore the cost feasibility of creating a fuel pellet manufacturing operation utilizing cotton gin by-products from a commercial gin processing 55,000 bales of cotton per year. An economic model was developed and evaluated in order to conservatively address the effects of key elements such as marketing, transportation, and manufacturing. The cost system model was developed and analyzed to examine the factors influencing the sensitivity of critical areas such as cost and profits. The cost system model simulated changes for twenty-three cost variables associated with the proposed fuel pellet operation. Results from the analysis indicate the probability of obtaining a 15% return on investment as 34.4% or 59.1% depending on whether the product was shipped to various distribution hubs via truck or rail, respectively. Based upon the information contained in this study, it appears that a fuel pellet operation can be a viable means of utilizing cotton gin byproducts to enhance revenue.

Manufacturing Vegetable Oil Based Biodiesel: An Engineering Management Perspective

Abstract: The search for alternative fuels has increased over the past years. In an era of high government subsidies for alternative fuel production, engineering managers will be tasked with evaluating the economic benefits of these proposed alternatives. This research was an exploratory process that examined biodiesel manufacturing as a potential alternative for cottonseed oil mills that could furnish an outlet for their product if their current market shrinks. The analysis was performed as possible future investment by an existing company with a no debt scenario. The cost modeling indicates that under current market conditions, cottonseed oil is not a viable alternative to traditional fossil fuels. With the expected wholesale price of

Microwave Moisture Sensing of Seedcotton: Part 1: Seedcotton Microwave Material Properties

0.91 per liter of bio-diesel and a production cost of

Cyclone Energy: Impact of Inlet Velocity and Outlet Évasé Designs

1.28 per liter, the current feasibility of the operation is questionable without the inclusion of governmental subsidies.

Optimization of a Cottonseed Dehulling Process to Yield Intact Seed Meats

Moisture content at harvest is a key parameter that impacts quality and how well the cotton crop can be stored without degrading before processing. It is also a key parameter of interest for harvest time field trials as it can directly influence the quality of the harvested crop as well as skew the results of in-field yield and quality assessments. Microwave sensing of moisture has several unique advantages over lower frequency sensing approaches. The first is that microwaves are insensitive to variations in conductivity, due to presence of salts or minerals. The second advantage is that microwaves can peer deep inside large bulk packaging to assess the internal moisture content without performing a destructive tear down of the package. To help facilitate the development of a microwave moisture sensor for seedcotton; research was performed to determine the basic microwave properties of seedcotton. The research was performed on 110 kg micro-modules, which are of direct interest to research teams for use in ongoing field-based research projects. It should also prove useful for the enhancement of existing and future yield monitor designs. Experimental data was gathered on the basic relations between microwave material properties and seedcotton over the range from 1.0 GHz to 2.5 GHz and is reported on herein. This research is part one of a two-part series that reports on the fundamental microwave properties of seedcotton as moisture and density vary naturally during the course of typical harvesting operations; part two will utilize this data to formulate a prediction algorithm to form the basis for a prototype microwave moisture sensor.

Influence of Seed Cotton Extractor Cleaners and Cleaning Rate on Gin Turnout and Fiber Quality

Abstract. Because electricity generation produces emissions, reducing cyclone pressure drop has the potential to benefit the environment. Enhanced 1D3D cyclones common in the cotton ginning industry were tested with various A©vasA©s, over a range of inlet velocities. With A©vasA©s it was possible to reduce the cyclone portion of energy consumption by 5%. It was possible to reduce the cyclone portion of energy consumption by 50% by reducing inlet velocity 28%. Particle size distribution analysis of cyclone emissions showed little change in PM 10 and PM 2.5 over this range of inlet velocities. If emissions at power generating facilities is balanced against emissions at rural agricultural processing facilities, then it is probable that increasing regulatory flexibility would benefit the environment more than more stringent regulations.