1 10 Time (h), log scale
E. RETURN ON INVESTMENT
The return on investment (R) for a single dryer system in terms of years required to pay back the initial capital investment involves all of the preceding determinations. The final equation to determinte the pay back years is then:
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C = Capital cost of investment
T = Dryer capacity of bone dry bagasse, tons per hour (2000 lbs/ton) E = Oil equivalence resulting from bagasse moisture reduction, gallons heavy oil
burned per ton of bone dry bagasse burned.
Co = Cost per gallon of heavy oil Cp = Total cost of electrical power per year H = Hours per year dryer system is in operation Cm = Cost per year of maintenance labor and materials
SAMPLE ANALYSIS OF DRYER PERFORMANCE
The performance of the dryer and the expected return on investment, as previously described is dependent on many factors. However, a sample analysis based on a set of given conditions is helpful to clarify the various relationships between these conditions.
The three matrix charts shown in Figure No. 3 are based on a set of fixed conditions, which approximate actual conditions for the sugar industry in the United States. The only variables allowed to change are the temperature of the stack gas ( T . ) , and the amount of moisture reduction in the bagasse (AM). The fixed conditions used in this analysis are as follows:
Dryer size = As shown in Figure No. 1 Dry capacity (T) = As shown in Figure No. 2 Ash content of bagasse (ASH) = 5 percent Cost of electrical power (e) = $0.03 per KWH Hours dryer operates (H) = 3600 hours per year Cost of labor (r) = $10.00 per man hour Cost of heavy fuel oil Co = $0.30 per gallon (USA)
CORRECTION: Page 153, ASSCT Proceedings of 1978 Meeting
Figure 3. Sample analysis of the effect varying stack gas temperature (T1) and moisture reduction (ΔM) has on dryer capacity (T), fuel oil equivalence (E), and return on investment (R).
CONCLUSIONS
The information presented in this report, and the sample analysis support numerous conclusions.
These conclusions are as follows:
1. The text of this report describes a systematic method for analyzing the economic justification of a rotary dryer system for dehydrating bagasse using boiler stack gas as the sole source of heat.
2. The sample analysis supports the following:
a. Depending on the amount of bagasse available and the local cost of fuel, power, and labor, a bagasse dehydrator may be a justifiable investment for stack gases in excess of 400 degrees F.
The greatest return on investment is obtained by drying less bagasse to lower moisture contents. For instance, bagasse dehydrated to 20% can be mixed with 50% bagasse and burned in the boilers. The blended mix will produce a greater return on investment than drying all of the bagasse to some intermediate moisture between 20% and 50%.
3. The sample analysis indicates clearly that the higher the stack gas temperature, the greater the return on investment for the dryer system. This same observation suggests that a by-pass ductt around existing air preheaters to increase the temperature of the stack gas fed into the dryer may produce greater fuel efficiency than the preheater.
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APPENDIX
GENERAL EQUATION FOR DETERMINATION OF BAGASSE HEAT OF COMBUSTION
The following derivation if used for the determination of the heat of combustion of bagasse as burned in the boiler at varying moisture and ash contents.
Let:
Heat of combustion of bone dry bagasse = 8350 BTU/1b M.C. = Moisture content of bagasse
Ash = Ash and non-combustible content Qi = Total heat of combustion of bagasse as burned
Qm = Heat of combustion required to evaporate bagasse moisture during combustion in boiler Q = Net heat of combustion available for steam production in boiler.
The net heat available (Q) is then equivalent to the total heat of combustion (Qi) less losses Qm:
Q = Qi - Qm
Then Qi = 8350 BTU/lb (1-M.C. - Ash)
Then Qm = M.C. x ΔH Change in enthalpy of saturated water liquid at Tp1 and superheated water vapor at Tp1 temperature.
Tp1 = Temperature of moisture in bagasse being fed into boiler T1 = Temperature of combustion gases and water vapor discharged
from boiler air preheater Qm = M.C. (H1 - Hp 1)
Common values of enthalpy for saturated liquid water are as follows:
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Common values of enthalpy for superheated water vapor at pressures assumed near atmospheric conditions are as follows:
Therefore, the net heat of combustion for bagasse of varying moisture and ash content, and based on the as burned (AB) weight of the bagasse is then:
Where: M.C. = Moisture content of bagasse being burned, Percent % 100.
Ash = Ash and non-combustibles, percent % 100.
Hp1 = Enthalpy of saturated liquid water at temperature Tp1
H1 = Enthalpy of superheated water vapor at temperature T1.
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The net heat of combustion for bagasse of varying moisture and ash content, and based on the bone dry (BD) weight of the bagasse is then:
BIOMASS AND SUCROSE PRODUCTION IN SUGAR CANE:
I. DIVERGENT SELECTION STRATEGIES R. D. Breaux and B. L. Legendre U. S. Sugar Cane Field Laboratory, USDA
Science and Education Administration Houma, Louisiana
(In cooperation with the Louisiana Agricultural Experiment Station)
The yield components desirable in a sugar cane variety to be used for biomass production differ from those in a variety for sugar production; total solids (fiber + Brix) percent cane and total solids per hectare replace sugar per tonne and sugar per hectare. All these yield components were measured in 30 clones each of an F1, B C1, B C2 and two B C3 progenies of S.
spontaneum US 56-158 bred to commercial-type sugar canes.
The highest mean yield of total solids per hectare occurred in the F1 progeny, but the highest mean yield of sugar per hectare occurred in the B C3 progenies. Backcrosslng to com- mercial varieties resulted in a sharp reduction in yield of tonnes of cane per hectare in the BC1 progeny and a more gradual reduction in total solids percent cane. The yield of sugar per hectare increased with the backcross generation, because the increase in sugar per tonne of cane more than compensated for the loss of cane tonnage. The data show that, if selection pressure for sugar per tonne of cane were removed, it would be possible to select varieties that yield much more biomass than varieties grown commercially for sugar production.
OVERWINTERING SUGAR CANE BORER POPULATIONS IN TEXAS, 1977-1978 T. W. Fuchs
Texas Agricultural Experiment Station Weslaco, Texas
Populations of the sugar cane borer, Diatraea saccharalis, were unusually high in the Rio Grande Valley of Texas during 1977. This was presumably due to the carryover of approximately 8,000 acres of unharvested sugar cane from the previous season, plus the reduced amounts of insecticide used by producers on the low-priced sugar cane. Ten harvested sugar cane fields chosen at random were sampled to estimate the number of overwintering sugar cane borer larvae remaining in fields after the 1977-78 harvest. The data indicated an average of 356 larvae per acre. One-third (33.3 percent) of the larvae were found in stubbles and two-thirds (66.7 percent) in trash left by harvesters. Data from studies designed to determine the percent mortality of sugar cane borers overwintering in cane stubbles indicated that no significant mortality occurred during the winter of 1977-1978.
POTENTIAL CYTOGENETIC APPROACH IN SUGAR CANE BREEDING Blkram S. Gill
University of Florida Agricultural Research and Education Center
Belle Glade, Florida
Two concepts have recently emerged from the cytogenetic analysis of genome in polyploid plant species. First, the diploid-like chromosome pairing in a polyploid is controlled by a single major gene. In the absence of this gene, multivalent formation occurs during metaphase I of meiosis. Secondly, in hybrids involving a polyploid plant (which is missing the chromo- some pairing gene) with related genera, intergenomic chromosome pairing also occurs. In wheat, a mutation (possibly a deletion) of the chromosome-pairing gene has been used to transfer genes from genera as far removed as Agropyron and rye. There is an urgent need for basic cytogenetic research in sugar cane to elucidate the genetic control of chromosome pairing and explicate its use in intergeneric gene transfers. Some other recent advances in chromosome cytology also need to be explored for possible application in sugar cane breeding.
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SCREENING FOR RESISTANCE TO RATOON STUNTING DISEASE-INJURY;
THE ENZYME-LINKED IMMUNOSORBENT ASSAY A. G. Gillaspie, Jr., and R. W. Harris USDA, Science and Education Administration
Beltsville, Agricultural Research Center Beltsville, Maryland
The microplate method of enzyme-linked immunosorbent assay (ELISA) will differentiate in greenhouse and laboratory tests, between clones that are susceptible or resistant to ratoon stunting disease (RSD) injury. The ELISA method could be useful for a large-scale screening program if it works as well in field tests as it does in the laboratory tests. Wells of a polystyrene microplate are coated with a gamma globulin preparation containing antibodies to the RSD-associated bacterium. Juice samples are then placed in the wells and are incubated for three hours at 37° C. During incubation, the RSD bacteria become attached to the well surface. After the wells are washed, the anti-RSD gamma globulin, coupled with an enzyme, such as alkaline phosphatase is placed in the wells, the plates are incubated at room temperature for one hour at 37° C. so that the enzyme-antibody complex attaches to the bacteria. Following a thorough rinse with physiological saline containing 0.1 percent Tween 20, the substrate for the enzyme is placed in the wells, the plates are incubated at room temperature for one hour, and the color formation is stopped with 3M sodium hydroxide. The intensity of the color development in the ELISA test is directly related to the number of bacteria present in a sample. Susceptible clones have been reported to contain a higher number of diagnostic bacteria than resistant clones and this makes possible the use of ELISA as a screening technique. The ELISA test will detect the RSD-associated bacterium down to a concentration of about 4 x 106 bacteria per milliliter or about 3 bacteria/phase contrast microscope field.
CLOSE ROW-SPACING AND SUGAR CANE YIELD J. E. Irvine and R. J. Matherne U. S. Sugar Cane Field Laboratory, USDA
Science and Education Administration Houma, Louisiana
(In cooperation with the Louisiana Agricultural Experiment Station)
Field plots with inter-row spacings of 61 centimeters, 91 centimeters and 183 centimeters with a single drill, and 183 centimeters with a double drill were sub-plots of a split-plot design; the main effects varied in the manner of N fertilizer application, either as a solid or in aqueous solution. The sugar cane variety CP 65-357 was planted in the fall of 1976 on level land at Houma, Louisiana. Monthly observations began in May, 1977, and included population counts, height measurements, leaf determinations, yield estimations and determinations of tissue nutrient levels. No significant differences were observed in response to spacing, and these included differ- ences in plant population, leaf area index, yield of biomass, and net cane and sugar per hectare.
Stalk populations were highest in June and declined until harvest in December; June populations for the 61-centimeter spacing peaked at 180,000 stalks per hectare, compared to 92,000 for the standard 183-centimeter spacing. Leaf area reached a maximum in September, when the ratio of leaf to land area for the 61-centimeter and the 183-centimeter single-drill spacings were 5.66 and 2.76, respectively. Yields increased steadily until the mid-December harvest, when sugar yields for 6 1 - centimeter, 91-centimeter and 183-centimeter double-drill, and 183-centimeter single-drill spacings averaged 18.0, 13.3, 11.9 and 10.9 tonnes per hectare, respectively.
NARROW-ROW SPACING OF SWEET SORGHUM IN OHIO W. T. Lawhoh and Stephen Kresovich Battelle-Columbus Laboratories, Columbus, Ohio
Since the mid-19th Century, the sweet sorghums have periodically attracted the interest of farmers and sugar producers in the United States because of the sucrose content in their stalks.
Preliminary results now indicate that sweet sorghums may show a great potential for a source of energy, particularly in the Midwest U. S.
A demonstration was performed at Columbus, Ohio, in the summer of 1977, the general results of which indicate that sweet sorghum can be grown in the Midwest with yields comparable to the rest of the sweet sorghum production regions. At the 0.5-meter row spacing, the Sart variety
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yielded 25.6 dry tonnes per hectare, Ramada yielded 18.1 dry tonnes per hectare, Rio yielded 15.4 dry tonnes per hectare and MN 1200 yielded 9.4 dry tonnes per hectare, based on projections from
"wheel"-type planting arrangements.
The juice qualities of these varieties were low, because the planting operations were late and the crop never completely matured. However, two variables, the narrow-row spacing and early maturing varieties of sweet sorghum, offer a possibility for an energy crop for the Midwest U. S.
BIOMASS AND SUCROSE PRODUCTION IN SUGAR CANE:
II. ASSOCIATION WITH YIELD COMPONENTS B. L. Legendre and R. D. Breaux U. S. Sugar Cane Field Laboratory, USDA
Science and Education Administration Houma, Louisiana
(In cooperation with the Louisiana Agricultural Experiment Station)
The relationship between yield components and biomass and sucrose production were studied in 30 clones of an F1, BC1, BC2 and two B C3 progenies of S. spontaneum US 56-158 bred to commercial types of sugar cane. Both total solids (a biomass component) and sugar per hectare were highly associated with tonnes of cane per hectare for all progeny generations. Sugar per hectare was positively associated with sugar per tonne of cane. Total solids were negatively associated with sugar per tonne when all generations were combined; however, there was no association of total solids with sugar per tonne of cane within generations. Total solids were associated with fiber percent cane, but, within a progeny generation, sugar per hectare was not. In all generations, total solids were associated with sugar per hectare and both were associated with tonnes of cane per hectare. Despite these associations, the opposite effects that selection for sugar per tonne of cane has on biomass and sugar production require separate breeding programs.
FUELS FROM SUGAR CROPS: STATUS AND PROSPECTS E. S. Lipinsky
Battelle-Columbus Laboratories Columbus, Ohio
The development of liquid transportation fuels from sugar crop biomass at costs that are attractive in the marketplace is a formidable task. An integrated Department of Energy program which started in 1975 is making progress in reducing raw material costs through narrow-row spacing of sugar cane and sweet sorghum, the use of Tilby cane separator, new methods of cellulose hydrol- ysis and improvements in fermentation processes. This paper presents an overview of new agricult- ural and processing technologies that relate to liquid fuel production. Potential impacts on sugar crop growers, processors and fuel consumers are discussed.
BREEDING FOR AND SELECTING SUGAR CANE GENOTYPES THAT RESPOND TO "RIPENERS"
F. A. Martin
Louisiana Agricultural Experiment Station Louisiana State Uiversity
Baton Rouge, Louisiana
For two consecutive years, 24 experimental sugar cane varieties were tested for response to the chemical ripener glyphosine. Six weeks after treatment, the effects of glyphosine on stalk weight, sugar per tonne and sugar per acre were determined. The genotypic variation of response was observed for the three yield components. Of particular interest was the range of the effect on stalk weight (from positive to negative) that was apparently associated with genotypic variation. The fact that crosses which yield high frequencies of positively responding progeny can be identified should make breeding and selection for response to chemical ripeners feasible.
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THE POTENTIAL OF THE SACCHARUM COMPLEX FOR THE PRODUCTION OF FIBER F. A. Martin and M. J. Giamalva Louisiana Agricultural Experiment Station
Baton Rouge, Louisiana
The possibility of using plants within the Saccharum complex for the production of fiber is explored. It is proposed that production of 100 tonnes of 35 percent fiber cane is techno- logically attainable. Production of this wilder-type cane may be less complicated than the production of domestic sugar cane. The monthly variations in available yield in relation to possible uses is also discussed.
RELATION OF POLLEN AND PISTIL CHARACTERISTICS IN SETTING OF TRUE SEED IN SUGAR CANE CROSSES
S. Nagatomi
Tanegashima Branch, Kyushu Agricultural Experiment Station M.A.F. Nishinoomote, Kagoshima, Japan, and
P. H. Dunckelman U. S. Sugar Cane Field Laboratory, USDA Science and Education Administration, Houma, Louisiana (In cooperation with the Louisiana Agricultural Experiment Station)
A study of the association between seed set in sugar cane crosses and the condition of the floral organs was made in Houma, Louisiana. A positive correlation was found between breeding generations and the size and variability of pollen grains. The more highly nobilized the gener- ation, the larger and more variable were the pollen grains. Seed set increased exponentially with pollen maturity and was closely associated with anther dehiscense and shedding of pollen in the male parent. Better seed set can be expected in interspecific crosses when 60 percent or more of the pollen grains of male parents are mature, and the stigmas of the female parents are fully extended beyond the glumes. Seed set in intergeneric crosses was apparently influenced by sexual incompatibility rather than by pollen maturity or stigma extension. Specific techniques for making intergeneric crosses are suggested.
WINTER AND SPRING PHOTOPERIODIC INDUCTION FOR SYNCRONIZING FLOWERING IN SUGAR CANE
Ellas D. Paliatseas Department of Plant Pathology Louisiana Agricultural Experiment Station
Louisiana State University Baton Rouge, Louisiana
Thirty-two varieties of sugar cane were grown in the greenhouse in the fall of 1977. Two to ten stalks from each of these, depending on the availability of mature shoots were marcotted from October 1 5 , 1977, through January 1 5 , 1978. When the roots had developed, the stalks were cut and transplanted into 10-gallon galvanized cans filled with a mixture of soil, peat moss and sand (3:2:1). Then, the 32 varieties were divided in three groups. The first group consisted of 10 varieties which were transferred into the plastic greenhouse and placed under inductive photoperiod treatment on November 2 0 , 1977. The second group of 10 varieties was placed under photoperiod treat- ment on January 1 0 , 1978. The third group was placed under photoperiod treatments on February 1 0 , 1978. The length of the inductive photoperiod treatments given to the three groups of varieties through April 8, 1978, was 139, 88 and 57 days, respectively. From April 9 through mid-summer 1978, the three groups of varieties will be given the same inductive photoperiod treatment.
Signs of flowering were visible on March 3 0 , 1978, in five varieties belonging to the first group. These varieties will probably flower in June, 1978. Other varieties from the first group and from the second and third group will probably flower in the middle and late summer. This will enable the crossing of these varieties with some early and mid-summer flowering cold-resistant Saccharum spontaneum L. clones, especially US 60-46 and US 61-21. This will probably result in the transmission of some cold resistance into the commercial sugar cane varieties.
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KNOWN DISTRIBUTION OF THE IMPORTED FIRE ANT SOLENPSIS INVICTIA BUREN IN FLORIDA SUGAR CANE FIELDS:
BENEFIT OR PROBLEM FOR THE FUTURE Jerry Prewitt
United States Sugar Corporation, Clewiston, Florida Ralph Brown
Florida Department of Agriculture Division of Plant Industry, Gainesville, Florida
T. L. Carpenter
South Bay Growers, Inc., South Bay, Florida G. B. Powell
Gulf + Western Food Products Co., South Bay, Florida, and T. E. Summers
USDA, Science and Education Administration Canal Point, Florida
Solenopsis invicta Buren was found to have penetrated the interior of sugar cane fields during 1977. Mounds along edges of fields had been observed in 1976, but were not reported.
The limits of observed infestations and the possible benefits of the fire ants as predators of the sugar cane borer and their effect as destructors of beneficial insect populations in sugar cane fields are discussed. The problems encountered by field personnel are reported.
NARROW ROW SPACINGS OF SWEET SORGHUM IN TEXAS Sim A. Reeves, Jr.
Texas Agricultural Experiment Station Weslaco, Texas
B. A. Smith
USDA, Science and Education Administration Food Crops Laboratory
Weslaco, Texas and B. W. Hipp Texas Agricultural Experiment Station
Dallas, Texas
Among crop plants of adaptation in the Lower Rio Grande Valley of Texas, sweet sorghum is a possible source of biomass with feasibility for fermentation into ethyl alcohol, a primary, alternate source of energy. The sucrose variety Rio and the syrup variety Sart were selected for this study and planted into 40 and 27-inch rows. Due to insect damage, Sart was discarded in the middle of the season and the strain MN 1500 which was growing on 27-inch rows, was substituted.
The Rio variety grown on 27-inch rows produced 52 percent more dry biomass than Rio grown on AO-inch rows. The total dry weight production of MN 1500, with a yield of 17.53 tonnes, was superior to Rio, with 8.69 tonnes per acre. The total sugars produced were higher in MN 1500, compared to Rio, and MN 1500 produced the greatest amount of dry fiber, with 8.90 tonnes, compared to 3.72 tonnes per acre for Rio.
METHODS OF PLANTING SUGAR CANE IN LOUISIANA R. Ricaud, B. J. Cochran and G. W. Newton Agronomy and Agricultural Engineering Departments
Louisiana Agricultural Experiment Station Baton Rouge, Louisiana
An experiment was conducted to determine the effects of type and width of planting furrows on the growth characteristics, yield and harvestability of sugar cane. The types of furrows were single and multiple drills on standard rows six feet wide. The multiple drills were planted with one line of seed cane in each drill spaced 12 inches apart. The total widths of the single and multiple drills were 12, 24, 36 and 48 inches. For each width, the same amount of seed was planted in both types of furrow. A standard V-furrow with one drill was used as a check. The plant population with each method of planting increased to a maximum in July and decreased thereafter until October. At harvest time the 36-inch width produced the highest stalk population, and plant height increased with increasing widths of planting. Stalk diameter was smaller with the V-furrow and 24-inch width than with the wider plantings. The methods of planting did not affect percent sucrose. The 36-inch width of planting produced the highest total biomass yield and sugar yield per hectare. The single and multiple drills produced similar results for each width of planting.
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