Filtration-Extraction Process. Cost Analysis Application - Industrial

Cost Analysis Application. K. M. Decossas, H. G. Many, O. J. McMillan, E. A. Gastrock, E. F. Pollard. Ind. Eng. Chem. , 1957, 49 (6), pp 930–935. DO...
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K. M. DECOSSAS, H. %. MANY, 0. J. McMILLAN, Jr., E. A. GASTROCK, a d E.

F. POLLARD

Southern Regional Research Laboratory, New Orleans, La.

Filtration-Extraction Process Cost Analysis Application

IN

THE COTTONSEED processing industry, historically a hydraulic press industry, the trend for decade or more has been toward more efficient oil extraction methodssolvent and screw presswhich by the 1952-53 season accounted for more than half of the cottonseed processed. Although the development of smallscale solvent-extraction plants for cottonseed and other oilseeds has received considerable attention, and extraction units of 25-ton capacity have been demonstrated and offered to the industry, the small mill has gradually disappeared because of economic and technological reasons. These include the ability of the large operator to provide large storage capacity, finance long-term operation, and purchase the bulk of the premium quality seed. Attention in this laboratory was focused on developing operating procedures and processing methods which would enable existing small mills to succeed in the highly competitive cottonseed-processing industry. The filtration-extraction process, a variation of the direct solvent process, was designed primarily to provide the smaller cottonseed crusher with a more efficient and practicable processing method, resulting in lower operating costs and increased yields while producing high quality oil and meal (3, 6, 7-77).

The Filtration-Extraction Process

This new simplified, versatile method of direct solvent extraction derives its name from separation of the oil in hexane solution (miscella) from extracted meal (marc) and countercurrent washing with hexane, both of which are carried out on a continuous, horizontal, rotary, vacuum filter. The process, built around the unit operation of filtration, first prepares the material by flaking (except for materials such as rice bran), cooking, and crisping; brings the oil into almost complete solution in a mixing vessel during a short soaking period; and then uses the continuous filter to separate the oil from the meal by filtration and countercurrent washing. Oil and meal

930

products are recovered by conventional methods. A continuous solvent-extraction plant includes solvent extraction, marc desolventization, and oil- and solvent-recovery facilities. Flakes do not require careful preparation as in other direct solvent-extraction processes or such extensive equipment as the presses used in solvent extraction with prepressing. The fines problem is minimized, a more concentrated miscella is obtained requiring smaller distillation equipment, and the solvent content of the extracted marc is lower. Residual lipides in the meal are 1yo or less as compared to current values of 4.0 to 5.0ye for hydraulic pressing and 2.8 to 4.0y0 for screw pressing; the free gossypol content can be as low as 0.03% and nitrogen solubility as high as 65 to 70Ye. The oil produced is high quality, comparable to the best produced by any commercial process. In many cases, the operating season can be extended only by processing more than one material. The filtration-extraction process fits well into this concept because the process is suitable for the efficient solvent extraction of a variety of oleaginous materials of high, medium, and low oil content with widely different physical characteristics. Commercialization

Commercial acceptance of the filtration-extraction process has progressed rapidly since its initial commercialization in February 1954. The Mississippi Cottonseed Products Co. successfully completed 2 years of operation in Greenwood, Miss., having processed approximately 50,000 tons of cottonseed and soybeans annually ( 6 ) . Operating profits have increased more than $750 per day over previous hydraulic pressing (7). That company is now installing a second filtration-extraction plant a t Hollandale, Miss., which will have a capacity of 140 to 200 tons per day for cottonseed and 80 to 130 tons per day for soybeans. Operation of the new plant is expected by the end of 1957. Another plant using the filtrationextraction process is now being installed

INDUSTRIAL AND ENGINEERING CHEMISTRY

in Santiago, Chile, by LaCia, Productora Nacional De Aceites, for processing rice bran and sunflower seed. Interest in the new process has been widespread and indicates its further acceptance costs

A preliminary cost study of the filtration-extraction of Cottonseed, prepared by Persell and others (72), included only investment costs because at that time detailed data were not available for estimating operating costs. This article includes an engineering cost analysis of the filtration-extraction process for cottonseed with emphasis on the effect of size and the feasibility of the process for small mills, and is concerned w-ith the immediate problem of enabling existing small mills to succeed. The construction costs, operating expenses, and profitability of hypothetical filtration-extraction mills, and costs for conversion from hydraulic and screw pressing to filtration-extraction in the North Delta (Arkansas) area are given for the 1954-55 season. Costs for hydraulic pressing, screw pressing, prepress, and direct solvent extraction ( 2 ) were adjusted to 1954-55 equipment- and building-cost levels, and were used wherever applicable in deriving filtration-extraction costs and for comparative purposes. Filtration-Extraction Investment and Operating Costs. Total investment costs prepared for hypothetical filtrationextraction cottonseed oil mills having daily capacities of 80, 160, and 240 tons. and operating for various lengths of season are given in Table I. Investment costs for equipment in the oilextraction department and to a lesser extent in the mechanical pretreatment department, were compiled from costs furnished by equipment manufacturers and contractors. The oil-extraction department investment costs include, as did Brewster’s costs, solvent extraction, oil- and meal-desolventizing, and accessory equipment; insulation for equipment; concrete foundations and paved area around the equipment; electric

Table

1.

Plant No. Daily crush, tons cottonseed Length of operating season, months Annual crush, tons cottonseed

Filtration-Extraction Mills [Area II,

North Delta, Arkansas), 1 954-55 Season 2 160 tons

1 80 tons 6

7.5

10,600

13,200

6 21,100

12 21,100

7.5 26,400

3 240 tons 12 42,200

5

8

26,400

42,200

10 52,800

12 63,400

INVESTMENT COSTS

Departments Dollars Mechanical Pretreatment 213,018 213,018 213,018 340,334 340,334 340,334 477,834 477,834 Installed equipment 477,834 477,834 Building 39,397 39,397 39,397 56,346 56,346 56,346 78,755 78,755 78,755 78,755 Baling press Installed equipment 17,414 17,414 17,414 18,157 18,157 18,157 29,721 29,721 29,721 29,721 Building 7,956 7,956 7,956 7,956 7,956 7,956 9,523 9,523 9,523 9,523 Oil extraction Installed equipment 214,606 214,606 214,606 280,960 280,960 280,960 310,489 310,489 310,489 310,489 Building Unhoused Unhoused Unhoused Unhoused Unhoused Unhoused Unhoused Unhoused Unhoused Unhoused Cracked cake or meal bins Installed equipment 20,416 20,416 20,416 29,642 29,642 29,641 38,867 38,867 38,867 38,867 Building 5,375 5,375 5,375 7,447 7,447 7,447 9,532 9,532 9,532 9,532 Cake processing 46,160 46,160 46,160 46,160 46,160 Installed equipment 46,160 46,160 46,160 46,160 46,160 Building 13,764 13,764 13,764 13,764 13,764 13,764 Id, 764 13,764 13,764 13,764 137,640 157,869 263,595 209,148 267,711 Storage 455,341 211,698 388,621 515,930 634,684 219,405 219,405 221,278 283,473 283,473 283.473 290,146 306,432 306,432 306,432 Services Subtotal 935,151 955,380 1,062,979 1,293,387 1,351,950 1,539,579 1,516,489 1,709,698 1,837,007 1,955,661 Land 3,145 3,365 3,586 4,083. 4,083 5,200 4,579 5,266 6,780 6,780 Total 938,296 958,745 1,066,565 1,297,470 1,356,033 1,544,779 1,521,068 1,714,964 1,843,787 1,962,441 Dollaxs per ton cottonseed crushed annually 88.52 72.63 50.55 61.49 51.36 36.61 57.62 40.64 34.92 30.95

--

OPERATING COSTS

Depreciation Interest and Taxes [4% 15% (0.048)1 Insurance Total

+

On above costs (subtotal) Seed procurement Seed cost (FOB gins) Seed buyer and hauls Labor Seed unloading, meal grinding, product loading Production Dormant Miscellaneous Administration Services and Protection Subtotal Total

Dollars per Year 49,496 54,426

56,120

61,805

65,191

68,190

64,005 7,184 120,685

71,341 6,441 133,902

80,946 8,377 151,128

87,027 9,569 161,787

92,627 9,384 170,201

34,715

35,172

38,103

47,955

44,288 4,299 83,302

45,253 4,462 84,887

50,342 5,256 93.701

61,241 6,599 115,834

7.858

6.430

4.440

5.490

65.247 1.790

65.247 1.810

65.247 1.920

65.247 1.920

65.247 1.990

0.415 2.610 0.870

0.410 2.610 0.522

0.402 2.610 0

5.694 2.797 1.233

5.730 2.719 1.267

5.817 2.492

0.402 1 .a70 0.623 5.642 2.492

1.319

1.150

80.656 88.514

80.315 86.745

79.807 84.247

79.346 84.a36

--

--

power supply, motors, controls, and wiring; lighting for the extraction area; small building near the extraction department to house electric controls and instruments and to provide shelter for the operators; conveyors supplying flakes to the extractor and returning extracted meal to the meal bins; trestlesupporting conveyors and piping between the preparation departments and the extraction departments; refrigeration system to supply chilled water to the condenser into which run the vent lines for solvent vapor; meal coolers; solvent storage tank; solvent-unloading

72,913 8,138 135,477

-Dollars per Ton 4.571 3.210

P

-

~

5.072

3.581

3.064

2.684

65.247 2.400

65.247 1.990

65.247 2.400

65.247 2.500

65.247 2.620

0.400 1.870 0.374 5.667 2.351

0.396 1.870 0

0.396 1.627 0.271

0.395 1.627 0.244

5.657 1.984

5.694 1.781

0.394 1.627 0 5.740 1.615

1.180

1.230

0.400 1.627 0.759 5.601 2.351 I . 122 ___.

79.079 83.650

78.881 82.091

79.097 84.169

-

5.754 1.984

pump and piping; utility piping and equipment to the department which are included in service piping; instruments and flame arrestors; fence enclosing the extraction department and solvent-storage tanks; and railroad siding to spot solvent cars for unloading. Figures 1 and 2 show that investment costs for the hypothetical filtrationextraction mills are less than those for comparable mills of the direct-solvent or prepress solvent types, and even less than those for screw press mills a t 240tons-per-day capacity. Like other solvent types, investment costs for filtration-

1.169 1.194 78.751 82.332

78.682 81.746

1.199 78.442 _ _ 81.126

extraction mills are substantially higher than similar ones of the hydraulic design. Total investment costs for filtration-extraction mills of 80, 160, and 240 tons, operating for a 12-month season were calculated to be $1,066,565, $1,544,769, and $1,962,441, respectively. Total investment costs for comparable prepress-solvent mills for a 12-month season were 80-ton prepress solvent, $1,094,312 or 2.6% more; 160-ton prepress solvent, $1,624,005 or 5.1% more; and 240-ton prepress solvent, $2,148,102 or 9.5% more. Total calculated operating costs for VOL. 49, NO. 6

JUNE 1957

931

Table II.

Total Operating Costs

Dollars per Ton Annual Crush, Tons

Daily Crush,

13,200

10,600

Tons

filtration-extraction plants include costs for depreciation, interest and taxes, insurance, cost of seed, manufacturing expenses, general and administrative expenses, and other relevant charges. A comparison between total calculated operating costs for mills of various types is given in Table 11. Plant investment cost rates used by Brewster (2) were applied in this analysis. Depreciation was computed at the rate of 2.5% for building, 47, for machinery, 10% for furniture, and 16.7% for trucks, Interest was charged at the rate of 470 on the entire initial investment for each mill, and property taxes were computed on a n assessment ratio (legal assessment as percentage of full value) of 15% and a tax rate of $4.80 per $100 assessed value, Insurance includes fire and extended coverage. Seed-buying cost of 40 cents per ton was allowed. In determining haul charges, average haul distances associated with specified annual crushes and Arkansas motor carrier schedules were employed. Filtration-extraction labor costs for seed unloading, meal grinding, and product loading were the same as that Brewster calculated for solvent extraction (2) using such man-hour requirements as: 0.128 man-hour per ton of seed unloaded; 0.51 man-hour per ton of meal ground; and 0.5 man-hour per ton of product loaded. Based on information from the industry, costs for filtration-extraction production labor were computed using production labor requirements (Table 111) and an hourly wage rate of 87 cents

26,400

21,100

~~~

52,800

._63,400

81.901 81.982 82.052

81.304

81.439 81.877

81.224

82.245

81.466

42,200

Hydraulic 4 Press 6 Press 8 Press 10 Press 12 Press 16 Press 20 Press 22 Press 24 Press

40 60 80 100 120 460 200 220 240

88.157 87.924 88.043

86.645 86.395

84.102 84.554 84.446

83.294 83.658 82.267 82.828 82.614

Screw Press 2 Press 3 Press 4 Press 5 Press 7 Press 8 Press

50 75 100 125 175 200 250

87.449 87.415

85.851 85.930 86.286

84.045 84.088

82.926 83.282 82.084 82.199

10 Press

Prepress Solvent 40 80 160 240

Plant 1 Plant 2 Plant 3 Plant 4

90.178 89.438

50 100 200

Plant 1 Plant 2 Plant 3

89.440 89.959

80 160 240

Plant 1 Plant 2 Plant 3

88.514

87.546

84.874 85.342

84.127

82.511

Direct Solvent 87.514 87.721

85.098

83.790 84.303

82.705

81.859

82.091 82.332

81.746

Filtration-Extraction 86.745

84.247 84.836

83.650 84.169

81.126

'.f 80

LEGEND:

FILTRATION E X TRACTION --- PREPRESS SOLVENT EXTRACTION

-.-

..-.. 0 Q

DIRECT SOLVENT EXTRACT ION SCREW PRESSING HYDRAULIC PRESSING HYDRAULIC PRESSING PREPRESS SOLVENT EXTRACTION

30-

L

I

IQOOO

I

15,000

I

20,000

I

25,000

I

30,000

I

I

ANNUAL CRUSH (TONS)

932

INDUSTRIAL AND ENGINEERING CHEMISTRY

I

35,000 40,000 45,000

I

I

50,000 55,000

I

60,QOO

Figure 1. Hypothetical cottonseed oil mills-total investment costs (dollars per ton of cottonseed crushed annually)

F I L T R A T I O N - E X T R A C T I O N PROCESS paid by solvent mills in the North Delta area. (On March 1, 1956, minimum wage was increased to $1.00 per hour.) Production labor is defined as all manhours, except meal-grinding and sacking labor, which are required in handling seed from storage up to and including the placement of products directly from the production line into truck or car for delivery purposes or in storage for later shipment.

Table IV. Crush,

Tons

52,800

42,200

63,400

40 60 80 100 120 160 200 220 240

4 Press 6 Press 8 Press 10 Press 12 Press 16 Press 20 Press 22 Press 24 Press

82.79 82.42 83.04

50 75 100 125 175 200 250

2 Press 3 Press 4 Press 5 Press 7 Press 8 Press 10 Press

84.65 85.08

82.49 82.56

82.79 82.45 82.42

82.79 82.49 82.79 82.41 82.54

82.79 82.59 82.49

82.78

85.01 84.61 85.23

84.65 84.75

85.01 84.65

84.90

86.83

87.12

85.01 84.65 84.82 84.65

40 80 160 240

Plant Plant Plant Plant

1 2 3 4

87.13 87.27

50 100 200

Plant 1 Plant 2 Plant 3

86.22 86.73

80 160 240

Plant 1 Plant 2 Plant 3

87.17

86.78

87.13 87.27

86.82

87.13

86.57 86.73

86.22

86.57 86.73

86.22

86.57

87.03 86.59

86.73

Filtration-Extraction 86.72

87.03 87.17

. -. -.- -

‘1

a.

87.03

FILTRATION EXTRACTION .-DIRECT SOLVENT EXTRACTION SOLVENT EXTRACTION - PREPRESS

\\\\

7-

86.72 87.17

LEGENO:

\

8-

0

0

26,400

Direct Solvent

W

0

21,100

Prepress Solvent

z

a

13,200

Screw Press

Dormant labor for fdtration-extraction mills operating 5 and 8 months was estimated a t 33l/& of the productionlabor requirement. For 10 months’ operation 75% of the production-labor requirement was used. Dormant labor costs were calculated by applying these percentages to a ratio of dormant to operating time. This expense can be omitted by the processor who will extract additional oleaginous materials during a season. Fuel, solvent, and water expenses were estimated from those previously calculated for prepress and direct solvent plants considering the differences in solvent-meats ratios and desolventization requirements. Fuel costs are

0

10,600

Hydraulic

3.00 2.15 1.87

e 2a

1954-55 Processing Year

Dollars per Ton Annual Crush, Tons

Daily

Table 111. Estimated Production Labor Requirements for Filtration-Extraction Mills Daily Crushing Capacity, Tons Man-Hours/Ton 80 160 240

Cottonseed Products Value, North Delta Area,

SCREW PRESSING HYORAULIC PRE5SlNG

\\

\

6-1 \

iB

\

5-

Figure 2. Hypothetical cottonseed oil mills-mechanical pretreatment and oil-extraction departments’ investment costs (dollars per daily ton)

4-

4;

,

20

I

I

80

100

I

I

I

120 140 I60 TONS PER DAY

I

I

I

180

200

220

VOL. 49, NO. 6

JUNE 1957

2

933

+6 +5-

t4 -

-x

,240 I ’

I

K

L

0-

63800

I100

TONS

42200

-LEGEND FILTRATION EXTRACTION HYDRAULIC PRESSING SCREW PRESSING

-- PREPRESS SOLVENT EXTRACTION -DIRECT SOLVENT EXTRACTION HYDRAULIC PRESSING I

-4

-

0 0 0

SCREW PRESSING PREPRESS SOLVENT EXTRACTION

ANNUAL CRUSH (TONS)

Figure 3.

Profitability of hypothetical cottonseed oil mills

for fuel oil needed in generating steam for cooking cottonseed meats and desolventizing oil and meal. Otherwise, the mills are electrically powered. Electric power requirements for filtration-extraction were the same as for direct solvent extraction. The cost of electric power per ton of cottonseed crushed increases for a given size plant with the length of the crushing season, because greater cottonseed-storage ventilation is required over a long period of time. Social security costs were computed on the employer’s payments of 2% of payroll including dormant labor. Product Value, The total values of products (oil, meal, hulls, and linters) for the various mills were calculated from yields and prices in effect during the 1954-55 season. Product prices used for 12 months’ operation are 13 cents per pound for oil, regardless of process; $66.84 per ton for solvent extracted meal; $68.80 per ton for hydraulic- and screw-press meals; 3.87

Table V.

Daily Crush, Tons

cents per pound for linters; and $314.29 per ton for hulls. For operating seasons of less than 12 months’ duration, cumulative weighted product prices were used for oil, meal, and hulls, reflecting seasonal fluctuations. Calculated product values are given in Table IV. Premium paid for filtration-extracted oil, a high quality oil, were not estimated because there is no way by calculation alone that the advantages of one process over another for oil quality may be determined accurately. However, Eaves and associates of this laboratory (4) indicate that there is a definite increase in the value of the total oil produced from cottonseed by the filtration-extraction process as compared with direct extraction of raw or tempered flakes. A filtration-extraction plant owner can blend subquality oil with filtrationextracted oil and still command premium prices. The quality of cottonseed oil and meal products from the filtrationextraction process shows to advantage

when compared with products of other processes on an over-all basis, considering refining loss of oil, gossypol in oil, residual oil in meal, free gossypol in meal, and alkali solubility of meal. If the premiums paid for higher quality products could be evaluated dollarwise in comparison with the other processes, the filtration-extraction process would be even more favorable than in this study. Profitability. Gross profits calculated for the various mills (Figure 3 ) , show that filtration-extraction profits are greater than those of similar sized mills of all other types. Profitability is based on the spread between the sum of the purchase price of seed plus processing costs, and the vaIue of products. Calculated gross profits for hypothetical filtration-extraction mills with capacities of 80, 160, and 240 tons were $2.78, $4.94, and $5.90 per ton of seed, respectively, for a 12-month operating season. Over the 6- to 12-month operating season, increased profits of at least 40 cents per ton of cottonseed were calculated for filtration-extraction mills of 80,160, and 240 tons as compared with the prepress design. Over a 5- to 12month operating season, increased profits of about 55 cents per ton of cottonseed were calculated for 240-ton hypothetical filtration-extraction mills as compared with 200-ton direct-solvent extraction mills. In all cases, increased profits for filtration-extraction of at least $1.40 and $3.45 per ton of cottonseed were calculated for similar screwpress and hydraulic mills, respectively. However, screw presses have practically disappeared in soybean processing, because the spread between the sum of the purchase price of beans plus processing costs and the value of products has made screw pressing unattractive. Losses, calculated for some of the smaller processing mills in the 1954-55 season, can be attributed to the prices of cottonseed and cottonseed products

Costs for Conversion to Filtration-Extraction and Increased Profits, North Delta Area, 1954-55 Season FjltrationExtraction Equip. Conversion ___ Increased Gross Profits (Dollars/Year above Dollars/Ton) Capacity, costa, Annual Crush, Tons Cottonseed Tons Dollars 10,600 13.200 21,100 42.200 52,800 63,400 Hydraulic

80

8 Press

80

262,926

160

16 Press

160

326,076

240

24 Press

240

367,877

28,000 2.64

39,500 2.99

77,400 3.67 167,000 3.95 213,300 4.04

239,018 3.77

94,500 1.79

119,800 1.89

Screw Press

a

75 175

3 Press

7 Press

80 240

262,926 363,900

250

10 Press

240

367,877

-0.20

Crushing rolls and cookers re-used from old extraction departments.

934

INDUSTRIAL AND ENGINEERING CHEMISTRY

0.27

51,900 1.23

FI L TR AT1ON-E X TR A CTI 0 N P R 0 C E S8 Table VI.

Pay-Out Times for Conversion to Filtration-Extraction, North Delta Area, 1954-55 Season FiltrationExtraction

Daily

Equip.

Crush, Tons 80

160 240

Conclusions

-

Capacity, __ Tons 8

Press

16 Press 24 Press

80 160 240

Years’ Annual Crush, Tons Cottonseed

10,600

13,200 Hydraulic 14.5 10.4

21,100

42,200

52,800

63,400

3.10

2.78

6.41 3.68

Screw Press 13.2

175 7 Press 200 250 10 Press 240 6.62 5.33 Allowance made for 47% income tax on increased profits (normal tax of 25% taxable income, plus surtax of 22% of taxable income in excess of $25,000).

brought about by strong competition both in the purchase of seed and the sale of vegetable oil and meal. The following table illustrates the comparison of the processing margin for 195455 with that for other years:

Processina Marain. U. S. Cottonseed Processin; Indv&y, 195 1-52 through 1955-56 Dollars/Ton Cottonseed Season 1951-52 1952-53 1953-54 1954-55 1955-56

basis of operation, filtration-extraction would show up more favorably.

Price Value Processpaid to of ing. farmer products margln 69.30 97.70 28.40 69.60 96.26 26.66 52.70 84.48 31.78 60.30 84.90 24.60 44.60 75.77 31.17

The smaller processing margin existing in industry in the 1954-55 season explains why it was necessary to process relatively large quantities of cottonseed that season to 0btain.a profit. Conversion from Mechanical Processes to Filtration-Extraction. Factors invo!ved in converting from mechanical pressing of cottonseed to filtrationextraction have been outlined and discussed by Gastrock (5). Conversion to filtration-extraction can be justified by the net increase in earnings from the additional oil produced and from resulting changes in operating costs. Increased earnings can provide enough additional income to pay for interest, depreciation, and taxes, and pay out the investment involved in making the conversion in a reasonable number of years. Conversion costs, increased profits, and pay out times are calculated (Tables V and VI). I n calculating conversion to filtration-extraction from hydraulic and screw pressing, it was assumed that the investment costs on buildings, machinery, and furniture had b d n written off and that the flakers and cookers could be

,

re-used from the existing mills. Under these conditions, increased gross profits for conversion of 80, 160, and 240 tons per day by hydraulic mills operating for 12 months were calculated to be $3.67, $3.95, and $4.04 per ton of cottonseed processed; and for conversion of 75, 175, and 250 tons per day by screw-press mills operating 8, 11, and 12 months, respectively, were calculated to be $0.27, $1.23, and $1.89 per ton, respectively. Conversion of the 80, 160, and 240 tons per day by hydraulic mills was particularly encouraging with pay-out times amounting to 6.41, 3.68, and 2.78 years, respectively, after allowance for income tax on increased profits. I n certain screw-press installations, the investment may have been amortized as assumed in this analysis. In other cases, reconditioned presses formerly used for soybeans, or new equipment, recently installed, may be in use and only partly amortized. For comparative purposes most of the basic assumptions made by Brewster and others ( 2 ) were used. These assumptions are that:

Mills were exclusively engaged in processing cottonseed into its primary products For analysis of comparative economies of different types of mills, all mills were new (the exception to this assumption is the analysis of conversion to filtrationextraction) Various mills studied were run under the same standardized rules Equivalent skills needed for operating different mills are available in any given locality at uniform wages The operating month includes an average of 22 working days of 24 hours each, allowing an average of 8 days for cleanups and other purposes For filtration-extraction and for solvent mills operations could probably be carried on for well over 300 days per year and in some cases as much as 350 days per year. On this more extended

This cost analysis shows that the filtration-extraction process provides the cottonseed crusher with a more profitable processing method in the highly competitive cottonseed-processing industry. Investment costs, operating expenses, and profitability of hypothetical filtration-extraction mills, and costs for conversion from mechanical pressing to filtration-extraction in the North Delta (Arkansas) area are given for the 1954-55 season. Investment costs for these hypothetical filtration-extraction mills are in all cases less than for comparable mills of the direct-solvent or prepresssolvent types. Profits are greater with these hypothetical filtration-extraction mills and indicate that conversion of 80, 160, and 240 tons per day by hydraulic mills to filtration-extraction can be paid for in a few years.

Literature Cited (1) Andrews, J. P., Kurtz, A. E., Cotton Gin d Oil Mill Press 5 4 (24), 12-13, 37-8 (1953).

(2) Brewster, J. M., U. S. Dept. Agr. Marketing Research Rept. No. 54, 2, 6 (1954).

(3) D’Aquin, E. L., Vix, H. L. E., Spadaro, J. J., Graci, A. V., Jr., Eaves, P. H., Reuther, C . G., Jr., Molaison, L. J., McCourtney, E. J., Crovetto, A. J., Gastrock, E. A., Knoepfler, N. B., IND.ENG. CHEM.45, 247 (1953). (4) Eaves, P. H., Spadaro, J. J., Crovetto, A. J., Gastrock, E. A., “The Value of Cottonseed Oils as Affected by the Degree of Oil Extraction and the. Method of Meats Preparation,” in process. (5) Gastrock, E. A., Cotton Trade J., Znternatl. Yearbook, 1953-54 ed., 34 (12), 36-8, 210 (4954). (6) Gastrock, E, A., Soybean Dig. 16 (12), 18-20 (1956). (7) Gastrock, E. A., D’Aquin, E. L.,

Vix, H. L. E., Offic. Proc. Ann. Convention Natl. Cottonseed Products Assoc. 56, 30, 32, 34, 36-7 (May 19-20, 1952). (8) Gastrock, E. A., Spadaro, J. J., Gardner, H. K., Knoepfler, N. B., Molaison, L. J., Oil Mill Gaz. 59

(Z),40-1

(1954).

(9) Gastrock, E. A., Spadaro, J. J., Graci, A. V., Jr,, Soybean Dig, 13,

(8), 16-17 (1953). (10) Graci, A. V., Jr., Bailie, G. E., Oil Mill Gaz. 60 (1) 9, 11-15, 15-18 (1955). (11) Graci, A. V., Jr., Reuther, C. G.,

Jr., Eaves, P. H., Molaison, L. J., Spadaro, J. J., J. Am. Oil Chmists’ SOC.30, 139-43 (1953). (12) Persell, R. M., Pollard, E. F., Deckbar, F. A., Jr., Gastrock, E. A., Cotton Gin 61 Oil Mill Press 53 (17), 18, 20 (1952). VOL. 49, NO. 6

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