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T H E J O U R N A L OF I N D U S T R I A L A N D ENGINEERING C H E M I S T R Y TABLE IV-SHOWING NITRITE-PRODUCING POWERO F Nitrite-Producing Power of 1000 cc. of the Urine in Terms of the Hydroxylarnino Derivative of T N T Designation of as the Standard URINE No. Worker Mg. 1 LI -48 3.9 2 LI -638 21.9 3 SF 231 12.4 LD - 8 4 7.7 L K -16 5 40.0 6 38.5 LK -401 7 12.1 L K -87 8 ..................... SF 205 5.0 S D -524 9 1.8 MD-733 7.4 10 133 5.0 11.. . . . . . . . . . . . . . . . . . . . M I 12.. SF 248 2.2 13 ..................... SF -372 Negative MJ -613 14 ..................... 5.0 MJ 703 2.2 S D -518 16 1 .a S D -523 17 2.2 MK 20 1.8 18 2.2 19 M I -232 1.8 MH 237 20.. MJ -5519 7.7 21...... M K - 195 22, 18.8 M E - 217 31.5 23.. M F - 56 2.9 24. SK 146 25., Negative M K - 153 3.4 2.9 27 MG - 198 5.0 28.. M H - 225 12.1 M I - 252 29. M F - 278 30.. 5.0
SOME
T N T URINES
.
..................... ..................... ..................... .....................
..................... ..................... ..................... ..................... .....................
...................
..................... ..................... ..................... ..................... ................... ............... .................... ................... ....................
................... ..................... ................... .................... ...................
-
Designation of U R I NNo. ~ Worker 31.. MD 375 S D -531 32 MF 793 33 34.. ................... KF -392
...................
-
..................... .....................
-
-
-
42 .......... 43 44
..........
..........
-
-
The results given in Table I V show t h a t t h e degrees of variation in the abnormality of T N T urines, as measured by t h e nitrite test. even when dealing with a comparatively limited variety of such urines, are actually more numerous t h a n t h e comparatively small number of degrees which we are given b y t h e Webster scale referred t o above. Hence it is apparent t h a t t h e procedure which was used in obtaining the results given in the above table enables us t o recognize a n d record differences which by t h e Webster scale we are unable t o handle. T h e above procedure has also t h e further advantage in t h a t all t h e results are expressed in definite amounts of a definite substance and thus enables us t o compare t h e results of different investigators.
Vol. 11, No. 9
54.. . . . . . . . . . . . . . . . . . . . 55 ..................... 56. .................... 57.. . . . . . . . . . . . . . . . . . . . 58 ..................... 59 ..................... 60 .....................
S D -429 MD 505 MJ -12 M I -177 SK 146 MI 149 LG - 199
-
-
Nitrite-Producing Power of 1000 cc. of the Urine in Terms of the Hvdroxvlamino Derivative of TNT as the Standard Mg. 3.4 28.9 12.1 29.7 21.7 69.9 17.8 75.7 36.3 33.2 33.2 2.8 21.1 107.4 10.0 15.9 7.5 27.7 80.7 30.0 26.0 20.0 41.1 21.1 137.0 8.0 21.1 5.0 21.1 35.5
Finally, it may be stated in this connection t h a t i t is t h e writer’s intention t o extend the study of t h e applicability of t h e nitrite test t o other nitro compounds. I n fact, a comparatively large number of experiments along this line have already been carried out. The results obtained thus far indicate t h a t not only can t h e nitrite test be utilized for t h e detection and estimation of small amounts of many nitro compounds, b u t i t may even be utilized for distinguishing between different members of this group. HYGIENIC LABORATORY
u. S. PUBLICHEALTHSERVICE WASHINGTON, D. c.
LABORATORY AND PLANT ence. This authority was enlarged in 1916 by t h e enactment of legislation instructing the Bureau t o develop methods for t h e commercial production of By J. W. TURRENTINE AND PAUL S. SHOAFX potash from a n American source and carrying an Received June 10, 1919 appropriation of $175,000. This enactment was conI n 1911 Congress authorized the Bureau of Soils summated late in 1915 and had specific reference t o of the United States Department of Agriculture t o the erection and operation of an experimental plant investigate the fertilizer resources of the United Statesa2 for t h e extraction of potash and other values from kelp, This authority was granted largely in recognition of the most important source of American potash not American dependence on Germany for all of t h e large under promising private development. The unexquantities of potash entering fertilizers and the highly pended balance of this appropriation was made available undesirable state of affairs resulting from t h a t depend- for t h e fiscal year 1917-18, and in 1918 a new appro* 1 Published with the permission of the Secretary of Agriculture. priation of $127,600 was made. 2 The preliminary report of work done under this authorization was I n t h e fall of 1916 an investigation was made .by embodied in Sen. Doc. 190, 62nd Congress, 2nd Session, entitled “Fertilizer Resources of the United States,” under authorship of F. K. Cameron, one of t h e present writers, of t h e then incipient kelpR. B. Moore, E. E. Free, J. W. Turrentine, W. H. Waggaman, C. I,. Alsberg, potash industry a t t h a t time under development due W. A. Setchell, G. B. Rigg, F. M. McFarland, W. C. Crandall, E, C. Johnson, t o a critical shortage of potash and t h e consequent A. R. Merz, C. C. Darwin, J. 0.Smith, and R. F. Gardiner. This document contained the result of surveys of certain of the areas of growing extremely high prices, t o see if this young enterprise Pacific coast kelps and showed them t o be of large potential importance as a bid fair t o solve t h e problem of t h e establishment of a source of potash. A second report was rendered embodying the results of surveys of all the main areas of kelp in American waters from the coast of permanent industry and if t h e results at t h a t time Mexico to the northwest peninsula of Alaska and was published as Report attained could be made t o show aught as t o t h e feasi100, “Potash from Kelp,” under the authorship of F. K . Cameron, W. C. bility of t h e proposed permanent industry. Especial Crandall, Geo. B. Rigg, and T. C. Frye. POTASH FROM KELP: THE EXPERIMENTAL PLANT OF THE UNITED STATES DEPARTMENT OF AGRICULTURE. PmLIMINARY PAPER’
k J t , '919
rnh
J O I / R ~ - A OF L I I V D U S T K I A L A ~ V DE N G I N E E R I N G
CHEMISTRY
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ND o* P I B R
dttention was pai involved in securing it as able impression crcntcd h tions led t o the formation of definite plans of p which were embodied in a report and subm' Secretary of Agriculture. Shortly thereaft was issued to proceed with the erection of the plant. PLAXT SITE
.4s a first step, it was necessary t o choos Various collaborative schemes wlth other concerns were proposed and invitations t o erect the plant a t ction with other plants various places and in were considered The otash industry, as then constituted, was cent ound the t w o points, San Diego and San Pedro, the two most commodious harbors advantageously situated with respect t o the these harbors supply of kelp Adjacent t o bot are large areas of growing kelp. In of the great advantages of safe harbor and proximity t o industrial communities, with their skilled labor and supply houses, an unlimited supply of kelp, one that could be drawn upon without danger of competing wlth private concerns, was considered of greater importance, Accordingly, it v a s determined t o erect the plant a t Summerland, California, a village on the coast of Santa Barbara county, near the city of Santa Barbara, and a spot centrally located with respect t o large kelp groves, not only along the coast t o the east and west and immediately In front of the village, but [ringing the channel islands, lying twenty mile shore, a location which a t that time was one hn miles distant from the nearest kelp-potash plant. Summerland is situated on the coast line of the
ds telephone, telend a water supply, crude petroleum. Fuel oil
While being only a small village and affording but limited housing facilities itself, it is connected wlth neighboring towns by bus lines, thus making it possible t o draw upon the labor supply of the entire neighbnrhood. T h a t part of the ocean upon which it fronts is known as the Santa Barbara channel. Here the coast trends in a n east and west direction the west it curves to the south to for
south, across the channel, 1 wise high and mountain0 1s formed, exposed only
om the former direce but little danger t o
and interfere with harvesting operations, hut t o date have not resulted in any serious damage t o the plant's built partly on the beach and partly on tion that are n
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T H E J O U R N A L OF I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y
ence, b u t neither of a serious nature. T h a t part of t h e plant which is on the beach is constructed on a foundation of piles driven through the sand t o a solid s t r a t u m , and a t such a height above t h e sand as t o conform in level with a wharf which extends 700 f t . offshore. The latter reaches a depth of water not only ample for the draught of the kelp harvesters, b u t also sufficient t o escape very materially t h e effects of the surge of t h e waves. Excepting times when there is a combination of very high tide and severe storm, t h e waves do not touch any of t h e stationary equipment. PLANS OF PROCEDURE
The situation with respect t o the kelp-potash industry as i t existed a t t h e time plans for this plant were being developed demanded t h a t t h e experiments Qf t h e Government be directed in such a way t h a t t h e results therefrom would be applicable t o the processes already in vogue; t h a t t h e plants already operating could be applied to t h e more elaborate processing of kelp by elaborating t h e plants rather t h a n rebuilding them. With the single exception of the Hercules Powd e r Company, which was proceeding from t h e munitions point of view, all the concerns then entering t h e kelp-potash industry were developing a process which involved drying as a preliminary step, and all were employing the rotary direct-heat dryer. It was desirable, therefore, t o develop a process which could be applied as a n elaboration of t h a t already about t o be employed. Furthermore, i t already has been demonstrated by a long series of experiments conducted on t h e laboratory scale t h a t d r y kelp could be further processed and made t o yield potash in a high state of purity and simultaneously various other products probably susceptible of commercialization. The situation demanded t h a t a plant be constructed which could supply materials for use in experimentation in any quantity a n d a t any time desired, and which could be made t o serve as the foundation on which t o build a commercial plant of any degree of elaborateness as the various processes, based on the results of the experimentation, were p u t into operation. The goal striven for was a plant in which kelp was t o be processed and made t o yield t h e greatest number of valuable products, all of which were t o be produced in commercial quantities and of commercial grades a n d their cost of production determined. Every step was taken with t h a t goal in view. The ultimate object being the establishment of an industry based o n the extraction of potash from kelp, it was realized t h a t t o accomplish this end it would be necessary t o show a profit obtained, not on paper, but in actual operation. I t , therefore, was considered necessary t o proceed on such a scale as not t o preclude t h e possibility of producing values in paying quantities. The purpose of the plant was first, experimentation, and second, production, t h e latter increasing as elaboration proceeded. It was t o yield experimental results, efficiency data, and profits. A plant was designed which would make possible the processing of I O O tons of wet kelp per day of 24 hrs., the least quantity, it was believed, which could be
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treated without danger of precluding profits. This was a quantity which could be supplied by one harvester. I n designing the apparatus and plant lay-out it was deemed wise t o adopt, in so far as possible, t h a t apparatus and plan of installation which a t t h a t time was being adopted by t h e concerns then operating. No plant had solved entirely t h e problems incidenta1 t o t h e handling of kelp in any stage of treatment. Advantage was taken, however, of what was known, and all t h e information in possession of the majority of t h e private concerns was made available for t h e use of t h e Government. Collaborative relations of t h e most cordial nature were established with all b u t one of these organizations a n d t h e writers here express their hearty appreciation of t h e value of t h e assistance rendered. While following in t h e still fresh footprints of the other operators, where i t appeared certain t h a t improvements in design or character of apparatus could be introduced, the a t t e m p t was made without hesitation, although i t was realized t h a t time lost in experimentation with t h e simpler apparatus used in t h e initial steps of the process would possibly delay t h e establishment of refined products t o a n equivalent degree. While b u t little was known as t o methods of handling this new raw material, t h a t little was made of use. From the point where t h a t information terminated i t was necessary t o proceed with the experience obtained in t h e handling of other materials of a n a t u r e approximating t h a t of kelp, or entirely empirically. PROCESS PROPOSED
While the plan of work called for t h e demonstration of various proposed processes, among which was t h e fermentation process, now happily worked out in magnificent detail by t h e Hercules Powder Company, the process considered of most immediate importance a n d probable usefulness, a n d t h e one, therefore, adopted, prescribed t h e harvesting of kelp, its chopping and storage in suitable quantities t o make possible a n uninterrupted operation of a plant, its drying a n d destructive distillation, t h e recovery of t h e ammonia and other volatile products and their refinement, t h e leaching of the resulting charcoal for the extraction of soluble salts, t h e refinement of t h e residual charcoal, the purification and evaporation of the resulting brine and t h e separation b y fractional crystallization of the potassium and sodium chlorides and iodides, the process yielding, as a main product, high-grade potassium chloride, and, as by-products, salt, iodine, decolorizing carbons, ammonia, and whatever of value could be developed from t h e crude pitch, oils, a n d creosote recoverable from the condensable products of destructive distillation. Construction was begun in March 1917 and t h e plant was p u t into operation in August of t h a t year. Soon after beginning construction t h e entrance of t h e United States i n t o the European war a n d the consequent great demand for materials of construction, tools, machines, and all other useful commodities tremendously increased t h e difficulties attending the construction of t h e plant, increasing the costs and t h e time consumed. A t the same time interest and en-
Sept., 1919
T H E J O U R N A L OF I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y
thusiasm were enhanced, Of certain supplies t h e western markets were entirely stripped. It became necessary t o enter into the most active competition with other buyers, t o proceed in making purchases with t h e greatest celerity, a n d t o enter t h e market for seconci-hand a n d used materials. A great deal of second-hand materials were employed, such as motors, tanks, iron pipe a n d fittings, corrugated iron, and various other supplies and apparatus, effecting large savings in money and time. I n fact, in some cases, only second-hand materials were available a t all, and t o refuse them was t o go without altogether. T H E P L A N T , ITS P R E S E N T E Q U I P M E N T A N D O P E R A T I O N
HARVESTING-The harvesting equipment consists of two harvesters, t h e “Joseph Priestley,” of I O O tons capacity, and the “Mayflower,” of 1 5 0 tons capacity. The former has been in operation from the beginning, the latter having been added recently as reserve equipment. Both harvesters are equipped with two internal combustion engines for propulsion and have twin screws. The engines are set well toward t h e stern. On the extreme bow is t h e cutting mechanism made up of a ten-foot horizontal and two five-foot vertical reciprocating knives, a vertical knife a t either end of the horizontal one. These are set in place a t the front end of a rectangular steel frame, I O f t . wide by 2 0 f t . long, which is mounted in a horizontal plane on a transverse axis and is so pivoted t h a t for cutting i t may be tilted down into t h e water a t such a n angle t h a t the knives are submerged in the water. This places t h e horizontal knife a t a depth of about 4 f t . below t h e surface. The rectangular space described by t h e f r a m e is taken up with a conveyor made up of wooden slats mounted on endless chains. The device is operated by a separate gasoline engine. When the mechanism i s tilted into the water, t h e lower end of t h e conveyor is situated just behind t h e knives in such a position t h a t i t catches the severed kelp. This travels up t h e conveyor and from its upper end falls upon t h e deck. The three knives when submerged in the water together with the surface of t h e water describe a rectangle, I O by 4 or 5 ft.; and as t h e boat, moviag forward, shoves them through the water, they cut a rectangular swath through the mass of growing kelp. Since a large portion of t h e kelp lies on the surface of the water in lengths of I O to 75 f t . , t h e yield from each plant is large, although from 40 t o 7 5 f t . are left standing in the water. Thus, practically only the tops of the plants are recovered, a very unfortunate fact when it is remembered t h a t after t h e growing tip of a kelp frond is severed, the balance of t h e frond probably dies and rots. It is probable, therefore, t h a t not more t h a n 50 per cent of t h e kelp plant is utilized, and will not be until some method of harvesting a t a depth of 40 to 7 5 f t . is devised.’ The kelp as delivered on board is distributed and stacked in the large deck space lying between the cutter on the bow and t h e pilot house on t h e stern. 1 There are other considerations. which will not be nresented here which make it seriously doubtful whether a closer cropping would not do such damage to the kelp groves that any advantage gained would be nulliBed. This is a problem t o be investigated.
867
The capacities given for the harvesters are the carrying capacities. They are able t o harvest a t a rate of 25 t o 50 tons per hr., depending on the thickness of the kelp, t h e weather, tides, currents, and other factors. This may be a n important matter since it makes possible the delivery of two loads per harvester per day with an almost 50 per cent decrease in harvesting costs. The speed of the boats is about 7 knots, The harvesters are equipped with complete living quarters and carry provisions for a cruise of several days and any ordinary emergency. Where t h e situation demands, they go such a distance €or kelp t h a t two nights and a day may be consumed in the round trip. T h e cruising radius, therefore, is determined more by the spirit of the crews than 6 y any other factor. The length of haul only adds t h a t increase in cost per ton of kelp due t o fuel consumption. Thus, a kelp plant with a sufficiently mobile harvesting outfit may regard t h e kelp areas of a very extensive region as its logical source of material.
FIG. 2-UNLOADING
KELP
UNLOADING-The harvested kelp is unloaded by means of an automatic fork whick is operated after
T H E J O U R N A L OF I N D U S T R I A L A Y D ENGINEERING CIIEMISTRP
868
the familiar manner of the clam-shell bucket, by means of a derrick and electric hoist. The fork, gripping with its prongs a mass of the long fronds of kelp, is able to lift about 1500 lbs a t a time. Each load is swung over the hopper of a chopper and dropped, the chopper clearing itself before the next load is delivered, Thus a harvester carryina 100 tons may be unloaded in about 3 . j hrs. The chopper employed consists of a hopper, feeding rolls, and revolving knives, the latter of the type used in ensilage cutters. They revolve a t such a speed relative t o that of the feeding roll that the kelp is cut into about 6411. lengths Derrick, hoist, and chopper are situated on the wharf a t a height of I O f t above mean high tide, a n distance of about 600 it. from the shore. Drag conveyors of pintle-chain and wooden slats begin a t the choppcr and extend up the wharf to the top of a storage elp from bin erected on the beach. They re the chopper and deliver it into the actically continuous stream. The juice from the kelp acts as a very effective lubricant and speedily covers the moving
Vol.
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No.
9
for this reason that a doiible instead of a single bin is used DnYIxc-Three dryers are installed. They are of the direct-heat, hot-air type, and are steel cylinders, j o f t long by j ft. in diameter. mounted in a sloping position on trunions and with a gear ring encircling the dryer so that they can he rotated Longitudinal shelves are provided on the inside so t h a t the material drying is frequently lifted and dropped as the cylinder rotates They are operated countercurrentwise, hot air being blown into one end and raw kelp fed into the other To overcome the opposition of the stre air, the cylinders are mounted on a slant and the shelves are built with a lengthwise slope so that the kelp is forced toward the hot end of the dryer. Each r is provided with a furnace wherein hot air is rated by means of two oil burners each. The furnaces are large enough t o make possible the come oil therein, so that no flame, the dryers. Low-pressure air IS 11 being burned, and a forced draught is admitted to the furnaces through the floors The three dryers enter a common “dust chamber” built of concrete and wood, which in turn leads t o a common stack, also of wood
is practically ne items of expend’ kelp plant.
In
the matter of deli STORAGE-The
Its bottom slopes f along which runs a drag conveyor, which likewise passes through the bottom of dischnrpina wells at both ends of the bins. .
-
tom and thus delivers itself into immediate proximity t o the cowcyor. Whcn the bin is full it is discharged through the sellsat eitherend, and, when almost empty, through openings in the floor made Ly lifting boards which cover che conveyor trough. The rate of discharge is controlld accurately by a workman, called n ieeder, who develops no little skill i n maintaining the constancy of dory of the issuing kelp. This stream of k e l p is maintained continuously day snd night and i s delivered by t!ie conveyor into a distributor which divides it crjually betwcrn two drvers. Tlie kelp 011 st:$ntling il i ~ w!lours iinilerjioes som? lernientatioii, mid undcr its own lv
Sept., 1919
T H E J O U R N A L OF I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y
and short receiving hoppers, and those a t t h e top with a sliding lid a n d a Y-branch for the escape of gas. The four are enclosed in a vertical furnace built on a steel platform and are heated with hot air from a small furnace adjoining. A storage bin for dry kelp is suspended above the tops of the retort so t h a t they can be filled by gravity. A conveyor delivers the dry kelp from t h e second-stage dryer into this bin. The gas evolved during distillation is passed immediately into small cyclone condensers, of which there is one attached t o each retort, for t h e separation of the less volatile t a r ; thence t h e four streams of gas are led collectively into the bottom of a vertical sheet-iron condenser, which is provided with frequent horizontal baffle plates, and is designed for t h e condensation of the oily and aqueous constituents of the gas. The resulting condensate separates itself into two layers, one oE oils and one of ammonia liquor. A slight vacuum is maintained on the retorts by means of a gas pump which maintains the circulation through the condensers and finally blows the gas through a gas burner into the retort furnace where it is consumed for fuel . A temperature of about 980' C. is maintained in the space surrounding the retorts. As viewed from above, t h e empty retorts show a full red heat for a portion of their length and of course t h e entire portion of the tube inside the furnace is a t a temperature approaching redness. The kelp fed into t h e top gradually works downward, shrinking in volume as i t undergoes distillation. The volatile products are drawn upward and exhausted a t t h e top. After passing the zone of most intense heat t h e char is discharged gradually into the small hopper constituting the bottom of each retort, where it partially cools, a n d a t regular intervals is removed and cooled completely. After being ground, i t is stored and is then ready for lixiviation. The pro'ducts yielded are heavy and light t a r , separable into oils, creosote, and pitch; a n aqueous distillate, containing ammonia and various other substances; and a combustible gas, as yet incompletely explored for useful constituents. A great deal of work has been required t o determine the nature of t h e various constituents of the products of distillation. This will not be gone into here even in summary, although i t may be said t h a t a n ammonia liquor of full commercial strength results and t h e oils a n d phenol bodies give great promise of useful application. The t a r is unlike either coal t a r or wood tar, although i t shows certain characteristics of both.' Both the crude t a r itself and t h e oils obtained from its distillation show pronounced activity when used as flotation agents in the concentration of certain ores, amounts as low as 0.1 lb. per t o n of ore being highly efficacious, The crude creosote likewise has been found t o be highly toxic t o bacteria and agencies of decay, especially as applied t o wood as a preservative. 1 This feature of the work was begun a t the Forest Products Laboratory of the IJnited States Department of Agriculture, Madison, Wis., b y Dr. Geo. C. Spencer, organic chemist attached to this organization, where he enjoyed full advantage of the experience and equipment of the Madison organization. Later he continued the investigation in the laboratory a t this plant and now is studying certain phases of it in the laboratories of the Bureau of Soils, in Washington, D. C.
869
It is evident t h a t it will find a usefulness comparable t o t h a t of creosote from wood or other sources. INCINERATION-The excess of dry kelp over t h a t required by the retorts in the past has been incinerated for the production of kelp ash, a crude fertilizer potash of about 3 5 per cent KzO content. For this purpose a rotary kiln is employed, 30 f t . in length a n d 4 f t . in diameter. It is lined with fire brick and is operated countercurrentwise. A small oil burner projects a flame directly into t h e kiln from the lower end while the dry kelp is delivered by a screw conveyor into t h e upper end. The products of combustion are exhausted by means of a fan and delivered into t h e several dryer furnaces, thence passing through the dryers and dust chambers. T h u s t h e waste heat is utilized, t h e smoke consumed, and t h e dust settled. The kelp is reduced t o a charcoal a n d flows out a t a low red heat. If piled in heaps, i t slowly burns t o a loose gray ash, which is ground and sacked for market. It possesses those characteristics which make i t a very acceptable potash carrier. I t mixes well, does not cake, and contains no deleterious substances. The material thus produced is the familiar kelp ash which, during the recent war, was t h e product of several kelp-potash plants of this region. Its manufacture a t war prices, in certain cases, was highly remunerative. A t present t h e charcoal produced by the incinerator is quenched instead of being heaped for ashing and is ground a n d stored for leaching. LIXIVIATION-The difficulties formerly encountered in t h e leaching of potash salts from finely divided material in such a way as t o secure commercial leaching simultaneously with a highly concentrated solution have been overcome by a device, here installed, and now operated continuously for several months with t h e greatest success, wherein mechanical filter presses of t h e rotary, vacuum type, are combined with leaching troughs and in series with each other, so t h a t t h e material undergoing extraction may be successively leached and filtered and may be passed through t h e apparatus by gravity in a continuous stream against a current of brine lifted by pumps operated as a p a r t of the filter press equipment. Continuous, countercurrent leaching is effected in an entirely mechanical manner; kelp charcoal enters one end of the apparatus, and a commercially extracted press cake is discharged from t h e other. The final extraction is effected with fresh, hot water while t h e first is accomplished b y leaching with a brine built up, and of t h a t strength established by preceding extractions. A hot brine of a high concentration is secured, which, after treatment t o remove undesirable impurities, is stored for evaporation. E X T R A C T I O N O F CHAR-The press cake from t h e lixiviator is further extracted successively with hot hydrochloric acid and water. It has been established bv t h e valuable work of Messrs. Zerban and Freeland' t h a t the retorting of dry kelp followed by the, proper activity extraction may yield a Of as a decolorizing agent for Various Organic liquids a n d of aqueous so~utionsof certain organic and inorganic 1
THISJOURNAL, 10 (1918), 812.
T H E JOURNAL OF INDUSTRIAL A N D ENGINEERING CHEMISTRY
RAW U C L D
100 TOW
WATER WATER
DRYER
29 TONS
DRYER NV2
N91
50 TONS
5 0 TONS
SEMIZ I TONS
DUST
DRYER 20 7 TONS
42
No3
rows
. , Fro.
4-OPERATIONS
AND PRODUCTS
I I
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Sept., 1919
T H E J O U R N A L OF I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y
substances. T h e charcoal obtained from t h e retorts in use in this plant has shown a n activity of t h e most encouraging nature, b u t varying in degree of activity over a considerable range of values. By a one-stage retorting operation carbon has been secured which shows a n activity exceeding t h a t of any other commercial carbon obtainable for comparison. I t represents a by-product of value a n d of great usefulness in a variety of industries a n d offers promise of a highly remunerative product. Conditions surrounding its certain production in its highest state of activity are not yet fully established. I n t h e meantime t h e lower grades of carbons are being extracted with hot hydrochloric acid and water. For this purpose t h e press cake, from which water-soluble salts have already been removed by t h e aforementioned lixiviator, is delivered into acid-proof tanks where i t is given successive treatments with acid, sufficient t o remove water.insoluble constituents of t h e char, and with hot water t o remove t h e acid. It is lifted into t h e syst e m of tanks as a sludge b y means of a centrifugal pump' is heated by means of steam coils, is agitated by compressed air, and is filtered over vacuum. T h e entire treatment is effected by t h e manipulation of valves in their proper order. Finally, t h e carbon is dried and sacked for shipment. EVAPORATION AND CRYSTALLIZATION-After the elimination of sulfates t h e brine resulting from t h e leaching of kelp charcoal contains only t h e chlorides of sodium a n d potassium, in t h e ratio of approximately one or two, respectively. These salts are easily separa,ble b y t h e so-called hot-cold method, by which is meant t h e alternate evaporation t o t h e point of saturation with respect t o potassium chloride a n d then cooling. Upon cooling, potassium chloride precipitates; while upon evaporating, after saturation with respect t o sodium chloride has been attained, t h a t salt precipitates. T h e apparatus employed is t h e standard type of vacuum evaporator joined in circuit with a vacuum crystallizer. T h e former is provided with one salt filter a n d t h e latter with two. I n operation t h e hot, concentrated brine from t h e storage tanks is admitted t o t h e evaporator where i t is raised by evaporation t o t h e desired concentration with respect t o potassium chloride. It is then drawn over into t h e vacuum crystallizer where i t is cooled by boiling in vacuum, and potassium chloride crystallized. T h e cooled brine is returned t o t h e evaporator for further evaporation, during which sodium chloride crystallizes. T h u s sodium chloride is obtained from t h e evaporator a n d potassium chloride from t h e crystallizer. Circulation back and forth through t h e apparatus is continued until t h e mother liquor becomes sufficiently concentrated in salts of iodine t o justify treatment for t h e recovery of t h a t element, whereupon t h e liquor is withdrawn for storage. The salts recovered are washed a n d partially dried in a centrifugal dryer and are then passed through a rotary, countercurrent, hot-air dryer and delivered into a sacker. They are packed for shipment in sacks of I O C lbs. each.
871
AUXILIARY OPERATIONS-A small laboratory, with working space for about six men and equipped f o r control work a n d some research, constitutes a part of t h e auxiliary equipment of t h e plant. Analyses are made t o effect control of potassium and sodium salts with special reference t o potash, water, and sulfur content; density and composition of brines yielded by t h e lixiviator, t h e evaporator, a n d crystallizer; t h e iodine content of the mother liquor a n d salts; t h e potash a n d moisture Gontent of t h e press cake; t h e decolorizing properties of t h e extracted charcoal; the acid a n d potash content of the waste liquors from t h e char extractor; t h e determination of t h e ammonia content of t h e ammonia liquors from t h e retorts; a n d the testing of fuel oil and other supplies. I n addition t o t h e routine work conducted, special tests are frequently made of raw materials and products respectively entering and yielded by the various apparatus over definite periods of time in order t o determine t h e performance of t h e apparatus and t h e efficiencies of t h e processes. As additional equipment may be mentioned a n office building, shop, supply and locker rooms, storage warehouse, transformer houses, a steam plant of 150 h. p. capacity, and storage tanks for oils and water. T h e total floor space of the buildings already constructed (exclusive of storage bin and wharf, 8,800 sq. ft.) is 13,800 sq. f t . RESULTS
The operations of t h e plant and the products yielded are represented graphically by the flow sheet, Fig. 4. This is based on a daily treatment of I O O tons of raw kelp. I n certain cases t h e quantities. yielded are also indicated. I n this schematic representation circles are made t o express materials and. products; rectangles a n d squares, apparatus. From a n examination of t h e plan i t p a y be seen t h a t two by-products, iodine and ammonia, of well-understood values, are established as obtainable in commercial form and quantities by t h e process employed. A third, a highly active decolorizing carbon, is likewise obtainable cheaply a n d in large quantities. But t h e certain adaptability of this material t o t h e established industries wherein such agents are used can be shown only by t h e actual plant test, and t h a t time has not yet permitted. Laboratory tests on a great variety of materials show this carbon t o be highly efficient a n d of great potential value. Conservative estimates strongly indicate t h a t its production as a by-product will be highly remunerative; a n d t h a t it, combined with iodine a n d ammonia, may prove t o be t h e solution of t h e problem of establishing by-products capable of producing revenue sufficient t o carry t h e operating expenses of such a plant. I n addition t o these, but of less probable importance, may be mentioned t h e by-products, common salt (obtainable in a state of purity sufficiently high t o warrant its exploitation for table use), a n d t h e oils, creosote, a n d pitch yielded by t h e distillation of the tar. Fig. 5 illustrates t h e by-products and derivatives so f a r established as obtainable, and indicates t h e source a n d , in cases, t h e application of each.
,
T H E J O U R N A L OF I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y
I
I
COMBUSTI6LE GAS
FJEL
ACIDS
1
(CRUDE)
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35PERCeNT K$
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FUEL
D ~ C O LR OI z E R s
FOR 6 R m A T VLIUICTY 0. INDUSTRIES
38 P t R C e N r
TABLE
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I M P O R T A NT LOCAL MARKET
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RESIDUAL O I L S I
PHENOLS
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CRESOLS
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II PYROGALLIC ACID
ORTHO-, HETA-, PARA-CRESOLS
KfTONES
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FLOTATION OILS
PYROCATECHIN
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AMMONIUM CHLORIDE
ALCOHOL
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No. g
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AMMONIA '
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AMMONIA
OILY
DISTILLATE
AQUEOUS
Vol.
AC(M0IIIUM 5 UL F A T E
Se p t ., I 9 J 9
T H E J O U R N A L OF I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y
873
DIRECTOR (1)
I LABORATORY
I
OFFICE DISBURSEMENTS AND RECORDS
I
I
Disbursing Officer (f’ I
Resaarch (1) . .
I
I
IGuards (2)
I Records klerk Supply Man (1) (1)
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SUPERINTENDENT (\’
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Unloading
Leaching
Char Extraction
Hoist Operator
Operator
Operator
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cabtain Captain “Joseph Priestley” ”Mayflower”
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(1)
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Fedder (1)
-1
Oiler (1)
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(;’
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Retort (2)
Feeder (1)
FIG.6-ORGANIZATION
It has been necessary t o operate the plant in a manner as closely approximating t h a t of a commercial plant as t h e nature of the enterprise would permit, in order t o train and t o maintain a force of trained operators, not only t o provide materials as cheaply as possible but also t o test machines and methods of operation, t o determine efficiencies a n d inefficiencies in operation, and t o obtain exact cost d a t a as yielded by t h e large-scale application of methods. Efficiency d a t a ha,ve been and are still being taken in detail and covering an increasingly long list of operations, from harvesting the raw kelp t o packing the finished products. During t h e period of warfare just ended i t was very gratifying t o be able to produce even a small quantity of a commodity in great demand by the military, agricultural, and other industries of t h e nation. T h a t produced incidentally has been marketed and made t o yield a revenue of $60,000. Thus, while t h e main project, t h e extraction of potash in its most desirable form and the simultaneous development of by-products from kelp, has been under investigation, t h e plant has been in operation on a producing basis. The great difficulties inherent in the extraction of adequate values from a raw material of such low grade as raw kelp seem t o be materially byovercome. The results so far obtained-the products so far established and the cost d a t a covering t h e operations yielding them so far determinedindicate in a positive manner t h e substantial nature of t h e profits ultimately t o be expected from t h e operation of such a plant. ORGANIZATION
The administrative a n d clerical, t h e research, construction, and operating forces constitute a personnel of about sixty men. Some of these are normal parts of any kelp-potash plant organization, while others are peculiar t o such an organization as this where re-
I Oiler (1) AND
Chief Mechanic (/)
Mechdnics (3)
Ashing Crew (5)
I Dryer Operator
I Dryer Operator
( 1,)
Retort (2)
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Operator (1)
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I Crystallization Drying & Sacking
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PERSONNEL
searches are being carried on, test apparatus constructed and altered, and plant elaboration is constantly under development, all of which require a large supplementary force in addition t o the normal operating one. Their distribution and duties are represented schematically by Fig. 6. I n addition t o the foregoing there are other individuals a n d organizations with whom collaborative arrangements have been made looking t o t h e investigation of certain problems and the testing of various products. This occasion is taken t o express t o each of these our heartiest appreciation of their efforts a n d the helpful results so far reported in connection with the various enterprises which they have undertaken i n our behalf. T H E KELP-POTASH INDUSTRY
It was an early prediction t h a t i t would not be possible t o produce potash alone from kelp in successful competition with foreign potash. Results obtained from the operation of these plants during t h e war period established cost d a t a which showed the accuracy of this prediction. Of t h e various plants a t one time in operation, only one was designed for byproducts, and t h a t one planned t h e production of materials principally of a war-time value. I t being evident then that, without by-products, upon t h e restoration of pre-war conditions, profits would not be obtainable, as soon as it became evident t h a t these conditions were about t o be restored all the privately owned plants promptly suspended operations. During t h e war period kelp was second in importance among t h e American sources of potash. T h e history of t h e plants has been enlightening. Aside from demonstrating the availability of kelp as an emergency source of potash, they have shown how i t may be harvested and, what is more important, in what quantities. They have demonstrated in t h e most conclusive
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T H E JOURNAL OF INDUSTRIAL A N D ENGINEERING CHEMISTRY
manner t h a t three t o four harvests per year may be obtained from t h e areas of growing kelp, t h a t t h e kelp promptly restores itself and can be made repeatedly t o yield large quantities of raw material without apparent injury t o t h e “stands.” During nine months of t h e year of 1918,400,000 tons of raw kelp were harvested from t h e kelp groves of Southern California. This represented repeated cuttings from t h e same areas. Methods of harvesting were being improved and t h e conservation of t h e groves was being practiced so t h a t recoveries seemed t o be on t h e increase. Groves subjected t o t h e most severe cutting show n o signs of damage. It may, therefore, be said with certainty t h a t t h e amount of kelp in t h e waters of Southern California, immediately available for t h e purposes of t h e industry, which i t is t h e design of this enterprise t o establish, is 500,ooo tons per annum, obtainable without further elaboration in harvesting methods. T h e kelp of Puget Sound and Alaska has not been subjected t o such a test. However, t h e areas there are well known and i t is possible t o predict t h e yields there obtainable. SUMMARY
I-The Experimental Kelp-Potash Plant of t h e United States Department of Agriculture, designed for the determination of t h e best methods of processing
Vol.
11,
No. 9
kelp for t h e extraction of potash salts and t h e simultaneous recovery of other valuable products, was erected during t h e summer of 1917and p u t into operation in t h e early fall of t h a t year. 11-One hundred tons of raw kelp per d a y are subjected t o a process involving drying, destructive distillation, lixiviation, evaporation, and fractional crystallization for t h e preparation of high-grade potassium chloride. 111-The by-products, kelp oils, creosote, pitch, ammonia, bleaching carbons, salt, a n d iodine are yielded in commercial quantities b y this process. T h e main problem now in hand is their commercialization. It is confidently believed t h a t they will be made t o yield sufficient revenue t o enable t h e main product, potash salts, t o be marketed successfully in competition with potash from foreign sources. IV-Complete operating cost d a t a are being tabulated covering t h e various details of manufacture. These, together with full specifications and designs, will be made available for t h e use of t h e interested public. V-The results obtained t o date indicate t h a t it will be possible t o establish on kelp as t h e basic raw material a new American chemical industry of considerable size and of importance a n d usefulness t o t h e nation. SUMMERLAND, CALIFORNIA
I
ADDRESSES AND CONTRIBUTED ARTICLES INDUSTRIAL AND AGRICULTURAL CHEMISTRY IN BRITISH GUIANA; WITH A REVIEW OF THE WORK OF PROFESSOR J. B. HARRISON B y C. A. BROWNE Received July 17, 1919
During a recent visit to the British Colonies of tropical America, it was the writer’s pleasure to observe some of the most interesting applications of chemistry to agriculture and industry which have ever come under his notice. The chemists of the United States, as a rule, have been so occupied in their own special fields that they have had little time to study the work of their English-speaking confr2res farther south. Much of this work deserves to be better known, and in the present paper the writer wishes to describe a few phases of agricultural and industrial chemistry in British Guiana. Although the first European settlements in British Guiana date back nearly three hundred years, the development of the agricultural and industrial resources of this section of South America can be said t o have only begun. An area of over go,ooo square miles, equal to that of the states of New York and Pennsylvania, has a population of only about 300,000. Immense tracts of land are waiting to be cleared for cultivation, large areas of valuable timber remain to be utilized, vast deposits of mineral wealth are still unopened, while back of all these are almost inexhaustible supplies of energy, the water power of the great Kaieteur Falls alone exceeding that of Niagara. The great obstacles in the development of all this latent wealth have been chidy two-difficulties of climate and scarcity of labor, the second of these factors depending somewhat upon the first. That the sanitary and other difficulties of a tropical climate need not impair the health or efficiency of labor has been sufficiently demonstrated by the building of the Panama Canal. With the example and results of this undertaking before us it is not
difficult to prophesy that a great industrial awakening in the tropical regions to our south will be an important factor in the newer developments which are to follow the recent European war. The leading exports of British Guiana, in the order of their value, for the year 1917,are as follows:
.............
.............
Sugar by. products (molasses, molascuit, etc.) .
.. . . .
103,535
In addition to the above there are exports of coconuts, coconut oil, coffee, rubber, timber, firewood, charcoal, cattle, hides, and other products with a value of over $ 2 5 0 , 0 0 0 . A glance at these products of field, forest, and mine shows that the chief industries of British Guiana are agricultural. Descriptions of a few of these industries in their chemical aspects are given. THE SUGAR INDUSTRY
Since 1664 when Jan Doenson built the first rude horse mill in Essequibo the chief product of British Guiana has been sugar, the value of which with t h a t of spirits and other by-products made up in 1917fully 80 per cent of the income derived from exports. Over one-third of the population of the colony is engaged, one way or another, in the sugar industry. The sugar estates of British Guiana form a fringe along the north coast of the colony and for a short distance up the banks of the Essequibo, Demerara, Berbice, and Courantyne rivers. In 1917there were 36 estates, which produced 114,007 tons Of sugar, 3,415,921 gallons of spirits and rum, 149,940gal!OnS Of
