BORATIVE
REPORT
LOUIS A. AGNELLO, Associate Editor in collaboration with ELLIS 0. BARNES, Union Bag-Camp Paper Corp.
Tall Oil
Savannah, Ga.
Fractionating capacity nears the billion pound-peryear mark; lYnion Bag- Camp’s process wrinkles boost plant throughput b y 300% of design
b This view shows pipe alley f rom the distillation tower to finished product storage tanks and to tank car loading ramps
TALL
OIL looms as a glaring highlight in the otherwise generally cheerless picture painted by the U.S. naval stores industry. From less than 27 million pounds just 20 years ago, crude tall oil output has zoomed above the 800 million pounds-per-year level (1 959 estimate by Pulp Chemicals Association, 810 million pounds). And industry observers look for annual crude production to hit the billion pound mark by 1965. Crude tall oil refining facilities have kept pace. Present installed U.S. fractionating capacity stands a t 764 million pounds a year-up from only 60 million pounds in 1950. Expansions already under way will push capacity to a billion pounds per year by the end of 1961. A by-product-not too long ago a fuel value waste product-of the sulfate (kraft) pulping of pine wood, crude tall oil is a mixture of rosin acids, fatty acids, and “unsaponifiab1es”-a catch-all for such compounds as sterols, higher alcohols, waxes, and hydrocarbons. Sulfuric acid converts the black liquor skimmings, called “soap,” from the kraft chemical recovery operation into crude tall oil. Crude oil yield in the southeastern U.S. varies from 0.5 to 1.5y0 of the weight of the pulpwood. Crude tall oil varies in rosin content depending on the geographic location of
726
INDUSTRIAL
AND ENGINEERING CHEMISTRY
What Are “Naval Stores”? Originally they were the pitch and rosin recovered from pine wood and used to caulk wooden ships and tar ship rigging. Today, there are three distinct segments:
GUM NAVAL STORES-gum, or oleoresin, obtained by tapping living pine trees and distilled to make turpentine and rosin, pine oils, and residues WOOD NAVAL STORESrosin, turpentine, dipentenes, and other mono- and dicyclic hydrocarbons and pine oil obtained b y solvent extraction of pine stumps SULFATE NAVAL STORES (includes tall oil)-rosin acids, fatty acids, and nonacids, collectively called tall oil, obtained from sulfate (kraft) pulping of pine wood
the pine tree. Trees grown in the Virginia area may contain as little as 30 to 3570 rosin. At the other extreme, crude from Florida trees will contain as much as 55 to 60Y0 rosin. Crude from Louisiana- and Texas-grown trees usually has about 35 to 40% rosin acid content. Without further processing, crude tall oil finds limited applications because of its dark color, strong odor, and the rosin acids portion’s tendency to crystallize. Most of the crude oil produced in this country today is refined by vacuum fractionation, although acid refined oil still has advantages in some uses. Union Bag-Camp Paper, one o€ nine companies operating 11 tall oil fractionating plants in this country, currently owns 100 million pounds of the capacity and is building toward 150 million by 1961. Earlier this year, the company raised engineering eyebrows by announcing that it had increased the capacity of its Savannah fractionating unit from a designed rate of 30 million pounds per year to 100 million pounds per year, without adding any new equipment. With the growing shrinkage of world rosin supplies, tall oil fractionation emphasis is on rosin production. The paper industry likely accounts for a majority of tall oil rosin output for sizing. Hercules,
black liquor is to evaporate a major portion of the water (solids are hiked from about 15% to 50%) by passing the liquor through multiple-effect evaporators. As the solids content reaches approximately 20 to 23%: the soaps salt out. The liquor then moves to skimming tanks where a retention time of about 45 minutes allows the soaps to float to the surface and be recovered. Skimmings, or soap, are pumped to the tall oil plant for conversion to crude tall oil. The soap-free black liquor is returned to the other effects of the evaporator which concentrate it to the 50% solids level. The liquor then goes to recovery boilers where organics are burned off and inorganics are recovered.
Monsanto-Emery, Crosby, and Arizona all have captive use for tall oil rosin in the manufacture of paper size. Other important rosin users a r e varnishes, paints, gums, and synthetic resins. The current market situation is almost a dircct reversal of tall oil fractionators’ earlier predictions. Fatty acids were to have been the big growth item. But tall oil fatty acids have run headlong into stiff competition from soybean oil in the huge protective coatings industry.
Crude Tall Oil Late in 1942, Union Bag-Camp Paper, in a natural diversification step, entered the tall oil business to produce crude tall oil and acid-refined whole tall oil. Its tall oil facilities are adjacent to the company’s mammouth kraft paper mill in Savannah, Ga. Billed as the world’s largest pulp and paper mill with a capacity of some 2400 tons of unbleached kraft paper and board and semichemical board per day, it supplies enough black liquor skimmings for about 2800 tons of crude tall oil a month. The company gets its remaining raw material needs by buying skimmings from other paper mills and crude tall oil from the other producers. In the kraft pulping process, pine chips are cooked in strong alkali solution (sodium hydroxide-sodium sulfide mixture) to dissolve the lignin and free the cellulose. At the same time, the alkali solution saponifies fatty and rosin acids in the wood. During the cellulose washing operation, these soaps go into solution in the wash liquor (called black liquor). First step in the recovery process for the inorganic chemicals in thr SULFURIC ACID
I
Two Routes to Crude The two basic processes to make crude tall oil are the batch and the continuous. Union Bag-Camp uses both. Converting black liquor skimmings to crude tall oil involves changing the soap to the corresponding fatty and rosin acidsessentially, sodium oleate and sodium abietate to oleic and abietic acids, respectively : ~ C I ~ H ~ ~ C-t OHzS04 ON~ 2C1eHa1COOH NazSOa -f
+
I n the batch prmess, skimmings, sulfuric acid, and water are pumped into a lead-lined steel vat and boiled, using steam for heat and agitation. The vat’s lead lining, in turn, is protected from sagging by a layer of acidproof brick. Ratio of skimmings to acid is 8 to 1 (by weight). At about 215O F., the acid converts the
soap to crude tall oil. The steam then is turned off and the batch is allowed to settle for 30 minutes to separate the components into three layers, The sodium sulfate-dilute sulfuric acid solution settles to the bottom. Next comes a middle layer of lignin, which results from some black liquor being left in the soap. The crude tall oil rises to the top and is pumped to storage. All of the piping must be of corrosion-resistant materials similar to Carpenter 20 stainless steel.
Continuous Crude First step in the newer continuous crude tall oil process is to dilute the skimmings with a mixture of nonionic surfactant and hot water. This reduces the soap’s viscosity and also allows the surfactant to contact, or “wet,” the lignin, and to “break” the emulsified soap present, in the skimmings-critical factors in conditioning the soap for acidulation and subsequent separation. The hot surtactant mixture is metered directly into the soap line, and the diluted soap stream is piped to a vertical acidulation mixer. Here it comes in contact with precooled dilute sulfuric acid feeding into the bottom of the mixer, producing a mixture of crude tall oil, lignin, and spent acid. This stream-tapped from the top of the mixer-passes through a self-cleaning screen to remove any fibrous solids left in the feed and prevent plugging the centrifuge separator. The screened stream drops to a catch tank where live steam raises its temperature from about 160’ to 200” F. Two other streams are fed into the catch tank:
\ SPARGE STEAM SODA ASH SOLUTION
CRUDE T A L L OIL TO STORAGE +
COOKING TANK (215O F1
LIGNIN T O WASTE
4
SPENT ACID STORAGE
I
I
0
8
5 W
m
L
n W
IE
z
II 0 c
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INDUSTRIAL AND ENGINEERING CHEMISTRY
metered hot water to reduce the spent acid’s density, and recycled spent acid. This hot mixture, together with some sulfate salts, moves next to a speciallymodified centrifuge. Nozzles in the periphery of the centrifuge continuously draw off any heavy solids (mainly lignin). Products leave the centrifuge in three streams: a light phase of crude tall oil; a heavy phase, or ring dam discharge, made u p of lignin and spent acid; and a nozzle stream composed of spent acid and a small amount of fine solids. The ring dam, and nozzle discharges funnel off to a compartmented tank where spent acid is returned to the centrifuge feed tank. The remaining spent acid, along with the lignin phase, discharges over a weir in the compartmented tank and is pumped back to the mill for recovery. From the centrifuge, the separated crude tall oil moves along from a catch tank to a settling storage tank to remove more moisture before being pumped to storage.
Acid Reflning Union Bag-Camp and National Southern Products are the last remaining producers of acid-refined tall oil. National Southern makes it exclusively, while Union Bag-Camp has both acid-refining and vacuum distillation facilities. Acidrefining of tall oil is somewhat akin to acid-refining of refractionating oils in the petroleum industry. And, as in the petroleum industry, the tall oil process depends primarily on techniques painstakingly developed by trial and error. And the chemistry of the process involves a maze of complex reactions. Refining doesn’t particlarly alter the proportion of rosin and fqtty acids present in the original crude. But it removes odor bodies, such as mercaptans and disulfides, and a large portion of the color materials-namely, oxyresin acids. And since the sulfuric acid treatment produces dimers of both the rosin and fatty acids, it eliminates the crystallization tendencies displayed by rosin in the crude oil. In acid refining-a batch processcrude tall oil is dissolved in naphtha, and then treated with concentrated sulfuric acid (88 to 100%). The temperature and the ratio of solvent to crude governs the product’s color, while the amount of sulfuric acid controls its viscosity. Following the acid treatment, a black acidic sludge, containing most of the coloring material and odor bodies, settles to the bottom of the tank and is drawn off. T h e sour oil solution remaining is then washed with water and a very dilute alkali solution to remove all residual sulfuric acid. Stripping off the naphtha leaves the refined tall oil product.
After operating a batch crude oil process for 14 years Union Bag-Camp installed a Sharpies continuous acidulation plani for the production of crude tall oil in order to secure improved yields
Move on to Fractionation I n April 1956, Union Bag breezed through start-up operations of its new $2.5 million tall oil vacuum distillation plant at Savannah. Designed and built on a turn key basis by Foster Wheeler, it uses a “blocked” process: some of the equipment does two jobs-one feed stream is blocked off while the other is in use. Part of the time it feeds crude tall oil and splits off a fatty acids intermediate in addition to the primary rosin product. This fatty acid intermediate is stored and, at regular intervals, plant operation switches over to this feed to make high-quality fatty acids. From a ton of crude, Union Bag retrieves about 300 pounds of pitch, 800 CONC. SULFURIC ACID
pounds of rosin, and 500 pounds of fatty acids at the distillation plant. Secondary products, such as distilled tall oil, and losses account for the remaining 400 pounds. Physically the plant consists of a main fractionating tower (about 125 feet high) with a small pitch-stripping tower immediately adjacent to it. Both towers are of conventional bubble cap design, and the main fractionating tower is equipped with an internal condensing section to avoid the danger of plugginga constant threat with conventional shell and tube condensers. All surfaces in the towers which come in contact with the feed are of Type 316 stainless steel with a minimum of 2.5y0 molybdenum. WATER
CRUDE T A L L STORAGE
EVAPORATOR
STEAM
SLUDGE TO WASTE
REFINED OIL TO STORAGE
WASHING TO WASTE
I
RECOVEREDNAPHTHATOSTORAGE
Acid refining of
CI
ude tall oil
VOL. 52, NO. 9
SEPTEMBER 1960
729
t
Rosin Production I n the first pass operation, crude oil is piped from storage through a dehydrator. As the crude contai&- small amounts of sodium sulfate, the equipment is designed to prevent contact of the wet feed with heat exchange surfaces until it has been dehydrated. The trick: Part of the crude from the dehydrator-after
first passing through heat exchangers to boost its temperature to about 350" F.is recycled to plant with the incoming wet crude. This circulating crude stream keeps the temperature of the oil leaving the dehydrator a t approximately 185" F., and thus reduces moisture content of the crude oil going into process to 0.29?.,. maximum. Also, dehydrating the crude before it ccntacts
Dowtherm vaporizer i s fully automatic and has its own instrument panel located immediately adjacent to the outside of the control room. The only attention required for this unit i s occasional readings of temperature and pressure
heat exchanger surfaces precipitates the: sodium sulfate as a fine anhydrous powder which does not cling to, and foul the heat exchanger surfaces. The crude moves from the dehydrator through the shell-and-tube feed preheater, where it is heated to about 500°F. by Dowtherm A (Dow Chemical's heat transfer agent-a eutectic mixture of diphenyl and diphenyl oxide). From there, it f l o ~ to s another shell-and-tube preheater, in which super-heated sparge steam reduces the partial pressure of the fatty and rosin acids to flash the major portion of the crude oil into vapor. Here Dowtherm A supplies the heat of vaporization and holds the temperature of the vapor-liquid mixture, leaving the flash feeder a t approximately the same level as that of the entering crude feed. More super-heated sparge steam is fed into the bottom of the pitch tower to further lou.er the partial pressure of the free fatty and rosin acids in the pitch, and to pare their losses to the minimum. Primary purpose of the pitch stripping tower is to remove lignin, inorganic materials, and color bodies, and, a t the same time, to minimize the amcunt of heavy unsaponifiables in the vapor feed to the main fractionating tower. The pitch fraction-some 157, of the original crude tall oil-leaves the bottom of the stripping tower a t 500 to 525" F., is cooled to about 350" F., and then piped to storage. The remaining 85y0 of the crude goes as vapor feed to the main tower. I n the main fractionating tower, highquality rosin is produced as a bottoms product ; the fatty acid intermediate goes off near the top. Naturally, to make any fractionating tower work, part of the top product must be returned as reflux to the tower and part must be reboiled. With heat-sensitive fatty and rosin acids, this fundamental is complicated by the fact that reflux and reboil time must be as short as possible to minimize degradation of the prcducts. Union Bag-Camp's chemical engineers have spent much time and effort in establishing optimum reflux ratios to give the right degree of separaticn with the least amount of product degradation.
Big Capacity Boost
Process pumps and heat exchangers are located in an area immediately adjacent to the fractionating tower. All critical process pumps are duplicated to prevent shutting down the plant in the event of pump failure
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INDUSTRIAL AND ENGINEERING CHEMISTRY
Early this summer, the company announced that it has succeeded in boosting the plant's capacity- by more than 3009?.0of design. Feed rate jumped from 35,000 to about 50,000 tons per year using essentially the originally-installed equipment, except for increasing the size of feed pumps and one heat exchanger. And, in the bargain, the new feed rate gives higher product purity because the heat-sensitive materials are held at the high distillation temperatures for a much shorter time than under design conditions.
StaSlndurtry As the rosin fraction is a final product in the first pass, its quality is the important thing in this operation. Thus, rosin acid content of the fatty acids intermediate is kept a t a level to produce a rosin product containing less than 2.5% fatty acids. The amount of pitch removed in the pitch stripping operation controls the rosin’s unsaponifiables content (less than 2.5y0 in the final rosin product). The main fractionating tower operates under 50-mm. top pressure. Superheated sparge steam is added to the reboiler to reduce the rosin’s partial pressure, thus keeping the temperature in the bottom of the tower at an optimum. Leaving the tower at about 480” to 525” F., the rosin is cooled in a shell-andtube heat exchanger which uses the crude tall oil leaving the dehydrator as the cooling medium. This innovation, part of the Foster Wheeler design, skirts the plugging hazards found in cooling rosin in a water-coolant heat exchanger. And italso means some savings in heating costs. The fatty acids intermediate leaves the tower at about 380” F., and is cooled in a shell-and-tube heat exchanger by tempered water. One big problem that generally plagues chemical processors who are cooling materials from very high temperatures is build-up of solids on the water side of heat exchangers when hard water is used as coolant. To eliminate this, Union Bag-Camp collects all steam condensate in the process and uses it in a closed tempered-water system as cooling medium for the fatty acids. The tempered water then is cooled in a water-to-water heat exchanger, using water from the cooling tower. Upon cooling to 160’ F., the fatty acid product is piped to storage for further processing in the second pass. A small odor cut is tapped from the very top of the tower during the first pass operation to make sure that odoriferous materials are removed before they can react with the fatty acids and produce fixed odor bodies which cannot be removed by distillation. Since the main tower is equipped with an internal condensing system, only the sparge steam (introduced at several points in the process) and a very small amount of fatty acids go off a t the top of the tower. These are trapped in a barometric condenser, which uses water from the cooling tower. Steam jet ejectors then pull the vacuum on this condenser.
Fatty Acid Pass Intermediate fatty acids from the first pass are fed back into the main fractionating tower a t about its midpoint. O n the way, the feed passes through the Dowtherm-heated preheater, but skirts the feed flasher and the pitch stripper. I t enters the tower a t about 460” F.
After reflux, the high-grade fatty acid product is tapped near the middle of the tower so that the heads cut can be used to control its unsaponifiables content. The distilled oil fraction, drawn from the bottom of the tower, controls the product’s rosin acids content. Close control of the fatty acid product is critical to maintain the company’s rigid product specifications. The product can contain no more than 0.6Y0 rosin acid and O.6Y0 unsaponifiable. And, as in
the first pass, it is imperative to keep distillation time and temperature as short as possible to minimize product breakdown. Here again, sharp engineering by Union Bag-Camp’s Savannah staff has resulted in a 3ooY0 increase in fatty acid capacity-duplicating the improved efficiency of rosin production in the first pass. An odor cut, taken a t the very top of the tower, removes any degradation products before they can affect the bland
Evolution of a n Industry Early 1900’s Swedish chemist discovers that cooking coniferous woods with strong alkali yields soapy material made up of fatty and rosin acids. Material called tallolja-pine oil or oil of pine as we know it
Mid-1920’s
U. S. chemists interested in Swedish product and in possibilities of separaLing rosin from fatty acid. Product kept Swedish name for pine and became known as tall oil
Mid-1930’s
First domestic commercial units on stream, distilled tall oil product contained 20 to %yorosin acids, rosin product held about 10 to 15% fatty acids. Both dark in color
1936
West Virginia Pulp and Paper becomes first U. S. producer to operate on a continuing basis
1942
Union Bag-Camp Paper started tall oil plant
1943
Union Bag-Camp Paper puts acid refining plant on stream using Gayer-Fawkes process (Patent No. 2,223,850). Armour started distilling crude tall oil a t Chicago plant, using Potts and McKee process (Patent Nos. 2,224,925 and 2,224,986). Rosin product contained 7070 rosin, and fatty acids contained 670 rosin
1948
General Mills starts operation at Kankakee, Ill., using Potts and McKee process
1949
Arizona Chemical, a joint venture of American Cyanamid and International Paper, demonstrates first successful separation of tall oil into high purity fatty acids and rosin on commercial scale-fatty acids contain less than 2y0rosin, its rosin less than 3Y0 fatty acids. Arizona’s plant uses distillation techniques used in petroleum industry and adapted to tall oil’s heatsensitive constituents by American Cyanamid and E. B. Badger manufacturing. Newport Industries (now Heyden-Newport) starts operation at Bay Minette, Ala.
1954 1955
Crosby Chemical starts operation at Picayune, Miss.
1956
Union Bag-Camp Paper began operation of “blocked distillation” unit at Savannah, Ga. Unit designed and built by Foster Wheeler Hercules Powder starts u p two units, a t Franklin, Va., and Savannah, Ga. Both units designed by Hercules and Ake Linder, Sweden West Virginia Pulp and Paper went on stream with new plant at Charleston, S. C. Unit built by Bell and Gossett, using process developed by Schultz of Chicago Monsanto-Emery build distillation plant at Nitro, W. Va., and Glidden started operation a t Port St. Joe, Fla. Both units designed and built by Badger Mfg. Hercules puts new unit on stream at Burlington, Ontario, Canada
1958 1960
Arizona Chemical brings on stream Badger-built unit at Spring Hill, La. Heyden-Newport is building new distillation unit at Oakdale, Calif., Foster Wheeler constructing
VOL. 52, NO. 9
SEPTEMBER 1960
731
Here’s Where Tall
Oil Fatty Acids G o %
Protective coatings Soaps, detergents, and disinfectants Chemical intermediates Others, such as flotation chemicals, hard floor coverings, and tallate driers
23.2
21.7 23.2 31.9
odor of the main acid stream. Plant operators also draw off a heads cut, very high in unsaponifiables and palmitic acid, from the condensing system. As in all tall oil distillation work in high purity products, a distilled tall oil fraction must be split off. This fraction is drained from the bottom of the main tower during the fatty acid pass. High in rosin acids content (35 to 40%) and noncrystalline in character, the distilled tall oil fraction goes off at about 480° to 500° F. High-grade fatty acid yield from the second pass is about 25y0 of the original crude oil feed. The heads fraction, odor cuts, distdled tall oil, and losses account for the remaining 20% of the starting crude. Besides their feat in boosting plant capacity, Union Bag-Camp’s engineering team takes pride in the ease of plant startup. First, equipment was heated by sending Dowtherm A to all users, and by blowing super heated steam through the towers. After 24 hours of this the crude was fed in at the design rate. Within 48 hours, the plant had met quality and performance guarantees for the first pass operation and ran continuously from startup in April until July. Then it was shut down for a complete inspection of tower internals, heat exchangers, and other units for corrosion. Finding none, the engineers started it u p again and it has been running continuously ever since, except for two routine shutdowns per year for repairs and inspection.
between the crude oil plant and the distillation unit. Looking into the economics, the company found it cheaper to use this system than to lay down some 3000 feet of insulated stainless steel pipeline, which would be used only part time. Now two giant tank cars, 19,000 and 20,000 capacities, are doing the job and for less money.
What‘s Ahead Rosin consumption is soaring both a t home and abroad and has already outdistanced productive capacity. This year, for the first time, reserve rosin stocks held by the Commodity Credit Corp. (Government rosin stockpile) were completely exhausted by the growing world demand. The Naval Stores year ending March 32, 1960, saw a domestic rosin disappearance of 1,533,000 drums (520 pounds each)-up 12% from the previous crop year of 1959. Exports in the same period were 782,000 drums, up 54Ye from 1959. The total disappearance was u p 23% and amounted to 400,000 drums more than the total rosin production of 1,914,000 drums. Production during the year ending March 31, 1960, showed a small increase of 3%. Despite the strong demand, the first three months of the current Naval Stores crop years show a production increase of only 6%. It is generally believed that the industry will be unable to increase more than this percentage during the balance of the year if, indeed, it can maintain this rate. What are the chances for stepping u p rosin output? Generally, not too promising, say industry observers. Gum rosin production, once the major source of rosin, has tumbled from nearly 2 million drums in 1909 to where it now accounts for only 171/’& (334,000 drums) of total rosin production. And although
Quality Safeguards The plant also boasts a host of company innovations for improved process efficiency and product quality control. T o protect fatty acid products from oxidation and moisture, Union BagCamp blankets all product storage tanks with inert gas produced a t the plant by burning the oxygen out of the air with natural gas. The inert gas is compressed and dried to a dewpoint of 10’ F. before it goes to the storage tanks. All tank cars and tank trucks are purged with this gas before loading. I n addition, all finished product pipelines and pumps are made of either Type 316 stainless steel or aluminum and all finished product storage tanks are aluminum. And all of them have agitators to continuously blend the contents and ensure product uniformity. Another Union Bag-Camp wrinkle is the plant’s tank car shuttle service 732
INDUSTRIAL AND ENGINEERING CHEMISTRY
Crude Tall Oil Breaks Down Like This Rosin Acids
% Abietic Palustric Neoabietic Dihydroxyabietic Isodextropimaric Unidentified
20-25 8-10 22-27 4-5 3-4 29-43
Unsaturated Fatty Acids Oleic 46-48 Linoleic 43-45 Linolenic 1-2 6-8 Saturates Unsaponifiables Phytosterols Higher alcohols Hydrocarbons
25-35 5-15 35-60
there is a strong movement afoot by paper companies such as Union BagCamp to inject new life into the industry, this will be a slow development because of the need to recruit new labor forces to collect gum in our southern pine forests. The situation is no more encouraging for wood rosin. Wood rosin production apparently has reached its plateau a t about 1.2 million drum level recorded in the crop years 1957 through 1960, experts believe. Look for wood rosin output to drop to 1 million drums in 1961, and to 850,000 drums by 1962 (‘unless prices should reach a level which would permit pulling of stumps in areas in which this has thus far been uneconomical and impracticable,” says H. L. Meyer of Chematar Pine Products. Tall oil contributed about 20% (382,000 drums) of rosin output for the year ending March 31, 1960. And although sulfate wood pulp production in southern mills will increase in the next five years, crude tall oil production is estimated by the Pulp Chemicals Association at 1 billion pounds in 1965 from present 800 million pounds. Based on these factors, it is expected that tall oil rosin production of 380,000 drums in 195960 will rise to 4.40,000 drums for 1960-61 and approximately 550,000 drums in 1965 if all crude tall oil is utilized by the fractionating industry. 1Yhile the tall oil industry has been straining to meet the demand for rosin, the high production rate has only fuurrher complicated the problem of marketing tall oil fatty acids. A relatively huge production of tall oil fatty acids, estimated at 150 million pounds in 1959 compared to a few thousand tons ten years ago, has combined with low prices on competitive oils and fats, principally soybean oil, to give the tall oil fractionating industry a monumental problem as to where to market this new fatty acid production. Union Bag is attempting to solve the fatty acid market problem by producing exceedingly pure grades. A new product, Unitol C M T , is noiv being marketed with color of Gardner 1-2 and approximately one half of 1% each of rosin and unsaponifiables. This product has unique applications in the field of epoxy vinyl plasticizers. No doubt, other fields of use will be found for tall oil fatty acids of high purity a t low costs. Nonetheless, tall oil products are o n the expansion trail [I/EC 52,29 A (August 1960)l. And Union Bag-Camp, for one, plans to stick with its present blocked process in future expansions. Reason: a continuous process must run relatively inflexibly to be efficient, while multiple blocked units can operate independently to give better control over inventory when shipments become irregular.
