SEVEN INORGANIC CHEMICALS
New technology and products offer challenges
H. CLIFFORD NEELY, Assistant Editor, New York City generation of chemists left the university laboratory armed with the knowledge that sulfuric acid was used to pickle steel. They were just as secure in their certitude that calcium carbide acetylene was a good starting point for the commercial synthesis of about anything. In a decade, these once sacrosanct principles have gone the way of all ancient technologies. One simply doesn't get there from here that way anymore. In coming months, technology is going to keep right on changing street signs along the established routes to uses for inorganic chemicals. The next decade will usher in a whole battery of new technologies and products to challenge chemists and engineers. Large-volume chemicals will be taken hors de combat with surprising swiftness. Synthetic materials will continue to replace natural products, large plants and complexes will remain the watchword, and the substitution of one inorganic chemical for another will be an ever present threat. A partial list of processes that would bring big changes for inorganics includes hydrocracking in gasoline refining, oxygen injection in blast furnaces, holopulping to eliminate chemical markets in papermaking, and the chance that phosphoric acid will be made from hydrochloric or nitric acid on a large scale. In one measure, the technological know-how and mammoth size of
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82A C&EN SEPT. 1, 1969
chemical complexes in the future will protect the industry from new competition. The risks in such projects will be so great that only established firms with what may be called "fail-safe" interlocking processes will be able to obtain capital.
Foundation in history Statistics on the production of inorganic chemicals bear witness to the fact that it is a rapidly growing sector of the chemical industry. In the 1963-68 period, the production of inorganic chemicals as measured by the Commerce Department's production index rose about 12% a year compounded, compared to a 7% rate for the previous five years. While production was soaring 12% annually, however, the value of shipments of inorganic chemicals grew only 5.3% per year in the 1963-68 period to $6.57 billion. This year, shipments should reach $6.7 billion. Lower prices for inorganics have been a mixed blessing. In terms of what profits might have been, lower prices have caused management to voice a long caterwaul. On the other hand, lower cost goods have spurred the growth in output. Although competitive pressures were in part responsible for the price erosions, improvements in production efficiencies contributed mightily to making lower prices possible.
Oxychlorination
reactions
Chlorine is an inorganic building block that is showing surprising year to year advances. Even specialists in its markets are hard pressed to explain the almost 10% growth chalked up by this handmaiden of the industry last year. The basic technology for producing chlorine hasn't changed much in decades, although dimensionally stable anodes and large circuits are the latest in a series of minor process changes that have lowered production costs. A rash of technology has developed, however, to reclaim chlorine values in the hydrochloric acid byproduct from chlorination reactions. These processes go a long way toward explaining the strong upturn in overall chlorine consumption. The processes for recovering chlorine from HC1 fall into two general classifications: • Those that isolate HC1 to treat it separately. • Those, such as oxychlorination, that do not separate HC1 from chlorination reaction streams. The first group is typified by such processes as the electrolysis of dilute HC1 streams, as developed by Hoechst in West Germany, and the Kel-Chlor process (C&EN, May 5, page 14) that Kellogg developed. A number of major chemical companies have developed oxychlorination and oxyhydechlorination processes. The object for all, in terms of a companywide or nation-
Production index for inorganics increased 24°/o from 1967 to 1968 FRB production index, 1957-59=100
wide balance, is to produce the required tonnages of chlorine while not strapping the producer with unwanted amounts of caustic soda or HCL Oxychlorination denotes the reaction of air, chlorine, and a hydrocarbon to produce a chlorinated hydrocarbon and water. Oxyhydrochlorination replaces chlorine in this reaction with HCl. These processes were mentioned in the technical literature for many years with the first plant possibly being built by Dow in the 1950's. However, it wasn't until the early 1960's that these processes began to make significant contributions to the economics of producing vinyl chloride. The widespread use of oxychlorination should have reduced the quantities of caustic soda by-product made by the industry and slowed down the growth in chlorine output as well. The opposite seems to have occurred. Oxychlorination processes permitted reductions in the cost of production that could be translated into lower prices for polyvinyl chloride goods. Large-volume markets at low prices made a 12.4% annual growth rate in the 1963-68 period possible for PVC. Oxychlorination aggravated rather than solved the potential caustic soda oversupply problem that haunts chlorine producers. If anything, chlorine producers have been overly concerned about finding new markets for caustic. Caustic soda is in extremely tight supply right now. Outlets for the use of caustic in the production of glass to replace soda ash and to supplant soda ash in alumina are growing, but it isn't easy to find the required caustic supplies. All but a few alumina producers have changed to caustic; the potential market for caustic is about 1 million tons. This year, about 9.2 million tons of chlorine will be produced in the U.S. About 95% of this production will be from sodium chloride brines. About 9.6 million tons of by-product sodium hydroxide will also be made. Propylene
oxide
Chlorine stands to lose a market should direct oxidation become the route of choice for making propylene oxide. Oxirane Chemical Co., a 50-50 joint venture of Atlantic Richfield's Arco division and Halcon International, is in full production at its 160 million pound per year propylene oxide direct oxidation plant at Bayport, Tex. As direct oxidation processes
for making ethylene oxide supplanted the chlorohydrin route, propylene oxide growth was absorbed by the conversion of old ethylene oxide chlorohydrin units to propylene oxide facilities. This switching has about run its course and the advent of propylene direct oxidation plants may sign the death sentence for the last of the chlorohydrin processes. Last year about 600,000 tons of chlorine were used to make propylene oxide by the chlorohydrin process. Sodium carbonate or soda ash has been the loser in several jousts over markets with caustic soda. Caustic's inroads in alumina and glass have already been mentioned. A third large market caustic producers hope to take from soda ash is the production of phosphates for the detergent industry. Chlorine producers would like to develop a situation where caustic first moves to fill N a 2 0 markets and soda ash acts as a flywheel for satisfying the remaining requirements (C&EN, March 3, page 11). The combined production of synthetic and natural soda ash will reach about 6.7 million tons this year, up about 2% from last year. The future is all in the hands of natural producers, however, since synthetic plants are not economical at today's prices. Synthetic production peaked in 1965 and has declined since, as production costs have climbed and caustic soda has competed for normal soda ash markets.
250 |
200
150
100 I 1964
1965 1966 1967 1968
Source: U.S. Department of Commerce
The development of a market for by-product ferrous chloride from HCl pickling would further enhance HCl's hold on pickling. One such possibility, the protege of Dow Chemical, is a ferrous chloride-based process for removing phosphates from municipal sewage wastes (C&EN, March 3, page 39). Hydrochloric acid could lose some of this market should a trend to regeneration of spent HCl liquors develop. Only two picklers in North America now are using regeneration processes, however, and the present economics favor disposal over recovery of the spent liquors.
Strip for cans The pickling of steel strip with hydrochloric acid brings a once-in-adecade fillip to this acid. It has been a market that developed very quickly. The steel industry used a miniscule amount of hydrochloric acid for pickling in 1962. This year consumption could reach 700,000 tons of 22° Baume acid. Hydrochloric acid has forged this gigantic market in steel pickling at the expense of sulfuric. A 1.1 million ton per year sulfuric business in pickling acids has dwindled to what may be about 400,000 tons this year. There are good reasons for HCl's moving so rapidly into pickling. It reacts faster with mill scale, and the capacities of existing lines can be ex-' panded at little cost. The HCl is also said to eat away less base metal and produce a better surface for subsequent tin plating for making cans.
Value of shipments of inorganics increasing about 2.6°/o this year Shipments, billions of dollars
11111
1966 1967 1968 1969*1970* *C&EN estimates and computer forecasts Source: U.S. Department of Commerce
SEPT. 1, 1969 C&EN
83A
The amount of HC1 actually produced in the U.S. is difficult to pinpoint. Commerce Department numbers indicate that 1.7 million tons of HC1 were produced in 1968. A reading of the fine print of the department's criteria for reporting states that only quantities produced for further processing in the same plant, intracompany transfers, and sales to other companies are tabulated. The number of tons of HC1 neutralized and ditched isn't reported and neither is the HC1 consumed captively for oxychlorination, which alone may total 1 million tons a year. Inclusion of these figures may double the reported production numbers for HC1. The loss of its market in pickling and the falloff in phosphate fertilizer demand have worked combined hardships on sulfuric acid. Whipsawed by the decline in these markets, sulfuric acid production has plateaued at the 28 million ton-per-year level since 1966. This year about 28 million tons will be produced. A breakthrough to new heights for sulfuric will depend on what happens to phosphate fertilizers, by far the acid's largest end use. A U.S. process for treating phosphate rock with HC1 would make a big dent in sulfuric acid markets. At least two firms in Israel have commercialized such a process. Also, nitric acid is being used in commercial operations and could pose a serious threat to sulfuric in this market. Industrial
gases
One of the most dynamic growth sectors for inorganic chemicals is industrial gases. As a group, the gases have probably grown at a 15%-a-year rate since the early 1940's. Cryogenics, which may supersede oceanology and space as the glamour industry of the 1970's, promises to give further impetus to consumption of the gases, especially hydrogen and helium. The basic oxygen furnace had tremendous impact on the air separation companies. Prior to 1960, chemical uses and steel shared equally the market for oxygen. Since the advent of the basic oxygen furnace, which injects a stream of oxygen to promote the carbon boil in steelmaking, this equilibrium has shifted to where steel now accounts for about 70% of the oxygen consumed in this country. 84A C&EN SEPT. l t 1969
This year, about 57 million tons or 42% of the total steel poured will be made in basic oxygen furnaces. This will probably increase to 65 million tons in 1970. Existing uses for oxygen in the nonferrous industry will continue to grow. Oxygen consumption in copper smelting, iron foundries, lead and zinc smelters, the melting of aluminum scrap, and the calcining of phosphate rock for phosphorus manufacture will likely expand. It will continue to be used in partial oxidation processes for acetylene. A host of new markets in chemical processing beckon oxygen producers. Huge volumes of oxygen could be required to make hydrogen via the partial oxidation process. The petroleum industry will probably shift from a net producer of hydrogen to a net consumer in the coming decade as hydrocracking replaces reforming as the basic refining process for gasoline in the U.S. Large amounts of hydrogen will have to be produced for this use and the continued use of hydrotreating processes to remove sulfur, olefins, and nitrogen from crude fractions. The partial oxidation process for producing petroleum hydrogen could represent a 4000 ton-per-day market for oxygen in the late 1970's, according to Linde's John B. Powers. Mr. Powers, marketing manager for Union Carbide's industrial gases division, lists some other potent growth areas for oxygen. In the decade of the 1970's, ethylene oxide may take 4000 tons per day of oxygen, liquefied petroleum gas oxidations and miscellaneous uses about 3000 tons per day, and titanium dioxide manufacture will consume about 3000 tons per day as the chloride route gains ascendancy over the sulfate process. Should oxychlorination processes switch to oxygen from air an additional 2000 tons per day of oxygen would be needed, he adds. Coal chemicals Two promising future markets for oxygen are blast furnace injection and sparging of rivers and streams to figjht pollution, Mr. Powers continues. Just as oxygen addition to open hearth or basic oxygen furnaces speeds up steelmaking, its injection into blast fur-
naces results in more output of pig iron per furnace. Oxygen injection also makes possible a reduction and even the elimination of coke to the blast furnace, since lower quality fuels can be used with oxygen. Obviously, the acceptance of oxygen injection in blast furnace operations would have far reaching consequences for coal chemicals. To date, however, the U.S. steel industry hasn't accepted the economies of this process, although it is being used in Japan, the USSR and, to a lesser extent, in England. As pollution control regulations become more stringent, it is easy to see how the market for oxygen in the treatment of wastes in rivers and streams could climb to anywhere from 5000 to 20,000 tons per day, Mr. Powers explains. Air separation producers, like their chlorine-caustic counterparts, have a problem balancing oxygen sales with by-product nitrogen demand. Some flexibility is afforded air separation plant operators by virtue of the fact that the ratio of nitrogen to oxygen produced can be varied fairly widely. In recent years, the distributable uses for nitrogen have been growing about twice the rate that they have for oxygen, but the overall balance problem is not serious. The major use for nitrogen is in blanketing, but refrigeration of freight cars and trucks holds a bright future for this gas. Float glass, a new technology that floats molten glass on a pool of molten tin while permitting the top surface of the glass to be flame polished in a nitrogen atmosphere, opens a new but relatively small outlet for nitrogen. Argon production surged ahead at an 18%-a-year rate in the 1963-68 period. Welding uses account for 75 to 80% of the consumption of argon. Such welding developments as MIG (metal inert gas) and TIG (tungsten inert gas), are widely accepted. Argon has successfully defended its position against carbon dioxide in these uses as the price of argon dropped. A method for producing stainless steel that uses argon and oxygen has been developed by Union Carbide (C&EN, July 15, page 20). The ferrous metals industry, in general, offers many opportunities for argon since most steels are nitrogen sensitive. Ar-
Production trends are up for most major inorganic chemicals 1965
Acids Hydrochloric acid, total, 100% HCI Hydrofluoric acid, total, 100% Nitric acid, 100% Phosphoric acid, 100% P 2 0, Sulfuric acid, 100% H2S04, millions of tons Chlorine and alkalies Chlorine, total Potassium hydroxide, total, 88-92% KOH Sodium carbonate Synthetic, 58% Na 2 0 Natural, 58% Na O Sodium hydroxide Total, 100% Dry Industrial gases Acetylene, billions of ft3 Argon, millions of ft3 Carbon dioxide Solid Liquid and gas Hydrogen High purity, billions of ft3 Lower purity, billions of ft3 Nitrogen, high purity, billions of ft3 Oxygen High purity, 99.5% Lower purity, 95% Inorganic fertilizer materials Ammonia, synthetic, anhydrous, 100% Ammonium nitrate Original solution Explosives and other uses Ammonium sulfate Synthetic and by-product Coke oven Other chemicals Aluminum chloride, anhydrous, 100% Aluminum sulfate, commercial, 17% Al203 Calcium carbide, commercial Calcium phosphate dibasic, anhydrous 100% Carbon, activated Hydrogen peroxide, 100% by weight Phosphorus, elemental, white, yellow, and red Phosphorus, oxychloride, 100% Phosphorus pentasulfide, 100% Potassium pyrophosphate, anhydrous, 100% Sodium bichromate and chromate, hydrous Sodium chlorate, 100% NaCI0 3 Sodium phosphate, tripoly, 100% Sodium silicate, liquid and solid, anhydrous Sodium sulfate, total high and low purity Titanium dioxide
Production, thousands of tons, unless otherwise stated 1966 1967 1968*
1969*
1,370 156 4,898 3,905 24.9
1,521 175 5,514 4,596 28.4
1,625 191 6,265 5,189 28.8
1,735 202 6,135 4,926 28.4
1,960 220 5,870 4,690 28
6,517 181
7,204 174
7,680 175
8,428 178
9,200 178
4,926 1,494
5,071 1,738
4,849 1,748
4,553 2,043
3,950 2,800
6,842 517
7,616 526
7,924 565
8,799 490
9,600 450
16.7 1,286
16.6 1,710
14.2 1,910
14.9 2,215
14 2,900
421 665
379 703
368 725
363 685
390 775
35.5 102 90
34.1 124 104
33.5 169 116
31 50f 120
30.1 91.5 73 7,570 2,170
8,800 2,097
10,100 1,972
10,300 1,790
10,600 1,690
8,869
10,605
12,200
12,093
11,800
4,663
5,117
5,707
5,223
4,950
550
648
648
577
650
1,947
2,106
1,937
1,993
1,880
709
753
745
721
590
33
36
38
34
39
1,063 1,098
1,121 1,063
1,039
1,090
1,200
263 85 53 555 27 49 55 141 134 923 588
290 92 55 566 31 54 53 141 154
912 392 83 59 587 33 49 55 135 155
916 411 85 65 609 34 47 48 145 166
1,001
1,048
1,176
623
613
632
660
1,404
1,445
' 1,364
1,472
1,540
577
594
589
627
695
865 475 82 72. 635 36 79 42 150 190 1,240
* Preliminary figures. **C&EN estimates and computer forecasts. tExcludes amounts produced in petroleum refineries for captive use beginning with 1969 production figure. Source: U.S. Department of Commerce SEPT. 1, 1969 C&EN 85A
Growth rates in 1963-68 period generally retained strength
Product Acids Hydrochloric acid, total, 100% HCI Hydrofluoric acid, total, 100% Nitric acid, 100% Phosphoric acid, 100% P205 Sulfuric acid, 100% H2S04, millions of tons Chlorine and alkalies Chlorine, total Potassium hydroxide, total, 88-97% KOH Sodium carbonate Synthetic, 58% Na 2 0 Natural, 58% Na 2 0 Sodium hydroxide Total, 100% Dry Industrial gases Acetylene, billions of ft 3 Argon, millions of ft 3 Carbon dioxide Solid Liquid and gas Hydrogen High purity, billions of ft 3 Lower purity, billions of ft 3 Nitrogen, high purity, billions of ft 3 Oxygen High purity, 99.5% Lower purity, 95% Inorganic fertilizer materials Ammonia, synthetic, anhydrous, 100% Ammonium nitrate Original solution Explosives and other uses Ammonium sulfate Synthetic and by-product Coke oven Other chemicals Aluminum chloride, anhydrous, 100% Aluminum sulfate, commercial, 17% Al203 Calcium carbide, commercial Calcium phosphate dibasic, anhydrous 100% Carbon, activated Hydrogen peroxide, 100% by weight Phosphorus, elemental, white, yellow, and red Phosphorus, oxychloride, 100% Phosphorus pentasulfide, 100% Potassium pyrophosphate, anhydrous, 100% Sodium bichromate and chromate, hydrous Sodium chlorate, 100% NaCI0 3 Sodium phosphate, tripoly, 100% Sodium silicate, liquid and solid, anhydrous Sodium sulfate, total high and low purity Titanium dioxide Source:
Compounded growth rate, % 1963-68 10.5 9.5 7.7 11.0 6.4 9.0 6.5 0 12.9
Enzyme 8.5 —3.8 0 18 -3.7 4.8 8 17 18 14.2 -1.6 5.0 5.5 6.5 10.5 2.2 6.3 2.9 -3.8 11.3 3.4 10.7 4.5 7.1 6.7 5.5 1.6 6 7.5 3 3.8 3.9
U.S. Department of Commerce
gon will probably be used increasingly in such steelmaking steps as degassing, atmospheric protection in continuous casting, furnace brazing, and in electronics and solid-state devices manufacture. The chemical industry's shift from acetylene to ethylene and propylene in making such products as acrylonitrile, acetaldehyde, trichloro86A C&EN SEPT. 1, 1969
prene production, may decline considerably. Although the great bulk of Du Pont's neoprene production continues to be founded on acetylene, its La Place, La., expansion is based on butadiene. Petro-Tex is also basing its chloroprene production on butadiene in Houston.
ethylene, vinyl acetate, and vinyl chloride is reflected in the production figures for acetylene and calcium carbide. Calcium carbide has had a negative 4% a year growth in the 1967-68 period. Acetylene production peaked out at 16.7 billion cubic feet in 1965. Even in welding acetylene has barely held its own. Another large market for acetylene, neo-
detergents
At midyear, detergent sales were off, but the demand for sodium tripolyphosphate by detergent makers remains strong. Producers are somewhat puzzled by the recent brisk demand for this material, which goes almost exclusively to detergents. One salesman to the detergent industry credits the raft of new enzyme detergents on supermarket shelves for tripoly's showing. "The pipeline has to be filled for every new brand," he explains. Sodium tripolyphosphate has grown at a 7.5% compounded rate in the 1963-68 period. This year, production will likely climb about 5.5%. Holopulping, a selective delignification process, poses a serious threat to chemicals now going to paper pulping uses (C&EN, May 19, page 30). The process is still in the laboratory stage. The inorganic chemical most vulnerable to the inroads of holopulping is salt cake (sodium sulfate). In 1968, 1.3 million tons valued at $35 million went to paper pulping. No salt cake is used in holopulping. Developers of the process claim it cuts the cost of chemicals to pulpers by twothirds. Paint Production of titanium dioxide, which still gives the best hiding properties in paints, increased about 3.9% compounded annually during the 1963-68 period. This year, production will climb 10%. Titanium dioxide white values are added to practically every paint. As is apparent, inorganic chemicals are quick to feel the impact of new technologies and new products. A chemical executive from Rome recently spotlighted the kinds of change the chemical industry must be prepared to face. "You know," he remarked in awe, "every minute a new product is born in this country." It is something to keep in mind.
