/ R E P HTP Hits The Public Eye Hoechst's
high
tem-
perature pyrolysis process makes acetylene and ethylene from liquid hydrocarbons such as light naphthas
E U R O P E A N PROCESSES for making chemical feedstocks from various petroleum fractions continue to flow forth in a slow but steady stream. One of the latest to issue from the shadows of proprietary secrecy is the high temperature pyrolysis (HTP) process, developed by Farbwerke Hoechst of West Germany, to make a mixture of acetylene and ethylene from a wide range of refinery and natural gases and light liquid fractions. The company showed its first model of this plant at this year's Achema Exhibit (Chem. Eng. News, p. 78, June 26), although
the unit has been operating since late 1959. Hoechst's HTP unit has a n annual capacity of 50,000 metric tons per year of combined ethylene plus acetylene. European interest in processes to make olefinic chemical raw materials from various oil fractions stems mainly from the historic shortage of refinery gases and natural gas in the area. Even now, despite the rapid build-up of refinery capacity there, chemical demands are far higher than the supply from these two sources. And with the ever-increasing relative cost of carbide-derived acetylene, a process which can make both acetylene and ethylene offers intriguing advantages in raw material availability, cost, and flexibility.
The HTP Process Hoechst's new cracking process works this way. Into hot gases from the burning of a hydrogenrich fuel are introduced steam and, shortly thereafter, the hydrocarbon fraction to be cracked. Final reaction times range from 1 to 5 milliseconds ; reaction temperatures range from about 1100" to 1300" C. Immediately after cracking, the hot gases are quenched to stop the reaction in its tracks. T h e cooled gas mixture then goes through a complicated but relatively standard procedure to recover the purified ethylene and acetylene (GO2 and acetylene absorption, low temperature ethylene distillation) plus a tail gas rich in hydrogen and suitable either as a fuel for H T P itself or as a feed for ammonia or methanol synthesis. The HTP burner is made of metal and has no ceramic parts. I t is watercooled, the heat removed being used to preheat the fuel. Either air or pure oxygen can be used as oxygen source, but with air the reaction Crux of the process is in the cracker
Many ideas and projects-big and little-can influence you, give you ideas for use in your work, and provide useful informationfor "current awareness." Each month IIEC's field editors and Washington staff select for detailed report and analysis, designed for easy reading, some of the most timely, in research and commercial development, process design, engineering, production, and marketing areas in the chemical process industries. W e present also our comments on other interesting happenings of business and professional interest.
The C h e m i c a l World Today products are more dilute and necessitate larger separation facilities. I n this case too, the tail gas cannot be used as readily as fuel, because of all the nitrogen in it. Flame temperature from combustion usually runs about 2600" C. Less than the stoichiometric amount of oxygen is used, so that a small excess of hydrogen remains in the combustion gases. During the period of flame formation, steam, usually preheated to 350" C. or higher, is added to the combustion gases to cool them and to scavenge any oxygen atoms or oxygenated hydrocarbon radicals formed during combustion. The steam also helps form a reducing atmosphere. Next, the hydrocarbon cracking stock, usually vaporized and superheated, is added to the hot combustion gas-steam stream. Cracking proceeds as the gases pass down a reaction tube. As they emerge from the cracking zone, the gases are quenched immediately. The quenching and subsequent cooling condense uncracked heavy hydrocarbons as a n oil fraction; these are separated from the main crackedgas stream. The oil can be used as a fuel for other processes; the heat of condensation can be recovered and used in subsequent stages of the gas separation scheme. Reaction time and reaction temperature, which determine the ratio of acetylene to ethylene in the cracked gases, as well as the combined yield of these two products, can be controlled by the amount and preheat temperature of the steam added and the amount and preheat temperature of the cracking stock added. As a result, product composition can be varied widely, from mostly acetylene to mostly ethylene, and most compositions in between. For a given feed, Hoechst points out, higher cracking temperatures and shorter reaction times favor acetylene and vice versa.
Basic steps in process are shown here
Various Suitable Feeds
HTP will crack hydrocarbon feedstocks ranging from natural gas to gas-oil fractions with boiling points over 350" C., Hoechst says. From a middle distillate, the highest ratio of acetylene to ethylene efficiently obtainable is about 4 to 1. Further, yields of the two Cz components range from 40 to 56y0, depending on the feedstock and the A/E ratio desired. Carbon deposition is not a problem, due to design of the quenching system. And the metal burner used means that the process can be started up and shut down quickly. Operating Flexibility
Hoechst uses HTP at its main plant near Frankfurt to supplement acetylene production (mainly from calcium carbide) and ethylene (mainly from a middle-temperature pebble cracker which uses crude oil as feed or by tubular heater with naphtha as feed). As demand for one or the other of these two chemical building blocks changes with the
market, Hoechst has the process flexibility to compensate and yet to keep its processes operating at efficient levels. And as prices for hydrocarbon feedstocks vary, the company can shift from one to another to take advantage of POtential economies. D.E.G.
Flower Hobbyists, Try Silica Gel New outlet for a 100year-old compound
WHEN Sir Thomas Graham first prepared silica gels back in 1861, he probably never even dreamed that years later, home gardeners would use a modern version of his product to preserve flowers. But a special blend of pure silica gel, featuring particles about the size of grains of sand, does just that. The blend is 9570 silica gel and 57, particles VOL. 53, NO. 12
DECEMBER 1961
31 A
REPORTS AND INTERPRETS
Fresh flowers are completely covered b y silica gel. Flower-Dri i s carefully worked around them so that it contacts all parts of the flowers
containing cobalt chloride as a moisture indicator, Indicator gives the blend the familiar blue color when dry, and a light pink when wet. The low percentage of cobalt chloride and the small particle size
make the pink color appear to be white. I n the new drying method, freshcut flowers are buried in the silica gel for about a week. The silica gel particles dehydrate the flowers
Edible Soy Protein
boosted livestock feed quality and has done this at a low cost. For instance, in 1930 a good feed for broilers might contain a dozen ingredients, produce a three-pound bird in 1 5 weeks at a rate of five pounds of feed per pound of chicken. Today the same bird is raised in eight weeks after getting a feed containing some two dozen ingredients, many not known in 1930, and converting 21/2 pounds of them to a pound of meat. Besides the protein, the growth is improved by other factors, too. These include vitamins, antibiotics, and other growth factors. Yet the average American still pays a little under 2OyOof his income for food. Oils from the bean reflect the same situation. Prior to World War 11, the U. S. imported more than 207@of its fats and oils. Soybean oil filled the wartime gap. Since then, the oil has become the prime reason that the U. S. is now the world’s largest exporter of fats and oils. And there’s no sign anywhere that meal and oil will diminish in impor-
Cheapest known source of U. S. protein getting active marketing
in food R A T T L I N G ALONG a t a rate of about 21 million tons per year is the country’s fourth largest cash crop, the soybean. Today the bean, relatively unknown in the U. S. in 1930, ranks as the chief source of vegetable protein used to make nutritionally balanced feeds for livestock and poultry. Its oil now makes up the major ingredient in margarines and shortenings; also it goes into salad and cooking oils. Both the meal and oil have industrial applications, too. And these are not minor. The edible uses currently account for some 570 of the meal produced and over 90% of the oil. Feed uses take about 95% of the meal. I n doing all these things, the bean has distinguished itself. It has
32 A
INDUSTRIAL AND ENGINEERING CHEMISTRY
by absorbing their moisture. When the silica gel is saturated, it loses its blue color. It may be reactivated by baking in a n oven, and it retains its usefulness indefinitely. After drying, flowers are said to remain as colorful and fresh looking as when they were first picked. They may be displayed under normal humidity conditions. Flower-Dri is made and packaged by W. R . Grace, Davison Chemical Division, a pioneer in silica gel manufacture; and it is distributed by Plantabbs Corp. of Baltimore. Introduced to the market in early August, Flower-Dri is sold presently in 11/2- and 5-pound cans, in garden supply and department stores, florist shops, supermarkets, and chain stores. A demonstration of FlowerDri in Chicago, during the ACS meeting in September, drew many interested observers. Flower preservation zould become a substantial silica gel market-the garden editor of one national magazine estimates that 20 million Americans are potential customers for flower-drying supplies. J.H.O.
tance. Rather, all signs point to a steady increase. For one thing, the American people’s taste for meat, milk, and eggs shows no sign of diminishing, and population is on the increase. Oils, in addition to reflecting this same influence, could come in for large growth because their unsaturation reduces blood cholesterol. Tagging along with meal and oil at a relatively low volume of production is what many industry men regard as the sleeper in the soy business : the chemically isolatable protein from the bean. Makers of soy protein can and have been producing this protein in 95Y0 purity to sell at a price of 35 cents a pound. This, on the basis of per cent protein, and on the added basis of the protein quality-per cent of necessary amino acids-makes it the cheapest source of U. S.-produced high quality protein. The addition of one amino acid, methionine, brings it to a quality par with milk protein. O n an ar-
(Continued on page 34 A )
Cont in uously-Adj usta ble AUTOTRANSFORMER
..
With DURA TRAKi Contact Surface
. t h e most useful device yet developed f o r the con. t r o l of a-c voltage heat light power speed.
-
-
-
-
-
low-loss VARIAC autotransformers do not High Efficiency dissipate large amounts of power as do resistive controls. Smooth, Continuous Control -carbon brush taps off any amount of voltage applied t o winding that is wanted; adjustment range is 0 t o 117% of line voltage. Good Regulation - o u t p u t voltage is substantially independe n t of current drawn. Extra-Long Life - patented DURATRAK contact surface eliminates brush-track oxidation problems. High Overload Capacity -thanks t o DURATRAK, shortterm overloads up t o 1000% of rated current can b e tolerated by VARIAC autotransformers.
-
Negligible Waveform Distortion VARIAC autotransformers do not destroy waveform purity, nor do they adversely affect power factor.
-
Control up t o 54 KVA models are available as single units or in gangs t o control low or high power, from .3 to 54 KVA.
Variacs are available in 2-, 5-, lo-, 20-, 30-, and 50-ampere ratings . . . for 120- and 240-volt service . . . single or . motor driven or manually operated ganged, cased or uncased, and as portable units with or without meters high frequency models for 350- to 1200-cycle use . . . - all backed by General Radio's TWO-YEAR WARRANTY. I
...
.
THIS T A B L E GIVES A P A R T I A L LISTING OF B A S I C V A R I A C M O D E L S FOR A COMPLETE LISTING, W R I T E FOR MORE INFORMATION
'For "0 t o Line Voltage" Connection.
QUANTITY DISCOUNTS ARE AVAILABLE
VARIACa autotransformers are made only by General Radio and i t s overseas licensees
tu. S.
GENERAL RADIO C O M P A N Y
Patent No. 2,949,592
WEST CONCORD, MASSACHUSETTS NEW YORK, Worth 4-2722 District Office in Ridgefield, WHitney 3-3140
N. J .
CHICAGO Oak Park Vlllage 8-9400
PHILADELPHIA Abington
WASHINGTON, D.C. Silver Spring
HAncock 4-7419 Juniper 5-1088 Circle NO. 18 on Readers' Service Card
SAN FRANCISCO Lor Altos WHitecliff 8-8233
1 0Los s ANGELES Angeler HOllywood 9-6201
I I
IN CANADA Toronto
CHerry 6-2171
=/ma
REPORTS A N D INTERPRETS
OPERATION COSTS Most effective. Dow Corning silicone defoamers are best for banishing space-filling, time-eating foam in the processing of any foamer . . from asphalt to beans to peas to zeins. Dow Corning Silicones start quicker, last longer. Eliminate messy and unsanitary foam-overs. Turn maintenance into production time.
.
Most efficient. Even the most violent foamers are tranquilized with a tiny amount of a Dow Corning silicone defoamer - often one part silicone solids per 10 million parts foamer is effective. For true economy, change to a Dow Corning antifoamer or defoamer. There’s one just right for your product and system - oil, aqueous or food.
FREE SAMPLE Send today for a generous trial sample and full data. Please specify type of system. Address Dow Corning Corporation, Midland, Michigan, Dept. 5724.
Dow CornIng Circle No. 14
34 A
Commercial soy food protein (Promine) is bagged at Central Soya’s Chicago plant
bitrary scale of protein quality it would rank along with meat in the completeness of its protein. However, its rate of use in human foods has been modest. For soy producers as a whole, it probably accounts for less than 1% of sales. Even the acknowledged leader in its development, Central Soya Co., of Fort Wayne, .Ind., chalked up less than 1% of sales to it last year. But indications in the trade are that isolated protein volume may increase sharply over the next few years. A number of soybean processors and others are known to be at least actively test-marketing the product, and evidence on grocery shelves shows that it is moving in to a number of food products. Food producers have been taking it on at increased rate because it adds nutritive value, it does it inexpensively, and it adds functional value. Central Soya lists four basic types of isolated, edible protein which it trade-names Promines, D, R, K, and C. All are made from the same basic starting point: the flake left after the cleaned, cracked, and de-
hulled bean is extracted with a petroleum solvent. After extraction, the flake contains less than 1% fat. This flake gets a steaming that drives off last traces of solvent. Then it goes through a batch extraction procedure in which water leaches out soluble protein, carbohydrates, and sugar. At this point, control is all important. Temperature, pH, and concentration of solute in the water have a marked effect on yield from this extraction. This information, Central Soya considers proprietary. After the liquor is screened to separate it from the insoluble residue, the protein is separated in one of two ways, which determines its characteristics. I t is first concentrated in a special process, then either spray-dried at its isoelectric point or solubilized by forming the proteinate with sodium, potassium, or calcium hydroxide. These dispersions are then dried and bagged. Neither the isoelectric protein nor the calcium salt is water dispersible immediately. But the so(Continued on page 36 A )
on Readers’ Service Card
INDUSTRIAL AND ENGINEERING CH:MISTRY
Circle No. 46
on Readers’ Service Card
+
VICTOR qQCLEANgg REGULATORS Control gases safely and accurately to 10,000 psig. Victor high pressure gas regulators are cleaned, assembled, tested and packaged under carefully controlled conditions to insure maximum product reliability. Cleaning is performed to Victor standard or to customer specifications in a room approved by industry
GD700 SERIES GAS-O.DOME REGULATORS Bronze or stainless steel Pilot operated-low torque Inlet to 10,000 psig. Outlet t o 10,000 psig. Flows t o 250 scfm. Panel Mounting
GD40, GD90, GD100, GD200 SERIES GAS-0-DOME REGULATORS Bronze or stainless steel Remote or integral controlled Inlet t o 6,000 psig. Outlet to 6,000 psig. Flows t o 80,000 scfm. Panel mounting i f desired.
and military agencies. Regulators shown here are typical of the available models covering a range of pressures to 10,000 psig. and capacities of 80,000 scfm. a t -67' F. to +250" F. Write for Regulator Inquiry Form 361B and regulator bulletins.
LR SERIES LOADER REGULATORS BPR SERIES BACK PRESSURE REGULATORS Bronze or stainless steel Inlet to 10 000 psig. Outlet to io,ooo p s i g . Flows t o 10 scfm. Low operating torque: 40 inch Ibs. at 7,000 psig. 60 i n c h Ibs. at 10,000 psig. Panel mounting.
844 Folsom St., San Francisco 7 3821 Santa Fe Avenue, Los Angeles 58 1145 E. 76th St., Chicago 19 J . C. Menzies & Co., Wholly-Owned Subsidiary
GD60 AND GD80 SERIES GAS-0-DOME REGULATORS Bronze or stainless steel Remote o r integral controlled Inlet t o 10,000 psig. Outlet t o 10,000 psig. Flows t o 2 000 scfm. Panel m o i n t i n g if desired.
hardfacing rods; blasting nozzles; cobalt IL tungsten castings; straight-line and shape cutting machines; roller and idler rebuilding machines.
73
------------------
.
use a
MARASPERSE* highly effective, low cost dispersant (usually i.n dry powder form) to reduce viscosity to the desired consistency Only a little Marasperse is needed to reduce slurry viscosities, or to prevent micron-sized particles from settling out of suspensions. Usually less than 396, based on the weight of the solids in the aqueous system, will do the job for you. For example, manufacturers of gypsum board require just 0.15% Marasperse in their stucco slurries to give them more fluidity a t lower water contents And producers of pesticide wettable powders include but 1.5% to 2.0% Marasperse in their powders to ensure satisfactory dispersion in spray tanks. What’s more, the Marasperses cost only a few cents a pound! Tell u s about your viscosity problem. If it’s typical of one of the many that the Marasperse dispersants have licked, we’ll give you specific information based on user experience. If it’s something new or unique, we’ll tell you how to test samples of the Marasperses to determine whether or not they’ll be useful to you.
...
MARATHON (&J A D i v i s i o n of A m e r i c a n C a n C o m p a n y
CHEMICAL SALES DEPARTMENT MENASHA, WISCONSIN
----- - A-D i v--------MARATHON i s i o n of A m e r i c a n C a n Co. *Registered U. S. t r a d e m a r k
C H E M I C A L S A L E S DEPT. Please send Information File No. 1-121 NAME
0
M E N A S H A , WIS.
m,Samples 0 of MARASPERSE for use in
~
TITLE
~
__________________
COMPANY..__._._._ __ _____._ ... ADDRESS ~
~
~
_._._ _....._____ ~
~
~
___ Please attach t o your company letterhead. Circle No. 25 on Readers’ Service Card
36 A
INDUSTRIAL AND ENGINEERING CHEMISTRY
-
dium and potassium salts are. The isoelectric protein can be dispersed if it’s made alkaline first. After dispersion p H can be reduced :again and the protein will still stay in dispersion. Dispersion isn’t necessary for nutrition, but it is if the protein is being added for its functional values as well. These cover a wide range. The dispersed protein will foam and coat with a thin film. I t adds adhesive and cohesive properties, thickens, and promotes gelling. I t will both stabilize and emulsify, and it boosts water-holding capacity, and makes dough-forming easier. Need for these properties in the food industry is high. It prompts Central Soya to list applications from the protein in baked goods from biscuits to zwieback. T h e familiar whipped topping is another example. Baby cereals, cooked cereals, and many meat products now contain added soy protein. As for the future, Central Soya and many of the other companies now checking the market, see nothing but continued growth. Application research is under way and continues. All-vegetable frankfurters, for instance, now closely approach the real thing in both taste and texture. 0ther simulated dairy products are coming along to add to the whipped topping. A slice of “beef” with good properties is a lab reality. Combinations of the protein with fats-particularly the lecithin isolated from the bean’s oil fraction-are finding their way into baked goods, particularly cookies and sweet dough products. Another product, a 70% protein concentrate, is going into baked goods. It doesn’t have all the functional properties of the isolated protein, just its water-holding capacity. But it’s less expensive. I t comes from solution by a solvent that removes everything but protein from the defatted flake. T o compound all this, producers mention new, ‘‘tailor made” foods in forms and compositions not even marketed presently. So, with the food industry now holding itself responsible for good nutritional products, the soy protein combination of nutrition and function seems on the way to making its application W.M.K broader daily.
Instant Yams
EVEN
HOLIDAY meals can be enjoyed by the housewife, now that chemical processing is taking over in the kitchen. A new plant will take the work out of fixing one of the favorite holiday dishessweet potatoes. Produce Processors, Windsor, N. C., will start their production line as soon as the yams are ripe, converting them to precooked, dehydrated flakes. The process, developed by USDA's Southern Regional Research Laboratory, can utilize less desirable yams to produce a better-than-natural product. Size and shape of the sweet potato, important when the whole potato is sold, do not matter. And because all fiber is removed in the process, the users like the product. The problem which plagues processors of natural products-nonuniformity-shows up, though. Some varieties turn an unappetizing brown. In the crop years studied by SRRL this was licked by preheating. Potato raw materials are first washed in an Aeroglide washer, then preheated (if necessary) in a Rietz Manufacturing Go. Thermoscrew. Conventional lye-peeling follows, after which trimming and cooking are performed. Up to this point, methods are identical with canning procedures, and the same equipment can be used. After cooking, however, the potatoes enter a F. H. Lansenkamp Co. pulper, and emerge as a purte. Dehydration in a Buflovac drum dryer produces thin, golden flakes. Problems of corrosion and sanitation are met by using all stainless equipment after the trimming step, except that the dryers have cylinders of a special close-grained fine-textured metal. The conveyors are the sanitary type, with vulcanized white neoprene bacto-proof belts. For preservation at present, it is necessary to vacuumize and package under nitrogen in cans. It is thought that this product will find additional uses as a food additive because of its high vitamin content E.W.M. and attractive color.
A N ENVIABLE RECORD OF S E R V I C E TO [PI From its major facilities in Santa Rosa, California and West Chester, Pennsylvania and its field engineering and service offices in Chicago, Houston, Seattle and Los Angeles-Rietz has supplied size reduction and heat exchange equipment to
MORE THAN 50 OF THE LARGEST CHEMICAL COMPANIES IN THE WORLD
R I E T 2 D I SI N T E G R A T 0 R S TYPICAL APPLICATIONS Dry pulverizing - coarse or fine. Wet grinding of solids to produce slurries or pastes.
Fine dispersion and homogenizing. Dissolving of solids in liquids. Intimate mixing of pastes, slurries and powders.
SPECIAL FEATURES AND ADVANTAGES Can be supplied for operating under atmospheric pressure, vacuum or internal pressure. 360" screen area insures maximum capacity, uniformity of grind and minimum temperature rise of product. Optional secondary discharge for continuous separation of disintegration-resistant material. Rugged, compact construction in carbon or stainless steel in vertical design (as illustrated), or in angle or inverted models.
VOL. 53, NO. i z
DECEMBER 1961
37A
