October, 1929
INDUSTRIAL A N D ENGINEERING CHEMISTRY
916
The Licorice Root in Industry’ Percy A. ISouseman*and H. T. Lacep M E L W N INSTii”l*:
“P 1h-ausixiai. II,e 1550 13. C.), “Suss Bier” is a constituent of a Inrgc iiiiniber of pxcscriptioiis and it has been conceived that this “Suss Bier” was an infusion of “Sussliolz” (licorice root). Licorice was used in the formulas of the Magical Papyrus (about 100 13. C.) according to the translation of Griffith and Tlioiripsoii ( 2 ) . It is noteworthy that tlie uses of licorice :is a rnedicine are practically identical in each of tliese ancient civilizations a.nd that they also correspond very closely with the ways in which the pexsant classes of Europe use licorice today. Tliese uses miglit be classified as follows: (1) a general tonic and blood purifier, ( 2 ) a relief for internal inflammations, ( 3 ) an ext.ernal application with honey for wounds and sores, (4) a quenclmr of thirst, and ( 5 ) a relief in cases of catarrh, hoarseness, and sore throat. Preliminary Handling of Licorice Root
Although niore licorice root is extracted in tlie lJiiited States than in any other country, none has lieeri grown liere except on an experimeiital scale. A recent large-scale experiment in licorice cult.ure in New Jersey, covering period of several years, proved commercially unsuccessful. The plant is now cultivated t o a slight extent in Spain and Italy, but most of tlie licorice in those eouiitries, as well as i n southern Russia, Asia Mirror, and southern Asia, grows wild over wide areas, establishing itself so tenaciously that it can hardly be
Bale Breaker
Early Uses
Because the “licorice belt” iiiclrides within its boundaries the “crrxlle of civilization,” the history of licorice ( 1 ) is especially interestiiig, and is repletc with folk lore and tales of religiws and occult uses. In tlic “Shen Nung Pen Ts’ao King,” the oldest of the Foil Ts’ao Cliinese hooks of ineilicine (e),licorice is a drug of the first class, and today it is used in China inore tliaii any other drug except ginseng (5). Licorice plriys an important part as a medicine in Brahmanism and Huddliisiii, two important religions of India (61, where the art of Ibe:ding and of presorving liealt,Ii is still in tlie liaiids of the priests. In f3rslimanisin licorice is one of the important drugs of “Tlie Susruta,” a pliurmacciit,ical text rem:nled to Susrutn lby Ilralima liimself, wlio bad composed tliis book before lie created man. In the Buddhist religion soine of the oriental niystir~isrnregarding tlie use of licorice is even more strikingly ],reserved. On tlie morning of ilnddlia’s birtliday, an infusion of tlie licorice root is poured over the statue of the god three times ilinidst grcat porn11 wlrile tlie priests cliarit mystical iiicniitatioiis and the worsliippers pray. The fluid whicli drips from tlre statue is carefully collected and treasured for its curative propcrties. Recent excavations in the lower Tigris-Euphrates valley have yielded tablets which tell of the use of licorice in this “Paradise” of the Old Testament. In May 27, 1929. Chief chrrniit. MacAndiews & Forbes Co.,Camden. N.J. Formerly Industrid Frilow. Mellon Institute of Industrial Research.
v Received 2
I
Shredded Licerice Root
eradicated. It grows best in tlie fert,ilc soil of the river valleys, and tlie perennial shrub reaches a height of 2 or 3 feet. The roots are tough and fibrous; they may be an inch or more in diameter at the tliickest portion and 25 feet in length. During tlie autumn months peasants dig these roots with primitivc tools, such as have heeii used by tlieir forefathers for tliousarrds of years, and haul i t to the nearest collecting station. Here the roots are sorted, cleaned, weighed, and paid for by wciglrt. Near Smyrna a small amouiit of green
Vol. 21, No. 10
INDUSTRIAL AND ENGINEERING CHEMISTRY
916
root is extracted for the European trade. Most of the roots, however, are piled in huge stacks for curing, where they are left through the following summer until they become dry enough for baling. These stacks are covered during the rainy season to prevent mildewing, and they are also frequently turned. When dry. the roots are pressed into bales weighing about 300 pounds and shipped to the United States. This industry is therefore of great benefit to those comparatively poor regions, employing as it does many thousands of natives
scrapers, and here the solution from the vacuum pans is further concentrated to a thick paste containing about 20 to 25 per cent moisture. I n the more soluble types the evaporation may be continued until the paste contains only 16 to 18 per cent moisture. The paste is drawn from the finishers while still hot and weighed in paper-lined cases which hold 260 pounds and into cartons of two sizes, which hold 52 pounds and 10 pounds, respectively. After the paste has cooled, it gradually hardens into the familiar semi-plastic licorice mass. It is dark brown in color and upon being hit a sharp blow breaks with a shiny conchoidal fracture. Varieties
. -.
.
. . ~. Extractors
Upon arrival at the wharves of the American factories, the baled root, amounting to about 35,000 tons per annum, is stored in warehouses according to the district from which it has come. The various brands of licorice extract that have been developed to meet the requirements of different consumers are made by blending roots which have been gathered in different regions. Extraction The extraction of the licorice root with hot water and subsequently evaporating the solution to form the commercial paste is a simple process, but to obtain a high-grade, standard product is no easy problem. I n the first place, the chemical character of the root from a certain region may change from year to year owing to a change in climatic conditions. Substances in the extract are subject to hydrolysis, thermal decomposition, and oxidation, as well as to the action of fermentation bacteria and molds. Then there are numerous mechanical difficulties due to the excessive foaming properties. The process of making the primary extract may be described briefly as follows: After the bales are broken and the strap iron or wire is removed, the roots are passed through a shredding machine, which reduces the tough fibers t o a coarse mass. If the root is especially selected, it may then be ground and bolted for the pharmaceutical trade; otherwise the shredded root is carried on belt conveyors to the extractors. The extractors are arranged in batteries and the root is extracted with water under low steam pressure. The extract is tested for glycyrrhizin a t regular intervals during the extraction process. The characteristics of the product are controlled by diastatic enzyming. The solution is next settled in a series of cascades and settling tanks. From here it is pumped to the vacuum pans, where it is evaporated to a concentration of about 18" BF. From the vacuum pans the concentrated solution goes either to a drum drier (the dried extract being powdered and screened and sold under the name of "powdered licorice extract"), or to the finishers. The finishers are steamheated copper evaporating kettles fitted with revolving
Ammoniated glycyrrhizin is made for the pharmaceutical trade by precipitating glycyrrhizic acid from the licorice extract by the addition of a slight excess of dilute sulfuric acid. The precipitate is then washed thoroughly by kneading with luke-warm water and is dissolved in ammonium hydroxide. This solution is painted on glass and the dried material scraped off in the form of shiny, dark brown flakes. The different brands of licorice mass are clasified under two general types, Spanish and Oriental. The Spanish licorice is an extract of Glycyrrhira glabra oar. typica or Spanish root, and the Oriental licorice is an extract of Glyqphiza glahra var. glandulifera-or Oriental root. Typical condensed analyses of the two kinds of licorice mass are given below. Methods of analysis for licorice root and licorice extract have already been published by one of the writers (S). G!ycyrrhizin Sugars
SPilNlS"
O.l%NT*I.
PI, call, IO
Per crnl
12
Starch and gums Moisture Ash
25 15-25 5
18 12 25 15-25 5
The figures for sugars and starch and gums may vary within wide limits, depending upon the degree of enzyming, if any.
Circ l l o u ~ efor Licorice Slnrr
Although Spanish mass contains less glycyrrhizin than Oriental, it commands a higher price because its flavor is milder. Uses Ahout 90 per cent of the licorice mass produced in this country is consumed by the tobacco industry. It is used as an ingredient of the casing liquor, which is applied to the leaf tobacco either by a dipping or by a spraying process. The function of the licorice is threefold: as a flavoring and sweetening agent, as a blending agent to make the flavor of the tobacco more mild, and as an aid in keeping the tobacco moist.
October, 1929
I-VDCTSTRI-412 A;L‘D ENGIXEERIa\TG CHEIWSTRY
The licorice is used in largest amounts in chewing tobacco, although it also finds extensive application in cigars and in pipe and cigarette tobaccos. The remaining 10 per cent of licorice mass produced is used in about equal amounts by the pharmaceutical and confectionery industries. At present the chief role of licorice in pharmacy is to cover the acrid taste of various drugs. It is also used as a constituent of cough sirups, throat lozenges, and pastilles. Its use as a corrector of cathartics is still recognized in the form of compound licorice powder, a mixture of powdered senna leaves, sulfur, fennel seeds, sugar, and licorice, the active ingredients of which are the senna and sulfur. Powdered licorice root and powdered licorice extract are also used in pharmacy as medicaments, excipients, and dusting powders. Licorice confectionery has been somewhat under a cloud in the past, owing in large measure to the widespread substitution of oil of anise for the genuine licorice flavor. The use of licorice as a wholesome ingredient of high-grade confections is gaining increasing recognition. By-products
The by-products of the manufacture of licorice extract are especially interesting. A portion of the spent root from the primary extractors is subjected to a secondary extraction with a 5 per cent solution of caustic soda under LOO pounds steam pressure for several hours. This secondary extract is evaporated to 12” Bb., in which form it is known as Firefoam Liquid and is used as a foam stabilizer in the Foamite fire extinguisher. The solutions in this extinguisher have the following composition: the first, 11 parts aluminum sulfate and 89 parts water; the second, 8 parts sodium bicarbonate, 3 parts Firefoam Liquid (12’ BE.), and 89 parts water. On mixing these solutions a tough, durable foam, which resists heat and mechanical abuse, is produced. This method of attacking fires has proved to be of great value in extinguishing oil fires and is now in almost universal use in the protection of oil tanks. This use, however, requires only a small part of the available licorice resins. There are still about 5 million pounds of these resins which might be extracted annually a t very little cost. Recent work indicates that this secondary
917
extract may be valuable as a wetting agent and as a foaming agent in the flotation process for ore extraction and also as a wetting, spreading, and sticking agent in insecticides, The remaining root fiber is used in making boxboard, Jacquard cards for the weaving industries, Fiberlic wallboard, JIaftex, and Maflath insulating board. The fibers of the licorice root are tough and wiry and they impart this characteristic to these products. The boxboard is made from a mixture of paper and licorice root pulp and is used in making pasteboard cartons. The Fiberlic wallboard consists of several layers of boxboard cemented together with sodium silicate. RIaftex insulating board is a single-ply board made with one surface smooth and the other surface with a ripple finish. For interior decorating and paneling effects the smooth side is usually left exposed. The ripple side offers an unusually good bonding surface for plaster. Tests have shown this board t o have the following properties: (1) Thermal conductivity rating of 0.33 B. t . u.
( 2 ) An ability to hold four six-penny nails up to 250 pounds pull, and then have an average of only one nailhead out of four pull through the hlaftex. (3) A bonding strength with gypsum plaster of over 1000 pounds per square foot. (4) High water resistance, not becoming wet on complete immersion in water for 24 hours. Conclusion
The licorice root is thus a contributor to human activities in no small degree. The primary extract serves the tobacco, pharmaceutical, and confectionery industries; the secondary extract is a fire-extinguishing agent; and the residual fiber is a valuable raw material for cardboard boxes and provides a new structural material for the architect and builder. L i t e r a t u r e Cited Beal and Lacey, J . Am. Pharm. Assocn., 18, 145 (1929). Griffith and Thompson, “Demotic hfagic Papyrus of London and Leiden” (1904). Houseman, A m . J . Pharmacy, 84, 531 (1912); 88, 97 (1916); 43, 388, 455, 481 (1921); J . Assocn. Oficial Agr. Chem., 6, 191 (1922). Joachim, “Papyrus Ebers,” Berlin, 1890. Simmonds, Bull. Pharm., 8, 205 (1894). Tschirch, “Handbuch der Pharmacognosie,” Band 11. Lief. 20, p. 20 (1905).
The Compression of Refinery and Casinghead Gases’ Wallace J. M u r r a y ARTHCR
D. LITTLE,I N C . ,
S T H E compression of refinery and casinghead gases
partial liquefaction usually takes place in either the compressor or the after-cooler, or both. The purpose of this paper is to describe a means of calculating the composition and quantity of both the liquid and gaseous phases produced in this compression. Since the compressor and after-cooler ordinarily act as one unit, only the combined liquefaction taking place in both will be considered a t this time. Binary systems have been investigated by Calingaert and Hitchcock ( A ) , but the more general case with many components has not been presented so far as the writer knows. The equilibria between liquid and gaseous phases have been studied by Brown and Caine ( I ) , Lewis (6), and by the California Natural Gas Association ( 2 ) . The inethod of 1 Received April 16, 1929. Presented before the Division of Petroleum Chemistry a t the 77th Meeting of the American Chemical Society, Columbus, Ohio, April 29 t o May 3, 1929.
CAMBRIDGE, hfASS.
calculation presented in this paper is founded on the work of these men and is intended as a fairly simple method of checking up compressor action on casinghead and refinery gases. Development of Method of Calculation of Rich G a s Compression
(I) Take initial volume of gas in cubic feet. ( 2 ) Look up on chart pound-molecular volume at initial temperature. This may be most easily obtained from a chart showing pound-molecular volumes a t different temperatures and pressures, such as is shown herewith. (3) Divide the initial volume by the pound-molecular volume to get pound mols. For convenience, it is best to base all calculations on 100-pound mols and then a t the end multiply by the factor to cdnvert to true initial volume. All steps beyond this point are based on 100-pound mols.
