Low Temperature Distillation of Sub-bituminous Coal - American

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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 CHEMISTRY

M a y , 1920

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ing endowment as shall be approved, the other (hereafter to be SUGGESTED USES FOR ENDOWMENT Conditions are now favorable €or American journals to assume referred to as the Endowment Finance Committee) to receive the leadership formerly held by German journals. The SOCIETY and invest such moneys as are collected for endowment. This publishes three journals, all ably edited; but if the budget could latter committee should have a banker included in its numbers. To start the project, it is suggested that the Advisory Comallow adequate appropriations for the Journal of the American Chemical Society and Chemical Abstracts, and permit the Journal mittee select definite objects, upon which the Endowment Colof Industrial and Engineering Chemistry to profit by its own lection Committee can make a campaign: that the appeal of this committee be for a Permanent Endowment Fund, the income earnings, all could be brought up to a better standard. We have also to face the problem of publishing monographs only of which shall be available for expenditure a t any time and and compendia. The urgency for the compilation and publica- the objects for which this income shall be expended to be determined by the Advisory Committee, the Directors or a new tion of these is extreme, but the funds are lacking. If the Secretary’soffice could act as a clearing house for chem- committee constituted for the purpose; that a t the present time ical information, coordinated with the National Research Council an attempt be made to secure one million dollars for this fund; and the government activities, it could accomplish much in col- that the Endowment Collection Committee consist of a chairlating and spreading reliable chemical information. A traveling man, who shall be appointed by the President and empowered assistant secretary, as suggested by Mr. Little, could be added to associate with himself such other helpers as may b.e approved by the President. to that office with much profit. Under present conditions, it will probably become necessary The following plans for use of the Endowment Collection Comto raise the dues of the SOCIETY before long, thus cutting off mittee are suggested: from its benefits chiefly students and young chemists in the formaI-Direct appeal for contributions, under the advice of the tive period. Such an increase in cost would, therefore, be a tax President, to the end the appeals may not be overdone. on progress. 2-Appeals for bequests of definite sums by will from chemists, While the more immediate purpose of the endowment is for the spread of knowledge rather than for its initial achievement, from chemical manufacturers, and from others. it would be unfortunate to forbid the authorities of the SOCIETY 3-Appeals for the purchase of Endowment Life Membership, to cost such a sum as shall by its interest during the life of the to use its funds for research if the need should arise. member defray his dues to the SOCIETY and a t his death be transPROPOSED PLAN O F SECURING ENDOWMENT ferred to the General Endowment Fund together with any exIt is proposed that the present Endowment Committee be dis- cess in income which may be derived from the Endowment Life charged after the completion of the work upon the plans for se- Membership Fund. This fund should be under the same mancuring endowment; that two new committees be appointed by agement and control as the General Endowment Fund, and enthe President; the one (hereafter to be referred to as the Endow- tirely separate and distinct from the present Life Membership ment Collection Committee) to carry out such plans of collect- Fund.

ORIGINAL PAPERS LOW TEMPERATURE DISTILLATION OF SUBBITUMINOUS COAL By H. K. Benson and R. E. Canfield ’

LABORATORY OF

CHEMISTRY, UNIVERSITY OR WASHINOTON, SEATTLE,WASHINGTON Received December 29, 1919

INDUSTRIAL

T h e results obtained from t h e low temperature distillation of a non-commercial lignite coal1 in t h e s t a t e of Washington appeared of sufficient value t o warrant further investigation on a semi-commercial scale. Such work is now under way with somewhat different apparatus on another lignite coal. I n connection with t h e mining of sub-bituminous coals i t has frequently been found unprofitable t o work certain veins on account of their high ash content or other unmerchantable properties. For instance, t h e Bagley vein a t Coal Creek, Newcastle, Washington, is described as being “too dirty” for t h e production of a commercial fuel a n d although of sufficient size is not worked. It seemed of interest, therefore, t o ascertain t h e suitability of this material for distillation purposes. DESCRIPTION

O F SAMPLE

The coal is black in color, but t h e streak is brownblack as t h e powder shades off t o brown. It has a rather dull luster, is massive in texture, without joints, a n d has a conchoidal fracture. T h e proximate analysis is given in Table I . TABLEI-PROXIMATE ANALYSISOF NEWCASTLE COAL(PER CENT) Laboratory Sample As Received Air-Dry 5.8 Moisture.. 12.1 39.4 Volatiles. 36.8 40.7 43.6 Fixed Carbon.. .... 11.15 Ash., 10.41 Sulfur.. ........... 0.34 0.36 1.47 Nitrogen.. 1.37 11150.0 B.t.u 10410.0

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1

Tma JOURNAL,9 (1917). 946.

Sample Reported U. S. Geol. Sur., Bull. 474 As Received Air-Dry 7.1 5.9 37.8 38.1 42.9 43.1 12.2 12.9 0.34 0.38 2.44 2.61 10410.0 11300.0

APPARATUS A N D PROCEDURE

T h e methods of procedure and t h e apparatus were with a few minor modifications t h e same as previously described. PRODUCTS OF DISTILLATION

T h e yield of raw products a t t h e different distillation temperatures is given in Table 2. TABLE2-YIELD Temverature C. 150 200 250 300 350 400 450 500 550 600

Total Distillate Per cent 6.9 9.2 17.1 18.3 19.8 18.9 18.7 17.7 17.1 16.1

OF

Dry Tar Per cent

...

0.5 1.9 2.8 3.5 3.2 2.8 2.3 1.6 1.0

DISTILLATION PRODUCTS Aqueous Gas Solution Coke Cu. Ft. Per cent Per cent per Ton 90.2 3 6.9 85.1 8 8.7 74.1 22 15.2 70.6 2070 15.5 67.2 3540 16.3 66.1 4850 15.7 5990 65.3 15.9 64.2 6910 15.4 63.1 7670 15.5 62.2 8310 15.1

GAS

A wet test meter was used for measuring t h e gas t h e yields being indicated in Fig. I. T h e gas samples were analyzed in a Morehead gas apparatus a n d t h e percentage composition is given in Table 3 . O

c.

250 3 00 350 400 450 500 550 600

TABLE3-PERCENTAGE Ill. coz OP 45.1 33.2 20.4 18.9 17.3 16.4 14.1 12.6

3.3 3.8 4.9 5.0 4.9 5.1 5.1 5.3

1.4 0.8 0.4 0.4 0.4 0.4 0.4 0.4

COMPOSITION OR GASES co CH4 Hz 0.3 8.6 7.1 0.9 10.7 8.3 8.1 23.6 9.6 9.8 21.2 11.8 20.2 13.3 11.5 18.4 14.5 13.0 17.8 15.6 15.1 17.2 16.8 15.9

Nz 34.2 42.3 33.0 32.9 32.4 32.2 31. 31.8

T h e calorific values calculated by Lunge’s method are plotted against t h e temperatures of distillation in Fig. 11. COKE R E S I D U E

The coke obtained up t o joo’ C. was of a dull black color and retained more or less t h e size and form

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of t h e original particles. From this point t o 600' C. t h e particles possessed more of a metallic or silvery luster and swelled slightly in size. I t s composition

9000

TABLE 5-PERCENTAGE COJIPOSITION O$ OILS To 150OAbove 150' C. 300: C. 300' C. Light Medium Paraffin H a r d Soft Oil Oil Oil Paraffin Paraffin Coke 10.3 42.1 33.1 1.3 9.6 3.9 42.5 1.8 10.0 10.7 33.4 5.0 33.9 5 .5 11.3 41.9 2.1 9.7 10.3 33.2 5.2 10.5 41.7 1.9 9.3 3.4 31.4 41.4 1.5 13.6 2.1 39.8 41.5 1.4 15.9 7.8 41.2 0.7 17.6 5.9 0.9 29.2 0.5 0.6 21.1 3.9 27.8 40.9

TABLE 6-YIELD Tzmp. C. 250 300 350 400 450 500 550 600

Temp.

c.

150 200

550 600

TABLE4-YIELD AND COMPOSITION O F COKE Coke Volatiles Ash Nitrogen Lbs. Per cent Per cent Per cent 38.0 14.3 2.9 15.1 2.7 31.8 2.5 17.5 26.7 1.8 18.2 22.5 1.4 19.3 19.4 1.1 19.5 16.2 0.9 19.9 13.1 0.7 9.9 20.1 0.6 20.4 1262 6.8 0.5 1244 20.7 4.1

12,

No. j

tures. I t s specific gravity ranged from 0.97j t o 1.033. The oils were distilled in small glass retorts a n d t h e percentage yields are given in Table j, including t h e hard and soft paraffin separated b y a modificationl of Eisenlohr's method.2 About half a gram of t h e paraffin oil was weighed t o t h e nearest milligram in a tared 7-in. test-tube and warmed slightly.

Temp. O C.

is given in Table 4, which also shows t h e yields per ton of coal. I n Fig. 111 is shown t h e increase in calorific value with increase of temperature. The thermal values of t h e coke were obtained by means of t h e Emerson bomb calorimeter.

Vol.

Raw Tar 38 56 70 64 56 46 32 20

O F OILS IN POWNDS PER

Light Oil 3.9 6.0 7.9 6.7 5.2 3.6 1.9 0.8

Medium Oil 16.0 23.8 29.3 26.7 23.2 19.1 13.2 8.2

Paraffin Oil 12.6 18.7 23.7 21.2 17.6 13.7 9.3 5.6

Loss 4.3 3.3 3.2 4.3 4.3 5.0 5.9 6.3

T O N OF COAL Hard Soft Paraffin Paraffin 1.5 0.5 2.8 1.0 1.5 3.8 3.3 1.2 1.9 0.8 1.0 0.6 0.3 0.2 0.1 0.1

Twenty cc. each of ethyl ether and ethyl alcohol were added and t h e mixture cooled t o - 2 0 ' C. in a. salt and ice bath. The flaky mass was filtered through a 4-in. funnel surrounded b y freezing mixture, t h e filt r a t e being evaporated and t h e soft paraffin determined b y freezing from a n ether-alcohol ( I : 2) mixture after evaporating upon t h e water bath. Any admixture of impurities was removed b y dissolving t h e paraffin in t h e filter b y pouring boiling ethyl alcohol through it and collecting t h e filtrate in a tared beaker,

4Qo 350

B. t. u. 11,800 12,210 12,500 12,690 12,790 12,870 12,930 12,980 13,020 13,040

FIG.

A M M 0 N I A C A L L I Q U 0 R AND C Y A N I D E S

The total distillate was well washed and t h e washings tested for ammonia and cyanides. Most of t h e ammonia was found t o be held by t h e t a r before i t reached the acid wash bottle, while t h e cyanogen content seemed t o be nearly all carried over t o its respective wash bottle. The cyanide precipitated out upon the addition of ferric alum even a t t h e lower temperatures. As this precipitate was intermixed with impurities, as noted by t h e color, no significance would attach t o t h e amounts obtained a t t h e various temperatures, b u t i t was estimated t h a t approximately 1.2; lbs. of cyanogen may be obtained a t 600' C. per ton of coal. The yield of ammonium sulfate in pounds per ton of coal is given in Fig. I V . TAR OILS

All of t h e water was extracted by calcium chloride from t h e crude distillate and t h e dry t a r obtained was red-brown in color and semi-solid at ordinary tempera-

Y'

/50

4

Q /oo 50

%. t h e alcohol evaporated and t h e hard paraffin (m. p. 45 O t o j j O C.) weighed. 1 2

Schocl of Mines a n d Metallurgy, Univ. of Missouri, Bulletin [41,3,55. Z. angew. Chem., 1897, 300, 332.

May,

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1920

P R O P E R T I E S O F T A R OILS

The light oils were washed with sodium hydroxide and sulfuric acid, 20 per cent being soluble in alkali.

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recovered. The light oils soluble i n sodium hydroxide constitute t h e cresols and unsaturated acids. The medium oil is made up in part of naphthalene, anthracene, and t h e higher paraffins, and is semi-solid a t ordinary temperatures. Soft pitch is contained only in t a r s obtained a t j o o o C. and above. coscLusIoss

I

I

I

I

I

I

I

I-The maximum yield of t a r oils is obtained at 350' C. 11-About 3.5 per cent of t h e coal may be obtained as raw oils. 111-These raw oils are a mixture of coal t a r and petroleum-like oil, with t h e former predominating. IV-The yield of light oils decreases rapidly as t h e temperature increases, t h a t of t h e paraffin oils less rapidly, while t h e yield of t h e medium oils remains fairly constant. V-About 5 . 3 lbs. of paraffin wax per t o n of coal may be obtained a t 3 j o o C. VI-The gas given off up t o 600' C. is small in volume and low in heat value, b u t relatively high in illuminants. VII-Appreciable amounts of ammonia may be obtained from t h e t a r water and also small amounts of cyanides.

//

-,

I

1

The washed oils were then treated with concentrated nitric and sulfuric acids in a reflux condenser, whereupon nitro derivatives were obtained t o some extent, b u t t h e limited amount of oils obtained made i t impractical t o ascertain t h e yield. Phenols also were isolated upon t h e addition of bromine water t o t h e cresols obtained from t h e alkali washings. The specific gravities of t h e various fractions are recorded in Table 7 . TABLE'?-SPECIFIC Temp. C . 250 300 350 400 450 500 550 600

Light Oil 0 807 0.815 0 812 0.815 0.816 0.816 0.818 0.821

GRAVITYOF TARFRACTIONS Medium Oil Paraffin Oil 0.905 0.908 0 915 0.926 0.935 0.938 0.946 0.995

0.939 0.950 0 957 0.968 0.966 0.978 0.983 0.985

DISCUSSION

The most striking feature of t h e investigation is t h e well-defined decomposition point between 350' C. and 400' C., approximating closely t h e same temperature as in t h e previous study, viz., 380' C. This marks a maximum i n t h e yield of t a r oils, and a n a b r u p t rise in the quantities of hydrogen and methane, t h e change of composition in t h e gas being evident from t h e shape of t h e curve (Fig. 11). At this point also occurs a decrease in paraffins, suggesting t h e possibility of t h e cracking of t h e oils. Unlike t h e previous study, t h e presence of cyclic compounds in t h e light oil was proved by t h e formation of nitro derivatives and phenols. The light oils were distilled1 and very small amounts of benzene (to g j" C.) and toluene ( 9 5 O t o 120' C.), and a considerable amount of solvent naphtha ( 1 2 0 ~t o zooo C.) were 1

Met. & Chem. Eng., 17 (1917), 551.

VIII-The specific gravities of t h e t a r oils and their respective fractions increase correspondingly with increase in t h e temperature of distillation. IX-This coal, when subjected t o destructive distillation, has a temperature of marked decomposition which corresponds t o a sudden increase in t h e amounts of hydrogen and methane evolved and a corresponding increase in t h e quantity of oil distilled which is generally t h e maximum point, and, as in most low-grade

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coal, this temperature lies between 350' and 450' C. X-The residue a t 350' has a calorific value of 1 2 , 7 9 0 B. t. u., which is an increase of 22.8 per cent over t h e coal as mined, and of 14.7 per cent over t h e d r y coal. HARDENING EFFECTS OF VARIOUS ELEMENTS UPON LEAD By Carl 0. Thieme MICHIGAN SMELTING AND REFININGCOMPANY, DETROIT,MICHIGAN Received November 22. 1919

During t h e war, t h e high price and t h e threatened famine in tin, due t o labor conditions, shortage of ship bottoms, and possibly t o the submarine warfare, caused t h e manufacturers of this country t o search a n d experiment with other metals and alloys t h a t could be used in place of those containing tin. Of course, t h e greater portion of this work was done on tin-base bearing metals, but t h e conservation of t i n was aided by the substitution of other metal for tin, in brass and bronze alloys. It is quite well known t h a t the composition of gun metal, 88-10-0-2, was modified t o 88-8-0-4, with results t h a t were just as satisfactory. I n other cases, t i n was entirely omitted from bronzes, and aluminum substituted, producing alloys t h a t were decidedly superior t o the tin bronze, with regard t o physical properties, although as a general rule difficulty was encountered in manufacturing aluminum bronze castings. Commercial manganese bronze, which is essentially a copper-zinc-iron alloy, found a greater use, and t h e use of yellow brass mixtures in general became more popular. The tin content of brass mixtures containing t h e four elements, copper, tin, lead and zinc, in many instances was decreased, a n d one or two of t h e other

Vol. 12, No. 5

show t h e hardening effect of the various elements upon lead. T h e hardening effect of the elements will be taken up in the order in which they appear in t h e accompanying table. CALCIUM-Lead may be hardened by t h e addition of about one per cent of calcium.' It then has a Brinell hardness of 15, and quite a metallic ring. The alloy does not long retain a luster, and in a short time darkens a great It shows numerous pearing on the surface of t h e metal, which pitill chip - off,. giving-the metal a sort of pocked appearance. We believe t h a t this alloy, upon remelting several times, loses its hardness, due, undoubtedly, t o t h e oxidation and consequent skimming off of the calcium, together with the lead oxide. An admixture of barium and calcium is sometimes added as t h e hardening agent. SODIUM-sodium added t o lead hardens i t considerably, giving a Brinell hardness of approximately 5 t o 6. This alloy also loses its hardness after several remelts. It is believed by some t h a t t h e hardening constituent in a n alloy of this kind is a substance having the formula Na2Pb6.2 The eutectic of leadsodium alloys is 2 . 5 per cent sodium, and 9 7 . 5 per cent lead. As the sodium is increased, t h e Brinell hardness gradually increases until a t 0.8 per cent (the maximum amount of sodium dissolved by lead) t h e Brinell hardness is 8. From 0.8 t o 2 . 5 per cent t h e hardness does not increase, b u t falls off with sodium values higher t h a n 2 . 5 per cent. ARSENIC-Arsenic hardens lead and increases the fusibility of t h e alloy. T h e quantity of arsenic added is generally under one per cent, and probably not more t h a n 0 . 5 per cent. On account of t h e increased fusibility, this metal is used t o advantage in making lead

HARDENING EFFECTOF VARIOUSELEMENTS ON LEAD -HARDNESS--Magnified COMPOSITION (PER CENT)--Hammer Brinell Fig. REMARKS Sn Pb Sb P Mg Ca Na Ni As Hg Scleroscope Test No. Cu 99.0 0.8-1.0 14.0 15.0 An admixture of barium and calcium, sometimes added as hardening agent 99.5 0.5 ... 5-6* 99.2 . . . . . . . . . . 0.8 . . . . . . . . . 7.5-8* 99.5 0.5 7.5-8.5* Known as shot lead, also added t o antimonial lead for bullets . . . . Hardness not determined . . 2 . 0 ... 98.0 14.0 1 10-1 1 Popularly known as antimonial lead 9 0 . 0 10: 0 ... 16.0 Metallic packings-filling and hammer metal 2 14.0 82.0 18.0 ... ... 24.0 3 ... 0 . 8 Trace 8 1 . 0 1 8 . 0 0 : is . . . 1 7 . 5 Experimental alloy 82.0 17.5 ... 0.5 15.5 8 2 . 0 17.5 0:s ... . . . 1 8 . 0 i i i i z 4 8 2 . 0 1 4 . 0 . . . . . . 4.0 19.0 11-13 ... ... ... . . . 5 . 0 81 .o 1 4 . 0 20-21 5 14-15 ... . . . 8 . 0 80.0 12.0 22.0 6 15-16 ... . . . ... . . . 11.0 7 5 . 0 1 4 . 0 12.0 15.0 7 Exoerimental allov ... 99 3 .. 0.7 ... 12.0 ... ... i : o 98:3 0.7 10.5 ... ... ... 0.7 ... ... 2.5 96.8 12 0 .. 0.7 5.0 94.3 ... ..... 0-7.0 4-9* . . . . . 1oo:o 4-4.5* . . . Cast lead 100.0 5-5.5* . . . Cold hammered lead Hardness numbers followed b y asterisk, 100 kilogram load and 10 mm: ball; all others, 500 kilogram load and 10 mm. ball.

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metals increased, producing alloys t h a t were cheaper a n d gave just as satisfactory results for t h e purposes for which they were used. As stated above, the conservation Of tin was due largely t o t h e use of lead-base and leaded white metals. It is not my intent t o enter into a discussion of t h e values of lead-base bearing metals a t this time, for there are many articles, pro and con, published on this subject, but t o present the following d a t a which will

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shot, for t h e time taken in solidifying gives t h e metal: better opportunity t o form a spherical drop. NICXEL--hTickel, when added t o lead, has a decided hardening effect, but on account of t h e great difference in their melting points, t h e of this alloy is rather out of t h e question. The component metals must be

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Met E n g . , Sept. 28 (1918), 253. C. H. Desch, "Metallography," 2nd Ed., 1918; C. H. Mathewson, z. anoyg. them., so (1906), 171. a