(37.5) IVoidich, I'ri. Ab+. 22, S o . 829 (1960). (??+I) I\-urziger, J., Chandra, U., Deut. ?.~:ieria,ti.-RundschazL55 i l l ) . 281 11959): ,, Ana! A I L d r . 7,3513 (1960):' (:381) Kiirziger, J., Chandra, U., Fleischwzrtschail 11. 926-7 (1959). (382) Wurziqer, J., Pohlmann, R., Deut L,,Deiism.-~,~niischau 54, 307-8 (1958).
(383) Wynn, J. D., Brunner, J. R., Trout, G. hl., Food Technol. 14, 248-50 (1960). (384) Yamada, Y., Kishi, H., S z p p o n k'agaku Zasshi 76, 48-50 (1955). (385) Yamagata, N., Yamagata, T., Bull. Chem. SOC.Japan 31, 1063-8 (1958). (386) Yamagata, N., Yamagata, T., Matsuda, s., Tajima, E., Watanabe, s., Japan Analyst 7, 433-8 (1958); Anal. Abstr. 6, No. 1849 (1959) (387) Yaphe, W.,X.u.4~.CHEM.32, 132730 (IQAOl.
(388)'Yaiuhara, S., hlasuyama, S Kagaku to Kogyo ( O s a k o ) 31, 399-401, (1957). (389) 1-oshihiro, Y., Nakumura, AI., J . Chem. SOC.Japan, lnd. Chern. Sect. 61, ( 8 ) , 972-5 (1958); Anal. Abstr. 6, No. 191.5 - - - - (19.m) ~-"-~,. (390) Ibid., 62 (2), 208-10 (1959); Anal. Ab&. 7, 609 (1960). ~
(391) Zimmerman, H., 2. Lebenstn.-Gntersuch. u.-Forsch 112, 46-9 (1960). (392) Zlatkis, A, Orb, 3. F., Kimball, A. P., A s . 4 ~ CHEX. . 32, 162-4 ( 1 960). (393) Zoet, B.,.I7&. M z l k Dairy J . 13 (4), 306-16 (1959): Dairn Sci. Abstr. 22. 1442 (1960). (394) Zonnt veld, H.. X c y e r , .L, 2. Leberis,,~.-Irnlersurh.'zc.-For,.ck. 111,'19820; (1960). (395) Zook, E. G., MacArthur, >I. *J., Toepfer, E. \I-,,U . S.Dept. Agr., Agr. Hiln~!liookS o . 97, 23 pp. (1956). (386) Zotti, G., de, Capella, P., Jacini, G.- Felte. Seifen. Anstrichmittel 61, 1114-9 (1059). (397) Ziihlsdorf. >IDeut. ., .lfikh. Wirtschafl 63-1 i 1959). '
"
I
lid and Gaseous Fuels W. H. Ode and Theodore Chrisfos E ~ e o of t ~ Mines, U. S. Department of the Interior, Pittsburgh, Pa.
1% iiie seventh of a series of rev i e w on methods of sampling, anal) zing, and tccting solid and gaseous fuels. The revim covers a 2-year period ending September 1960, and iolloas the general pattern of previous revsew.
'HIS
SOLID FUEL5
'I'his s e h o n discusses sampling, ardysis, and ttxting of such solid fuels as
ic roal samplers and
i ! .thwr:; ~ ?f mil saniplhg. Of the m t :i nietliods > J S I : ~f c t ~calculating varis
~
i
ioux! more rational. o y i l nil2 Scnxerd (,?A) listed the s o i a niechanical coal &cm+>rL:
7
:tnd spout anti rotatirig slotted cone. The! also iiescritxd n method for testing the aLc:uracy qf Lampling. P ~ L I(7.4) I made an investigation of th- nun:i:cr of iricrements that should ~
be taken for raw coals and for prepared coals. Examples showed the relation of errors of sampling, sample preparation, and analysis to the total error. Norman (6A) investigated a n automatic device for sampling coal from railroad cars as they are unloaded by tipping. H e concluded that, although the sampler may have bias for coals difficult to sample, it is better than taking samples from tops of cars or from under cars during discharge. Chakraborty, Tarafdar, Ghosal, and Dah Gupta ( I A ) proposed a sampling procedure designed for preparation of laboratory samples of coke. The procedure is based on a statistical consideration of the magnitude of errors occurring a t different stages of size and weight reduction of the original sample. Liplavk and Boliter (5A) described a method for determining the degree of mixing for multicomponent coal charges using radioactive sulfur as an indicator. Different types of mixing apparatus were evaluated by the method. Proximate Analysis. Elphick ( I S B ) developed a niethod for proximate analysis of coal a h e n only a small amount of sample is available for analysis -4 0.5-gram sample IS suffioient for a complete proximate analysis and determination of calorific value. MOISTURE. Blanzat (6B) described a n all-glass apparatus for determining moisture by entrainment in xylene or toluene. The ascending column is insulated Kith a silvered vacuum jacket; the descending column assures that all of the water falls into the graduated receiver. The apparatus is designed for use with 50- t o 100-gram samples of
coal of lrss than 3-mm. size. The principle, apparatus, reagents, and procedure for the distillation method adopted in Spain by the Instituto Xacional dcl Carb6n also were described (15B). Banerjee and Paul (6B)reported that, in determining moisture in coal and coke by loss of weight during heating, a cooling period up to 40 minutes has no effect on the moisture value if the empty dish and n-ell-fitted lid are cooled for the same length of time as the dish containing the coal or coke. GAl, Lbsz16, and Varga (I4B) proposed for the rapid determination of moisture in coal that the sample be dried a t 120" ?Z 2" C. for 30 minutes rather than a t 105" to 110" C. for longer periods of time specified in several standards. Comparative results indicated that the method is accurate. Zagrodzki and Kicdzielski ( 2 M ) modified the standard Karl Fischer met,hod by extracting the moisture from coal with anhydrous methanol and titrating the resulting solution. Tyman (bfB) found that the Fiwher method gave results agrccing with those obtained by sylvne distillation. In detcrmining moisture in brown COSlS, Jandisek (16B) showed that rapid drying hy high-frequency heating has advaritngrs over usual ovcn mcthods in that ovrrheating and oxidation are minimized. Iiiihn ( I i B ) rc.portcd that moisture in various matc~ialsincrluding coal could be determined by measuring the thermal neutrons in the immediate virinity of a fast-neutron sourcc anti the nnatc>ri:d. ASH AND ~ I I N E R A MATTER. L hrsin VOL. 33, NO. 5, APRIL 1961
a
61 R
(2B) found that, if the coal sample is briquetted and heated for 5 minutes a t 500" t o 600" C. to remove volatile matter, ashing may be done rapidly at 800" C. Results may be rather inaccurate for coals containing considerable calcite because of retention of SO3 in the ash. She also reported that adequate ventilation of the muffle minimizes the SO8 retention (3B). Tarpley and Ode (IOB) demonstrated that the acid-extraction method developed in Germany by Radmacher and Rlohrhauer for determining mineral matter in coal was suitable for all ranks of American coals if modified slightly for coals containing considerable amounts of calcite or calcium humate. Brown, Durie, and Schafer (7B) investigated two methods for determining mineral matter in Australian coals, one based on low-temperature oxidation and the other on acid extraction. Difficulties with each are overcome by a combination of the two methods (8B); the combined method also provides a direct means of estimating the water of hydration of the silicate minerals in the coal. Continuous determination of the ash content of coals by means of x-rays using the method developed at the Dutch State Mines was described (IOB, IdB, 19B). Rays from a n x-ray tube are split into two beams; one strikes the coal sample; the other strikes a standard object. The difference in intensity of the reflected beams is measured by an automatic compensation method. An apparatus using the same principle also was reported by Bushin (9B). ' VOLATILEMATTER. For estimating the volatile matter of the pure coal substance, Leighton and Tomlinson ( I @ ) developed a correction factor for coals with high percentages of pyritic sulfur, carbonates, and chlorides. The correction has the form
+ +
+
Correction = 0.13 ash 0.2 S,, 0.7 COz 0.7 C1 - 0.20 To avoid the necessity of determining pyritic sulfur, a simplified correction was deduced which has the form Correction = 0.13 ash
+ 0.2 8 +
0.7 CO,
+ 0.7 C1 - 0.32
where S is the total sulfur. Arsin and Pavlovic (4B)reported that if the volatile matter determination is made a t 820" to 870" C., a compromise is reached between the deficiency of volatile matter from the coal substance and the surplus of COZ derived from the mineral constituents. A temperature of 950" & 10" C. should be allowed only for those coals containing less than 1.4% CO2 (1B). Dahme and Echterhoff ( I I B ) found
62 R
ANALYTICAL CHEMISTRY
that the volatile constituents of hightemperature coke determined by conventional methods consist mainly of adsorbed gases and do not represent loss of chemically bound constituents. Ultimate Analysis. CARBONA N D HYDROGEN.Edwards (4C) and Mendoza ( 1 0 0 reported that, in the Liebig method for determining carbon and hydrogen, oxides of nitrogen are evolved in sufficient quantity to cause a n error of approximately 0.2% in the carbon determination. Their removal by passing the products of combustion through a tube containing Mn02 is recommended. Edwards reported, however, that only traces of oxides of nitrogen are evolved in the Sheffield high-temperature combustion method. Radmacher and Hoverath (1%') described a semimicro technique for determining carbon and hydrogen that is based on the Sheffield macro hightemperature method. The technique is reported to have advantages in that i t provides a wider range of application with respect to sulfur, carbonates, and volatile matter, and is simpler and more rapid to use. Gardelka (SC) reported that silver permanganate is useful in accelerating the determination of carbon and hydrogen in 10- to 15-mg. samples of fuel and fuel products. OXYGEN. Radmacher and Hoverath (12C) described an apparatus for directly determining oxygen in coal based on the Unterzaucher method. The coal first is demineralized by an acid-extraction procedure using HF and HCl which eliminates any error that otherwise would arise from oxygen released as water or carbon dioxide from the silicate and carbonate minerals. Results obtained by d ~ e r e n operators t showed deviations from the mean of 10.08 for 2.5% of oxygen to *0.2 for 9.2% of oxygen. SULFUR. Ahmed and Lawson (2C) determined milligram amounts of sulfur by a modification of the Carius method in which the organic sulfur is oxidized with H N 0 3to sulfate, the sulfate precipitated with 4amino-4'-chlorobiphenyl, and the excess of precipitating agent determined spectrophotometrically. When applied to coals and humic acids, the method gave recoveries within 1% of the theoretical amount for samples containing 3 to 7.5 mg. of SOa. Aarna ( I C ) described a rapid combustion method in which the coal is covered with VzOj and burned in oxygen a t 800" to 850" C., the oxides of sulfur converted to SO8 by bubbling through H202,and the solution titrated with a standard solution of NaOH. Petrenko ( I l C ) used a temperature of 1150" to 1200" C. to ensure complete conversion of the sulfur to SO,; the SO2 evolved is determined iodimetrically. Bhattacharyya and Bhaduri (SC)
developed a method for total sulfur in coal based on combustion of a 0.1- to 0.2-gram sample in a flask containing oxygen using B platinum-rhodium gauze cover over the coal. The sulfur oxides are absorbed in H202to form sulfuric acid and the sulfur determined gravimetrically or titrimetrically. Van Hees and Early (8C) determined pyritic sulfur in coal by successive extraction of the same sample with 5 N The pyritic sulfur HCl and 2N "03. is calculated from the iron content of the second extract. Several workers (5C, YC, 9C) described the application of amperometric titration of the sulfate ion in the solution obtained from the Eschka decomposition procedure. A standard solution of Pb(N03)Z is used as titrant. Calorific Value. M o t t and coworkers of the British Coke Research Association continued their comprehensive studies of bomb calorimetry. They found t h a t the SOI formed in the combustion of a solid fuel dissolves to a negligible extent in the water added to the bomb, and t h a t most of i t is in the water released or produced during combustion and deposited as fine droplets on the walls and cap of the bomb. Various recommendations were made for accurate assessment of the sulfuric acid formed (ID). Examination of the gases remaining after combustion of anthrarite and coke often showed a significant quantity of CO even when no residual carbon is detected. The formation of CO was minimized by using crucibles of proper dimensions and oxygen a t pressures of 30 to 35 atmospheres
(W.
Getoff and hlackowski (ID) investigated the sources of error in determining calorific values of coals sensitive to osidation. In addition. they described methods for determining the calorific value of low-grade coals and the effect of the cooling coefficient of the calorimeter on the accuracy of the results. Inorganic Constituents in Coal and Coal Ash. To replace time-consuming wet-chemical methods for analyzing coal ash, clinker, slag, and boiler deposits, Archer, Flint, and Jordan ( I E ) substituted colorimetric procedures for determining silicon, aluminum, iron, titanium, manganese, and phosphorus. Calcium and magnesium are determined by titration with disodium(ethy1enedinitri1o)tetraacetic acid, and sodium and potassium, by flame photometry. The methods are particularly suitable for batch analysis; five samples can be analyzed in duplicate in a week by one analyst with an accuracy of better than 0.4% for all constituents except A1201, for which the accuracy is about 1.0%. Doming0 (9E) described methods for major constituents in coal ash based on
normal wet-chemical procedures for silicate minerals. General colorimetric techniques also were reviewed. Several investigations were made of spectrographic methods for determining trace elements in coal ash. Smith (%E) used a graphite buffer to make the samples more conductive, and LiCO3 was added to reduce the volatility of some elements. At least two internal standards were found necessary. The determination of 30 trace elements can be completed in about 5 hours if standards and analytical working curves are prepared previously. Radmacher and Hessling (33E) described qualitative and quantitative procedures for spectrographically dekermining trace elements. For qualitative work, the ash is mixed with XH4C1 and graphite (2:l:l); for high sensitivity, continuous direct current arc excitation is used. In the quantitative method, the ash is mixed with InpOs as internal standard and Na2B407,and then fused to a clear melt. The cooled melt then is mixed with graphite and pressed into the electrode. Hegemann, Giesen, and Kostyra (16E) gave the details of a spectrographic method for determining trace elements without previous ashing of the coal. O'Keil and Suhr (S2E) determined trace elements spectrographically using a controlled atmosphere of CO,. Under this condition, C N bands are suppressed, line to background ratio is improved, and simultaneous determination of many elements can be made. ARSENIC. Cranford, Palmer, and Wood (YE) determined arsenic in microgram quantities in coal and coke using a technique whereby the organic matter is destroyed by wet oxidation; the arsenic is determined spectrophotomc,trically in a Folution containing the blue arsmomolybdenate complex. To avoid the time required for n e t oxidation, Crook and Wald (8E) substituted a dry oxidation procedure to destroy the carbonaceous material. The coal or coke is mixed with MgO and K J I n 0 4 and is burned in oxygen. BORON. Millet ( M E ) determined boron by a method in which the sample is mixed with graphite, ignited in an electric arc, and the boron determined spectrographically using the line 2496 8 A. with the carbon line a t 2582.9 A. as reference. Konieczyfiski (20E)developed a spectrographic method for boron in coal, coke, pitch, and tars using a technique in mhich the carbonaceous material is first destroyed by wet oxidation and the boron dctermined in the solution. FLCORINE. McCowan (24E)adapted a spectrophotometric method for determining fluorine in coal. The sample is prepared for spectrophotometric measurement by ignition in a
PHOSPHORCS. Several investigations were made of modifications of well known methods for determining phosphorus in the ash of coals and cokes (1OE, 11E, 12E, 1$E). Moitra, Banerjee, and Chatterjee (29E) found that oxygen-bomb combustion or wet oxidation of coals gave values ranging from 0 to 66% greater than those obtained by usual combustion methods; low-temperature ashing in the presence l-(2,4-dihydroxyphenylazo)-2-naphthol- of CaO gave intermediate results. Radmacher and Schmitz (34E) reported 4-sulfonic acid(sulfonaphtho1azoresorthat, for coals they esamined, similar cinol) for the fluorimetric determination of gallium in a variety of materials results were obtained using either wet or dry combustion. including coal. The lower limit of Cosstick and Schafer (6E) proposed detection is 0.01 wg. the substitution of HC1 and H2SOI GERMANIUM.Several spectrographic in extracting phosfor HF and "03 methods were developed for determining phorus from coal ash. The replacegermanium in coal ash and coal prodment eliminates the need for platinum ucts. In the quantitative method developed a t the Federal Bureau of ware and the disadvantages associated with the use of HF. Mines, bismuth was used as an internal SODIUM AND POTASSIUM. The standard; the lower limit of detection is method adopted in Spain by the Insti50 p.p.m. when determined quantitatively, but concentrations of less tuto Nacional del Carb6n consists in extracting the ash with HF and HClO, than 20 p.p.m. can be detected qualitaand then dissolving in hot water. In tively (6E). Gregorowicz (1bE) deone part of the solution, sodium is pretermined germanium in ash over the cipitated nith zinc uranyl acetate and range of 0.003 to 0.3% GeO,; an auxiliary copper electrode containing 0.1% weighed as the triple salt; and in another part, potassium is precipitated nickel provides a nickel line as the and weighed as the tetraphenylborate standard. Malinek (25E) used iron as an internal standard; his method for (CE). Rekus (%E) reported the use of tar ashes gave a relative standard indium as an internal standard foi deviation of 8.6% for ashes covering the spectrographic determination of potasrange of 0.01 to 1.0% Ge. hlantea, sium in coal ashes varying widely in Petrescu, and TritSl (26E) used a preliminary enrichment method before composition. The standard deviation of the method is slightly less than spectrographically determining ger&6% for K20 contents ranging from manium in coal. Several modifications were made of 0.8 to 2.3%. SCANDIUM.Kul'skaya and S'dovenko the well known phenylfluorone colori(22E) described a spectrographic metric method (2E, 18E, dTE, SOE, method for determining scandium in 3'7E). Kunstmann and Niiller (2323) found that the phenylfluorone method coal ash, and Gornyi (lCE),a precipitagave high results in the presence of as tion method. little as 0.004% manganese owing to TITANIUM.Kessler and DoEkalo~b (19E) investigated two methods for oxidation of HC1 to chlorine; they eliminated the trouble by introducing determining titanium in coal ash. FeS04 in the distillation flask before the Although the polarographic method is addition of HCl. more complicated and takes longer, it is W~clewsliaand Popanda (4ZE) desuitable for determining 0.3 to 0.8% scribed a polarographic method for TiO2 in the presence of more than germanium in coal ash and flue dust at a 0.05% vanadium. The photometric minimum detectable concentration limit method is simpler, more rapid, and does of 0.5 pg. per ml. The results compared not require removal of iron. well with those obtained by spectroURANIUM. Methods that xere exphotometric and spectrographic methamined for determining uranium included colorimetry (17E, SQE, LO&), ods. IRON AXD ALUMINUM. *4 chelatopolarography and ultraviolet fluoresmetric method was developed by cence (21E ) , and an autoradiographic Radmachw and Schniitz (S6E) for technique using a nuclear emulsion determining iron and aluminum in fuel (SEI * ash. First, iron is determined by Laboratory Coking Tests. PLAStitrating with a standard solution of TICITY TESTS. Indian investigators disodium (ethylenedinitri1o)tetraacetate ( S F ) described an electric heater that a t p H 1.4 to 1.8 using salicylic acid as provides the same temperature condithe indicator; subsequently, in the same tions as standard gas burners used in solution, aluminum is determined a t pK determining the free-swelling index of 3 with I-(2-pyridylazo)-2-naphthol as coal. A graphical method for relating the indicator. area or volume to swelling index is
calorimeter bomb, conversion of the soluble fluorides to hydrofluosilicic acid, and preparation of a test solution using thorium-alizarin as a color reagent. The fluorine content is determined by its bleaching effect on the color reagent. The fluorine content of a 1-gram sample may be determined within 7.5 p.p.m. over a range from 0 to 300 p.p.m. GALLIUM. Nazarenko and Vinkovetskaya ( S l E ) proposed the use of
VOL. 33, NO. 5, APRIL 1961
63 R
suggested for evaluating buttons which do not conform to the standard profiles. I n evaluating the plastic properties of highly-swelling coals, Bandopadhyay, Sarkar, and Das Gupta ( I F ) proposed mixing the coal samples stepwise with increasing proportions of electrode carbon, testing the mixtures in a Gieseler plastometer, plotting the percentage of electrode carbon against the logarithm of maximum fluidity, and extrapolating the straight line plot to zero inert content to arrive a t the true maximum fluidity. CARBONIZATION TESTS. Mott (4F) described a 15-pound test oven for the study of blending of coals for coke making. By packing the charge to proper bulk density, a coke is obtained whose apparent specific gravity is only a little lower than that of commercial blast-furnace coke. Durand and Lahouste ( d F ) also described a 20-kg. test oven for studying the coking quality of coals. The hlicum drum test was adapted to evaluate the cokes. Schulte-Herbruggen (6F) performed experiments using the Jenkner smallscale carbonization assay in which thermal and catalytic cracking conditions were varied. Results were compared with plant practice. Wilson and Naugle ( 6 F ) developed a bench-scale tester for evaluating the effect of operating variables on the expanding properties of coal. The standard error of estimate for predicting sole-oven results from bench-scale results is 1 5 . 3 percentage points. The effect of operating variables with both types of equipment is similar. Standard Methods. KATIONAL STASDARD~. A conipilation of standards on coal and coke was published by the American Society for Testing Materials (XSTM), which assembles, in convenient form, specifications, definitions, and methods of sampling, testing, chemical analysis, and classification ( I G ) . The standards also were published in the 1958 Book of ASTM Standards. Furthermore, in 1960 the ASTM adopted tentative standards for dctermining CO, in coal (D 175&60T), sulfur in coal ash (D 1757-60T’l, and plastic properties of coal by the Gieseler plastometer (D 1812-60T). The British Standards Institution continued its revision of B. S. 1016. The revisions include modifications to improve accuracy and alternative procedures to reduce the time required for analysis. Part 6, Vltimatp Analjsis of Coal (SG) and Part 7 , Ultimate -2nalysis of Coke (4G), deal with the dctermination of carbon, hydrogen, nitrogen, and sulfur. The background in dpveloping the two standards was reviewed by King (26G). Part 8, Chlorine in Coal, describes the Eschka and the hightemperature combustion methods (5G). 64 R
ANALYTICAL CHEMISTRY
Table 1.
Standards Adopted
Czechoslovakia Determination of strength of coke by the Micum test India Coal and coke, proximate andysis, total sulfur, and calorific value Coal and coke, ultimate analysis Coal and coke, special impurities Coal carbonization, caking index, swelling properties, and Gray-King (L.T.) coke types Coke, special tests Coal and coke, test for ash
CNS441327
IS 1350 IS 1351 IS 1352 IS 1353 IS 1354 IS 1355
Netherlands Determination dilatometer Determination Determination Determination Determination
of coking properties of coal and coal mixtures by the
of of of of
fusibility of ash crucible swelling number volatile components total sulfur by the Eschka method
Poland Wnekowska-Czubek method for total phosphorus content of coal
KEN KEN XEN KEN SEN
934 1289 3039 3187 5251
PN C04347
Rumania Sampling Determination Determination Determination Determination
of ash of bulk density of moisture of mechanical strength by the hlicum drum test
Spain Determination of ash Crucible swelling index of coal Mechanical strength of coke. Micum test
UXE 32004 UKE 3200.5 CXE 82018
Cnion of Soviet Socialist Republics Method of selecting samples for testing Determination of sulfur Determination of moisture Test method for clinker formation Determination of characteristics for distinguishing bron n coals from hard coals Determination of caking capacity Determination of chlorme Determination of mcisture by direct volumetric method Coke: Rules for process and methods of selection and sampling Coal briquettes: Samples and methods of test Peat for fuel: Methods of selecting samples for testing content of fines Peat for fuel: Methods of selecting samples for testing of inflammable impurities Table
Item
II.
Status of
Work of IS0
1 Determination of mois-
ture
GOST 6105
GOST 8606 GOST 8719 GOST 9271 GOST 9276 GOST 9318 GOST 9326 GOST 9339 GOST 2669 GOST 6114 GOST 8472 GOST 8475
Technical Committee 27
Stage of Development
Item
NO.
STAS 5573 STAS 5629 STAS 5630 STAS 5631 STAS 5632
(i) Revised draft proposals on three methods for total moisture have been approved by Working Group 2. (ii) Revised Draft, I S 0 Recommendations for moisture in analysis sample by direct gravimetric method and direct volumetric method are being p r e pared for submission to IS0 Council. (iii) Revised draft propoeal for moisture-holding c& pacity (general method) is being prepared. Simplified and rapid methods are being investigated.
2 Determination of ash
I S 0 Recommendation approved for publicat,ion.
Determination of calorific value
Draft roposal for calorimetric bomb met,hod circuited for postal ballot,; comments are under review. (ii) Adiahatic bomb method to be studied.
4 Determination oi carbon and hydrogen
(i) Revised Draft I S 0 Recommendation for Liehig method is being prepared for suhmissmn t o IS0 Council. (ii) Revise6 draft proposal for hlgh temperature method is being prepared for postal ballot.
3
(il
(Contznued)
Table 11.
Item
Status of Work of I S 0 Technical Committee
27 (Continued)
Stage Development
NO.
Item
5
Determination of total sulfur
(i) I S 0 Recommendation for Strambi method approved for publication. (ii) Revised Draft IS0 Recommendations for high temperature method and Eschka method are being prepared for submission to IS0 Council.
6 Determination of ni-
Revised Draft IS0 Recommendation for Kjeldahl method and semimicro Kjeldahl method are being prepared for submission to IS0 Council. In aheyance.
trogen
7 Determination of oxygen 8 Determination of volatile matter
Draft proposal circulated for postal ballot; comments are under review.
9
Reporting of results
In abeyance.
IO
Determination of ash fusibility
Draft proposal circulated for postal ballot; comments are under review.
I1
SNelling and caking tests
(i) Draft proposal for crucible swelling number circulated for postal ballot; comments are under review. (iij Draft IS0 Recommendation for Audibert-.%mu test circulated by General Secretariat; comments under review. (iii) Draft proposal for Gray-King test circulated for postal ballot; comnients are under review. (iv) Limit of agglutinating value: in abeyance. ( v) Revised Draft I S 0 Recommendation for Roga method is being prepared for submission to I S 0 Council. Other methods: questionnaire in preparation.
12
Determination of phosphorus, chlorine, and arsenic
(i) Draft proposals for phosphorus by the gravimetric method, volumetric method, and colorimetric method to be circulated shortly for postal ballot. (ii) Direct method for phosphorus: questionnaire circulated. (iii) Revised Draft I S 0 Recornmendations for chlorine h. the Strambi melhod and the high temperature mFt>hod,are being prepared for w b mission to I d 0 Council. (iv) Draft proposal on chlorine by the Eschka method to be circulated shortly for postal ballot. (v) Draft proposal for arsenic by the absorptiometric method to be circulated shortly for postal ballot.
13
Determination of forms of sulfur 14 hiethods of sampling
IS0 Recommendation approved for publication,
15
Dr$ft proposals being studied by Korking Group t on preparation of the analysis sample and sampling from conveyors and faliing streams; draft proposals in preparation by Rorking Group 7 on sampling from wagons, sampling from ships, and preparation of the moisture sample. Draft proposal to be circulared for postal ballot.
Mineral matter
16 Coal preparation
(i) Draft proposal for coal preparation terminology under revision by Subcommittee 1. (ii) Draft proposals in preparation by Subcommittee 1 on methods of expressing performance of coal preparation plant, flow sheets, and sj-mbols.
17 Brown coals and lig-
(i) Revised draft proposal on yields of tar, water, gas. and coke by low temperature distillation being prepared by Subcommittee 2. (ii) Draft proposals on moisture and ash under discussion by Subconiniitt,ee 2.
I S Physical testing of coke
Draft proposals on hlicum and Shatter tests circulated for postal balluts; comments under review. Size analysis, bulk density, and other physical tests are being studied by Working Group 8 . Methods to be studied.
nites
19 Physical testing of coal 20
Chemical analysis of coke
Draft proposals in preparation by Working Group 8 on total moisture, moisture in the analysis sample, and ash.
I’art 9! I’!iosphorus in Coal anti (’&e, sliecifies the usc of either a volumetric, or colorirnrtric procedure (OG). Ptirt 11, Fornis of Sulfur in Coal, is based on the classicai method of Parr and h i - e l l modified with respect to faster dt,twmination ( 7 G ) . Part 12, Caking anti Sn-elling Propertics of Coal, deals n-it11 the determiiiation of the crucibk swelling number (free-sn-elling indesj and the Gray-King coke-Lype tcst: electric heating is introciuced as a!t,wnati1-i. t o gas heating ir. the crucible swelling test (SG;.Part 1 5 Fusibility of Coal Ash and Coke Ash, differs from the earlier standard in thnt the type uf furnace and the composition and fi(i\\rate of the atmosj)hei-e passing through it are specified more closely (QG). A smaller specimen and a n optical ins:runient t o measure its deformRt’1011 :ire provided. The British Standards Institution also revised its B.S. 1017 with issuanv of P a r t 1 (10G) and Part 2 (11Gj fi)r sampling of coal and coke, respectivcaiy . A new feature is the incliision of n i r t h d s for measuring sampling accuracy nnd fcr adjusting sampling procedures to obtain the required accuracy. The d i ’ \ d < ~ p ment of the sampling standards a a s reviewed by Badger (ZG), Dunninghmi (fSG), and Tonilinson (16G). The latest compilation of Gernisri Standards published in 1960 IncIiiCeti those for coal and coke ( r l G j . Standards adopted in other countries :ire sumniarized in Table I. IKTERNATIONAL STANU.~RI)IZATIOS. Technical Comniittee 27 c,n So!irl IIineral Fuels of the International Organization for Standardization (JBO) under the secretariatship of the Ilritibh Standards Institution continued its eseellent progress in del eloping intcrnational standards for sampling, a lyzing, and testing coal arid coke (1; Table I1 s h o w thc status of the work t c the middle of 1960. Despite the lericlh of tlic table, it can no more than outlinc briefly the large amount of tinir and effort devoted to careful consideration of the twenty subjects listetl. The first methods to be published are 150 Recommendutions for sulfur by tlie Strambi nicthod, ash, and forms of sulfur. .kklitionxil~~,Draft TSO Rcconmendotions were prq)ared for six othrr subjects. Miscellaneous. T h e accuracy of many determinat,ions in fuel analysis depends on various types of u-eigliing dcl-ices. Ward ( i H j described ri method of measuring precision as applied to threr types of equipment, and the experirncntal results n-ere compared with the order of 1)recision required in various procedures. TT’ard and IIillott (Hi) ins.estigated the use of partial demineralization of coal for reducing error when analyses are reported on t>hemineral-matter-free VOL. 33, NO. 5 , APRIL 1961
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basis. They concluded that, for highash coals, values based on this method probably are more accurate than those obtained using empirical formulas when applied to calorific value, carbon, and hydrogen. Improvement in results for volatile matter were less evident. Friehmelt and Steinbrecher ( I H ) determined the amount of oil added to coal during preparation. The method consists of Soxhlet extraction with benzene and subsequent gravimetric determination of the extracted oil. Veprek ( 6 H ) described a method for determining residual tar in semicoke based on the extraction of the coke by a benzene-alcohol mixture and measurement of the intensity of the color of the solution obtained. A centrifuge used in float-and-sink analysis of coal was described by Zarubin ( 9 H ) . Samples of up to 500 grams may be used. Several investigations were made of modifications in equipment for determining the specific gravity of coals and cokes. A description was given of the principles, apparatus, prqcedure, and calculation of results as used in Spain by the Instituto Nacional del Carb6n (2”). Syskov and Verbitskaya ( 6 H ) designed a special pycnometer for use with 50-gram samples of 6- to 13mm. coke. Kijewska (SH) investigated the effect of particle size and experimental conditions; the use of methanol is suggested for coals, semicokes, and cokes. Smith ( 4 H ) described a simple helium-density apparatus for measuring the true density of coal and coke that avoids the necessity of weighing large quantities of mercury or of using large and fragile apparatus. GASEOUS FUELS
The term “fuel gas” may be applied to any gas which can be burned. A list of fuel gases includes the following: blast furnace top gas, carbureted water gas, coal gas, coke-oven gas, gas from underground coal gasification, industrial gas, liquefied petroleum gas, manufactured gas, natural gas, producer gas, synthesis gas, and water gas. Boivin ( I J ) reviewed the methods used industrially for the precision analysis of gases. A description is given of sampling, chemical and physical separation methods, identification and determination without separation, and analysis by combustion and by polarography. Borehani (PJ) published an outline of new methods for the sampling, testing, and analysis of gaseous fuels. Sampling. Standard methods for the sampling of fuel gases have been publibhed by the British Standards Institution (1K ) . Well established procedures are described for taking snap and period samples of purified gases, storing the sample, and removing solid 66 R
ANALYTICAL CHEMISTRY
and liquid particles from the crude gases before entry into the sampling apparatus. Specialized types of sampling apparatus are described. Suspended Matter. Doyle, Smith, and Wiederhorn ( I L ) have reviewed the work on suspensoids in a book on collection, monitoring, and identification of particles in gas distribution systems. Eifel (ZL)surveyed known methods of dust measurement in gases. He described a n electricaI contact method that permits continuous determination of the dust content of gases. An apparatus embodying the principle is illustrated and results obtained with i t are reported. Rammler and Breitling (SL) discussed recent developments in fly-ash measurement in technical gases. Sasano and Iguchi (4L) have determined the efficiency of Cottrell’s tar mist collector. The tar mist in a gas is determined, within =t0.4%, by an electrophotometric method. The tar mist is absorbed in pure toluene and compared with a standard tar solution a t 450 and 500 mp. Varshavskif, Kogan, Levin, and Shevchenko (6L) have shown an apparatus for determining the concentration of dusts in coke-oven gas. The over-all apparatus and the filter section are illustrated in detail with schematic drawings. Wasilewska (6L) described an apparatus with which the dust, tar, and water in the gas can be estimated while the producer is working. Measurements made simultaneously with this apparatus and with Jenkner’s method gave the same results. Chemical Methods of Analysis. Muzyczuk ( I 7 M ) stated that the error of analysis used with the Orsat apparatus depends on the pressure stability. Other errors arise from buret readings, from high cross sections of absorption pipets, and from temperature changes. H e has shown how these errors may be limited and what steps may be taken to reduce the time of an analysis. Chapman and Rlurche (431) illustrated the use of a new absorption pipet and magnetic shaker for the constant volume gas analysis apparatus. Advantages are (a) the agitation of the reagent is more uniform, (b) the period of agitation is controlled by a time switch, (e) the whole apparatus no longer has to be shaken and hence is less susceptible to breakage, (d) the reagents may be stored in reservoirs which can be attached by a manifold to the absorption pipet. The modified apparatus also has the advantage of shortening the mmplete analysis time for fuel gas to 11/, hours. Karnard and Hughes (2M) discussed inodifications of the absorption methods of Stover, Partridge, and Garrison (20-21)lor the analysis of mixtures of carbon monoxide, oxygen, and methane.
Kusler ( l 2 M ) described a continuously sampling and automatically averaging gravimetric method for analyzing blast furnace top gas. The method provides the average composition in terms of volume per cent over a wide range of time or sampling intervals (from less than 1 hour to more than 24 hours). C.4RBOs MONOXIDE. A rapid method for the determination of small amounts of carbon monoxide in gas mixtures was developed by Lysyj, Zarembo, and Hanley (ISM). The CO is oxidized over a decomposed AgMnOl catalyst and is then absorbed on Ascarite and weighed. This permits 0.3 to 1.5% of CO to be determined with an accuracy within k0.85% in a 500-ml. gas sample containing N (75 to 78%), 0 (18 to 2173, and unsaturated hydrocarbons (1 to 5%). OXYGEN. Egalon, Jarcsek, Tella, and Copin ( 7 M ) have studied the continuous recorded determinations of traces of oxygen in industrial gases. An electroconductimetric method is based on the reaction Caotlve O2 = COZ. The CO, formed is determined directly in the presence of a Na electrolyte. In a second method, a photocolorimetric determination, the gas to be analyzed reacts with a weak solution of bright red Na anthraquinone disulfonate. The oxygen reacts quantitatively to decolorize it. This method is rapid, has good sensitivity (0 to 20 to 0 to 200 p.p.m.), and needs a minimum of maintenance. HYDROCARBONS. Gruzdeva, Khoklova, and Shevchenko (9.41) have determined naphthalene in coke-oven gas by absorption in picric acid and iodometric titration to the sharp change of color from green to yellow. They found that compounds such as methylated naphthalenes, and indene, pyridine, quinoline, dicyclopentadiene, and NHI can form insoluble picrates in aqueous solutions of picric acid and must, therefore, be removed with 75% H2SOi. Hofmarin (10,lI) critically examined Creusot and Pommel’s method for the determination of the pure naphthalene content of a gas and showed that a good approximation to the actual content as obtained. deHeer and Esther (6X)describe a continuous method of determining benzene gases from coke ovens. A partial gas stream is divided into tnio parts. To obtain small concentrations of C&, one part is completely purified from C6H6and is then reunited with the other. The brightness of the flame of the gas IS compared photometrically with that of a coniparison flame. The ratio of gay flow to the tu,I J flames is held constant. XPDROGEN C Y A X I ~ EGulyand . and Adon‘eva (8-11)h a w dptermined the C S - content of coke-oven gas, including HCN and (CN/*. The gas is
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absorbed in sodium polysulfide solution and the S C S - that is formed is titrated by Schulek's C S B r method. S o interference is caused by large amounts of 11,s and CO,. SULFURCohwouNDs. Egalon, Hoebeke, and Gerin (Sill) have adapted their elcctroconductimetric procedure for SO, to the determination of H2S in air and gaseous mixtures (CO, H, COz, S),and to the siniultaneous determination of H,S and SO2. The absorbing clcctrolyte is KaC1 in 0.1.V H2S04. This method has good sensitivity, ])recision of 1 to 1.5%, rapidity of detcction, and ease of calibration. Abel and Barth ( I X ) have determined microgram amounts of SOn in industrial gases by adsorption of the gas on silica gel and then reduction by 13 to H,S. The H,S is determined colorimetrically as the molybdenumblue complex. SO2 can be adsorbed from gases containing less than 10-1 gram SO, per liter and flowing at rates u p to 300 liters per hour. Michaelis (16M) determined the range of applicability of three methods for the determination of hydrogen sulfide in coke-oven gas. These methods were (1) the lead acetate paper method for the colorimetric analysis of spot samples, (2) the cadmium acetate method, and (3) the caustic soda solution method. Mason and Hakewill (14%') described the analytical methods and apparatus used to determine types and amounts of organic sulfur compounds in town gas and synthesis gas. The sensitivity of the methods described is sufficient to permit the determination of sulfur compounds in concentrations of less than 1 grain per 100 cubic feet of gas. Rapoport ( I Q M ) developed a method for the separate determination of CS,, COS, thiophene, and mercaptans in coke gas. The procedure depends on di1,ision of the gas flow into three et,reams; a separate analysis is then performed on each stream. Mason and Hummel (1551) have described an oxygen lamp which is more convenient and reliable than the air I S I I ~ ~ I generally used for oxidizing the sulfur compounds present in fuel gases. NITRIC OXIDE. Pierrain (1831) described an apparatus in which the S O in a gas stream from the coking plant is oxidized by electrolytically generated 0, to X203and N205 xhich Eire measured by the color formed with Griess reagent. For the range 0 to 0.25 mg. p r r cubic meter, a change of 1% ('an be detected. A similar method by Borok (3.11) differed principally in the use of a device to introduce ozonized 0 in the test gas which m:ay contain from 0 to 18 cc. per cubic meter of Y O . Kontorovich (1I 31) tested the permanganate method of oxidizing small
quantities of nitric oxide in gases and determined the nitrogen peroxide by absorption in Griess reagent. Physical Methods of Analysis. Kainz (6N)has reviened the most important of the newer physical methods of gas analysis and has discussed their advantages and disadvantages. GAS CHROMATOGRAPHY. Favre, Hines, and Smith (2.V) have given a detailed description of apparatus and procedures used for the chromatographic analysis of natural gas. Grassman (35) described a method for the complete analysis of natural gas a i t h the det'ermination of He and of single hydrocarbons by using simple and h e \ pensive equipment. Hobbs (4iY)analyzed natural gas by passing it through tn o columns in series u ith an activatedcharcoal trap betneen them. The first column separated C1 to Cg paraffins which were then removed with the activated charcoal. The second column, which is packed with Molecular Sieve Type 5A, separated K, 0, and methane. The two columns had separate detectors and recorders. Hultschig (6.1)described the use of a semiautomatic gas chromatograph in the determination of products of butane distillation. Alumina and alumina 15% cetane were used as column materials. Sharfe ( 9 N ) reported on an apparatus developed for the routine chromatographic analysis of cracking gases. Twelve analyzing units were each connected to one of four recorders. The columns contained different stationary phases and each was used for the separation of a different group of gases. Data were tabulated for the analyeis of a 40-component mixture. Velut and Jourda ( f 2 Y ) reported on an analyzer recorder for gas chromatography used at the Marseille gasworks. A rapid and precise method was developed for determining hydrocarbons up to C4. Boreham and ,Marhoff ( I N ) described the application of chromatographic analysis to town gas and refinery gas. Spencer, Baumann, and Johnson ( I O N ) described the analysis of natural gas odorants by gas chromatography. The odorants, mercaptans or sulfides, are separated a t 50' C. on a column of Johns-Manville C-22 firebrick with dinonyl phthalate as the liquid phase and He as the carrier gas. Relative retention volumes are given. T6th and GrBf ( I l W ) have developed a method involving the use of gas chromatography and microcombustion for the determination of the gasoline contents of natural gases. The gas is dried and is then separated on a silica gel column n i t h dry air as the carrier. The column temprrature is raised after introduction of the sample. The eluted C5 and higher fractions arc passed
+
through a Pregl-type apparatus and are burned to COz and H20. These are absorbed on Ascarite and hIg(C104)2 and the C and H contents are calculated. .2 complete analysis requires 30 to 35 minutes. INFRAREDMETHODS. Rao, hlurty, and Lahiri (8N)have determined low concentrations of ethane and propane in natural gas streams. The presence of C2Hs or C3Hs alters the relative intensity of the P branch of the C-H stretching band of CHa which occurs a t 3.31 microns. The lower limit of detection is 0.077,. Upper limits are obtained by matching the spectra of the sample with spectra of known blends. The method is of value only for low concentrations. MASS SPECTROMETER. Postif (1s) has reviewed the application of the mass spectrometer in the analyses of hydrocarbons in industrial gas. Examples of the analyses are reported. Calorific Value. M o t t and Parker (QP)have reported the use of a bomb calorimeter for determining the calorific value of butane gas and manufactured gas. They state that the volume of gas can be estimated with greater precision than when a flow-type calorimeter is used. This method is recommended for use in determining the calorific value of unpurified coal gas, and as a basis for the calibration of flow-type calorimeters, which are liable to be biased. Hartmann and Braun ( I P ) described an apparatus for determining the calorific value of a gas based on the amount of oxygen used by the combustible components of the gas mix. The gases were reacted with a predetermined amount of oxygen, and the oxygen concentrations before and after the reactions were measured. They used a paramagnetic 0-meter in which the gas flon. was exposed in a thermal conductivity cell to a constant inhoniogeneous magnetic field. Padovani and Caffo (SP) discusscd the applicat,ion of the carbon index of gaseous fuels. The carbon index, w!iich is the volume of C 0 2 produced by winplete combustion, is characteristic for a given gaseous fuel and correlatm with the calorific value and the reiatiw density. It can be applied in the determination of the correction factor for tlip Wobbe index and in the detrrmination of the combustion potential. lt also gives accurate values in tile (+termination of the soot indes. Standard Methods. Thp compilation of standards on gaseous
