Active Carbon from
Chlorinated Coal
S. BOYK AND H. B.
HAss
Purdue University, Lafayette, Znd.
T
H E chlorination of aliphatic Bituminous coal of various sizes was chlorinated at several temperatures. In the compounds has received much apparatus used (a 36-inch length of a/,-inch nickel pipe) 6-20 mesh coal could be chlorinated to a 100% gain in weight in 24 hours. Small amounts of "chloattention in this laboratory, and this work has been extended to rinated hydrocarbons were produced, but the principal product was an activated carbon. After chlorination the coal was powdery in texture and smelled strongly include aromatic compounds and of hydrogen chloride. This material was pelleted with a small amount of hydrocoal. The purpose of the investigalyzed starch as binder. The pellets werk baked in the absence of air for 1 hour at tion was t o prepare valuable prod500°C. After baking, the hardened pellets were crushed and sieved to 8-20 ucts from the reaction of chlorine with coal. At t h e outset it was mesh size and were steam-activated at 800" C. for 3 hours. As produced, the activated carbon had an apparent density of about 0.5 gram per CC., a n accela moot point whether these proderated chloropicrin life of 67 minutes, heat of wetting of 12 calories per cc., and ucts would be chlorinated hydroa chlorine content of about 0.12Yc. carbons or active carbon or, possibly, both. The investigation culminated in the development of phase of the work was explored to some extent, it was decided means for preparing an excellent gas-adsorptive cirbon; to attempt to prepare activated carbon. the indications are that this process may yield small amounts As Figure 1 shows, the chlorinator consists CHLORINATOR. of valuable. chlorinated compounds as by-products. Carbon of a vertical nickel tube, A , which passes through a salt bath, B. tetrachloride and hexachlorobenzene were identified in the The bath is heated by resistance wires around the outside, C , exit tube from the chlorinator but were not determined and is well insulated. Kickel tube A is connected t o an iron, quantitatively. water-cooled condenser, D, which, in turn, is connected t o a oneOnly a small amount of work has been done on the chlorinaliter suction flask. The flask leads t o B flowmeter which contion of coal with the aim of preparing valuable products from it. nects to a waste vent. The salt bath contains a thermocouple Most of the literature on this subject. deals with the value of well, E , t o facilitate temperature measurements. halogens as an analytical tool for the study of coal. Attempts STEAMACTIVATOR.Material t o be activated was placed have been made t o produce an active carbon from coal without in a stainless steel (18-8)chamber (Figure 2), which was in the chlorine ( 2 , 3 ) and with chlorine (1, 2.4, 5 , 6 , 7 , 8 ,10, 11). These form of a rectangular parallelopiped, 2 X 2 X 8 inches. This processes do not describe the properties of the carbon in terms OI chamber connects a t both ends t o stainless tubing which rests in modern tests or else produce a carbon of doubtful value. There iron tees, H,used as bearings. One of the tee supports, J , is held have bccn only a few attempts t o obtain chlorinated products in place by an iron plate (not shown) held with three bolts and from coal. Of these the most significant is that of Weiler (9). wing nuts. The wing nuts are easily removed, the plate is lifted, He treated coal xith chlorine and antimony pentachloride for G and support J slid out. The chamber separates a t the indicated days a t 200" C., then 4 more days at 400" C. The volatile prodpoint, and the larger port'ion can be readily removed for charging ucts obtained were carbon tetrachloride, hexachloroethane, hexaor emptying. One of the two open tubes has a stainless steel chlorobenzene, and other unidentified, highly chlorinated hydrothermocouple well through it, K , and through the other there is a carbon derivatives. Even under this drastic treatment the steam inlet tube, L. Both of these tubes are fitted with welded volatile products accounted for only .5yoof the carbon originally collars to prevent coal granules from falling out during rotation present in the coal. while activation is going on. The activation chamber is heated by wires wound around the furnace walls, N , and is kept from MATERIALS AND APPARATUS moving longitudinally by spacers, 0, and Jransite insulators, P. COALS. Four 100-pound samples were obtained from a local During a run the furnace is heated by an electrically controlled coal company. The description of these samples were: (1) Adjust-A-Volt. The activation chamber proper is rotated durSewell seam coal from \T7hite Oak Coal Company, McDonald, ing use by motor Q, the speed of which is reduced by t F o 48:l K.Va.; ( 2 ) Island Creek Pocahontas Coal from Island Creek Coal reducers in series (only one is shown). Company, Holden, K.Va ; (3) anthracite from Avoca Coal ComPELLET PRESS.This apparatus was a hand-operated coal pany, Getz, Pa. (4)Indiana coal from Walter Bledsoe Company, pelleting press described in Cenco Catalogue J. 1941, So. 23770. Terre Haute, Ind. The analybes of these coals follow: ACCELERATED CHLOROPICRIN TESTER ASD HEATOF KETTING APPARATUS. Details of this apparatus are given as a chloropicrin (PS) test on charcoal, in Part I1 of Chemical Warfare Service Coal KO. 1 2 3 1 Pamphlet 2 (Canister and Absorbent Test hlethods). Moisture, % 0.5 0.8 1.4 7 0 Volatile matter,
Fixed carbon, 5% Ash, Z m Sulfur Calorific 'value. cal./gram
24.4
72.7
2.4
0 3 8700
37.0
54 7 7.5 1.0
6300
5.9
83.6
9.1 0.8
7390
34 0 52 7 O B 2 2 6500
CHLORINATION
A typical
