ITEM No. 22 FILE No. XXII—i COPY No., CHEMISCHE WERKE HUES A.G. COMBINED INTELLIGENCE OBJECTIVES SUB-COMMITTEE REPORT ON CHEMISCHE VjERKE EttLS A.G. h&ls,geriiany 19 April, 1945 Repcr ted by F. J. CURTIS, M. F. FOGLER CWS, HQ ETOUSA CWS, HQ BTOUSA 14 May, 1945 CIOS Blaok List Item - 22 Miscellaneous Chemicals COMBINED INTELLIGENCE OBJECTIVES SUB-COMMITTEE G-2 DIVISION, SHAEF (REAR) APO 413 1 TABLE OF CONTENTS Subject Page No, L General..... 1 2. Acetylene Manufacture 2 a. Raw Materials 3 b. Power. ••••••• 4 o. Arc Apparatus 4 3. Styrene Manufacture. •••••••• 5 a. Ethyl Benzene......... 5 b. Dehydrogenation of Ethyl Benzene to Styrene. 6 PERSONNEL CF INSPECTION TEAM Mr.Francis J.Curtis CWS, Hq.ETOUSA Maj .F.E.Da MC, Eq.ETOUSA Cmdr. R.CRnnon Eley, .MC, USNR Cindr, Chas.L,McCarthy . MC, USNR Dr .Mayor F.Fogler CWS, Hq.ETOUSA Lt.Col.Joseph E, 6madel...MC, Hq.ETOUSA Lt,Col.Hamilton Southworth........USPHS Dr .Ernest H.Volwiler CWS, Hq.ETOUSA 2 REPORT ON CHEMISCRE WERKE EttLS A. G. !• GENERAL. a. HUls is one of the important synthetic rubber plants in Germany and has been investigated thoroughly from that stand- point. Our interest was confined to acetylene and styrene, although the following chemical products are made in this plants- Acetylene Ethylene (from Acetylene) Aldol Acetaldehyde Kybol Styrene Hexanetriol Solvents A and AE Acetophenone Resin SAX (from styrene, acetophenone, xylene, hydrofluoroboric acid) Ethylene oxide Glycol Glycerine D Triglycol Resin AP for surface coating (acetophenone, formaldehyde, methanol) C acid (crotonio) Plasticizer 111 (butyl crotonate, hydrogen, sulfide) 2. ACETYLENE MANUFACTURE. The plant produces 150,000 cu meters acetylene per day by arc cracking. a. Raw Materials Thar© have been three sources of raw materials x- (l) Natural gas from Bentheim used directly 92/o CE. HpS + COp 5% Na (2) Coke oven gas which was first put through the Linde apparatus. 3 (3) Gas from Hydrierwerk© containing 85% hydrocarbons averaging 4 which was used directly. b. Power Power consumption is 8.5 kwh per kg crude acetylene and 9.5 - 10.5 kwh per kg pure acetylene. AC at 6,000 V 50 cycles is converted in a mercury rectifier to 7,000 V DC at 7,000 kw. Each arc uses 7,000 kw and produces 4,200 cu m/hr product gas. The plant has 17 arc units. o. Arc Apparatus. (Sketch below) The gas at 1.5 atmospheres enters the top section at the side and is whirled by the vanes into the arc tube. The arc is not constant in position but rotates around in the tube. Immediately on leaving the arc section, the gases are quenched by water spray to 150°C. At this point the composition isj- Hjj .....56* CpHp 1Z% (3% diaoetylene) Cpin Ifo CH. (other H.C.).23* COg, N2, ©to Qfo d. About Z% carbon is produced based on the original hydro- carbon. The gases pass to four cyclone separators to take out water and carbon, the latter being used in the rubber industry. Further cooling with spray to 70°C takes place and then the gases go through 8 filter towers equipped with cloth bags. The tempera- ture is then reduced to 25°C and the gases washed with tar oil to remove aromatic hydrocarbons such as naphthalene and polymerized hydrocarbons. To regenerate the tar oil it is blown with waste gases (nitrogen, CO and from the Linde plant and a side stream distilled with high pressure steam. Gas Gas Cu Fe Plan .90 mm I.D. -Water cooling water Quenoh Elevation Hydrocyanic acid is removed by water scrubbing in tall towers to form a 3$ solution which is distilled to recover HGN. Hydrogen sulfide is then removed by passing thru boxes packed with Luxmass (hydrated iron oxide). The gas now con- taining 20$ C2H2 passes to a gasometer. The gas from the gasometer is then compressed to 18 atmospheres in compressors having 4 stages with intercoolers. There are six compressors each handling 13,000 cu m per hr. At this point the partial pressure of the acetylene is 5 atmos. Temperature is reduced to 15°C and acetylene dissolved using 750 cu m of water per 8,000 cu m of gas. Water is also sprayed into the gas lines to avoid explosions. The washed-off gas contains 0.1$ CgHg. The pressure of the aqueous solution is dropped in 4 steps to 1.5 and 0.1 atmospheres and to 0.15 and 0.05 atmospheres absolute. Gas from the first step at 50$ CgHg goes back to the compressors after mixing with arc gas causing the rise to 20% CgHg £as mentioned above. The gas from the 2nd, 3rd and 4th steps are mixed and give 97 - 98% acetylene of which 87% is CgHg and 10% diacetylene and higher. The diacetylene is washed out with tar oil which is blown with Linde gas and the diaoetylene sent through the system again. At this point the product gas contains 95% CgHg hydrocarbon, 1% nitrogen and 1% COg, The last traces of diaoetylene are removed with 96% H2SO4 and the gas neutralized with 10% NaOH and passed to the final gas holder. The original off gas from the water solution of acetylene step containing 0.1$ CgHg Passes 15 atmos to the Linde plant where it is fractionated to 97$ pure hydrogen, a mixture of CO and Ng, and a hydrocarbon fraction which after passing through the diaoetylene oil washer is joined with the original gas feed to the arc. 3. STYRENE MANUFACTURE. a. Ethyl Benzene isthylation of benzene takes place in 6 enamelled iron towers (with 2 in reserve) 11 m high x 1.4 m diameter operated continuously but not in series. Each tower handles 350 cu m/hr of 95$ moist ethylene from a gasometer. They were originally 3/4 filled with Raschig rings but are not now. Ethylene goes in at the bottom through an open pipe and passes up through the benzene and aluminum chloride* Complete absorption is obtained at 95*105°C with a consumption of Z% AlClg on ethyl benzene* Ho EC1 is added since it forms with the moisture of the gas* The raw ethyl benzene containss- 55% ethyl benzene *45/£ benzene 15fo polyethylbenzene 5% residue It passes to a cooler and separator for the A1C1 complex which is returned to the bottom of the tower. The new A1C1, is added periodically at the top mixed with benzene. The overflow from the separator is washed with water and then with NaOH in a stoneware lined tank* It is settled and dried with solid caustic soda* Distillation takes place in a series of towers each with a duplicate so that, for instance. No 3 is the second step in the series. No 5 the third, etc* Towers are about 28 meters high and have 45 plates* All except the last are bubble cap plates and last is packed with Rasohig rings. Reflux on the ethyl benzene tower is 1:1* Tower Ro Diameter Temperature Vacuum Product 1 0*8 m mmm, Carbon Bisulfide 3 1.0 80° C — Benzene 5 1.6 — -- Intermediate 7 1.1 136°C — Ethyl benzene 9 0.8 130°C 20-25 mm Polyethyl benzene 11 — 200° C 25 mm Residue Polyethylbenzenes are returned to the ethylator* b* Dehydrogenation of Sthyl Benzene to Styrene, The catalyst chambers for dehydrogenation are vertical cylinders in brick settings fired with gas on two sides. The 12 chambers are of various types some having 22 to 26 tubes of 20 cm diameter, others 90 tubes of 10 cm diameter and are 2 m diameter x 3 m high. They contain 2 cu m catalyst of 4 - 7 mm particle size made at Ludwigshafen and of the following approxi- mate composition Zn 0 85% Ca 0 5% AlpO, 5 % KjjCrC 25 KISO* 2% 2 4 Each converter is first swept out with nitrogen, then fed with a 1-1.5 : 1 ratio of steam to ethyl benzene. The feed is vaporized and preheated by heat exchange with flue gases and product gas. Temperature in the converter is 630° and in the product gas 600°C. Each handles 450 kg/ir ethyl benzene with 33$ conversion per pass and 90% yield* After condensation of the crude product 0.001$ hydro- quinone is added. This is the only addition of inhibitor. The crude product containing 38$ styrene passes into the middle of the first distilling column, a tower 2 m diameter x 25 m high with 45 plates and operated under 20 mm vacuum. Ethyl benzene passes over the top to re-use. The bottoms go into the middle of the second column which is 2 m diameter x 15 m high with 25 plates and operated under 15 mm vacuum. The overhead containing 38$ styrene and 62$ ethyl benzene is returned to the first column. The crude styrene bottoms testing 102.5$ on account of the residues goes into the middle of the first final distillation tower and thence to the second. These towers are 1.1 m diameter x 15 m high, some packed and some plate and run under 15 mm vacuum. 99.5 - 99.8$ styrene is taken overhead. There are two sets of two towers for preliminary and the same for final distillation, one presumably for stand-by. Capacity of the plant is 120 tons/mo per catalytic converter or 1440 tons/mo total. F. J. CURTIS, CWS, HQ ETOUSA M. F. FOGLCR CWS, HQ ST0U3A 7