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CAST IRON, JACKETED, CIRCULAR, CRYSTALLIZING PAN, WITH ADJUSTABLE STIRRING DEVICE AND AUTOMATIC DISCHARGE.

8 ft. in diameter, 2 ft. deep, stands 52 ft. high, capacity 550 gal., weight 12,000 lbs., can be built for $900.00 including pattern work.

8 sheets of detail drawings and names of manufacturers who have submitted bids. Price, $100.00.

would endanger the lives of the operators, and destroy portions of the apparatus, or make necessary the construction of much expensive apparatus additional to the real requirements of a Synthetic Phenol plant.

The correct use of Lime in neutralizing is not for the purpose of preparing a Calcium salt solution, but for the purpose of quickly and cheaply getting rid of the excess Sulphuric Acid.

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The production of the Calcium salt is merely incidental to this purpose and unavoidable.

2(C, H, SO, H) + Ca (O H), = (C, H, S O,), Ca + 2(H, O)

After this it is then an easy matter to produce the Sodium salt from the Calcium salt and no evolution of C O, or noxious vapors accompanies either of these proper reactions.

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(C, H, S O2), Ca + Na2 C O, = 2(C, H, S 0, Na) + Ca C O,

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This production of the Sodium salt, finally dry and in suitable condition, and appropriate quantities ready for fusion with Caustic Soda, are important steps and the methods for effecting them should be recommended by a competent Engineer having extended experience in this particular work.

The fusion of the Benzene monosulphonic acid with Caustic Soda is probably the most important portion of the Synthetic Phenol process. It also is probably the most unsatisfactory portion under the methods that have generally prevailed in the past.

C, H, SO, Na + 2(Na O H) = C, H, O Na + Na, S O2+ H2O

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The Caustic Soda melting at 590° F. has usually been stirred in open kettles where the contents could spatter and become dangerous in case of burns. The melt has been ladled by hand much like molten lead, and the vapors that escaped have undoubtedly cut down the per cent. of yield materially.

Frequently recommendations are found advocating the separation of the products of fusion in the hot open fusion kettle, and the skimming off of one and leaving of the other.

These products are Sodium Phenolate, Sodium Sulphite and excess Caustic. These under some circumstances will separate

as two different layers, and while theoretically their separation is possible, it is readily seen that such a procedure is impractical and even dangerous.

The most approved methods of procedure and now coming into general use, are to fuse in closed Autoclaves and discharge the fused contents by pneumatic pressure when the reaction is completed. This is followed by dissolving the melt in a closed unit and thus conserve the vapors and obviate all the hand work. Here again the competent Engineer's services are very necessary to avoid the frequent errors and usual methods of unsatisfactory fusion, and provide instead a thoroughly prac tical and safe means of producing the Sodium phenolate and its subsequent aqueous solution.

The Sodium Sulphite and excess Caustic readily eliminate themselves under the acidification or decomposition of the aqueous melt and so the safe and economical fusion is quite different from the ways that have been so frequently advocated and followed in the past.

The last reaction of the process is the acidification of the dissolved melt and the decomposing of the Sodium Phenolate into Phenol and Sodium Sulphate.

2(C, H, O Na) + H2 S O1 = 2(C, H, O H) + Na, SO,

2(Na O H) + H2 S O1 = Na, S 01 + 2(H., 0)

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The reaction can be accomplished by the use of any mineral acid. Carbonic Acid is mentioned in much of the literature and advocated by various people, but there are numerous reasons for not making use of it, and good reasons for using Sulphuric Acid instead. In case it is used the reactions are as follows:

2(C, H, O Na) + CO2+ H2 0 = 2(C, H, OH) + Na, CO,

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The Engineer again is necessary in directing the proper procedure, and his process must minimize the evolution of S O2 and prevent the loss of Phenol in the Sulphite and Sulphate solutions that are discarded. His design of apparatus must effect the separation of the Phenol with as little change of the Sulphite into Sulphate as possible and with a minimum amount of acid. Such change in the Sulphite is shown in the following reaction:

Na, SO, + H2 S 01 = Na2 S 0, + S 0, + H, O

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The saving of by-products is frequently attempted by many and much effort is often made toward bending the process to this end.

There are no by-products, aside from Calcium Carbonate, that are worth while making any effort upon. This carbonate can be used to take the place of a portion of the Lime, but the others should all be discarded. They consist of Calcium Sulphate cake, and a mixture of Sodium Sulphite and Sulphate solutions, and the recoverable portions would cost more in the recovery than they are really worth.

Such Calcium Carbonate as is used in the neutralizing of the Benzenesulphonic Acid, and excess Sulphuric acid, is represented by the following formula:

2(C, H. SO, H) + Ca C O1 = (C, H, SO2), Ca + CO2 + H2O

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H2 S O1 + Ca C 0, = Ca S 0, + C O2 + H2 O

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There should be no departures then from the accepted methods that experience has taught, and a competent Chemical Engineer is necessary in putting these methods into workable condition for you.

The production of Synthetic Phenol then through the sulphonation method is thus very clearly defined.

From a chemical standpoint the production of Phenol from Benzol is the substitution of the hydroxyl (O H) for one of the Hydrogen atoms of the Benzol.

Benzol is C, H.. Sulphonation replaces one atom of H with the sulphonic group S O, H. One such replacement produces a Mono-sulphonic acid. If two Hydrogen atoms are replaced the result is a Di-sulphonic acid. No Carbolic Acid will result from the Di-sulphonic Acid, as that is the starting point for Resorcinol by the same means, and so the sulphonation must be properly done.

The procedure is then to replace the Sulphonic group (S O, H) by the Hydroxyl group (0 H).

This can be best done if the Benzene Sulphonic Acid is converted into a Sodium salt, and the Sodium Salt is easiest produced by first producing the Calcium Salt.

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CAST STEEL AUTOCLAVE, WITH AGITATOR, CLOSED TOP, SYPHON DISCHARGE, TO SET IN BRICK.

180 gal. capacity, stands 500 lbs. working pressure, 32 inches diameter, 56 inches deep, 2 inch walls, height 8 ft. 8 in., weight 6,500 lbs., can be built for $800.00, including pattern work.

8 sheets of detal drawings and names of manufacturers who have submitted bids. Price, $100.00.

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