166 -ACCI Coalefins
Process
For just over two years, AECI have been operating a pilot plant at ModderSouth fontein, near Johannesburg, Africa, for the development of a process for the production of olefins from methanol. This work has been carried out using a Mobil catalyst. AECI's aim in this work has been to give the company the ability to make olefins feedstocks from coal-based methanol. At present, a detailed design study for a commercial Coalefins plant is being carried out with contractor assistance. The pilot plant is currently being run to provide data for this study and this experimental programme is expected to be completed by mid-1984. AECI have indicated that the pilot plant could then be made available to other organisations on a contract basis. It is a modern computer-controlled plant with a methanol feed capacity of 20 to 120 kg/hr and the facility to recover and recycle unconverted reactants. The reaction system consists of several fixed bed adiabatic catalytic reactors in series and there are facilities for catalvst regeneration. Further details can be obtained by those interested from Mr. L.J.Partridge, AECI Ltd., Fuel and Feedstocks Project, Modderfontein, P.O.North Rand, Transvaal, 1645, South Africa.
Resorcinol
Synthesis
The commercial synthesis of resorcinol (III in the scheme below) requires four or five steps and produces large amounts of by-products. One of a number of alternative routes has been described in a patent to Koppers Co., Inc. (West German Patent 33 02 848) where the cyclisation of$-keto esters (I) to diones (II) is followed by dehydrogenation to resorcinol (III):
I II III The preferred catalyst for the transformation of I to II is a high-surfacearea activated charcoal while Pd on carbon is effective for the second step. The item in Catalytica Highlights (lO(1984)Nol) which reports this devel-
-- Volume tl No. 1 -July
1984
opment also reports a patent to Sun Tech, Inc., (European Patent 93,540 (1983)) which discloses a method of preparinghydroquinone (1,4-dihydroxybenzene) from phenol by sequential oxidation and hydrogenation of the intermediate p-benzoquinone in one vessel using the same copper catalyst for each step. Catalytica Highlights notes that a significant complication of this and similar methods is the generation of the relatively stable 1:l addition compound of p-quinone and hydroquinone, commonly known as quinhydrone.
Zirconium
Phosphate
A recent Japanese patent (Japanese Kokai 58-135,824, reported in Catalytica Highlights, lO(1984) Nol) shows that zirconium phosphate, a solid acid with a layered structure, is an efficient catalyst for the production of light olefins from methanol. The product distribution was found to be a function of the crystallinity and crystal structure of the catalyst. Amorphous zirconium phosphate gave low conversions to primarily methane and butane while crystalline phases with the larger interlayer spacings gave more ethylene and propylene. For example, a gamma phase with a d-spacing20fl12.2 A gave and a surface area of 21.8 m g 99.4% hydrocarbons with a conversion of 49% at a temperature of 380°C and a lifear hourly space velocity of 1.0 h ; the products in this case included 28.8 % ethylene, 29 % propylene and 11.2 % butane.
Pillared
Clays
An article by R.Highfield in New Scientist (19 April 1984, ~21) entitled "Pillared Clays Turn Oil into Petrol" gives an interesting outline of the history of work on pillared clays and present perspectives for their use as catalysts. One of the early workers in the field was Professor Richard Barrer of Imperial College (now Emeritus Professor) who gave up the work in favour of his well-known investigations of zeolites. It would seem that there is now a race between a number of, academic and industrial laboratories to solve some of the problems associated with the use of these interesting materials as catalysts. Pillared clays are