GB2182933A - Catalysis: alkanol synthesis - Google Patents

Abstract

Carbon monoxide and hydrogen are reacted in the presence of a catalyst to give one or more alkanols, such as alkanols having more than one carbon atom per molecule ('higher alkanols'). The catalyst used is a ferrite, such as a nickel ferrite which may be unsubstituted or substituted, e.g. with Mn, Co or Zn; or cobalt ferrite.

Description

SPECIFICATION Catalysis: Alkanol synthesis This invention relates to the catalytic production of alkanols, preferably those having more than one carbon atom per molecule.

Certain alkanols having more than one carbon atom per molecule (termed 'higheralkanols' herein) have potential use as gasoline extenders and in other high value applications. Their production bythecatalysed reaction of carbon monoxide and hydrogen is therefore of interest. However, on an industrial scale, this reaction has been used to manufacture methanol only. Watson and Somarjai in Journai of Catalysis, 74, 282-295 (1982) describes the use of lanthanum rhodate as a catalystforthe hydrogenation of CO under laboratory conditions to give oxygenated products having more than one carbon atom per molecule.

This invention is concerned with the catalytic production ofalkanolsfrom synthesis gas (CO and H2) using a catalyst lacking a precious metal, namely a ferrite catalyst. Ferrites are known as catalysts, (see, for example, M. Pijolat and V. Perrichon, Applied Catalysis, 13,321-333 (1985)), but mostly for the production of hydrocarbons and notfortheproductionofalkanols.

The invention comprises a process for the catalytic production of one or more alkanols by the reaction of carbon monoxide and hydrogen in the presence of a ferrite catalyst.

The process ofthe invention has been found to give rise to methanol, ethanol and otheralkanols asexemplified in the specific examples hereinafter, and also to give rise to minimal production of methane and other hydrocarbons.

It is also possible that the process may give rise to diols.

An example of a ferrite catalystthat may be used is a nickel ferrite which may be substituted orunsubstitu- ted, for example of the general formula: Ni X Mx Fe2O4 where 0 S x < 1, and M is Mn, Co orZn. xis preferably 0.5. Furtherexamples offerritesthat may be used are those of cobalt.

Ferrites, which are sometimes considered as mixed metal oxides of Fe(lll), are known materials and may be purchased commercially or made by methods known in the art.

Several ways of carrying out the invention will now be described by way of example.

The ferrite catalysts were tested in powder form and, before testing, were characterised by: (a) X-ray diffraction (XRD); (b) BETsurface area; and (c) thermogravimetric analysis (TGA). The X-ray pattern of XRD confirmed that the catalysts had the ferrite structure and the TGA showed decomposition of precursor materials where freshly prepared catalysts were used.

The general testing procedure involved placing a ferrite catalyst (1g) in a quartz reaction tube, which was then heated to 280"C in a flowing mixture (25 ml/min) of CO and H2 in the volume ratio of 70% H2: 30% CO.

This temperature was maintained for 24 hours. The product gases were bubbled through distilled water (5 ml) which was later analysed for alcohol content. During testing, gas samples were taken attwo-hourly intervals and analysed for hydrocarbons and CO2.

The above liquid product was analysed by gas chromatography wherein samples (2 FI) were injected onto a Chromosorb 102 column at 140"C on a Perkin Elmer (P.E.) sigma gas chromatograph, calibrated using standard solutions. The above gas samples were also analysed by gas chromatography using a spherecomb column, P.E. F30 gas chromatograph. The results are summarised in the table below.

Products Ex. Catalyst & et surface area CH3OH C2HSOH Others {m*~ ) (moleslgcat/ (molesig caV sec x 10-9) sec x 10-9) 1 Ni05Mn05Fe2O4* 1.00 1.19 (66.1) 2 Co0.8Fe2.204 0.52 0.79 (141.1) 3 Ni0.5Zn0.5Fe204 0.54 0.67 (101.0) 4 Cove204 0.29 0.34 ( < 1.0) 5 CoFe2O4 1.00 0.10 (14.7) 6 NiFe204 0.60 0.05 ( < 1.0) * the weight of this catalyst was 0.37 g.

Figures given are percentages by volume. Atick indicatesthatthe named constituent was detected in the product and dash thatthe named constituent was not detected.

The above results showthatferrite catalysts are capable of catalysing the reaction of CO and H2 to give higher alkanols without necessarily producing hydrocarbons.

CLAMS 1. A process for the catalytic production of one or more alkanols by the reaction of carbon monoxide and hydrogen in the presence of a ferrite catalyst.

2. A process according to claim 1 wherein the ferrite catalyst is a substituted or unsubstituted nickel ferrite.

3. A process according to claim 2 wherein the nickel ferrite is of the general formula: Ni1.x Mx Fe204 whern0x < 1,and M is Mn, Co orZn.

4. A process according to claim 3 wherein xis 0.5.

5. A process according to claim 1 wherein the ferrite catalyst is a cobalt ferrite.

6. A process forthe catalytic production of one or more alkanols substantially as described herein with reference to any of the examples.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. Figures given are percentages by volume. Atick indicatesthatthe named constituent was detected in the product and dash thatthe named constituent was not detected. The above results showthatferrite catalysts are capable of catalysing the reaction of CO and H2 to give higher alkanols without necessarily producing hydrocarbons. CLAMS

1. A process for the catalytic production of one or more alkanols by the reaction of carbon monoxide and hydrogen in the presence of a ferrite catalyst.

2. A process according to claim 1 wherein the ferrite catalyst is a substituted or unsubstituted nickel ferrite.

3. A process according to claim 2 wherein the nickel ferrite is of the general formula: Ni1.x Mx Fe204 whern0x < 1,and M is Mn, Co orZn.

4. A process according to claim 3 wherein xis 0.5.

5. A process according to claim 1 wherein the ferrite catalyst is a cobalt ferrite.

6. A process forthe catalytic production of one or more alkanols substantially as described herein with reference to any of the examples.