AU624964B2

AU624964B2 - Manufacture of ferrous picrate

Info

Publication number: AU624964B2
Application number: AU57904/90A
Authority: AU
Inventors: Alan Frederick Elliott
Original assignee: FUEL TECHNOLOGY Pty Ltd
Current assignee: FUEL TECHNOLOGY Pty Ltd
Priority date: 1990-03-12
Filing date: 1990-06-27
Publication date: 1992-06-25
Anticipated expiration: 2010-06-27
Also published as: AU5790490A

Description

COMMONWEALTH OF AUST'RALIA PATENTS ACT 1952-1969 COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE Fofm Int. Class Class Application Number: Lodged: *Complete Spocification-Lodged: Accepted: Published: Priority: Related Art: TO BE COMPLETED BY APPLICANT oName 0f Applicant: Fuel Technology Pty. Ltd.

Addes o Aplcat:6 Cremorne Street, Richmond, Victoria, Australia, 31121 Acetual Inventor: ,,Aigap -,Xr-ed1rick Elliott Address for Servce: 6 Cremorne Street, Richmond, Vj~toria, Australia, 3121 Complete Specification for the invention entitled: "Manufacture of Ferrous Picrate" The following statement is a full description of this invention, InclUding the best method of performing 4~ known to me:-* *Note: The description Is to be typed In double spacing, pica type face, In an area not exceeding 9j" In deopth and 6.1 in width, on tough white paper of good quality and It Is to be Inserted Inside this form.

14717/73-L D. ATKINSON, OavcrnmenL Printer, Canberra

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2.

This invention relates to the manufacture of ferrous picrate. For some purposes, for example as a liquid additive for carbonaceous fuel, it is highly desirable that ferrous picrate be substantially free from ferric compounds and other undesirable impurities. It has proved difficult to produce ferrous picrate free from such impurities by a commercially acceptable method. All processes of purification described in the patent literature involve several steps, resulting in low yields and rendering the product expensive. Also, as ferrous picrate and picric acid in the solid state may be explosive, the necessary precautions in the manufacture and handling of the solid materials further increase the oocost.

It is the principal object of the present invention to provide a process for producing ferrous picrate ooo ,"whereby the number of process steps is reduced, and the presence of ferric compounds and other impurities is minimised.

It is a further object of the present invcntion to oo-4o provide a process for preparing ferrous picrate in a manner which is safe, and which produces a product suitable for incorporation in an additive for carbonaceous o o fuel.

In order to achieve the above stated objects, the present invention provides a process for preparing ferrous picrate comprising the following steps perfonrmed under a continuously maintained inert atmosphere: A. reacting an aqueous solution of a ferrous salt with an alkali hydroxide to produce a ferrous hydroxide SQ precipitate; B. removing water and by-products from the ferrous hydroxide; C. adding the ferrous hydroxide and a straight- or branched- chain aliphatic alcohol to a solution of picric acid in an aromatic solvent from which the water has has been removed, to produce a solution of ferrous p crate; and 4 i- I^ D. removing from the said solution any insoluble material that is present.

The preferred inert atmosphere is an atmosphere of nitrogen.

The preferred ferrous salt is hydrated ferrous sulphate or hydrated ferrous ammonium sulphate.

The preferred alkali hydroxide is sodium, potassium, or ammonium hydroxide.

The ferrous picrate solution resulting from the process, i.e. ferrous picrate dissolved in a mixture of a straight- or branched-chain aliphatic alcohol and an aromatic solvent, may be added directly to a quantity of an aromatic nitro compound dissolved in an aromatic solvent, for example toluene, xylene, or mixtures thereof, to produce a fuel additive. It is o preferred that a phenolic antioxidant, for example hydroquinone, be also added to the fuel additive.

The following Examples illustrate the invention.

EXAMPLE 1 In one practical example of a process according to the present invention, 4g hydrated ferrous sulphate were dissolved in 250ml water at 80 0 C containing O.lg hydroquinone whilst sp-rging with nitrogen. While maintaining the nitrogen blanket, a 5% by weight solution of carbonate-free sodium hydroxide was added to the ferrous sulphate solution until it became alkaline, the solution was then boiled, still under a nitrogen blanket, until a ferrous hydroxide precipitate coagulated, and 2g "Supercel" filter aid was added. While o maintaining the nitrogen blanket, the resulting slurry was filtered by suction on glass fibre filter paper and the precipitate was washed with hot water on the paper until the washings were neutral. While maintaining the nitrogen blanket, the precipitate was washed twice with isopropanol and once with butanol to remove water, and held under an atmosphere of nitrogen.

Wet picric acid containing 2.5g picric acid on a dry basis and 2.5g water was added to 200ml xylene in a 500ml flask and the mixture was azeotropically distilled in a v suitable apparatus until the water was removed from the flask. To the liquid in the flask after cooling to

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iJ 4.

below 50°C, 200ml butanol was added and the air above the liquid was replaced with nitrogen. The filter pad was transferred to the flask, and the resulting mixture stirred while maintaining the r 'rogen blanket. At this point, the mixture became intensely green as ferrous picrate formed. The mixture was then filtered on glass fibre filter paper which was then washed briefly with isopropanol and the filtrate was retained. The nitrogen blanket was discontinued. Analysis revealed that the resulting solution contained 450mg/L of ferrous ions.

EXAMPLE 2 Fuel additives for addition to diesel fuel were formulated from the above solution as follows: A B o Ferrous picrate 0.92g 0.92g S"Picric acid 2.0g Hydroquinone 0.5g Butanol 122g 122g Xylene to make up to 1L 1L 0 0o 0

Claims

2. A process according to claim 1, wherein the alkali hydroxide is sodium, potassium, or ammonium hydroxide.
3. A process according to claim 1 or 2, wherein the S ferrous salt is hydrated ferrous sulphate or hydrated ferrous ammonium sulphate.
4. A process according to any one of the preceding claims, wherein the inert atmosphere is an atmosphere of nitrogen.
5. A liquid additive for addition to carbonaceous fuel, a 4, 4 o4' comprising ferrous picrate produced by a process according to any one of the preceding claims, an aromatic solvent, an 0"a aromatic nitro compound and a straight- or branched- chain aliphatic alcohol.
6. A liquid additive according to claim 5, wherein the ou aromatic nitro compound is picric acid. 0 7. An additive according to claim 5 or 6, further comprising a phenolic antioxidant.
8. An additive according to claim 7, wherein the antioxidant is hydroquinone.
9. A process for preparing ferrous picrate substantially as herein described with reference to Example i. An additive for addition to carbonaceous fuel substantially as herein described with reference to Example 2. Dated this o4 day of 1990 Fuel Technology Pty. Ltd.