Coal Industry (patents) Limited

Lexington Carbon Company LLC

Geoffrey M Kimber

Terry D Rantell

Michael David Gray

James W Clarke

Marit Jagtoyen

David W Price

William Derek Jones

Gordon Dennison

James McLaren

Stephen T Walton

Colin E Snape

David Ernest Shipley

A method for the recovery and purification of water from the exhaust gases of an internal combustion engine is disclosed. An apparatus for carrying out that method is also disclosed. In this method, the water is condensed out from the vehicle's exhaust (for example, by using a countercurrent flow heat exchanger in combination with a chiller), and the condensed water is then purified. The purification typically includes passing the water through one or more particulate filters; passing the water through one or more activated carbon filter beds, and passing the water through one or more ion exchange resin filter beds.

Apparatus and method for the recovery and purification of water from the exhaust gases of internal combustion engines

A method is provided for testing the activity of a catalyst for a chemical reaction in which naphthalene is reversibly hydrogenated by gaseous hydrogen into tetralin, which avoids the need to pressurize a test vessel with hydrogen, enables simple apparatus to be used and gives good accuracy. Tetralin and catalyst are introduced into a sealed container, the container is heated to a reaction temperature for a predetermined time, and the amount of naphthalene formed by dehydrogenation is determined. The method is applicable to the measurement of catalyst activity for catalysts used in the production by hydrogenation of coal-derived liquids.

Test for catalyst activity

Recycled oil solvents for coal extraction have their content of saturated cyclic species reduced by thermal cracking at 470.degree. to 540.degree. C. for a few minutes, restoring their effectiveness as solvents for coal.

Coal extraction

Coal is extracted using a mixed solvent which includes a substantially aromatic component and a substantially naphthenic component, at a temperature of 400.degree. to 500.degree. C. Although neither component is an especially good solvent for coal by itself, the use of mixed solvent gives greater flexibility to the process and offers efficiency gains.

Coal extracts from hydrogenative liquid extraction of coals can be more easily and more quickly filtered if the extraction is carried out at a temperature over 420.degree. C. and the resulting extract is fractionated using a cut point in the range 200.degree. to 300.degree. C. to remove low boiling material. The product is then filtered to give a filtrate containing less than 0.1% by weight of mineral matter.

A low-impurity coke suitable for the production of electrodes for aluminium manufacture is prepared by extracting coal volatile matter content greater than about 28% by weight on a dry ash free basis with a highly aromatic hydrocarbon extractant of which the middle 90% boils in the range 250.degree. to 350.degree. C at a temperature of about 380.degree. to 450.degree. C, in the liquid phase, insoluble matter is separated off and the extract is heated to remove distillable oil and coked wherein the residence time of coal in the extraction step is controlled and the weight ratio of extractant to coal during extraction is maintained greater than 3:1 to maintain a substantially constant specific resistivity of the filter cake.

Manufacture of coke

Coal can be extracted with high boiling aromatic oils produced by extracting the aromatic constituents of a heavy petroleum material, e.g. a bitumen residue, using a selective solvent, mixing the extract with a low-boiling aromatic solvent, adding water and separating the aromatic-containing phase and recovering said aromatic constituents. The resulting coal extract is particularly suitable for the production of electrode coke.

Extraction of coal

A process for the production of coke which process comprises extracting coal at an elevated temperature with a suitable solvent, filtering undissolved material from the extract, concentrating the extract and thereafter coking the concentrated extract while recovering the solvent for re-circulation characterised in that prior to digestion of the coal the solvent is subjected to coking under conditions comparable with the conditions under which the coal solution is subjected to coking until coking of all the cokable components in the solvent is substantially complete.

Improvements in and relating to the production of coke

The invention relates to a process for the production of coke having a low mineral matter content which process comprises digesting coal in a high boiling aromatic oil solvent at a temperature within the range of 350.degree.C. to 480.degree.C. separating insoluble matter from the coal digest to give a coal extract and coking the coal extract characterized in that the coal prior to digestion has a volatile matter content within the range of 13% to 28% by weight.

Growing community of inventors

Cheltenham, United Kingdom

Geoffrey M Kimber