GB2159876A

GB2159876A - Catalytic treatment of i.c. engine fuel supply

Info

Publication number: GB2159876A
Application number: GB08414101A
Authority: GB
Inventors: Timothy Michael William Fryer
Original assignee: Individual
Current assignee: Individual
Priority date: 1984-06-01
Filing date: 1984-06-01
Publication date: 1985-12-11
Also published as: GB8414101D0

Abstract

Fuel after being vaporised in a vessel A is passed through a catalyst, contained in vessel B, in order to convert it into aromatic hydrocarbons and hydrogen prior to being consumed by the engine C. The fuel and catalyst are heated by exhaust gases from the engine. The catalyst is regenerated by passing through it oxygen or a gaseous mixture containing oxygen. The vessel A contains alumina to remove lead from the fuel. <IMAGE>

Description

SPECIFICATION Integral catalytic reformer for internal combustion engines The present invention provides a means by which the octane number of fuel for internal combustion engines is raised immediately prior to its combustion.

The high octane number necessary for high compression ratios in internal combustion engines and hence high efficiency has hitherto been achieved by the introduction of lead alkyls into petrol. However, this results in lead pollution. The current invention, by converting low octane aliphatics and alicyclics to aromatics, enables lead free fuel to be used in high compression engines. In addition, the hydrogen which is a by-product of the reforming process assists combustion and enables leaner mixtures to be used. As a result, less fuel is wasted by incomplete combustion thereby enabling the engine to run more efficiently with less pollution from carbon monoxide and hydrocarbons.

According to the present invention, there is provided a catalyst which catalyses the conversion of aliphatic and alicyclic hydrocarbons to aromatic hydrocarbons. During operation, fuel is passed through the catalyst before being consumed by an internal combustion engine. In the preferred mode, the catalyst is heated by exhaust gases from the internal combustion engine. It is preferred that the fuel is passed over a purifier bed in order to remove impurities such as lead before being passed over the catalyst. In the preferred mode, the purifier bed consists of bauxite or alumina although purifier beds of different composition may also be used. It is preferred that the purifier is heated by exhaust gases although it may also be heated by other means. It is preferred that the fuel is vaporised prior to being passed through the catalyst.When a purifier is used it is preferred that the fuel is vaporised before passing through the purifier. More than one catalyst bed may be used and they may be of different composition. More than one purifier bed may be used and they may be of different composition.

The fuel may be passed over the catalyst at atmospheric pressure but in the preferred mode, it is passed over the catalyst at a pressure which is greater than atmospheric.

It is preferred that, from time to time, the catalyst is regenerated, when hot, by passing a gaseous mixture containing free oxygen over it. This may be done in various ways. Thus air may be passed through the catalyst or combustion products, such as exhaust gases, passed through it or any gaseous mixture containing free oxygen may be passed through it. During regeneration the catalyst may be heated in various ways. It may be heated by the application of a flame, hot air, hot exhaust gases or hot combustion products to the vessel containing it. Alternatively, hot gases may be passed through the catalyst.

It is preferred that the fuel is cooled after it has left the catalyst chamber. This may be done in various ways; it may be cooled by means of a liquid or a gas, for instance air, or by means of an evaporating liquid; thus it may be used to vaporise fuel.

A specific embodiment will now be described by way of example with reference to the accompanying drawing in which: Figure 1 is a block diagram of the system.

Figure 2 shows the cross section of the vessel containing the catalyst and that containing the purifier.

Figure 3 is a diagram of the cross section of the catalyst bed and/or purifier bed in an alternative mode.

Referring to Fig. 1 the fuel is vaporised and passed through the purifier contained in vessel A. It then flows into vessel B where it is passed through the catalyst which contains or consists of molybdenum oxide, chromium oxide, a metal or metals of the platinum family, cobalt molybdate or any other substance which catalyses the conversion of aliphatic or alicyclic hydrocarbons to aromatic hydrocarbons. The fuel then flows through pipe E where it is cooled before being consumed by the internal combustion engine C. Both the catalyst and the purifier are heated by the exhaust gases from the internal combustion engine C, flowing through the pipe D.

In the preferred mode, the vessels A and B, containing the purifier and the catalyst respectively, consist of an inner compartment J separated from the outer wall by a cavity L as shown in Fig. 2. The catalyst and the purifier are contained within the compartment. During operation, the fuel flows through the cavity either prior to or after passing through the compartment. The compartment is annular and coaxial with the exhaust pipe of the internal combustion engine. The exhaust pipe may either be in contact with the contents of the compartment or it may be separated from them by a wall.

In another mode, also incorporating a cavity wall and illustrated by Fig. 3, the compartment J has a crescent shaped cross-section.

In such a mode the vessels A and B are clamped onto the exhaust pipe so that the inside wall of each compartment is in contact with it. It is preferred that the two vessels are attached to the same section of pipe so that they are coaxial.

1. A system in which fuel is passed through a catalyst which converts aliphatic and alicyclic hydrocarbons into aromatic hydrocarbons and hydrogen immediately before being consumed by an internal combustion

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Integral catalytic reformer for internal combustion engines The present invention provides a means by which the octane number of fuel for internal combustion engines is raised immediately prior to its combustion. The high octane number necessary for high compression ratios in internal combustion engines and hence high efficiency has hitherto been achieved by the introduction of lead alkyls into petrol. However, this results in lead pollution. The current invention, by converting low octane aliphatics and alicyclics to aromatics, enables lead free fuel to be used in high compression engines. In addition, the hydrogen which is a by-product of the reforming process assists combustion and enables leaner mixtures to be used. As a result, less fuel is wasted by incomplete combustion thereby enabling the engine to run more efficiently with less pollution from carbon monoxide and hydrocarbons. According to the present invention, there is provided a catalyst which catalyses the conversion of aliphatic and alicyclic hydrocarbons to aromatic hydrocarbons. During operation, fuel is passed through the catalyst before being consumed by an internal combustion engine. In the preferred mode, the catalyst is heated by exhaust gases from the internal combustion engine. It is preferred that the fuel is passed over a purifier bed in order to remove impurities such as lead before being passed over the catalyst. In the preferred mode, the purifier bed consists of bauxite or alumina although purifier beds of different composition may also be used. It is preferred that the purifier is heated by exhaust gases although it may also be heated by other means. It is preferred that the fuel is vaporised prior to being passed through the catalyst.When a purifier is used it is preferred that the fuel is vaporised before passing through the purifier. More than one catalyst bed may be used and they may be of different composition. More than one purifier bed may be used and they may be of different composition. The fuel may be passed over the catalyst at atmospheric pressure but in the preferred mode, it is passed over the catalyst at a pressure which is greater than atmospheric. It is preferred that, from time to time, the catalyst is regenerated, when hot, by passing a gaseous mixture containing free oxygen over it. This may be done in various ways. Thus air may be passed through the catalyst or combustion products, such as exhaust gases, passed through it or any gaseous mixture containing free oxygen may be passed through it. During regeneration the catalyst may be heated in various ways. It may be heated by the application of a flame, hot air, hot exhaust gases or hot combustion products to the vessel containing it. Alternatively, hot gases may be passed through the catalyst. It is preferred that the fuel is cooled after it has left the catalyst chamber. This may be done in various ways; it may be cooled by means of a liquid or a gas, for instance air, or by means of an evaporating liquid; thus it may be used to vaporise fuel. A specific embodiment will now be described by way of example with reference to the accompanying drawing in which: Figure 1 is a block diagram of the system. Figure 2 shows the cross section of the vessel containing the catalyst and that containing the purifier. Figure 3 is a diagram of the cross section of the catalyst bed and/or purifier bed in an alternative mode. Referring to Fig. 1 the fuel is vaporised and passed through the purifier contained in vessel A. It then flows into vessel B where it is passed through the catalyst which contains or consists of molybdenum oxide, chromium oxide, a metal or metals of the platinum family, cobalt molybdate or any other substance which catalyses the conversion of aliphatic or alicyclic hydrocarbons to aromatic hydrocarbons. The fuel then flows through pipe E where it is cooled before being consumed by the internal combustion engine C. Both the catalyst and the purifier are heated by the exhaust gases from the internal combustion engine C, flowing through the pipe D. In the preferred mode, the vessels A and B, containing the purifier and the catalyst respectively, consist of an inner compartment J separated from the outer wall by a cavity L as shown in Fig. 2. The catalyst and the purifier are contained within the compartment. During operation, the fuel flows through the cavity either prior to or after passing through the compartment. The compartment is annular and coaxial with the exhaust pipe of the internal combustion engine. The exhaust pipe may either be in contact with the contents of the compartment or it may be separated from them by a wall. In another mode, also incorporating a cavity wall and illustrated by Fig. 3, the compartment J has a crescent shaped cross-section. In such a mode the vessels A and B are clamped onto the exhaust pipe so that the inside wall of each compartment is in contact with it. It is preferred that the two vessels are attached to the same section of pipe so that they are coaxial. CLAIMS

1. A system in which fuel is passed through a catalyst which converts aliphatic and alicyclic hydrocarbons into aromatic hydrocarbons and hydrogen immediately before being consumed by an internal combustion engine.

2. The system as in claim 1 in which the catalyst is heated by exhaust gases from the engine.

3. The system as in claims 1 or 2 in which the fuel leaving the catalyst is cooled before being consumed by the engine.

4. The system as in claims 1,2 or 3 in which the catalyst is regenerated by passing oxygen or a gaseous mixture containing oxygen through it.

5. The system as claimed in claims 1,2,3 or 4 in which the fuel is passed through a purifier bed before being passed through the catalyst.

6. The system as in claim 5 in which the purifier bed is heated by exhaust gases from the engine.