WO2002049735A1

WO2002049735A1 - Crude oil conditioning apparatus and method

Info

Publication number: WO2002049735A1
Application number: PCT/AU2001/001572
Authority: WO
Inventors: John H. Mathiasen; Gordon John Gargano
Original assignee: Gosfern Pty Limited
Priority date: 2000-12-20
Filing date: 2001-12-05
Publication date: 2002-06-27
Also published as: AUPR221700A0

Abstract

A pumping apparatus for pumping crude oil comprises a pump means operatively positioned in a crude oil pipe line for pumping oil therethrough, an engine operatively connected to the pump means for driving said pump means, a heater and flash vessel for receiving and heating a portion of the crude oil therefrom arranged to flash/evaporate the majority of the lighter fractions from the portion of the crude oil, to leave a residue of crude oil which has a flash point of greater than about 60°C, and means to convey conditioned crude oil having a flash point of less than 60°C to said engine to provide a fuel for driving the pump. In a variant, two additional flash vessels are provided which vaporise crude kerosene and diesel fractions in sequence from the conditioned crude oil, and which are condensed for use as fuels.

Description

Crude oil conditioning apparatus and method

Field of the Invention

This invention relates to a crude oil conditioning apparatus and method.

Background of the Invention

Although crude oil is a fuel, it has to be conditioned by being separated into its various fractions before it is possible to safely use crude oil as a source of energy. This is traditionally done in a refinery using the well known process of fractional distillation in a fractionating column also known as a distillation tower, in which the various fractions of the crude oil are separated from one another.

Because crude oil is not a safe fuel, pipe lines transporting crude oil use external energy sources to provide the energy necessary to drive the pumps which pump the crude oil along the pipe line despite the fact that the pipelines are pumping a fuel. Further, many oil pipelines are in remote locations where roads and other infrastructure are poor or non-existent and in some cases fuel for operating pumps has to be flown in by helicopter which makes maintenance and running of remote oil pipelines expensive and difficult.

US 3656872 in the name of Rolls Royce Limited discloses the idea of using a gas turbine to drive a crude oil pump in which lighter fractions of the crude oil are extracted and used as a fuel to power a gas turbine operating an oil pump. However, the process disclosed in US 3656872 has not been adopted by the industry perhaps due to the proposal being impractical or unsafe.

The present invention seeks to provide an improved crude oil pumping apparatus which addresses the problems of the prior art. Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed in Australia before the priority date of each claim of this application. Summary of the Invention

According to a first aspect of the present invention, there is provided a pumping apparatus for pumping crude oil comprising: pump means operatively positioned in a crude oil pipe line for pumping oil therethrough; an engine operatively connected to the pump means for driving said pump means; evaporating means operatively connected to the pipe line for receiving a portion of the crude oil therefrom and being arranged to evaporate the majority of the lighter fractions from the portion of the crude oil, to leave a residue of crude oil which has a flash point of greater than about 60° C; and means to convey the crude oil having a flash point of less than 60° C to said engine to provide a fuel for driving the pump.

A major problem with crude oil, is its inflammability, with the lighter oil fractions being more volatile than the heavier oil fractions. The apparatus of the present invention safely removes the lighter fractions from the crude oil to provide a liquid having a flash point of greater than 60° C which is considered to be a class 3A liquid according to the NFPA safety classification for liquid petroleum fuels which can safely be used to drive an engine such as a diesel engine.

Typically the evaporating means comprise a flash vessel. Prior to entry into the flash vessel a heater is provided for heating the oil. Control means may be provided for maintaining the temperature of the heater at a desired temperature which may typically be from 180°C to 260°C and is most preferably about 210 degrees but which depends on the crude oil composition. The heater may be an electric heater or a steam heating means. In a preferred embodiment a condenser is provided for condensing the fractions evaporated from the portion of crude oil. The apparatus includes a return means for returning the condensed portion to the crude oil supply pipeline.

Typically the apparatus of the present invention will include remotely operable control means allowing the apparatus to be started up and shut down remotely and operated with very little need for intervention by an operator in a fully automated and safe manner allowing the apparatus to be run "unmanned". The apparatus of the present invention can also be used to produce a safe fuel from crude fuel oil for uses other than pumping crude oil.

Thus in a second aspect of the present invention there is provided an apparatus for providing a safe fuel form crude oil including :- supply means for supplying a crude oil portion to a heater; heater means for raising the temperature of the crude oil; a flash vessel for receiving a portion of the crude therefrom the arrangement being such that the majority of the lighter fractions from the portion of the crude oil, are evaporated to leave a residue of crude oil which has a flash point of greater than about 60° C.

For example a crude oil tanker could use the apparatus for making a fuel for use in its engines or boilers for driving the tanker directly from its crude oil cargo. Alternatively, the safe fuel may be use for powering generators or the like or for other uses. In a particular refinement of the invention additional heaters and flash vessels are incorporated into the apparatus to produce different, relatively crude, cuts of oil such as diesel and kerosene.

Thus in a further aspect of the present invention there is provided an apparatus for providing fuel cuts from crude oil including:- supply means for supplying a crude oil portion to a heater; a first heater means for raising the temperature of the crude oil; a first flash vessel for receiving a portion of the crude therefrom the arrangement being such that the majority of the lighter fractions from the portion of the crude oil, are evaporated to leave a liquid residue of crude oil; a second heater means for heating the liquid residue of crude oil from the first flash vessel and a second flash vessel arranged to receive the heated liquid residue of crude oil arranged to vaporise a first cut of fuel from the heated liquid residue means for condensing the first vaporised cut; and a third heater means arranged to heat the non-vaporised liquid residue from the second flash vessel and a third flash vessel arranged to receive the heated liquid residue of crude oil from the second flash vessel and vaporise a cut of fuel from the heated liquid residue from the second flash vessel.

Typically the crude oil enters the second flash vessel at 145 to 175° C, most typically about 175°C and the pressure in the second flash vessel is from 5 to 200 kPa, most typically about 40 to 50kPa. The pressure in the third flash vessel is also from 5 to 200 kPa, typically about 40 to 50 kPa, but the crude oil enters that vessel at 320°C to 375°C, most preferably about 350°C. The cuts of fuel produced by the second and third flash vessels are kerosene and a diesel and light oil mixture respectively. Although containing multiple fractions the cuts are suitable for many applications in place of refined fractions.

Thus in a broad aspect the present invention also relates to the segregation of crude oil fuel cuts without fractionation.

The invention also provides a method of producing a safe fuel form a supply of crude oil comprising the steps of:- taking a portion of the crude oil, typically on a continuous basis; supplying said oil portion to a heater means and raising the temperature of the oil therein; supplying the heated oil to a flash vessel; evaporating the lighter fractions from the oil such that the remaining liquid phase has a flash point of greater than about 60 degrees Centigrade; retaining the remaining liquid phase for use as a fuel.

The evaporated fractions may be condensed and returned to the crude oil supply.

Means may be provided for monitoring the temperature, level and pressure in the flash vessel.

Means may be provided for monitoring the temperature of the heater

Brief Description of the Drawings

A specific embodiment of the invention will now be described by way of example only and with reference to the accompanying drawings in which: Figure 1 is a schematic drawing of a first embodiment of a crude oil conditioning apparatus; and

Figure 2 is a schematic drawing of a second embodiment of a crude oil conditioning apparatus.

Detailed Description of Preferred Embodiments

Referring to the drawings Figure 1 shows an apparatus includes a pump 1 which draws crude oil through a pipeline 20 connected to a crude oil supply pipeline, not shown. The pump 1 may not be required if crude oil is drawn directly from an oil pipeline, in which case it might be replaced by a pressure reduction station, not illustrated. The pipeline 20 extends to a flash vessel 5 via a crude oil safety shut- off valve 2, an electric heater 3 and a flow control valve 4 which is disposed between the flash vessel and an electric heater 3.

The electric heater is automatically controlled by a dedicated controller, not illustrated. However external energy set points are controlled by a process control system. On start-up the control system ramps the temperature up to 100 degrees initially over a fifteen minute period, holds the temperature for a soak period of one minute and then ramps the temperature up to approximately 210 degrees at which time the desired flash point temperature is achieved. The opposite takes place if the apparatus undergoes a normal shutdown. In the event of a safety emergency an automatic safety control system shuts down the apparatus and trips the heater 3.

The flow control valve 4 is controlled via a dedicated controller and controls the flow of crude oil through the heater 3. The crude oil passes under control of the flow control valve 4 into the flash vessel 5. At 210° C or thereabouts, the lighter fractions of the feed crude oil flash to vapour on entry. An exit pipeline is provided at the top of the flash vessel from which the lighter fractions which have been flashed off the crude oil exit via a pipeline 22 from where they pass into an overhead condenser 6. The flash vessel operates at 25 to 30 kPa or thereabouts at a temperature of 210°C. In the condenser 6, approximately 96% of the vapour recondenses as a liquid. The condensed liquid may be subsequently injected into the crude oil supply pipeline via a pipeline 23 incorporating a reject return safety shut-off valve 11. The remaining non-condensed vapour is vented to atmosphere.

To ensure the safety of the system and to assist in the automation of the system, the temperature and pressure in the vessel 5 are monitored by sensors 46 and 42 referred to in more detail below.

The non-vaporised remaining liquid phase portion of the crude oil fills the bottom of the flash vessel 5. The liquid phase passes via pipeline 24 into a rundown cooler 7 under the control of a pump 8 disposed in the pipeline after the cooler 7. A modulating speed control on the product pump controls the level of liquid in the flash vessel at typically approximately 500mm deep. In the cooler 7 the temperature of the liquid phase is reduced from 210° C to This liquid phase should now have been conditioned to a flash point of greater than 60° C and accordingly is considered to a class 3A liquid according to the NFPA 30 ( National Fire Protection Association) safety classification for liquid petroleum fuels. In contrast crude oil is typically categorised as a Class 1 dangerous liquid fuel.

The cooled liquid phase is then pumped by the pump 8 and is analysed to check its flash point either manually or preferably via an automatic analyser incorporated in the outlet line. Liquid phase which meets the flash point requirements passes along a pipeline 26 to a fuel holding tank (not illustrated). Any product whose flash point is below 60° C (this usually will only occur during start-up), is passed along a different pipeline 28 to an "off- spec" stream from whence the liquid phase may be returned to the crude oil pipeline. The flow of the liquid phase along the pipelines is controlled by product safety shut-off valve 9 and off spec safety shut-off valve 10 respectively. Shut-off valve 9 is opened and closed by the control system during the run-up and run-down sequence. The valve is closed automatically if a safety emergency shutdown occurs. Shut-off valve 10 is also automatically controlled by the control system and is open until the start-up sequence is complete (flash point >60° C ) at which time the valve is automatically closed. If an emergency shutdown occurs the valve 10 is automatically closed. Means (not shown) are provided for measuring the volume of liquid phase pumped.

The apparatus incorporates a water based cooling system for cooling the rundown cooler 7 and the overhead condenser 6, although alternative cooling systems such as aerial coolers could be used. The apparatus incorporates a cooling water pump 14 which pumps water along a pipe 30 which splits into two pipes 32 and 34 respectively to supply cooling water to the overhead condenser 6 and the rundown cooler 7. The pump 14 is started via the control system at start up and is stopped at the end of the shut down sequence. The two pipes 32 and 34 re-join after passing through the condenser and cooler respectively and pass into a cooling tower 12a incorporating a fan 12. The fan is started and stopped automatically by the control system and runs during the start-up sequence and while the system is running normally in service. Cooled water exiting the cooling tower passes back to the pump and back along pipeline 30. A pressure control valve 13 which is in a line 36 running in parallel to the pump 1 is automatically controlled by a crude oil pressure control loop and maintains a constant pressure to the process.

In order to enable safe, efficient and unmanned operation, the apparatus is controlled automatically using a computer controlled safety and automatic control system, the control system. Field instrumentation used to provide information to the control system for safe operation of the process includes :- a crude oil pump outlet pressure transmitter a crude oil flow transmitter an oil heater inlet pressure transmitter an oil heater temperature transmitter 40 a flash vessel pressure transmitter 42 a flash vessel oil level transmitter 44 a product flow to holding tank transmitter a flash vessel temperature transmitter 46

As described the apparatus incorporates an automatic control system to maintain the process variables at the desired operating points. The system includes the crude oil supply pressure control loop, the crude oil flow to oil heater control loop, the oil heater temperature control loop, the flash vessel level control loop and the flash vessel pressure control loop.

For safety reasons the automatic safety control system shuts down (Emergency Shut Down) the process safety shutdown valves and oil heater in the event that a potentially unsafe situation could occur. The various causes for an automatic safety shutdown are as follows :- oil heater 3 tripped product pump 8 tripped instrument air pressure low crude oil pump 1 tripped cooling tower fan 12 tripped cooling water pump 14 tripped loss of power operator emergency trip crude oil supply shut-off valve 2 not open product supply shut-off valve 9 not open reject return shut-off valve 10 not open fire detected gas leak detected.

Following is a description of the operation of the apparatus of the present invention.

Operation

Interlocks

The heater 3 must not be turned on before: • pump 14 is running

• cooling tower fan 12 is running

• crude supply pump 1 is running

• product pump 8 is running

Start-Up

For this description, it is to be understood that the system has been purged and filled with crude oil has previously been operating and has been shut down in an orderly manner.

1. Ensure that all manual block valves on oil lines and cooling water lines are in the open position.

2. Start the cooling water circulation pump 14. Ensure that cooling water is circulating through exchangers in the overhead condenser 6 and rundown cooler 7, respectively. Start the cooling tower fan 12 and ensure airflow through the cooling tower. 3. Check there is a sufficient supply in the crude oil supply storage tank.

4. Check there is sufficient storage capacity in the fuel holding tank.

5. Ensure that Heater 3 if OFF. Set heater temperature control TC051 at minimum. 6. Set the controller of crude oil supply to heater 3 at minimum.

7. Set The level controller (LC051) for the flash vessel 5 at 500mm (50%).

8. The shut down valve 2 on the crude supply must be open. The shutdown valve 9 on the product supply must be closed; the reject return line shut valve 10 must be open. The shutdown valve 11 on the off-spec product line 23 must be open. 9. If the level in flash vessel 5 is below 200mm (20%), the ESD LALL051 must be in override.

10. Because there is no flow in the crude oil line to the heater, the ESD FALL031E must be in override. 11. Start pump 1.

12. Adjust the flow controller (FC041) to gradually increase flow to 15 1/min in the crude line 20.

13. When flow has passed, and greater than, 2.0 1/min, FALL031E override automatically returns to normal. 14. Monitor the level in the flash vessel. If it was below 200mm, the

ESD override should automatically reset when the level rises to 200mm or greater. When the level nears 500mm (50%) start product pump 8 and allow the level control to maintain the level in the flash vessel 5 with a flow rate of 15l/min on FC041. 15. Turn heater 3 ON. Ramp up the heater temperature control

TC051, over a period of 20 minutes, to a temperature of 100° C and allow stabilising for 10 minutes, the ramp up again over 15 minutes to 204° C. Allow the temperature to stabilise at 204° C.

16. When the temperature has stabilised, test the Flash point of the off-spec product. When the flash point is equal to or greater than

60° C, open valve 9 and close valve 10.

17. Ensure that FC041, TC051 and LC051 operating in automatic mode.

18. The apparatus is now operating at design capacity and producing approximately 14.4 1/min of fuel product.

Normal Shutdown

1. Ramp down temperature set point of TC051 over a period of 20 minutes to 100° C, at the same time. 2. Close fuel product line shutdown valve 9 and open off-spec product line shutdown valve 10.

3. Reduce liquid level in flash vessel V-51 to approximately 275mm.

4. Ramp down temperature set point of TC051 to minimum 60° C over a period of 15 minutes. Turn heater 3 OFF. Continue circulation of crude oil until the temperature of flash vessel 5 is reduced to minimum, <60° C on temperature transmitter 46. 5. Stop product pump 8.

6. Stop crude supply pump 1.

7. When temperature indicators in the condenser and cooler have reached ambient water temperature, stop cooling water circulation pump 14.

8. Stop cooling tower fan 12.

9. Close oil line manual valves to isolate all hydrocarbon liquids on the skid.

10. Close shutdown valves 2,9,10,11. 11. Close water line manual valve HV04 and manual valve on by-pass line to cooling tower. 12. The unit is now shutdown, but ready for re-start as described above.

In the case of an emergency shutdown (ESD) the following occurs.

1. Close

• valve 2 in Crude supply line

• Reject returns line valve 11 after a delay of 15 seconds • Product fuel line valve 9

• Off spec product line valve 10

2. Open

• Main contactor of LP31, de-energising heater 3

3. Stop

• pump 1

• pump 8

4. The cooling water circulation pump is to remain running to provide cooling to 6 and 7, while off spec product valve 10 is opened to allow any excess liquid to be returned to a storage tank. Start-Up After Emergency Shutdown Cause of ESD

The cause of ESD must be corrected. When the reason has been determined for the ESD and the cause has been corrected or fault removed the apparatus can be placed into service Via the H.M.I. (Human Machine Interface).

List of Actions that CANNOT occur

1. Start • Crude Supply Pump 1

• Product Pump 8

2. Open

• Crude Supply Line valve 2

• Reject Return Line, valve 11 • Product Fuel Line valve 9

Off-spec Product Line valve 10

3. Close

Main Contractor of LP31 for heater 3

Shutdown Cause Corrected

When the shutdown cause(s) has been corrected the apparatus can be placed into service via the HMI.

This will activate the apparatus start us sequence.

The apparatus can now be put into service following the procedure listed above.

Figure 2 shows a second embodiment of the present invention. In this embodiment additional flash vessels are provided to provide fuels which are not merely safe fuels but approximate more closely to refined fuels, in particular diesel and kerosene. In this second embodiment, the crude oil supply pump 1, the inlet pressure control 13, the heater 3, first flash vessel 5 and first overhead condenser 6 remain the same as in the first embodiment and retain the same reference numbers in the drawing. The vaporised fractions from the first flash vessel pass from the overhead condenser 6 to a first rundown tank 109 from which they are pumped via a re-injection pump 111 back into the crude oil supply pipeline. The rundown tank facilitates the pumping of the condensed liquid.

In this second embodiment, by using additional flash vessels it is possible to produce "cuts" of fuel which approximate more closely to fuels such as kerosene and diesel produced by fractional distillation and although the cuts are relatively impure and crude compared with refined crude oil they are quite useable as fuels. This embodiment of the invention is particularly suited to producing fuels for more general use than merely crude oil pumping. For example it can be used to provide a safe diesel like fuel for operating generators or for use in marine engines.

In order to produce a 'kerosene' type fuel a second supply pump 102, electric heater 104, second flash vessel 106, and second overhead condenser 108 have been added to the system of Figure 1. As is the first embodiment, the second flash vessel is monitored by a temperature transmitter 110 and an oil level transmitter 112.

The un-vaporised liquid fraction from the first flash vessel is pumped via heater 104 into flash vessel 106 at a temperature of approximately 175°C. On entry to the flash vessel at approximately 40 to 50 kPa, the lighter fractions vaporise and pass to a second overhead condenser 108 via an exit pipeline. The pressure is dependent on the operation of the condenser and is preferably about 40kPa. These fractions which are evaporated from the second flash vessel are re-condensed in the overhead condenser and pumped via a rundown tank 114 and pump 116 to storage or for use. The heavier fractions which are not vaporised and remain in the liquid phase are pumped via a third supply pump 118 to a third electric heater 120 at approximately 650 kPa or thereabouts where the temperature is raised to approximately 350°C and pass into a third flash vessel 122 operating at 40 to 50 kPa or thereabouts, where a diesel type cut is flashed into vapour and passes via an exit pipeline to a product condenser 124 and thence to a product rundown tank 126. Again there are temperature 128 and oil level 130 monitors and transmitters for then third flash vessel From there the diesel type cut can be pumped via pump 132 to a product storage tank or the like. The diesel type cut of fuel produced is not identical to the isolated fractions produced in a traditional fractionation column but is a combination of gas oils which comprise diesel grades and is suitable for use in most applications where diesel fuel is required. The heavy ends from the third flash vessel are directed to the first rundown tank 109 via a rundown cooler 134 for re- injection into the pipeline.

In the second embodiment described the coolers and condensers are aerial coolers however they could be replaced by water coolers as in the first embodiment.

It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS :-

1. An apparatus for providing a safe fuel from crude oil including:- supply means for supplying a crude oil portion to a heater; heater means for raising the temperature of the crude oil; a flash vessel for receiving a portion of the crude therefrom the arrangement being such that the majority of the lighter fractions from the portion of the crude oil, are evaporated to leave a liquid residue of crude oil which has a flash point of greater than about 60° C.

2. An apparatus for providing a safe fuel from crude oil as claimed in claim 1 wherein a condenser is provided for condensing the lighter fractions evaporated from the portion of crude oil.

3. An apparatus for providing a safe fuel from crude oil as claimed in claim 2 further including a return means for returning the condensed lighter fractions to the crude oil supply pipeline.

4. An apparatus for providing a safe fuel from crude oil as claimed in any preceding claim including a control means and means for monitoring the temperature, level and pressure in the flash vessel and means for monitoring the temperature of the heater.

5. An apparatus as claimed in any preceding claim further including a heater means for heating the liquid residue of crude oil and a second flash vessel arranged to receive the heated liquid residue of crude oil arranged to vaporise a cut of fuel from the heated liquid residue.

6. An apparatus as claimed in claim 6 wherein the pressure in the second flash vessel is maintained between 40 to 50kPa and the crude oil residue is supplied to the flash vessel at a temperature of 150 to 200°C, preferably about 175°C, and wherein the vaporised cut is kerosene and further including means to condense the vaporised kerosene.

7. An apparatus as claimed in any one of claims 5 to 6 further including a third heater means arranged to heat the non-vaporised liquid residue from the second flash vessel and a third flash vessel arranged to receive the heated liquid residue of crude oil from the second flash vessel and vaporise a cut of fuel from the heated liquid residue.

8. An apparatus as claimed in claim 7 wherein the pressure in the second vessel is maintained between 40 to 50 kPa and the liquid residue of crude oil is supplied to the third flash vessel at a temperature of about 325 to 375°C, and wherein the vaporised cut is diesel and light gas-oil and further including means to condense the vaporised diesel and light gas-oil.

9. An apparatus for providing fuel cuts from crude oil including :- supply means for supplying a crude oil portion to a heater; a first heater means for raising the temperature of the crude oil; a first flash vessel for receiving a portion of the crude therefrom the arrangement being such that the majority of the lighter fractions from the portion of the crude oil, are evaporated to leave a liquid residue of crude oil; a second heater means for heating the liquid residue of crude oil and a second flash vessel arranged to receive the heated liquid residue of crude oil arranged to vaporise a first cut of fuel from the heated liquid residue and means to condense the first vaporised cut; and a third heater means arranged to heat the non-vaporised liquid residue from the second flash vessel and a third flash vessel arranged to receive the heated liquid residue of crude oil from the second flash vessel and vaporise a second cut of fuel from the heated liquid residue from the second flash vessel and means to condense the second vaporised cut.

10. A pumping apparatus for pumping crude oil comprising: pump means operatively positioned in a crude oil pipe line for pumping oil therethrough; an engine operatively connected to the pump means for driving said pump means; evaporating means operatively connected to the pipe line for receiving a portion of the crude oil therefrom and being arranged to evaporate the majority of the lighter fractions from the portion of the crude oil, to leave a residue of crude oil which has a flash point of greater than about 60° C: and means to convey the crude oil having a flash point of less than 60° C to said engine to provide a fuel for driving the pump.

11. A pumping apparatus for pumping crude oil as claimed in claim 10 wherein the evaporating means comprises a flash vessel and a heater for heating the oil prior to its entry into the flash vessel.

12. A pumping apparatus for pumping crude oil as claimed in claim 11 wherein the heater is an electric heater or a steam heater.

13. A pumping apparatus for pumping crude oil as claimed in claim 11 or 12 further including a control means for maintaining the temperature of the heater in a predetermined temperature range.

14. A pumping apparatus for pumping crude oil as claimed in claim 13 wherein the predetermined temperature range is from 180°C to 260°C.

15. A pumping apparatus for pumping crude oil as claimed in any one of claims 10 to 14 further including a condenser for condensing the fractions evaporated from the portion of crude oil and a return means for returning the condensed portion to the crude oil supply pipeline.

16. A method of producing a safe fuel from a supply of crude oil comprising the steps of:- taking a portion of the crude oil, typically on a continuous basis; supplying said oil portion to a heater means and raising the temperature of the oil therein; supplying the heated oil to a flash vessel; evaporating the lighter fractions from the oil such that the remaining liquid phase has a flash point of greater than about 60 degrees Centigrade; retaining the remaining liquid phase for use as a fuel.

The evaporated fractions may be condensed and returned to the crude oil supply.

17. A method as claimed in claim 16 further including step of maintaining and monitoring the temperature of the heater between 180°C to 260°C, in use.

18. A method as claimed in claim 16 or 17 further including step of analysing the liquid phase to check its flash point via an automatic analyser incorporated in the outlet line.