In particular, the invention is intended for upgrading oil products by means of selected natural microorganisms such that the oil products do not emit, or emit fewer fine particles, carbon monoxide (CO) and nitrogen oxides (NOx) during the combustion process. An overview of the use of microorganisms for extracting and upgrading crude oil was given by J.D. Van Hamme et al. (Recent Advances in Petroleum Microbiology, in Microbiology and Molecular Biology Reviews, Dec. 2003, pg. 503-549). In this review, bacterial cultures are injected into deep oil reservoirs with the aim of getting more yield from the oil reservoir (page 527). In situ bacterial growth can increase the pressure in the reservoir, or plug the more permeable region of the reservoir, such that more crude oil can be recovered from the reservoir.

Crude oil, but also refined oil products such as petrol and diesel fuels, contain hydrocarbons which form straight chain hydrogenated carbon atoms, such as octane in petrol, but also chains that are not straight but branched, or clustered with intra-molecular bridges. The hydrocarbons with straight chain hydrocarbons combust completely and at a lower temperature than the non-straight chains, which only combust at higher temperatures and, if they combust, do so incompletely, emitting carbon monoxide and soot, which are uncombusted particles that are emitted into the exhaust gas with each piston stroke of a combustion engine.

The higher combustion temperature of the non-straight chains causes hotter places to form in an engine cylinder where, due to the heat, not only NOx is formed but there is also a higher heat loss through the engine cylinder walls, which leads to lower engine efficiency.

Complete combustion of hydrocarbons produces CO ₂ , a greenhouse gas, and H ₂ O. Incomplete combustion of hydrocarbons also produces CO, which is also a greenhouse gas, and the harmful nitrogen oxides or NOx, which affect the ozone layer, acidify the atmosphere and are harmful to health.

The purpose of the present invention is to provide a solution to the aforementioned and other disadvantages, by providing a method and a device which allows the non straight chain hydrocarbons in the fuel to form into truncated but straight chain hydrocarbons with the formation of a more efficient fuel with less CO and CO ₂ emissions per litre of fuel and with little or no air pollution from soot and NOx. To this end, the invention relates to a method for upgrading crude oil or mixtures of crude oil, whereby in a first phase: a first biological additive which contains a first mixture of natural microorganisms is added to the crude oil or mixtures of crude oil, said first biological additive truncating the non-straight chain hydrocarbons in the crude oil into straight chain hydrocarbons; and in a second phase:

- a second biological additive which contains a second mixture of natural microorganisms, including sulphur consuming micro-organisms or spores thereof, is added to the already truncated crude oil, said second biological additive reacting with the present sulphur and other unwanted impurities and after passing through a sulphur separator, i.e. a sloping, heated sheet in an enclosed space, forming a high sulphur precipitate which together with the treated crude oil is guided further, whereby the light, volatile components that are released are collected in the sulphur separator and processed into compressed, natural gas or CNG; and in a third phase:

- the treated crude oil with the high sulphur precipitate, is guided either to the desalination and dewatering installation of a refinery and further to a refining column where the mixture is separated into heavier and lighter fractions, including diesel and petrol fuels with reduced sulphur content; or is guided to a centrifuge to separate the high sulphur precipitate from the treated oil, and to use this treated crude oil either as a low sulphur heating oil or bunker oil, or guided to a refinery tower for fractionation into heavier and lighter fractions, including diesel and petrol fuels with greatly reduced sulphur content.

Preferably the first biological additive contains one or more natural strains selected from Lactobacillales, Bacillus stratosphericus, Bacillus thermoaerophilus, Brevilbacillus brevis, and Bacillus coagulans which are chosen because they thrive on a substrate with non-straight chain hydrocarbons. Bacillus stratosphericus is very tolerant to Fe, Co, Ni and Cu ions and averagely tolerant to Cd and Zn ions, such that the heavy metals in the treated fuels are reduced by 50%.

Preferably, the second biological additive contains one or more natural strains or spores selected from Bacillus cereus, which precipitate the sulphur and other unwanted impurities in the crude oil, as well as Bacillus subtilis, which form a film around the sulphur and unwanted impurities which they encapsulate during further treatment, and further also Bacillus altitudinis, Bacillus amyloliquefaciens, Nitrobacter and Azotobacter . The Nitrobacter are useful for oxidising nitrite ions NO2 into nitrite ions NO3. The biological additives are pre-selected for the type of oil to be treated, and are cultivated into a biological additive mixture with a plate count of 10 ⁷ -10 ⁸ cfu/ml, which is administered to the oil at a pH of 9.0 +/- 0.5.

The biological additives will multiply in the oil, forming a biomass, which contains sugars, as in the peptidoglycans of their cell wall, consisting of amino acids and sugars. These sugars represent carbon skeletons on which oxygen atoms are bound, which remain present in the upgraded oil until they dissolve in a refining step at high temperatures into smaller but oxygenated molecules, which remain present in the refined fuels such as petrol and diesel. This bound oxygen, already present in the fuel, causes additional post-combustion in the combustion chambers when combusted in the cylinders of a driven combustion engine, whereby additional energy is released and the fuel is combusted more completely.

Experimental effects of the upgraded petrol and diesel fuels treated with biological additives

The upgraded fuels lower the CO2 emissions of engines and lower the soot, fine particles, SO2, CO and NOx emissions. The use of these upgraded fuels adds 50,000 km more travel distance for the same fuel consumption over the lifetime of the vehicle. A first reason for these effects is that the combustion of the upgraded fuel is more complete, more uniform and at a lower temperature.

An additional reason is that the upgraded fuels contain compounds in which oxygen is bound to carbon and cause the aforementioned extra post-combustion in the cylinders of a combustion engine.

The combustion engines consequently suck in 7% less oxygen and cause 7% less air pollution.

An added advantage of said upgraded fuels is that they do not require any adjustments to the existing infrastructure and pumps for upgrading fuels, nor to the existing engines in the existing fleet of vehicles.

The following table I shows the measured remaining percentages (x %) of components in the exhaust gases of combustion engines after upgrading a number of fuels in relation to the percentage (100%) of the same components in the exhaust gases of the same fuels without upgrading, obtained by analysis of the exhaust gases in controlled conditions .

Fuel C0 ₂ CO NOx S0 ₂ TOC Substance

% % % % % % petrol 5 62 30 25 82 46 diesel 46 53 >30 >-522 65 30 heavy crude oil -29 68 50 0 26 57 light crude oil 25 68 >7 74 33 89

Table 1: Remaining percentages of components in the exhaust gases of an engine after upgrading the fuel.

For petrol, this means a 95% reduction in C02 emissions, a 38% reduction in CO emissions, and a 70% reduction in NOx emissions. The total organic carbon (TOC) is reduced by 18%, and fine particles by 54%.

For diesel this is a 54% reduction in CO2 emissions, 47% reduction in CO emissions, and a 70% reduction in NOx emissions. The total organic carbon (TOC) is reduced by 35%, and fine particles by 70%.

It needs to be noted that the combustion of one litre of diesel releases 2.7 kg of CO2, which refers exclusively to the CO2 present in the diesel fuel. However, this is just a fraction of the total quantity of CO2 that is released in diesel fuel as a product. According to the source-to-wheel method, all the CO2 released during the detection, production, refining, transport and storage of the diesel fuel is also included. This can amount to an extra 30%, such that emissions are increased to 3.5 kg CO2 per litre of diesel fuel. In general, bio-fuels are evaluated using the stricter source-to-wheel method.

The second biological additive is able to upgrade the hydrocarbons within about ten seconds. After upgrading, the second biological additive can be separated 99.99 % from the hydrocarbon in a centrifuge, and the biological additive can be reused up to two times. The residual hydrocarbons contain no more than 10 litres of water per tonne, and meet the standards of the petrochemical sector.

The biological additives are continuously produced at the crude oil storage site with known techniques by means of an installation for cultivating biological cultures on a suitable commercially available substrate, which allows an infinite flow of biological additives to be produced. Obviously these biological additives can also be produced elsewhere and transported to the site, but since the stream of biological additives must be sufficient to keep the production of upgraded fuels going, it is safer to produce them at the site itself.

The biological additives cannot only be used for upgrading hydrocarbons in crude oil, but also for upgrading already refined products such as petrol, diesel, heating oil or kerosene which were already refined from non-upgraded crude oil, whereby the resulting upgraded refined products do not need an additional refining step.

In this case, it is sufficient in the method to replace the crude oil in the storage tank with petrol or diesel, for example, and to treat this fuel in a first phase with the first biological additive, and in a second phase with the second biological additive, after which in a third phase the treated fuel is sent directly to a centrifuge to separate the upgraded fuel from the sulphurous precipitate from which the second biological additive and sulphur can be recovered.

The upgraded fuel such as petrol or diesel is now ready for use, and no longer needs to be fractionated in a refining column as it was already refined before the treatment with biological additives.

With the intention of better showing the characteristics of the invention, a preferred embodiment of the method for upgrading oil products according to the invention is described hereinafter, by way of an example without any limiting nature, with reference to the accompanying drawings wherein:

Figure 1 shows a device used to execute the method for upgrading crude oil according to the invention.

Figure 1 shows a device 1 used to execute the method for upgrading crude oil according to the invention, said device comprising the following components:

- a storage tank 2 for crude oil provided with a supply pipe 3 for supplying new crude oil, said supply pipe 3 being provided with a feed pipe 4, connected to a supply vessel 5 of a first biological additive, said first biological additive being fed in a volumetric additive/crude oil ratio of 10/90. The storage tank 2 is also provided with a discharge line 6 for discharging upgraded crude oil 7;

- a culture station 8 for cultivating cultures of a first and a second biological additive, from which an endless stream of biological additives is fed to a first supply vessel 5 for the first biological additive 5', and to a second supply vessel 9 for the second biological additive 9';

- a number of reaction vessels 10 for treating the upgraded crude oil, into which a guantity of the upgraded crude oil 7 is fed via the discharge line 6 of the storage tank 2, after which an appropriate quantity of the second biological additive 9' is added from a feed pipe 11 connected to the second supply vessel 9 with the second biological additive 9' and this in a volumetric second biological additive/ refined crude oil ratio of 5/159. The mixture is intensely mixed by means of a stirring or mixing device 12 that is provided or can be introduced in the reaction vessel 10, after the second biological additive 9' has been injected via a distribution system with multiple injectors 13 at several locations in the reaction vessel 10.

- a coupling 14 with which a reaction vessel 10 which reacted a sufficient time with the second biological additive 9', is coupled to the entry of a sulphur separator 15; - a sulphur separator 15 comprising a downward sloping, long, heated sheet 16 which is preferably 20 m long and 1.5 m wide, enclosed by gas-tight walls 17, and provided with a gas exhaust 18 at the top, through which the volatile hydrocarbons released in the sulphur separator 15 are guided to a collecting tank 19 and an installation in which the released vapours can be processed into compressed natural gas or CNG; a coupling 20 with which the exit of the sulphur separator is coupled to a pipe 21 which feeds the treated oil to a two-way cock 22 which, depending on the position of the valve, allows the treated oil to pass

- either to a desalination and dewatering installation 23 of a refinery from where the treated oil is guided further to a refining column 24 for fractionating into heavier and lighter fractions, including diesel 25 and petrol fuels 26 with reduced sulphur content of < 0.5 %;

- or a centrifuge 27 in which the high sulphur precipitate 28 is separated from the treated oil after which the separated low sulphur treated oil 29 is guided to either a refining column 24 for fractionating into heavier and lighter fractions, including diesel and petrol fuels with a strongly reduced sulphur content; - or to a storage tank in which the low sulphur treated oil is stored as heating oil or bunker oil. The operation of the device 1 for upgrading crude oil or already refined products such as petrol, diesel, heating oil or kerosene which were already refined from non- upgraded crude oil, can be described as follows.

In a first phase a storage tank 2 is filled with crude oil or a refined but non-upgraded oil product, via a supply pipe 3, which is provided with a feed pipe 4, which first feeds a biological additive 5' in the oil collecting in the storage tank 2. The first biological additive 5' truncates the non-straight chain hydrocarbons to straight chain and shorter hydrocarbons and does this within ten seconds after being mixed with the non-upgraded oil product, such that the oil product is upgraded and obtains a higher combustion efficiency and is environmentally-friendlier. The first biological additive 5' is fed to crude oil up to a volumetric biological additive/crude oil ratio of 10/90. The first biological additive 5' does not damage the petroleum at all and can even be stored in the storage tank 2 up to a year as upgraded oil or oil product in anticipation of further processing.

The first biological additive 5' contains selected natural strains chosen from Lactobacillales, Bacillus stratosphericus, Bacillus thermoaerophilus, Brevilbacillus brevis, and Bacillus coagulans, which truncate the non straight chain hydrocarbons into straight chain and smaller hydrocarbons.

In a second phase a reaction vessel 10 is filled with a quantity of upgraded crude oil or oil product via the discharge line 6 of the storage tank 2, to which for every 159 litre barrel of upgraded oil an appropriate quantity of 5 litres of a second biological additive 9' is added from a feed pipe 11, which is supplied from the second supply vessel 9 for the second biological additive 9' and via a distribution system with multiple injectors 13 is injected in different locations in the reaction vessel 10 after which the additive 9' is intensely mixed with the upgraded oil or the oil product by means of a stirring or mixing device 12.

The second biological additive 9' contains selected natural strains chosen from Bacillus cereus, Bacillus subtilis, Bacillus altitudinis, Bacillus amyloliquefaciens, Nitrobacter and Azotobacter, and concentrates all polluting impurities, including sulphur, from crude oil in a slurry which precipitates in the sulphur separator 15 within ten minutes. For the treatment of already refined oil products, much less sulphur is present and this step may be unnecessary.

The selected strains of bacteria for the first and second biological additive are not limited to these examples and may vary depending on the crude oil or oil product to be treated.

The treated crude oil is guided further to a sulphur separator 15 in which the oil flows over a long, downward sloping sheet 16 which is preferably 20 m long x 1.5 m wide, said sheet having a temperature between 30 and 40 °C and enclosed by gas-tight walls 17. Due to the heat, volatile components including volatile hydrocarbons, such as methane and the short hydrocarbons of ethane, propane and butane evaporate. Said volatile vapours are led via a gas exhaust 18 at the top of the sulphur separator to a collecting tank 19, from where they can be processed into compressed natural gas or CNG.

The emptied reaction vessel 10 is returned to the discharge 6 of the storage tank 2 for filling a next batch of upgraded crude oil or oil product for the same treatment.

The crude oil with the sulphurous slurry of impurities is guided further to a two-way valve 22, which allows the stream to be guided to a refinery, or to a centrifuge depending on the fuel to be obtained.

The most economical choice for the refinery is to guide the stream directly into the standard desalination and dewatering process 23 and further to a fractionating column 24, from which refined petroleum distillates such as petrol 26 and diesel fuels 25 are obtained with a sulphur content of less than 0.5%, whereas this was still 2% or more in the crude oil.

Analyses have shown that refining a 159 litre barrel of crude oil in this way generates 1.2 litres of additional yield per fuel derivative, thus reducing the refinery price by €1 per treated barrel. If 125,000 barrels are produced every day, the difference in price results in an added value of 45 million € a year. The other choice made possible by the two-way valve 22 is to guide the treated oil from the sulphur separator to a centrifuge 27, in which the high sulphur precipitate 28 is separated from the treated crude oil 29 after which the separated, now lower sulphur, treated oil 29 is guided to either a refining column 24 for fractionating into heavier and lighter fractions, including diesel and petrol fuels with a strongly reduced sulphur content;

- or to a storage tank in which the low sulphur treated oil is stored and from here can be used as heating oil or bunker oil.

The high sulphur precipitate 28 can be used to extract pure sulphur as a raw material. Each refinery has the Claus process for extracting pure sulphur from the sulphurous waste products produced in the processes to make petrol or diesel.

An advantage of the treatment of crude oil or refined oil products with biological additives according to the present invention, is that the sulphur fraction is strongly enriched in the high sulphur precipitate 28 after the second phase of the treatment.

The present invention is by no means limited to the embodiments described as an example and shown in the drawings, but such a device and method for applying said device can be realised according to different variants without departing from the scope of the invention, as is defined in the following claims.