DE102009012507A1 - Process for the desulphurisation of crude oil - Google Patents

Abstract

The invention relates in particular to a process for the desulfurization of crude oil or crude oil. In order to improve the quality of the desulfurization and thus the quality of the oil after desulfurization, it is proposed to use for desulfurization mesophilic, obligate chemolithotrophic microorganisms and / or at least one enzyme system of such microorganisms.

Description

The The invention relates to a process for at least partial desulfurization a petroleum or a refining product of petroleum comprehensive substance.

oil or crude oil is widely known as a fossil energy source. Depending on the deposit contains the crude oil different proportions of sulfur and sulfur compounds. at combustion of sulphurous petroleum products including environmentally harmful sulfur dioxide. Besides that are used in the further processing of petroleum and refining products the same often used sulfur-sensitive catalysts. Especially for these reasons, it is desirable the sulfur content of petroleum or reprocessing products to reduce.

to Desulfurization of petroleum are different procedures known. In the so-called Claus process, sulfur is made using special Catalysts extracted. These are comparatively high temperatures in the range of 300-400 ° C and pressures between 2.5 to 6 MPa required, which comparatively high costs connected is.

Besides such chemical processes, microbial processes for desulfurization are also known. Here, by selective action of microorganisms or their enzyme systems carbon-sulfur compounds of petroleum and the like. Oxidative or reductively cleaved, so that the sulfur can be removed. Exemplary is on the DE 69115507 T2 and on the US 5,002,888 directed.

at The aforementioned method has various disadvantages. Partially In addition to the carbon-sulfur compounds, shares of the Carbon recycled and implemented, resulting in a reduction of the calorific value. Partially it comes with microbial Process for foreign colonization with undesirable microorganisms, thereby reducing the effectiveness of desulfurization and quality losses for the end products be caused. Foreign colonization occurs, for example Consequence of usually taking place under non-sterile conditions Desulphurization on. Quality losses arise even with microorganisms, such as. B. pseudomonads, which too high Biomass formation rates tend.

outgoing It is an object of the invention, the disadvantages of the State of the art to eliminate. In particular, an effective, comparatively inexpensive microbial desulphurization process to be provided.

These The object is solved by the features of the claims 1 and 14. Further developments of the invention will become apparent from the dependent Claims 2 to 13 and 15, 16.

According to the Invention is a process for at least partial desulfurization a petroleum or a refining product of petroleum comprehensive substance. The process involves desulfurization using mesophilic, obligate chemolithotrophic microorganisms and / or at least one enzyme system of such microorganisms. That means that for desulfurization mesophilic, obligate chemolithotrophic microorganisms, at least one enzyme system of such microorganisms or a combination from microorganisms and enzyme system (s). Such Microorganisms can be used under conditions in which Fremdbesiedelungen with unwanted microorganisms at least be suppressed. Furthermore, can be avoided with the proposed microorganisms that the Substance in the desulfurization by the microorganisms themselves energetically utilized.

Under Petroleum is in the context of this invention, in particular crude oil Understood. Be among refining products of petroleum especially petroleum distillates, so-called fractions, understood, which in the further processing and processing of crude oil arise.

at The microorganisms may be bacteria of a pure or mixed culture act. This allows a flexible adaptation of the method the desired degree of desulfurization and the to decompose carbon-sulfur compounds, which u. a. depending on the deposit, d. H. geological Origin of petroleum are. Particularly good desulphurisation results for Petroleum and its reprocessing products could with bacteria of the genus Thiobacillus. Within this genus In turn, particularly advantageous desulphurisation results could be achieved for crude oil and its processing products with the bacterial strains Thiobacillus ferrooxidans, Thiobacillus thiooxidans, Thiobacillus thioparus and Thiobacillus novellus.

As already mentioned, the bacterial strains can be used in pure culture or in mixed culture. It is within the scope of the invention if one or more enzyme systems isolated from such microorganisms are used. The corresponding enzyme systems can be used alone or in combination with microorganisms. The enzyme systems and microorganisms can be selected according to the desired degree of desulfurization and the particular carbon-sulfur compounds present to get voted. Thus, the process can be adapted in a particularly simple manner to different compositions of the petroleum and the workup products.

Especially advantageous desulphurisation results can be achieved when the process is performed in a multiphase system becomes. For example, the method in a three-phase system, comprising a liquid, gaseous and solid Phase, to be performed. It can be the liquid Phase through the substance and the solid phase through the microorganisms and / or enzyme systems are formed. The gaseous phase can be introduced into the substance during desulfurization or air dispersed therein. By introducing air or a suitable other gas can for the microorganisms created suitable growth and environmental conditions so that optimal desulphurisation results are achieved.

The Desulfurization in a multiphase system can be comparatively effective and cost effective way in conventional Bioreactors are performed. Optionally, the multi-phase system an aqueous phase. In this case, the desulfurization at a pH of the aqueous phase in the range between 3 and 6.5 are performed. For those in the acidic pH levels can be detrimental to desulfurization Foreign settlements are at least suppressed.

A particularly high desulfurization efficiency can be achieved by: the microorganisms and / or enzyme systems dispersed in the substance become. Comparable results can be achieved if the microorganisms and / or the enzyme systems on a support material are fixed and the substance comprising the carrier material the desulphurising microorganisms and / or enzyme systems flows around.

It can be used essentially any bioreactors become. In particular, microbial desulphurisation can occur so-called fixed bed reactors in which the microorganisms and / or enzyme systems in a fixed bed, comprising a carrier material, are fixed, and the liquid and gaseous Streams through the fixed bed. The leadership of the individual phases in the bioreactor can after the countercurrent or DC principle. The former will be different Phases, for example, the liquid phase and the gaseous Phase in different, opposite directions through the Bioreactor led. This can, for example, be increased Mixing the phases contribute.

The Intake and / or removal of the individual phases can u. a. dependent of the type of bioreactor used, the respective desulphurisation time, the desired degree of desulfurization and the microbial Desulphurisation efficiency, discontinuous, quasi-continuous or continuously.

For the bacterial strains already mentioned above could in a temperature range between 32 ° C and 36 ° C particularly good desulfurization can be achieved. That is true in particular for a mixing system comprising the bacterial strains Thiobacillus ferrooxidans and Thiobacillus thiooxidans.

All in all it can be stated that mesophilic obligate chemolithotrophe Microorganisms and / or their enzyme systems for desulfurization of petroleum and its work-up products can. In particular, bacteria of the genus come into consideration Thiobacillus. Within this genus have proven to be special suitably exposed pure or mixed cultures of bacterial strains Thiobacillus ferrooxidans, Thiobacillus thiooxidans, Thiobacillus thioparus and Thiobacillus novellus. In particular, such bacterial strains have the advantage of having quality factors, such as the calorific value will not be significantly affected, and that microbial contaminants, e.g. By microbial biomass, be at least largely avoided.

following is an embodiment of the invention, in particular with reference to the attached figure, described in more detail.

to Desulfurization of crude oil or crude oil will become one Mixed culture of the bacterial strains Thiobacillus ferrooxidans and Thiobacillus thiooxidans.

at a variant not shown in the figure is the petroleum Desulfurized crude oil in a bioreactor, the Mixed culture in crude oil or crude oil evenly is dispersed. To supply the bacteria with oxygen at the same time dispersing air in the crude oil or crude oil. The dispersing can be done for example by stirring. Temperatures at The desulphurisation is in the range between 32 ° C and 36 ° C.

In one variant, an aqueous phase may be present during desulfurization. In this case, it is particularly advantageous for the abovementioned microorganisms if the pH of the aqueous phase is in the range between 3 and 6.5. In the aforementioned temperature and pH range, for example, the growth of undesired foreign microorganisms can be suppressed become.

at an embodiment in which reference is made to the figure, the microorganisms and / or enzyme systems thereof are on a carrier fixed. In this case, so-called. Fixed bed reactors can be used in which the crude oil or crude oil, or the liquid phase, in cocurrent or countercurrent to the air can be performed.

The (only) figure shows a fixed bed reactor 1 with a matrix 2 ie, a carrier on which one or more strains of the aforementioned microorganisms are fixed. As indicated in the figure by arrows, the petroleum or crude oil from bottom to top through the matrix 2 , which forms a fixed bed, led. This will be the matrix 2 and the microorganisms fixed thereto flow around the oil or the liquid phase. The microorganisms oxidize or reduce carbon-sulfur compounds contained in the petroleum oil so that the originally contained organic sulfur can be removed. For the growth of microorganisms required oxygen is - not shown - in co-current with petroleum through the fixed bed reactor 1 guided. It should be noted that the oil and the oxygen can also be carried in countercurrent. Apart from that, it is also possible that the fixed bed is sprinkled from above and oxygen is supplied in countercurrent from below. Other process controls are conceivable.

Next Fixed bed reactors can also be any other bioreactor, such as stirred reactors and the like.

ever For example, depending on the type and sulfur content of petroleum Process times between 1 and 8 days into consideration. However, that is Duration of desulfurization to a great extent dependent of the composition of petroleum, the type of bacterial culture used and the respective process parameters such as temperature, pressure and pH.

Of the The fixed bed reactor shown in the figure can be continuous, quasi-continuous or operated discontinuously. This refers the information "continuous" and the like. in particular on the supply and removal of petroleum.

Though The invention was based on the desulfurization of petroleum or crude oil explained. It is understood that that Method also for work-up products made from petroleum or crude oil can be applied. However, it may vary depending on the work-up product be necessary to adjust the process parameters accordingly.

1

Fixed Bed Reactor

2

matrix

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 69115507 T2 [0004]
• US 5002888 [0004]

Claims (16)

Process for at least partial desulphurisation a petroleum or a refining product of petroleum substance, with desulfurization using mesophilic, obligate chemolithotrophic microorganisms and / or at least one Enzyme system of such microorganisms takes place. The method of claim 1, wherein the Microorganisms around bacteria of a pure or mixed culture, preferably of the genus Thiobacillus. The method of claim 2, wherein the bacteria comprises selected from the group: Thiobacillus ferrooxidans, Thiobacillus thiooxidans, Thiobacillus thioparus, Thiobacillus novellus. Method according to one of claims 1 to 3, wherein the desulfurization in a multi-phase system, preferably in a three-phase system. The method of claim 4, comprising an aqueous Phase. The method of claim 5, wherein in the desulfurization the pH of the aqueous phase in the range between 3 and 6.5 is. Method according to one of claims 4 to 6, wherein the multiphase system comprises a gaseous phase, which is preferably formed by dispersed air. Method according to one of claims 1 to 7, wherein the microorganisms and / or enzyme systems are dispersed. Method according to one of claims 1 to 7, wherein the microorganisms on a carrier material ( 2 ) are fixed. Method according to one of claims 1 to 9, wherein the desulfurization takes place in a bioreactor. Process according to Claim 10, in which the desulfurization is carried out in a co-current or countercurrent bioreactor, in particular a fixed bed reactor ( 1 ), he follows. Method according to one of claims 10 or 11, the desulfurization taking discontinuous, quasi-continuous or continuous conditions. Method according to one of claims 1 to 12, the desulfurization in a temperature range of 32 ° C to 36 ° C is performed. Use of mesophilic chemolithotrophic microorganisms and / or enzyme systems of such microorganisms in a process for the desulphurisation of a petroleum or a reprocessing product petroleum-containing substance. Use according to claim 14, wherein the Microorganisms around bacteria of the genus Thiobacillus, preferably Thiobacillus ferrooxidans, Thiobacillus thiooxidans, Thiobacillus thioparus and / or Thiobacillus novellus. Use according to claim 15, wherein the Microorganisms to a pure culture or a mixed culture, preferably a mixed culture of Thiobacillus ferrooxidans and Thiobacillus thiooxidans, acts.