JP2003201484A - Method for electrobiologically desulfurizing petroleum - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive and a safe method for electrobiologically desulfurizing petroleum. <P>SOLUTION: This method for desulfurizing petroleum is provided by bringing anerobic sulfur-oxidizing bacteria in contact with petroleum under an anerobic condition or a slightly aerobic condition. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for reducing the sulfur content in crude oil and petroleum products at room temperature under anaerobic or microaerobic conditions.

[0002]

2. Description of the Related Art From the viewpoint of protecting the global environment, the desulfurization of petroleum is more and more necessary. There are a wide variety of sulfur compounds that exist in crude oil and need to be removed, but there are many sulfides (RS-R's) such as alkyl sulfides, and the main components are the marcaptans (R-SH) and alkyl-thiophenes. Is. Sulfur content depends on the crude oil. With the increase in the amount of crude oil mined, high-quality crude oil (low sulfur content) is becoming rare and expensive. Heavy crude oil with a high sulfur content is inexpensive, but it is difficult to use due to the increased addition of sulfur to the petroleum refining process and the possible environmental impact.

In the current oil refining process, cobalt
A hydrodesulfurization method using a catalyst such as molybdenum is used (for example, US5897768: Desulfurization process for
removal of refractory organosulfur heterocycles f
rom petroleum streams). In recent years, regulations on exhaust gas from diesel vehicles have been tightened, and it has become necessary to reduce sulfur content in light oil. Technological development of treatment (deep desulfurization) that can cope with this is progressing, but for that purpose, a more expensive and high energy use process is required.

[0004] In an attempt to overcome the difficulty of desulfurization based on chemical reaction, so-called biodesulfurization utilizing the enzymatic reaction of microorganisms has also been proposed (eg US5919683: Rho
dococcus flavin reductase complementing DSZA and D
SZC activity). However, since conventional biodesulfurization is an aerobic process that requires oxygen, there is concern that an explosive mixture of volatile hydrocarbons and oxygen will be produced. Therefore, the reaction vessel used for biodesulfurization must be robust and expensive. Because of this, biodesulfurization has not become a commercial process.

[0005]

If a microorganism capable of anaerobically or slightly aerobically desulfurizing petroleum is found, it is much cheaper and safer than conventional chemical and biological methods. The law can be developed. For example, this method allows desulfurization of crude oil and petroleum products during transport by tankers and storage in tanks. An object of the present invention is to provide a new petroleum desulfurization method using a microorganism that grows while desulfurizing petroleum under anaerobic conditions.

[0006]

Means for Solving the Problems As a result of extensive studies to solve the above problems, the present inventors have found that bacteria capable of growing even under anaerobic conditions contain sulfur under anaerobic or microaerobic conditions. When crude oil or diesel oil is layered on a non-existent culture solution,
It was found that it grows while producing sulfuric acid in the culture solution,
The present invention has been completed.

In other words, the present invention is a method for desulfurizing petroleum which comprises contacting anaerobic sulfur-oxidizing bacteria with petroleum under anaerobic or microaerobic conditions.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.

The method for desulfurizing petroleum of the present invention is to bring anaerobic sulfur-oxidizing bacteria into contact with petroleum under anaerobic or microaerobic conditions.

The anaerobic sulfur-oxidizing bacterium means that a substance other than oxygen, such as nitric acid or ferric iron (Fe ³⁺ ) is used as an electron acceptor under anaerobic conditions, or under microaerobic conditions (for example, Oxygen is used as an electron acceptor under the condition that the oxygen in the gas phase is 1% or less), and at the same time, a sulfur compound (for example, sulfide, elemental sulfur, thiosulfuric acid, thiocyanic acid, organic sulfur compound, etc.) is used as an electron donor. Bacteria that can grow while being used as.

The bacterium used in the desulfurization method of the present invention is not limited as long as it is a bacterium corresponding to the above definition of anaerobic sulfur-oxidizing bacterium, but it is preferable to use a bacterium belonging to ε proteobacteria. ( Thiomicrospi
More preferably, a bacterium belonging to the genus ra ) or the genus Sulfuricurvum is used. More specifically, the YK-1 strain isolated from a crude oil storage tank (this strain has been deposited at the Patent Microorganism Depositary Center, National Institute of Advanced Industrial Science and Technology, under the deposit number FERM P-17620.
Deposit date: October 26, 1999) and isolated from oilfield saltwater
Thiomicrospira sp. CVO strain (Diane Gevertz, Anita J. T
elang, Gerrit Voordouw, and Gary E. Jenneman. 200
0. Isolation and Characterization of Strains CVO a
nd FWKO B, Two Novel Nitrate-Reducing, Sulfide-Oxi
dizing Bacteria Isolated from OilField Brine. App
66.2491-2501), etc. can be used. Further, not only the YK-1 strain but also its similar strain can be used. As "similar strain of YK-1 strain",
For example, a 16S rR represented by a nucleotide sequence having 90% or more homology with the nucleotide sequence of the 16S rRNA gene of the YK-1 strain (shown in SEQ ID NO: 1)
An example is a strain having the NA gene. The homology of the 16S rRNA gene between the YK-1 strain and its similar strain may be 90% or more, preferably 92% or more, more preferably 95% or more, and 100% homology. Is most preferred.

Petroleum refers to petroleum products such as heavy oil, light oil, kerosene, gasoline, and crude oil.

Since the desulfurization method of the present invention is carried out under anaerobic conditions or microaerobic conditions, unlike the conventional biodesulfurization methods, aeration is not required.

The method of contacting the anaerobic sulfur-oxidizing bacteria with petroleum is not particularly limited, and for example, an inorganic medium containing no electron donor such as a sulfur compound (eg, MBM medium) is inoculated with the anaerobic sulfur-oxidizing bacteria. The method of layering petroleum on which desulfurization is performed can be exemplified. This method can be used for desulfurization in storage tanks and transport tankers. in this way,
Oxygen in the medium is consumed at an early stage of the culture and then becomes anaerobic, so that it is possible to create anaerobic or microaerobic conditions without any special operation, but titanium citrate (Zehnder AJ , Wuhrmann K. 1976. Titanium
(III) citrateas a nontoxic oxidation-reduction bu
ffering system for the culture of obligate anaerob
es. Science 194: 1165-1166.) and ascorbic acid (Rabu
s, R., and F. Widdel. 1996. Utilization of alkylben
zenes during anaerobic growth of pure cultures of
denitrifying bacteria on crude oil. Appl. Environ.
Microbiol. 62: 1238-1241.) May be added to the medium to make it anaerobic. If necessary, this may be stirred to improve the contact between petroleum and the culture solution. Sulfate ions generated in the culture solution in the desulfurization process may be precipitated in the form of calcium sulfate, barium sulfate or the like, or may be recovered and removed using an ion exchange resin or the like.

Further, in an underground petroleum storage tank or the like, anaerobic sulfur-oxidizing bacteria are activated by injecting the electron acceptor and other nutrients as described above into the groundwater accumulated under the oil in the storage tank. And desulfurization may be performed.

[0016]

Example: YK-1 strain was grown in MBM medium (Table 1) using sodium sulfide (2 mM) as an electron donor.

[0017]

[Table 1] * SL-4 is DSM (German Collection of Microorganisms an
d Cell Cultures) catalog. The cells were collected by centrifugation, washed with sterile water, and then washed with a new MBM.
The cells were inoculated into 10 ml of the medium. Titanium citrate method (Z
ehnder AJ, Wuhrmann K. 1976. Titanium (III) citrat
e as a nontoxic oxidation-reduction buffering syst
em for theculture of obligate anaerobes. Science 1
94: 1165-1166.) And then overlaid with 5 ml of crude oil (Arabian light) or diesel oil (JOMO).
This was put into a glass bottle (33 ml) equipped with a butyl rubber stopper, the gas phase was filled with nitrogen, and the mixture was gently shaken. The culture solution was sampled with a syringe at appropriate time, and the bacterial concentration was measured by DAPI fluorescence microscopy (Wa
tanabe, K., M. Teramoto, and S. Harayama. 1999. An
outbreak of nonflocculating catabolic populations
caused the breakdown of a phenol-digesting activa
ted-sludge process. Appl. Environ. Microbiol. 65: 2
813-2819), the sulfuric acid concentration was measured by an ion chromatography method (IA-100 ion analyzer, Toa DKK).

The results are shown in FIG. In this experiment, YK
-Sulfuric acid was produced in the aqueous layer (in the culture solution) with the growth of strain -1. Since the medium contains no sulfur component, it is considered that this sulfur is derived from crude oil or diesel oil. In addition, in the control experiment without inoculation, the production of sulfuric acid was not observed, which indicated that crude oil or diesel oil contained sulfuric acid and was not simply eluted. The diesel oil used is commercially available and is chemically desulfurized. Therefore, it was suggested that the anaerobic desulfurization method can desulfurize the sulfur components that could not be completely removed by the chemical desulfurization treatment.

[0019]

INDUSTRIAL APPLICABILITY The present invention provides a novel desulfurization method using microorganisms. Since this desulfurization method does not include an aerobic process, there is no concern about the formation of an explosive mixture resulting from the mixing of volatile hydrocarbons and oxygen, and it is possible to perform desulfurization of petroleum products inexpensively and safely. is there.

[0020]

[Sequence list]                               SEQUENCE LISTING       <110> MARINE BIOTECHOLOGY INSTITUTE CO., LTD. <120> METHOD OF ANAEROBIC BIO-DESULFURIZATION OF PETROLEUM <130> P01-074 <160> 1 <170> PatentIn Ver. 2.0 <210> 1 <211> 1438 <212> DNA <213> Unknown <400> 1 tggcggcgtg cctaacacat gcaagtcgaa cgatgatagg aagcttgctt ccttgattag 60 tggcgcacgg gtgagtatac catagataat gtacctctta gttcgggata gccactggaa 120 acggtgatta ataccggata ctccttcttg tcttaaggcg agtcgggaaa gttttttcgc 180 taagagatca gtctatgtcc tatcagctag ttggtgaggt aatggctcac caaggctatg 240 acgggtatct ggtttgagag gatgatcaga cacactggaa ctgagacacg gtccagactc 300 ctacgggagg cagcagtgag gaatattgca caatggagga aactctgatg cagcaacgcc 360 gcgtggagga tgacgcattt cggtgtgtaa actcctttta agagggaaga taatgacggt 420 acctcttgaa taagcaccgg ctaactccgt gccagcagcc gcggtaatac ggagggtgca 480 agcgttactc ggaatcactg ggcgtaaagg gtgcgtaggc tggcttctaa gtcagatgtg 540 aaatccaatg gcttaaccat tgaactgcat ttgaaactgg gagcctagag ttcagaaggg 600 gcagatggaa ttagtggtgt aggggtaaaa tccgtagata tcactaggaa tatcaaaagc 660 gaaggcgatc tgctgggatg atactgacgc tgaggcacga aagcgtgggg agcaaacagg 720 attagatacc ctggtagtcc acgccctaaa cgatgaatgc tagtcgtcgg ggagctcgtc 780 tcttcggtga tgcacttaac agattaagca ttccgcctgg ggagtacggt cgcaagatta 840 aaactcaaag gaatagacgg ggacccgcac aagtggtgga gcatgtggtt taattcgaag 900 atacacgaag aaccttacct ggccttgaca tggtaggaac ccttaagaga ttagggggtg 960 ctagcttgct agaacctaca cacaggtgct gcacggctgt cgtcagctcg tgtcgtgaga 1020 tgttgggtta agtcccgcaa cgagcgcaac cctcgtcttt agttgctaac agtttggctg 1080 agcactctaa agagactgcc ttcgtaagga ggaggaaggt gaggacgacg tcaagtcatc 1140 atggccctta cggccagggc tacacacgtg ctacaatggg gcgtacaaag agctgcaata 1200 ccgcgaggtg gagccaatct cttaaagcgt ctctcagttc ggattgttct ctgcaactcg 1260 agaacatgaa gctggaatca ctagtaatcg tagatcagct atgctacggt gaatacgttc 1320 ccgggtcttg tactcaccgc ccgtcacacc atgggagttg atttcacccg aaatcgggat 1380 gccaaactgg ctaccgctta cggtggaatt agcgactggg gtgaagtcgt aacaaggt 1438

[Brief description of drawings]

FIG. 1 is a diagram showing the results of an anaerobic desulfurization experiment of Arabian light crude oil and diesel oil using YK-1 strain.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kazuya Watanabe             75-1 Stock Exchange, Hirata District 3 Kamaishi City, Iwate Prefecture             Marine Biotechnology Research Institute Kamaishi Research             In-house (72) Inventor Shigeaki Harayama             75-1 Stock Exchange, Hirata District 3 Kamaishi City, Iwate Prefecture             Marine Biotechnology Research Institute Kamaishi Research             In-house F-term (reference) 4B024 AA03 CA02 HA20                 4B065 AA01 AC20 CA54

Claims (5)

[Claims] 1. A method for desulfurizing petroleum, which comprises contacting anaerobic sulfur-oxidizing bacteria with petroleum under anaerobic or microaerobic conditions. 2. The contact between the anaerobic sulfur-oxidizing bacteria and the petroleum is to inoculate the medium containing no electron donor with the anaerobic sulfur-forming bacteria and overlay the petroleum on the medium. 1. The method for desulfurizing petroleum according to 1. 3. The method for desulfurizing petroleum according to claim 1, wherein the anaerobic sulfur-oxidizing bacterium is a bacterium belonging to ε-proteobacteria. 4. The method for desulfurizing petroleum according to claim 1 or 2, wherein the anaerobic sulfur-oxidizing bacterium is a bacterium belonging to the genus Thiomiclospira or the genus Sulflibacarb. 5. The method for desulfurizing petroleum according to claim 1, wherein the anaerobic sulfur-oxidizing bacterium is YK-1 strain or a similar strain thereof.