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EP-4022033-B1 - BACTERIAL OIL TREATMENT COMPOSITION FOR HANDLING A DECOMMISSIONED OIL CABLE

EP4022033B1EP 4022033 B1EP4022033 B1EP 4022033B1EP-4022033-B1

Inventors

  • STAEDLER, Davide
  • SPINETTI, Thibaud
  • TORRIANI, Marco

Dates

Publication Date
20260513
Application Date
20200729

Claims (5)

  1. A bacterial growth culture medium for hosting a bacterial oil treatment composition for the biodegradation of oil in a decommissioned oil cable and/or for the production of bio-surfactants in a decommissioned oil cable comprising a bacteria community consisting of 20% of Pseudomonas fluorescens, 40% of Bacillus subtilis, 30% of Bacillus licheniformis and 10% of Rhodococcus rhodochrous, characterized in that said bacterial growth culture medium comprises water and standard salts selected from the group comprising NH4Cl, NH4NO3, K2HPO4, KH2PO4, Na2HPO4, MgSO4*7H2O, FeSO4*7H2O and NaNO3; characterized in that said bacterial growth culture medium further comprises: a) an organic started mix selected from the group comprising yeast extracts, malt extract, cane molasses and methyl-β-cyclodextrin, wherein the composition of 1 litre of organic started mix comprises: 40 g/L of yeast extract; 40 g/L of malt extract; 100 g/L of cane molasses; and 1 g/L of methyl-β-cyclodextrin; b) a biocompatible antifoam mix selected from the group comprising Na2EDTA, polydimethylsiloxane, simethicone and rapeseed oil, wherein the composition of 1 litre of biocompatible antifoam mix comprises: 500 mg/L of Na2EDTA; 200 g/L of polydimethylsiloxane; 50 g/L of simethicone; and 100 mL/L of rapeseed oil; and c) a mix of essential amino-acids selected from the group of branched-chain amino acid comprising: Na Leucine, Na Valine, Na Isoleucine and Na Glutamate at a ratio 1:1:1:1 in combination with a mix of nitrogen fertilizers selected from the group comprising: urea, uric acid and water soluble lecithin at a ratio 2:1:1, wherein the composition of 1 litre of mix of essential amino-acids and nitrogen fertilizers comprises: 1-500 mg/L of the mix of branched-chain amino acid; 1-500 mg/L of Na glutamate; 1-500 mg/L of uric acid; 1-500 mg/L of urea; and, 1-500 mg/L of water soluble lecithin.
  2. The bacterial growth culture medium according to claim 1, wherein 1 litre of said bacterial growth culture medium comprises: 0.05-8 g/L of the bio-compatible antifoam mix; 5-200 g/L of the organic started mix; 0.5-20 g/L of the mix of essential amino-acids and nitrogen fertilizers, and wherein the final volume is adjusted to 1 litre with water and standard salts selected from the group comprising NH4Cl, NH4NO3, K2HPO4, KH2PO4, Na2HPO4, MgSO4*7H2O, FeSO4*7H2O and NaNO3.
  3. A bacterial oil treatment containing liquid for the biodegradation of oil in a decommissioned oil cable and/or for the production of bio-surfactants in a decommissioned oil cable, characterized in that said bacterial oil treatment containing liquid comprises a bacterial oil treatment composition for the biodegradation of oil in a decommissioned oil cable and/or for the production of bio-surfactants in a decommissioned oil cable comprising a bacteria community consisting of 20% of Pseudomonas fluorescens, 40% of Bacillus subtilis, 30% of Bacillus licheniformis and 10% of Rhodococcus rhodochrous and the bacterial growth culture medium according to any of claims 1-2.
  4. The bacterial oil treatment containing liquid according to claim 3, wherein the bacterial oil treatment containing liquid further comprises a defoamer.
  5. Use of the bacterial oil treatment containing liquid according to any of claims 3-4, for the biodegradation of oil in a decommissioned oil cable and/or for the production of bio-surfactants in a decommissioned oil cable, wherein said bacterial oil treatment containing liquid is capable of removing the oil contained in said decommissioned oil cable.

Description

FIELD OF THE INVENTION The invention relates to an improved bacterial oil treatment composition or pool for handling a decommissioned oil cable, which may be laid in particular as part of a power grid in the ground, lakes and sea. The present invention further relates to an adapted or tailored bacteria growth culture medium containing said bacterial oil treatment composition for refurbishing an oil cable and a corresponding use thereof. BACKGROUND OF THE INVENTION Since the 1930s, utilities have used oil cables in their power grids, especially for low voltage, medium voltage and high voltage. Oil cables are used in particular in the voltage range of 10 to 500 kV. The oil cables are usually laid in the ground, especially in the soil, lakes and sea. An oil cable has one or more electrical conductors within an outer shell. For isolating the electrical conductors from each other and from the outer shell, the electrical conductors are surrounded on the one hand by a respective oil-soaked matrix, for example of paper. On the other hand, gaps between the electrical conductors are filled with each other and between the electrical conductors and the outer shell with oil, which is continuously pumped through the oil cable during operation of the oil cable. These spaces thus form an oil channel. The oil in the matrices and the oil in the oil channel cause a particularly uniform electrical insulation, because inhomogeneities of the remaining insulation can be compensated by the typically thin liquid and dielectric oil. Without the oil, uneven performance of the remaining insulation, along with trapped air and / or dirt, could lead to localized increases in electrical field strength with partial discharges that could damage the oil cable. The oil in an oil cable poses a potential ecological hazard. If an oil cable is damaged, escaping oil can lead to environmental pollution, in particular by the oil getting into the groundwater. Since about the 1990s, therefore, alternatives to oil cables are increasingly used, such as cables with insulation made of cross-linked polyethylene. Unused oil cables are taken out of service accordingly. The oil can be pumped out of the oil channel. However, oil remains in the matrices. For example, 50% of the oil that is in an oil cable during operation may remain in the dies. Thus, oil cables pose a potential hazard to the environment even after decommissioning. Therefore, for example, in Germany it is legally required to monitor oil cables even after decommissioning, for example electronically and / or hydraulically. In Germany, for example, the Ordinance on Installations for the Handling of Substances Hazardous to Water (AwSV) contains corresponding specifications. Such monitoring can detect damage to an oil cable and thus limit the damage to the environment. However, environmental pollution in the event of damage to an oil cable cannot be ruled out. Furthermore, the monitoring causes significant costs for the public authorities. These costs are no longer useful in decommissioned oil cables. Also, these costs are ongoing costs, which in principle are incurred indefinitely. It would be conceivable to remove unneeded oil cables from the ground. But if, for example, a road surface has to be opened, this can cost millions. Compared to this, the costs of monitoring are often lower. The opening of a road surface can also cause restrictions for the population, for example due to traffic congestion or noise. WO 2015/191582 A1 (BIOWISH TECHNOLOGIES INC [US]) relates to microbial compositions and a process for reducing hydrocarbon contamination. The composition for hydrocarbon remediation, comprising a microbial mixture of Bacillus and Pseudomonas organisms, wherein each of the organisms, in the mixture is individually aerobically fermented, harvested, dried, and ground to produce a powder having a mean particle size of about 200 microns, with greater than about 60% of the mixture in the size range between 100-800 microns. Also disclosed is a process for remediating an oil contaminated substrates comprising: a) grinding the substrate to a particle size less than 1000 microns to produce a ground substrate; b) adding the ground substrate to an aqueous solution comprising a microbial mixture of Bacillus, Pseudomonas, and a nitrogen source to produce a solution and c) stirring the solution for up to 72 hours. KR 2015 0062130 A (UNIV INJE IND ACAD COOPERATION [KR]) relates to a strain Bacillus pumilus IJ-1 capable of decomposing oil; and, more specifically, to a method for culturing Bacillus pumilus IJ-1 which is capable of decomposing oil and produces a bio surfactant. The strain Bacillus pumilus IJ-1 of this invention has excellent capability of decomposing oil such as crude oil, gasoline, kerosene, and diesel and furthermore has capability of producing the bio surfactant. According to the invention, an optimal culture condition for growth of Bacillus pumilus IJ-1 and for producing the bio surfactant i