Odorized methane fluid and processes for producing odorized methane fluids and the use thereof

Abstract

An odorized methane comprising fluid has an odorant and a carrier. The odorant is ethyl acrylate and/or ethyl mercaptan. The carrier is propane, n-butane, iso-butane, or a mixture of two or more thereof. The odorized methane-comprising fluid may be prepared by adding the odorant and the carrier separately or pre-mixed to a methane comprising liquid or slush.

Claims

1. An odorized methane comprising fluid comprising: a methane comprising fluid, an odorant in a range of from 1 to 100 ppm, and a carrier in a range of from 0.1 to 10 m/m %, calculated on the total mass of the odorized methane comprising fluid; whereby the carrier is propane, n-butane, iso-butane, or a mixture of two or more thereof, and whereby the odorant is ethyl acrylate, ethyl mercaptan, or a mixture thereof, and whereby the odorized methane comprising fluid is a liquid, or a slush of liquid and solids.

2. The odorized methane comprising fluid according to claim 1, whereby the odorized methane comprising fluid comprises 2 to 10 ppm odorant, calculated on the total mass of the odorized methane comprising fluid.

3. The odorized methane comprising fluid according to claim 2, whereby the odorized methane comprising fluid comprises 4 to 6 ppm odorant, calculated on the total mass of the odorized methane comprising fluid.

4. The odorized methane comprising fluid according to claim 1, whereby the carrier is iso-butane.

5. The odorized methane comprising fluid according to claim 1, whereby the odorant is ethyl acrylate or a mixture of ethyl acrylate and ethyl mercaptan.

6. The odorized methane comprising fluid according to claim 1, whereby the odorized methane comprising fluid additionally comprises methyl acetate in a range of from 1 to 250 ppm, calculated on the total mass of the odorized methane comprising fluid.

7. The odorized methane comprising fluid according to claim 1, wherein the odorized methane comprising fluid is at a temperature in the range of from 62 C. to 185 C., and at a pressure in the range of from 20 mbara to 120 bara.

8. The odorized methane comprising fluid according to claim 1, wherein the odorized methane comprising fluid is at a temperature in the range of from 62 C. to 185 C. and at a pressure of from 250 mbara to 76 bara.

9. A process for preparing an odorized methane comprising fluid, the process comprising the following step: a) adding an odorant in range of from 1 to 100 ppm and a carrier in a range of from 0.1 to 10 m/m % to a methane comprising liquid, or to a methane comprising slush of liquid and solids, whereby the odorant and carrier are added separately and/or mixed, whereby the carrier is propane, n-butane, iso-butane, or a mixture of two or more thereof, and whereby the odorant is ethyl acrylate, ethyl mercaptan, or a mixture thereof.

10. The process according to claim 9, comprising the following steps: a1) adding the odorant to the carrier, and a2) adding at least a part of the mixture obtained in step a1) to the methane comprising liquid, or to the methane comprising slush of liquid and solids.

11. The process according to claim 9, wherein methyl acetate in a range of from 1 to 250 ppm is added separately and/or mixed with the odorant and/or the carrier to the methane comprising liquid, or to the methane comprising slush of liquid and solids.

12. The process according to claim 9, wherein a stream comprising the odorant is added to a gas stream, a liquid stream, or a stream of a slush of liquid and solids, using a flow controller or an injection pump and a PLC (programmable logic controller).

13. The process according to claim 9, wherein the liquid or slush comprising methane is at a temperature in the range of from 62 C. to 185 C., and at a pressure in the range of from 20 mbara to 120 bara.

14. The process according to claim 9, wherein the liquid or slush comprising methane is at a temperature in the range of from 62 C. to 185 C., and at a pressure in the range of from 250 mbara to 76 bara.

15. A process for preparing an odorized methane comprising fluid, the process comprising the following steps: a) adding an odorant in a range of from 1 to 100 ppm and a carrier in a range of from 0.1 to 10 m/m % to a methane comprising gas, whereby the odorant and carrier are added separately and/or mixed, whereby the carrier is propane, n-butane, iso-butane, or a mixture of two or more thereof, and whereby the odorant is ethyl acrylate, ethyl mercaptan, or a mixture thereof, and whereby the methane comprising gas is at a temperature in a range of from 40 to +200 C., and; b) liquefying the mixture obtained in step a) to a temperature in a range of from 62 C. to 185 C. and a pressure in the range of from 20 mbara to 120 bara.

16. The process according to claim 15, comprising the following steps: a1) adding the odorant to the carrier, a2) adding at least a part of the mixture obtained in step a1) to the methane comprising gas, and b) liquefying the mixture obtained in step a2) to a temperature in the range of from 62 C. to 185 C. and a pressure in the range of from 20 mbara to 120 bara.

17. The process according to claim 15, wherein in the range of from 1 to 250 ppm methyl acetate is added to methane comprising gas by separately adding and/or by mixing with the odorant and/or the carrier.

18. The process according to claim 15, wherein the methane comprising gas is at a temperature in the range of from 25 to +85 C.

19. The process according to claim 15, wherein the pressure in step (b) is in a range from 250 mbara to 76 bara.

20. A fuel for automotive industry, marine industry, or for power generation, comprising an odorized methane comprising fluid according to claim 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

(1) The invention relates to an odorized methane comprising fluid, and processes for producing odorized methane comprising fluids, and the use thereof. The invention especially relates to odorized LNG, processes for producing odorized LNG, and the use of odorized LNG. The odorant, and optionally a tracer, may, for example, be added at natural gas production facilities, at an LNG terminal, or at a retail station. The odorant, and optionally a tracer, may be added to a methane comprising fluid before or after liquefaction.

(2) Odorized Methane Comprising Liquid or Slush

(3) The present invention relates to an odorized methane comprising liquid, and to an odorized methane comprising slush of liquid and solids. The invention especially relates to odorized LNG, whereby the LNG can be a liquid, or a slush of liquid and solids.

(4) The present invention relates to an odorized methane comprising fluid comprising: a methane comprising fluid, in the range of from 1 to 100 ppm of an odorant, and in the range of from 0.1 to 10 m/m % of a carrier, calculated on the total mass of the odorized methane comprising fluid. The carrier is propane, n-butane, iso-butane, or a mixture of two or more thereof. The odorant is ethyl acrylate, ethyl mercaptan, or a mixture thereof. The odorized methane comprising fluid is a liquid, or a slush of liquid and solids. The odorized methane comprising fluid preferably is at a temperature in the range of from 62 C. to 185 C., and at a pressure in the range of from 20 mbara to 120 bara, preferably 250 mbara to 76 bara.

(5) Odorant and carrier preferably are used in a ratio of from 1:20 to 1:50000, more preferably 1:100 to 1:5000, even more preferably 1:650 to 1:1500.

(6) Preferably the odorized methane comprising fluid comprises 2 to 10 ppm odorant, and preferably 0.2 to 1 m/m % carrier, calculated on the total mass of the odorized methane comprising fluid.

(7) More preferably the odorized methane comprising fluid comprises 4 to 6 ppm odorant, and preferably 0.4 to 0.6 m/m % carrier, calculated on the total mass of the odorized methane comprising fluid.

(8) Preferably the carrier is iso-butane.

(9) Preferably the odorant is ethyl acrylate or a mixture of ethyl acrylate and ethyl mercaptan.

(10) In a preferred embodiment the odorized methane comprising fluid according to the invention additionally comprises a tracer. A tracer compound may be used as a kind of fingerprint. It may, for example, be used to indicate the source of the methane comprising fluid. Alternatively, it may be used to indicate the purpose of the methane comprising fluid, for example for domestic use or for industrial use. The presence of a tracer in a methane comprising fluid may be determined by means of any suitable commonly used gas detector.

(11) A highly suitable tracer is methyl acetate. Preferably the odorized methane comprising fluid comprises in the range of from 1 to 250 ppm, more preferably 1 to 100 ppm, even more preferably 1 to 50 ppm methyl acetate, calculated on the total mass of the odorized methane comprising fluid.

(12) Process in which Odorant is Added to Liquid or Slush

(13) The present invention also relates to a process in which odorant is added to a methane comprising liquid or slush. Preferably a labelled methane comprising liquid or slush according to the invention is obtained. All embodiments of the labelled methane comprising liquid or slush as described above can be obtained with this process.

(14) The invention relates to a process for preparing an odorized methane comprising fluid, in the range of from 1 to 100 ppm of an odorant, and in the range of from 0.1 to 10 m/m % of a carrier. The process comprises the following step:

(15) a) adding odorant and carrier to a methane comprising liquid, or a methane comprising slush of liquid and solids. The odorant and carrier are added separately and/or mixed. The carrier is propane, n-butane, iso-butane, or a mixture of two or more thereof. The odorant is ethyl acrylate, ethyl mercaptan, or a mixture thereof. The liquid or slush comprising methane preferably is at a temperature in the range of from 62 C. to 185 C., and at a pressure in the range of from 20 mbara to 120 bara, preferably 250 mbara to 76 bara.

(16) Odorant and carrier preferably are used in a ratio of from 1:20 to 1:50000, more preferably 1:100 to 1:5000, even more preferably 1:650 to 1:1500.

(17) Preferably the obtained odorized methane comprising fluid comprises 2 to 10 ppm odorant, and preferably 0.2 to 1 m/m % carrier, calculated on the total mass of the odorized methane comprising fluid.

(18) Preferably the obtained odorized methane comprising fluid comprising fluid comprises 4 to 6 ppm odorant, and preferably 0.4 to 0.6 m/m % carrier, calculated on the total mass of the odorized methane comprising fluid.

(19) Preferably the carrier is iso-butane.

(20) Preferably odorant is ethyl acrylate or a mixture of ethyl acrylate and ethyl mercaptan.

(21) Preferably step a) of the process is performed by:

(22) a1) adding odorant to carrier, and

(23) a2) adding at least a part of the mixture obtained in step a1) to a methane comprising liquid, or a methane comprising slush of liquid and solids.

(24) In a preferred embodiment the process of the invention a tracer is added in addition to the odorant and the carrier. A highly suitable tracer is methyl acetate.

(25) Preferably in the range of from 1 to 250 ppm, more preferably 1 to 100 ppm, even more preferably 1 to 50 ppm methyl acetate is added separately and/or mixed with odorant and/or carrier to a methane comprising liquid, or a methane comprising slush of liquid and solids.

(26) Preferably a stream comprising odorant is added to a gas stream, a liquid stream, or a stream of a slush of liquid and solids, using a flow controller, e.g. a control valve, or an injection pump, e.g. a fixed volume injection pump, and a PLC (programmable logic controller).

(27) Process in which Odorant is Added to Gas, Followed by Liquefaction

(28) The present invention also relates to a process for preparing such an odorized liquid or slush by liquefying odorized methane comprising gas. Preferably a labelled methane comprising liquid or slush according to the invention is obtained. All embodiments of the labelled methane comprising liquid or slush as described above can be obtained with this process.

(29) The invention relates to a process for preparing an odorized methane comprising fluid comprising in the range of from 1 to 100 ppm of an odorant, and in the range of from 0.1 to 10 m/m % of a carrier. The process comprises the following steps:

(30) a) adding odorant and carrier to a methane comprising gas, whereby the odorant and carrier are added separately and/or mixed, and

(31) whereby the carrier is propane, n-butane, iso-butane, or a mixture of two or more thereof, and

(32) whereby the odorant is ethyl acrylate, ethyl mercaptan, or a mixture thereof, and

(33) whereby the methane comprising gas preferably is at a temperature in the range of from 40 to +200 C., more preferably 25 to +85 C., and;

(34) b) liquefying the mixture obtained in step a) to a temperature in the range of from 62 C. to 185 C. and a pressure in the range of from 20 mbara to 120 bara, preferably 250 mbara to 76 bara.

(35) Odorant and carrier preferably are used in a ratio of from 1:20 to 1:50000, more preferably 1:100 to 1:5000, even more preferably 1:650 to 1:1500.

(36) Preferably the obtained odorized methane comprising fluid comprises 2 to 10 ppm odorant, and preferably 0.2 to 1 m/m % carrier, calculated on the total mass of the odorized methane comprising fluid.

(37) Preferably the obtained odorized methane comprising fluid comprising fluid comprises 4 to 6 ppm odorant, and preferably 0.4 to 0.6 m/m % carrier, calculated on the total mass of the odorized methane comprising fluid.

(38) Preferably the carrier is iso-butane.

(39) Preferably odorant is ethyl acrylate or a mixture of ethyl acrylate and ethyl mercaptan.

(40) Preferably steps a) and b) of the process are performed by:

(41) a1) adding odorant to carrier, and

(42) a2) adding at least a part of the mixture obtained in step a1) to a methane comprising gas,

(43) whereby the methane comprising gas preferably is at a temperature in the range of from 40 to +200 C., more preferably 25 to +85 C., and

(44) b) liquefying the mixture obtained in step a2) to a temperature in the range of from 62 C. to 185 C. and a pressure in the range of from 20 mbara to 120 bara, preferably 250 mbara to 76 bara.

(45) In a preferred embodiment the process of the invention a tracer is added in addition to the odorant and the carrier. A highly suitable tracer is methyl acetate.

(46) Preferably in the range of from 1 to 250 ppm, preferably 1 to 100 ppm, more preferably 1 to 50 ppm methyl acetate is added separately and/or mixed with odorant and/or carrier to the methane comprising gas.

(47) Preferably a stream comprising odorant is added to a gas stream, a liquid stream, or a stream of a slush of liquid and solids, using a flow controller, e.g. a control valve, or an injection pump, e.g. a fixed volume injection pump, and a PLC (programmable logic controller).

(48) Use

(49) The invention further relates to the use of an odorized methane comprising fluid according to the invention, or prepared in a process according to the invention, as fuel in automotive industry, marine industry, or for power generation.

EXAMPLES

(50) Odorized LNG samples were prepared according to the invention. Natural gas was odorized, followed by liquefaction in a cryostat. The odorized natural gas was analyzed before and after liquefaction. Also comparative samples were prepared by using a different odorant, or by only adding a tracer.

(51) The results are summarized in the following tables.

(52) Sample Preparation:

(53) TABLE-US-00001 Concentration in Concentration liquid phase added to after natural gas liquefaction Sample Odorant [ppm] [ppb] A Ethyl acrylate 5 550 12% RSD B Ethyl acrylate 5 5000 2.6% RSD C Methyl acrylate 5 350 8% RSD D Methyl acetate 5 4000 20% RSD E t-butyl mercaptan 1 1000 20% RSD F t-butyl mercaptan 5 2063 20% RSD G diethyl sulphide 5 4550 4% RSD H ethyl mercaptan 1 969 3.8% RSD I ethyl mercaptan 5 4803 4.6% RSD J dimethyl ether 5000 500000 17% RSD

(54) From the sample preparation follows that some odorants do not dissolve well at very low temperatures. They crystallize out.

(55) Measurements were performed on the odorized natural gas before liquefaction. In other words, measurements were performed on odorized NG. The measurements were performed using a gas detector and by smelling.

(56) Measurements on Odorized Natural Gas Using a Gas Cylinder:

(57) TABLE-US-00002 Amount of odorant (using Odor at 20% Sample gas detector) [ppm] LEL A 5 0.3% RSD Yes B 5 0.1% RSD Yes C 5 0.2% RSD No D 5 0.3% RSD No E 1 0.8% RSD Yes F 5 0.3% RSD Yes G 5 0.1% RSD Insufficient data H 1 0.7% RSD Yes I 5 0.3% RSD Yes J 4947 0.1% RSD No 20% LEL stands for 20% of lower explosion limit. Odor at 20% LEL stands for whether or not odor could be smelled at 20% LEL. RSD stands for relative standard deviation.

(58) Measurements were performed on the odorized natural gas which was liquefied in the cryostat. In other words, measurements were performed on odorized LNG. The measurements were performed using a gas detector and by smelling.

(59) In the headspace of the cryostat none of the odorants was detected by either gas detection or smelling.

(60) Measurements on Odorized LNG in Cryostat:

(61) TABLE-US-00003 Temperature Pressure Odor at 20% Sample of liquid [K] [PSI] LEL A 114 18 Yes B 124 35 Yes C 114 18 Yes D 114 18 No E 114 18 Yes F 114 18 Yes G 114 18 Insufficient data H 114 18 Yes I 114 18 Yes J 114 18 No

(62) Measurements on Boil Off Gas of the Odorized LNG:

(63) TABLE-US-00004 Boil off gas (using Odor at 20% Sample gas detector) [ppb] LEL A 0 Insufficient data B Yes C No D 100 8 RSD No E No F No G No H Insufficient data I Yes J No

(64) From the above data is clear that ethyl acrylate and ethyl mercaptan are suitable to be used as odorant for LNG. From the above data follows that methyl acetate is suitable to be used as tracer.