Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G OR C10K; LIQUIFIED PETROLEUM GAS; USE OF ADDITIVES TO FUELS OR FIRES; FIRE-LIGHTERS
  • C10L3/00—Gaseous fuels; Natural gas; Synthetic natural gas obtained by processes not covered by subclass C10G, C10K; Liquefied petroleum gas
  • C10L3/06—Natural gas; Synthetic natural gas obtained by processes not covered by C10G, C10K3/02 or C10K3/04
  • C10L3/10—Working-up natural gas or synthetic natural gas
  • C10L3/108—Production of gas hydrates
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G OR C10K; LIQUIFIED PETROLEUM GAS; USE OF ADDITIVES TO FUELS OR FIRES; FIRE-LIGHTERS
  • C10L2290/00—Fuel preparation or upgrading, processes or apparatus therefore, comprising specific process steps or apparatus units
  • C10L2290/06—Heat exchange, direct or indirect
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G OR C10K; LIQUIFIED PETROLEUM GAS; USE OF ADDITIVES TO FUELS OR FIRES; FIRE-LIGHTERS
  • C10L2290/00—Fuel preparation or upgrading, processes or apparatus therefore, comprising specific process steps or apparatus units
  • C10L2290/56—Specific details of the apparatus for preparation or upgrading of a fuel
  • C10L2290/567—Mobile or displaceable apparatus

Definitions

• the disclosure relates generally to an apparatus for storing gaseous hydrocarbons and in particular an apparatus for efficient and safe storage of hydrocarbon gas such as natural gas or methane-rich gas in stationary or portable facilities.
• Natural Gas is transported primarily through pipelines or in the form of liquefied natural gas (LNG). Natural gas can be stored in the form of LNG or as compressed natural gas (CNG). Although pipeline transportation has been found to be the most reliable and cost-effective method of NG transportation, pipeline projects have a high gestation period, besides being cost intensive. Natural gas storage as LNG or CNG is very costly and not energy efficient. Natural gas can also be stored in depleted reservoirs, salt caverns, or aquifers but these have not developed so far in India. In addition, in case of emergency situations, such as war, gas pipeline failures, etc., safety and uninterrupted supply are a major concern. It is thus required to develop alternative technologies in the area of NG Storage and transportation that are safe and cost-efficient.
• LNG liquefied natural gas
• CNG compressed natural gas
• Natural gas hydrates are of great interest to the scientific community for their potential to store large amounts of natural gas.
• Natural gas hydrates are crystalline solids that are formed from water and light hydrocarbons such as methane, ethane, in which the molecules of natural gas are trapped inside a 3- dimensional lattice structure (cage) made by the water molecules.
• the NGH are formed at high pressure and low temperature conditions (e.g. at 13°C, a minimum pressure of 100 bar is necessary to form NGH). It is reported that one m J of gas hydrate can store about 160 m 3 of natural gas at atmospheric conditions. As gas hydrates can store large amounts of natural gas, these also have a potential for use in storage and transportation of natural gas.
• US20090035627 discloses a semi-clathrate hydrate compositions formed from water, a semi-clathrate hydrate forming compound and a gas used for energy storage and separation of gases.
• US5787605 discloses a method of storing and transporting gases by- bringing the gas into contact with a porous material in presence of water at room temperature. Gholinezhad experimentally investigated the semi-clathrate hydrates in a micromodels comprising porous structure etched in the glass, towards the application of gas storage, transportation and separation.
• the natural gas can first be converted to gas hydrates (solid form) which can then be used for storage and/or transportation. Thereafter the gas hydrate is dissociated to natural gas by destabilizing the phase equilibrium condition, typically, either by raising the temperature or decreasing the pressure or both. Chemical inhibitors can also be used in this process.
• the process of hydrate formation is slow due to slow nucleation even in the presence of vigorous stirring which requires large amount of energy.
• the gas hydrates once formed are stable at high pressure and low temperature conditions and may not dissociate rapidly at the required rate.
• the invention addresses some of the drawbacks of conventional apparatus and satisfies the need of an apparatus for storage and transport of natural gas in the form of gas hydrates in porous media with or witliout further additives, with further related advantages as set forth here.
• an apparatus for storing and transporting gaseous hydrocarbons comprises a tank filled with porous media comprising a sparger system configured for introducing pressurized gas and liquid through the porous media.
• the tank is provided with insulated jacket and heat exchanger means for regulating temperature within the tank.
• the tank is configured for promoting the formation of a gas hydrates on infusion of pressurized gas and liquid into the porous media.
• the tank is configured with means for facilitating decomposition of the gas hydrate to release the gas.
• the gas is selected from one of natural gas, biogas or a methane-rich gas, and the gas hydrate is a semi-clathrate hydrate.
• the porous media in various embodiments is silica sand or a silica gel or activated carbon or a zeolite or a bed of carbon nanotubes.
• the sparger system comprises piping with nozzles located at various levels within the porous media.
• the heat exchanger means comprises piping distributed within the porous media or enclosing the tank or a combination thereof.
• the liquid comprises an aqueous solution of one or more of a thermodynamic promoter, a kinetic promoter, surfactants or an ionic liquid.
• the thermodynamic promoter is tetra-n-butyl -ammonium halides or a tetrahydrofiiran (THF) or a combination thereof and inorganic salts such as chlorides of sodium or potassium or magnesium or calcium or a combination thereof.
• tetra-n-butyl-ammonium halide of various embodiments is selected from tetra-n-butyl-ammonium bromide (TBAB) or tetra-n-butyl-ammonium chloride (TBAC) or tetra-n-butyi- ammonium fluoride (TBAF) or a combination thereof.
• TBAB tetra-n-butyl-ammonium bromide
• TBAC tetra-n-butyl-ammonium chloride
• TBAF tetra-n-butyi- ammonium fluoride
• the decomposition of the gas hydrate is carried out by chemical inhibition, depressurization or thermal stimulation or a combination thereof.
• the apparatus is a stationary installation, an underground installation or a portable kit.
• FIG, 1 shows an apparatus for storing natural gas or other hydrocarbons in porous media
• FIG. 2 shows a flow chart for the method of storing natural gas or other hydrocarbons in porous media.
• FIG. 3 shows underground depleted reservoir for hydrocarbon gas semiclathrate hydrate storage.
• FIG. 4 and FIG. 5 sho the number of moles of gas consumed per mole of water molecule in gas hydrate system for the initial pressure at 7.5 MPa and for different temperatures.
• FIG. 6 and FIG. 7 sho the number of moles of gas consumed per mole of water molecule in gas hydrate for the initial pressure at 5.5 MPa and for different temperatures.
• FIG. 8 and FIG. 9 shows the comparison has been made on methane gas consumption in gas hydrate for pure water in silica sand bed for methane hydrate system.
• the proposed invention relates to apparatus for forming, storage and transportation of hydrocarbon gas hydrate, comprising porous media.
• the apparatus is provided with sparger system for injecting an aqueous solution of one or more of thermodynamic promoters, kinetic promoters, or ionic liquid into the porous media, along with natural gas to form the gas hydrate.
• the apparatus is intended to serve as efficient and safe storage of hydrocarbon gas such as natural gas or methane-rich gas in stationary or portable facilities as further described with reference to the embodiments to follow with reference to the sequentially numbered figures.
• An apparatus 100 for storing and transporting gaseous hydrocarbons according to one embodiment of the invention shown in FIG. 1 comprises a tank 101 filled with porous media 102.
• a pressure sensor 103 and temperature sensor 104 are inserted into the hydrate formation tank 101 for measuring the variation in pressure and temperature respectively.
• the tank 101 is provided with a jacket 110 with thermal insulation 111.
• heat exchanger 120 is provided, with inlet 120 and outlet 122 for regulating temperature within the tank 101.
• the tank 101 is configured for promoting the formation of a gas hydrate on infusion of pressurized gas and liquid into the porous media 102.
• the pressurized gas may be introduced into the tank through a gas piping system 130 comprising an inlet 131 and outlet 132.
• the liquid may be introduced into the tank by means of liquid piping system 140 with inlet 141.
• the tank 101 with gas piping 130 and liquid piping 140 may connected to sparger system 150 comprising nozzles 151 and pipes 152 for introducing and uniformly distributing the pressurized gas and liquid throughout the porous media 102.
• the tank 101 is configured with means for facilitating decomposition of the gas hydrate to release the gas.
• the gas is selected from one of natural gas, or biogas or a methane-rich gas and the gas hydrate is a semi-clathrate hydrate.
• the porous media 102 is silica sand or a silica gel or activated carbon or a zeolite or a bed of carbon nanotubes.
• sparger system 150 comprises piping 152 with nozzles 151 located at various levels within the porous media 102.
• the heat exchanger 120 comprises piping 121 distributed within the porous media 102 or enclosing the tank 101 or a combination thereof, so as to maintain uniform temperature during formation or decomposition of gas hydrate.
• the liquid comprises an aqueous solution of one or more of a thermodynamic promoter, a kinetic promoter, surfactants or an ionic liquid.
• the thermodynamic promoter comprises one or more of a tetra-n-butyi-ammonium haiide, a tetrahydrofuran (THF), chlorides of sodium, potassium, magnesium, or calcium.
• the tetra- n -butyl-ammonium halide is selected from tetra-n-butyl-ammonium bromide (TBAB) or tetra-n-butyl-ammonium chloride (TBAC) or tetra-n-butyl-ammonium fluoride (TBAF) or a combination thereof.
• TBAB tetra-n-butyl-ammonium bromide
• TBAC tetra-n-butyl-ammonium chloride
• TBAF tetra-n-butyl-ammonium fluoride
• the decomposition of the gas hydrate is carried out by chemical addition, depressurization or thermal stimulation or a combination thereof.
• the apparatus 100 is a stationary facility or an underground facility or a portable kit.
• a system 200 for underground storage, retrieval and transportation is disclosed as shown in FIG. 2.
• the system comprises an underground depleted reservoir 201 storage and transportation apparatus 100 for natural gas semi-clathrate hydrate is disclosed.
• the depleted reservoir 201 can be an oil or a gas reservoir.
• a combination of vertical 202 and horizontal 203 wells may provide access for injection of liquid and gas to one or more apparatus 100A located within the system 200.
• apparatus 100A comprises porous media and piping system for forming, storage and retrieval of hydrocarbon gas hydrate.
• the system further comprises transport vehicle 204 fitted with a portable storage apparatus 100B for storage and transportation of gas as hydrate.
• Transport vehicle 204 provides safe means for transporting hydrocarbon gas under pressure, while enabling retrieval from 100B at the desired destination, as earlier disclosed with reference to system 100.
• an aqueous solution of promoters is first injected into the apparatus 100, 100A or 100B, followed by the injection of natural gas.
• the aqueous spraying may be carried out concurrently with pressurization. Absorption of the aqueous liquid with promoters and interaction of the gas with the liquid in the porous media enables easy formation of semi-clathrate gas hydrate. Since hydrate formation is exothermic, heat is liberated, which is drawn away by the heat exchange system 120.
• the hydrate formation storage apparatus is shown in FIG. 3.
• the mam part of the apparatus is made of stainless steel (SS-316).
• a pressure transducer and platinum resistance thermometer (Pt ⁇ i00) are inserted into the hydrate formation apparatus.
• a dead weight pressure testing apparatus is used for calibration of the pressure transducer in the range of 1 to 7 MPa.
• the uncertainty in the pressure and temperature sensor is ⁇ 0.005 MPa and ⁇ 0.05 K, respectively.
• a syringe pump with a capacity of 507.38 ml is used to compress and transfer gas from a cylinder to the apparatus with a flow rate range from 0.001 ml/min to 204 ml/min for any pressure up to 25.86 MPa with a flow accuracy of +0.5% (maximum. ⁇ . ⁇ /min seal leakage).
• a jacket is surrounded to the hydrate formation apparatus through which a cooling agent, such as water, glycol, alcohol, or any refrigerant can be used to maintain the temperature by using a heat exchanger.
• a cooling agent such as water, glycol, alcohol, or any refrigerant
• Example - 2 [0031] The storage vessel is filled with porous media such as silica sand of 0.16 mm size particle up to a bed height of 7 cm. A temperature sensor (Pt-100) is inserted into the bed properly so as to avoid temperature fluctuation .
• the bed of silica sand is made with a height of 7 cm and having a pore volume of 15 cnrVgm,
• the conditions at which experiments are carried out are initial pressures of 7.5 and 5.5 MPa and temperatures at 273.65 K and 276.15 K.
• the silica sand bed is having pore volume of 15 cm Vgm which accounts for about 88.09 mL of distilled water to attain water saturation of 75% in the given bed of height.
• Pure water and with different concentration of TBAB and SDS have been used for making the bed by uniform, layering of sand and aqueous solutions in order to remove any air pockets.
• the pressure transducer and temperature sensor are inserted properly at a suitable depth inside the porous bed and by closing the storage vessel from top to align properly to avoid any leakage.
• the methane gas from gas cylinder is charged to the storage vessel through a syringe pump.
• the pure water and/or of TBAB with SDS aqueous solution is taken from liquid solution tank with the help of a liquid pump.
• Hie heat exchanger is connected to a jacket which is surrounded to the hydrate apparatus storage vessel. The temperature of the apparatus is maintained at a suitable hydrate formation temperature (in this case at 273.65 K or 276.15 K) throughout the hydrate formation process.
• the heat exchanger is used for reducing the temperature of the storage vessel as desired before injecting the methane gas.
• the methane gas is injected in the storage vessel through nozzle from the gas cylinder up to a desired hydrate formation pressure conditions (in this case 5.5 MPa or 7,5 MPa).
• the pressure and temperature sensors are connected to a data acquisition board in order to record the pressure and temperature data at every 30s interval for about 12 h.
• the storage vessel is charged up to desired initial pressures (7.5 and 5.5 MPa).
• desired initial pressures 7.5 and 5.5 MPa
• the hydrate formation experiment was earned out for porous media in silica sand at initial pressure 7.5 MPa, and maintaining two different temperatures individually at 273.65 K and 276.15 K for 12 hrs. t is observed from FIG. 4 and 5, that the number of moles of gas consumed per mole of water molecule in gas hydrate system for the initial pressure at 7.5 MPa and for different temperatures 273.65 K and 276.15 K is more for 0.1 mass fraction TBAB +600 ppm SDS as compared to 0.1 mass fraction TBAB+0 ppm SDS and 0.2 mass fraction TBAB+0 ppm SDS in silica sand.
• tlie gas consumption in hydrate of pure water in porous media is lower as compared to the hydrate of TBAB and hydrate of TBAB in the presence of SDS.
• the gas uptake is concerned, since TBAB alone with different concentration 0.1 and 0.2 mass fractions is not so much helpful for increasing the gas uptake with respect to time.
• the TBAB is a sample semiclathrate hydrate system taken along with sample surfactant SDS system for tl e hydrate formation of methane in porous media.
• the invention in general, is applied to all the possible combinations of promoters such as, tetra-rc-butyl ammonium bromide (TBAB), tetra-n-butyl ammonium chloride (TBAC), tetra-H-buty] ammonium fluoride (TBAF), tetrahydrofuran (THF), tetra-n-butyl ammonium nitrate (TBANO3) along with all possible surfactant, for ex., anionic types - sodium dodecyl sulphate (SDS), sodium dodecyl benzene sulfonate (SDBS), cationic types - quaternary ammonium salts, polycyclic alkyl and amines and nonionic type - ethoxylated ali

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• Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Filling Or Discharging Of Gas Storage Vessels (AREA)
• Hydrogen, Water And Hydrids (AREA)

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Cited By (6)

Citations (4)

• 2014
  • 2014-12-30 WO PCT/IB2014/067398 patent/WO2015101923A1/en active Application Filing
  • 2014-12-30 IN IN6199CH2013 patent/IN2013CH06199A/en unknown

Patent Citations (4)

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