DESC:FIELD OF THE INVENTION

The present invention relates to dispensing system for High Pressure & Low-Pressure Natural Gas. More particularly relates to an automatic natural gas dispensing system wherein Compressed Natural Gas (LCNG) and Low Pressure Piped Natural Gas (LPNG) is dispensed by converting LNG from Transportable Liquefied Natural Gas Containers / Tankers / Trailers using extremely low power, eliminating use of oil and by utilizing automatic PLC-SCADA operating & safety system.

BACKGROUND OF THE INVENTION

Natural Gas is the safest, cleanest & economical burning fuel on Planet Earth as of today as compared to other heavy and fossil fuels like Petrol, Diesel, Propane, LPG, which have been in use. Natural Gas is recovered from natural resources and it is not produced.

The challenge in supplying Natural Gas for several applications is “How efficiently, economically and effectively it is delivered to the last mile customer” so as to benefit from its use, reduction in cost and reduction in pollution.

Natural Gas is available in several pockets on Earth in very large volumes and delivered to many countries by liquefaction of this Natural Gas, popularly known as LNG (Liquefied Natural Gas).

In many countries, Natural Gas is available and it is distributed through Steel and MDP Pipelines Network in order to reach end user customers.

Even after few decades of heavy investment in such steel pipeline network and it is impossible to reach all the last mile customers, difficult terrains, remote markets, small volume consumption pockets, etc. because it is extremely expensive, cumbersome time taking to lay pipelines in populated areas and remote locations specifically in developing, populated countries and densely populated urban areas.

As compared to Petrol, Diesel and LPG, which are used as automobile fuel for three wheelers, two wheelers and cars as well as LCVs, Natural Gas is a less expensive, safe and efficient alternative and produces least pollution.

In several countries, Natural Gas pipeline is made available at many locations where Gas Compression Stations are installed. These Natural Gas Compressing Stations are called as Online CNG Stations.

(a) Online CNG Mother Stations:
Steel Pipelines carrying Natural Gas from domestic source / LNG Regas Terminals distribute Natural Gas at different pressures considering volume, flow and distribution requirements. At City Gate Junctions, pressure from such gridlines is reduced from 70-90 Bar to 20 Barg (g).

Conventional Online CNG Mother Stations are installed on such steel pipelines having 15-30 Bar gas pressure. Multi stage oil lubricated booster compressors are installed at online Mother Stations, which boost Natural Gas pressure & increase gas pressure up to >250 Bar. At this elevated pressure (CNG) High Pressure Natural Gas is stored in stationary cylinder banks and dispense into
(i) Incoming vehicles having High Pressure Cylinders.
(ii) Transportable cylinder banks popularly known as CNG cascades. Such Cascades then travel to remote areas where steel pipeline network has not reached.

(b) CNG Daughter Stations:
CNG D/o Stations are installed at locations / existing petrol / diesel dispensing stations where piped natural gas is not available. At such dispensing stations, these CNG Cascades are parked and with the help of similar but smaller booster compressors CNG is dispensed into 2/3/4 wheelers. Once pressure in these cascades reduce to 55-80 bar, they go back to online CNG Stations for refilling / top up.

The entire value chain calls for high idling time for vehicles and derivers, multiple handling, transportation of high-pressure gas in the public domains, much higher tonnage of steel transportation than gas, large amount of power and expensive & frequent maintenance for such multi stage compressors.

The main problem is cited into conventional system is that these compressors use oil for lubrication and this oil is always carried over into the entire CNG storage & dispensing system. This oil ends up burning along with Natural Gas thereby creating unacceptable pollution, carbon deposition in engine cylinders, which reduces life of engine and damages the piston.

The significant advantage of using CNG as automobile fuel is lost considerably due to consumption of this lubrication oil, which ends up burning in the vehicle engine along with the stream of Natural Gas. Many representations & researches have been made by the Pollution Control Boards and statutory as well as regulatory bodies. While until now it was not possible to reduce / eliminate such infusion of oil, The Present Invention completely eliminates the requirement of oil and therefore the LCNG from the present invention is considered to be completely oil free produced using zero loss (zero venting of un-burnt natural gas in the air) produced using fraction of power.

• Extremely high amount of idling at time of number of vehicles and drivers
• Multiple handling
• Transportation and parking of high pressure gas in large volume in public domains. Extremely high-risk factor
• Extremely poor ratio of gas pay load to the truck with cascade GVW capacity.
• Large amount of power required for production of CNG
• Large amount of lubrication oil usage, which results in unacceptable pollution
• Every cycle of compression converts moisture into water, which gets deposited in the CNG cylinder and CNG cylinder banks
• Frequent, irregular and highly expensive maintenance of multi stage compressors

OPTIMAL OIL CONCENTRATION RANGE IN CNG

“HOW MUCH OIL can be allowed through”, The High-Pressure Cylinders are required to undergo strength test and inner cylinder wall surface test every five years / periodically to ensure that the thickness of the cylinder wall due to corrosion is not reduced. During such testing individual cylinders are removed from the vehicle / CNG Cascades and cylinder valve is removed and the contents are emptied to enable periodic tests.

Reference: OPTIMAL OIL CONCENTRATION RANGE IN CNG &
HOW TO MINIMIZE OPERATIONAL PROBLEMS

REPORT 2015:144 by: KARINE ARRHENIUS, NIJAZ SMAJOVIC, HALEH YAGHOOBY, PER KLOCKAR

An indicative range is considered from 1 to 20 mg/m3 as calculated by method of subtraction.

There are two main types of stations:

There are two types of refueling stations for cars:
- The Mother Station; the gas delivered to these stations is from available local or national gas network.
- The Daughter Station; the gas delivered to daughter stations is stored in mobile gas cylinder cascades.

Oil coming from Over-lubrication: can cause deposits in valves and gas passages and lead to carry over into the gas stream.

Dilution of the oil by the process gas: Some oils are more prone to dilution than other oils. Higher discharge gas pressure will cause greater oil dilution; higher discharge gas temperature will cause less oil dilution.

Thermal degradation of oil: Because the gas temperature increases with increasing pressure, if the heat is not removed, the lubricant may be exposed to high temperatures and decompose. Under the right thermal conditions lubricating oil may give off a volatile vapor from one of its original constituent components or form new pyrolytic vapor degradation products.

Accelerated oxidation due to poor oil quality or high temperatures

Oil carry over is often expressed in ppmM (part per million by weight). The principle of the measurement is to determine the amount of oil (in g) in a certain volume of gas (in Nm3) in order to express the oil carry over.
Oil carry over in ppmM = (moil (g) / (Vgas (Nm3) * ? (g.Nm-3))) * 10e6

Oil carryover can also be expressed in mg/m3,

Oil carryover in mg/m3 = moil (mg)/Vgas (m3)

Ironically, such cylinders are found to contain moisture, large amount of oil, mixture of oil and water resulting in heavy rusting on the inside surface of the cylinder.

Due to water the cylinder wall from inside corrodes and the thickness reduces. In the present invention, LCNG is completely free from water & oil is not used at all during the entire operation cycle and hence water / oil is eliminated completely.

Large volume of black oil is recovered from individual cylinders and cylinder banks. It is required to understand that this oil is a residual oil from the cylinder. Categorically displaying the amount of oil, which remains dead for years together in each trip and accumulates inside the cylinder. It is also easy to understand that in addition to the oil recovered, large amount of oil ends up in the combustion chamber of the engine due to which the emission has heavy amount of pollution generation and carbon deposition on valves, gas passage, piston blocks and engine heads.

Table 1 provides significant clarity on volume of oil recovered and keeps no doubt, why pollution levels do not reduce despite use of CNG in many of the cities where online CNG stations are installed. The present invention eliminates use of oil and therefore brings total advantage of use of natural gas as automobile fuel to the developing countries and heavily populated countries.

? Table – 1: significant clarity on volume of oil recovered
Size of cylinder in WL Type of vehicle No. of such cylinder Appx. Volume of oil recovered during periodic testing

30 Lit Auto / Tuktuk 1 0.5 to 1 lit.
65 lit Car 1 2 to 3q lit
75 lit Bus / Trucks 6 65 to 70 lit
80 lit LCU trucks 8 70 lit
75 lit CNG cascade 3000 WL 40 330 lit
75 lit CNG Cascade 4500 WL 60 400 lit

CNG Dispensing at remote location using CNG cascade is popularly known as CNG Daughter Station Network. This Daughter Station is extremely inefficient due to the fact that as much as 25 to 35% of gas always remain in the Cascade, which is transported back and forth resulting in high cost of transportation per Kg of CNG dispensed apart from safety in the public space.

PAYLOAD EFFICIENCY:
It is observed that high pressure Cascades are able to dispense only 350 to 400 Kgs of Natural Gas in each trip whereas the cascade has capacity of 800 to 900 Kg of Gas payload capacity on the vehicle. On a 12000 Kg GVW vehicle with 6000 kg. payload, merely 400 Kgs gas is delivered in each trip supply. Other types of aluminum and type III, IV cylinders are lighter can carry higher payload but very expensive.

LNG is compact, easy to transport, has the highest safety record in the industry and considered to be the purest form of Natural Gas with high calorific value and potential to eliminate pollution related problems at large and the fact that when handled accurately, LNG based landed cost of LCNG is most economical. H2O, N2, CO2, S are removed during the liquefaction process, therefore LCNG from LNG is purest quality.

The present invention provides a method for dispensing LCNG, which is extremely safe, fully automatic, extremely efficient and major advantage is to provide cleanest CNG, which is not contaminated with oil and it requires low capital cos. This finally results in lowest landed cost of gas.

SUMMARY OF THE INVENTION

The principal object of the present invention is to provide a dispensing method of oil free CNG using transportable liquefied natural gas (LNG) Containers & Tankers and produce compressed natural gas (LCNG), which is dispensed to vehicles. Further, the present invention provides a method wherein low pressure re-gasified LNG to pipe network to cater to other nearby natural gas users and replace consumption of heavy fuels.

Another principal object of the present invention is to provide a dispensing method of LCNG from transportable Liquefied Natural Gas tanker loaded on truck comprises of:

a. A transportable LNG tanker / container: Liquefied Natural Gas which is filled into transportable vehicle is utilized at the dispensing station for suppling Natural Gas in the form of LCNG and PNG. Moreover, the said container consisting of Boil off Gas recovery connection A; Connection of Vapor return from Pump B; LCNG dispensing connection C; LPNG dispensing connection D; and Pressure maintenance connection E.

b. High Pressure Pump Priming system consisting of:
i. Cryo pump is primed by means of circulation of LNG from Tanker;
ii. High Vacuum Multi-layered Vacuum Jacketed Cryogenic grade Pipelines are used for priming of High Pressure Reciprocating Pumps, referred to as Priming System;
iii. Said priming system reduces flashing and evaporation of LNG while priming and during operation of the LCNG station, which is one of the main objectives of the present innovation.
iv. Small amount of Boil-off produced during priming is diverted to PNG network to attain loss free system.
v. Said cryo pump is authorized by PLC to start pumping of LNG after the installed temperature detector confirms to have reached preset cryogenic temperature and priming is established and understood by the PLC.

c. LCNG production and Dispensing system consisting of:
i. Liquefied Natural Gas is pressurized to 225 bar (g) pressure by means of High Pressure Cryo pumps;
ii. Atmospheric heat exchangers convert said High Pressure LNG into pure oil free compressed natural gas called as LCNG. Said LCNG is stored into LCNG Stationary Cascade. Other types can be used and above condition requirement
iii. Temperature sensors, pressure sensors and gas leakage detectors are installed in the said dispensing system;

d. LNG Vapor recovery system consists of:
i. Said LNG Vapor recovery system recovers boil off natural gas occurred into transportable LNG tanker by means of heat-in-leak
ii. Flash gases at the time of priming / priming of pump is recovered by means of said LNG vapor boil-off gas recovery system;

e. Odorizing system consists of
i. Odorant Storage tank;
ii. Odorant system;
iii. Odorant systems adds odorant into high-pressure LCNG stream & PNG for detecting potential gas leakage at the point of usage.

f. Power Generation System: Natural gas based Genset provides required electricity to the entire LCNG Station and Cryogenic H.P. pumps by using required natural gas at the time when grid power is not available; this feature enables Pure LCNG Dispensing at extremely remote locations, terrains, without having to wait for pipeline or even power connection.

g. Control unit: Control Unit consists of

i. Safety control system wherein gas leakage and pressure relief valves are controlled;
ii. Data logging system;
iii. Control Unit controls the rate of Liquefied Natural Gas from tanker, flow rate of natural gas to be dispensed, measures amount of vapor gas into tanker, controls amount of odorant to be inserted into high-pressure natural gas and control above said systems by means of providing feedback signals.

Another object of the present invention is to provide low pressure PNG to nearby users and ensure zero loss system wherein odorized Natural Gas is supplied into low pressure Piped natural Gas which provides gas to the potential users near the LCNG dispensing station.

One of the objects of the present invention is to provide a method for dispensing High- & Low-Pressure Natural Gas is converted from Liquefied Natural Gas.

The present invention comprises objective as under here:
i. Sub-cool the LNG in Tanker
ii. Auto priming of pump
iii. Auto refilling of the Station Cascade
iv. No left-over gas carried back
v. Fully automated operations & safety systems
vi. Oil free LCNG for automobile application
vii. LCNG can be distributed in areas without power

One of the objects of the present invention is to provide a method for dispensing highly pure oil free LCNG converted from Liquefied Natural Gas (LNG), using very little grid power or not at all.

One of the objects of the present invention is to provide a method wherein atmospheric heat exchanger converts Liquefied Natural Gas into Compressed Natural Gas.

Another object of the present invention is to provide a method wherein losses are completely eliminated. BOG generated in the tanker due to natural evaporation and LNG, which, flashes during priming of the H.P. Pump is compressed and transferred to the Dispensing system or transferred in low pressure Natural gas pipeline for use by nearby users.

One of the objects of the present invention is to provide a method wherein temperature sensors are provided on high pressure pumping system such that in case the high pressure pump loses its priming for any reason, the automatic system will activate automatic gas recovery system gas compression such that small amount of gas vent from the High Pressure Compression is heated and compressed into the station cylinder bank thereby ensuring good priming of the High Pressure Cryogenic Reciprocating Pump and also eliminate venting of LNG.

Another object of the present invention is to provide a method, which does not use oil lubricated booster compressor and provide clean high-pressure natural gas.

One of the objects of the present invention is to provide Genset, which provides required electricity from said converted natural gas to the Cryo pump any time when grid power is not available. Said Genset enables LCNG dispensing at all times.

One of the objects of the present invention is to provide a method, which does not require pipeline network.

BRIEF DESCRIPTION OF DRAWINGS

Figure 1: illustrate perspective view of the present invention wherein a transportable LNG container is detachably attached with the dispensing station.
Figure 1A: discloses back side view of the present invention wherein said container consisting of at least four connection.
Figure 1B: discloses top view of the present invention.
Figure 1C: discloses an embodiment of the present invention wherein container is connected with LCNG dispensing system.
Figure 1D: discloses an embodiment of the present invention wherein container is connected with LPNG dispensing system.
Figure 2: discloses a whole P&ID system of the present invention.
Figure 2A: disclose P&ID system from container to connection in detail.
Figure 3: discloses P&ID system of connection A.
Figure 4: discloses P&ID system of Connection B and C.
Figure 5: discloses P&ID system of connection D.
Figure 6: discloses P&ID system of connection E.
Figure 7: discloses P&ID system of sequencing panel to dispenser.
Figure 8: discloses P&ID system of LCNG storage cascades.

DETAILED DESCRIPTION OF THE INVENTION

The word “P&ID” is referred as “Piping and Instrumentation Diagram”.

The principal embodiment of the present invention is to provide a dispensing method of oil free CNG using transportable liquefied natural gas (LNG) and produce compressed natural gas (LCNG), which is dispensed to vehicles. Further, the present invention provides low pressure re-gasified LNG to pipe network to cater to other nearby users and replace heavy fuels.

Another principal embodiment of the present invention is to provide a dispensing method of LCNG from transportable Liquefied Natural Gas tanker loaded on truck comprises of:

a. A transportable LNG Tanker: A Liquefied Natural Gas which is filled into transportable vehicle said transportable LNG tanker, which is installed at the dispensing station for suppling Liquefied Natural Gas. Purpose built LNG tanker with accurate piping manifold is considered for automatic PLC based operations, PLC based safely, pump and vent connections in order to ensure ZERO losses, use of low power, lowest maintenance and highest efficiency, oil free LCNG.

b. High Pressure Pump Priming system consisting of:
i. Cryo pump is primed by means of circulation of LNG from Tanker;
ii. High Vacuum Multi-layered Vacuum Jacketed Cryogenic grade Pipelines are used for priming of High Pressure Reciprocating Pumps, referred to as Priming System;
iii. Said priming system reduces flashing and evaporation of LNG while priming and during operation of the LCNG station, which is one of the main objectives of the present innovation.
iv. Small amount of Boil-off produced during priming is diverted to PNG network to attain loss free system.

c. LCNG production and Dispensing system consisting of:
i. Liquefied Natural Gas is pressurized to >225 bar (g) pressure by means of High Pressure Cryo pumps;
ii. Atmospheric heat exchangers convert said High Pressure LNG into pure oil free compressed natural gas called as LCNG. Said LCNG is stored into LCNG Stationary Cascade. From this Cascade using Auto Dispensing LCNG is dispensed into automobile vehicles with preferential piping.
iii. Temperature sensors, pressure sensors and gas leakage detectors are installed in the said dispensing system where nearby Natural Gas consumers are available, this recovered gas is supplied for their consumption to limit the cost of recovery.

d. LNG Vapor recovery system consists of:
i. Said LNG Vapor recovery system recovers boil off gas occurred into transportable LNG tanker by means of heat-in-leak and compress said boil off gas; Boil Off Gas Recovery of Natural Gas from LNG Tanker: In this any amount of Boil Off in the Transport Tanker will be recovered, vaporized, heated and compressed with the help of compressor pump, which will transfer this Boil Off Gas into station based LCNG Cascade after duly odorizing the same or to the number of users of Natural gas in low pressure pipeline.

ii. LNG flashes each time LNG is sent to the High-Pressure Reciprocating Pump for priming. LNG primarily consists of Methane, which is excellent green fuel but if sent to the atmosphere unburned, then, it is the worst greenhouse gas. The vapor recovery system collects this flash LNG and with the help of purpose-built atmospheric heat exchangers, heat the same to atmospheric temperature allowing the compressor to transfer it into station based LCNG cascade with due odorization for further dispensing.

iii. During the normal course of LCNG refilling and dispensing, at times, there are certain losses, which arises in the high-pressure reciprocating pump system due to heat in leak into several non-insulated parts like valves as well as increases in the saturation temperature of LNG. the present invention also recovers such regular operational boil-off gas and with the help of vapor recovery system transfers the same into Stationary LCNG Cascade after duly odorizing the high-pressure LCNG stream for further dispensing to the public automobile vehicles or PNG network.

e. Odorizing system consists of
i. Odorant Storage tank
ii. Odorant system
iii. Odorant systems adds odorant into high-pressure LCNG stream or PNG network for detecting potential gas leakage at user points

f. Power Generation System: Natural gas based Genset provides required electricity to the Cryo pump by using required natural gas at the time when grid power is not available; this feature enables Pure LCNG Dispensing at extremely remote locations, terrains, without having to wait for pipeline or even power connection.

g. Control unit: Control Unit consists of
i. Safety control system wherein gas detectors, temperature Sensors, Emergency Push Buttons and pressure relief valves are provided;
ii. Data logging system;
iii. Control Unit controls the flow of Liquefied Natural Gas from tanker, rate of amount of natural gas to be dispensed, measures amount of vapor gas into tanker, controls amount of odorant to be inserted into high-pressure natural gas and control above said systems by means of providing feedback signals.

h. PLC & SCADA based Control unit consists of
i. Dedicated PLC and SCADA system for operation, safety and data logging at the LCNG Dispensing Station.
ii. Once LNG tanker is properly connected, pressure check tested for the hose connections, operator enables automatic operation.
iii. The forward flow happens when LNG from tanker is fed to high pressure reciprocating pump, which boosts LNG pressure from 4-5 bar/g to 255 bar/g. This high-pressure LNG is vaporized with the help of atmospheric H.P. Vaporizers. This high pressure LCNG is dozed with required odorant, which is also controlled by PLC system and the odorized LCNG is stored in the station LCNG cascade bank, which is dispensed into incoming onboard CNG cylinders.

iv. However, the actual automatic operation happens in the reverse way. When incoming vehicle / vehicles connect to the dispensing pump, based on the static pressure of CNG cylinder on the vehicle, the priority panel discharges LCNG from H/M/L stream from the station LCNG cascade.
v. Once the pressure on the LCNG station cascade reduces the PLC system enable power to the pre-primed H.P. Reciprocating Pump, which sucks required amount of liquid from the LNG Tanker and with due atmospheric vaporization and odorization refills the station CNG cascade for extremely efficient operations. The system also reduces the total fill time for the incoming vehicle. In fact, with this invention two major problems will be sorted out:
(a) Each incoming vehicle will be refilled with maximum allowed fill pressure. This will ensure that the vehicle will have longer mean time between two refilling and vehicle utilization rate will increase.
(b) As the frequency of refills reduces, the queue at the dispensing stations will also reduce considerably.

Control Unit also controls the flow rate of Liquefied Natural Gas from tanker, flow rate of amount of natural gas to be dispensed, measures amount of vapor gas into tanker, controls amount of odorant to be inserted into high-pressure natural gas and control above said systems by means of providing feedback signals.

Another embodiment of the present invention is to provide low pressure PNG to nearby users and ensure zero loss system wherein odorized gas is supplied into low pressure Piped Network, which provides PNG to the potential users near the LCNG dispensing station.

One of the embodiments of the present invention is to provide a method for dispensing natural gas wherein compressed natural gas is converted from Liquefied Natural Gas.

One of the embodiments of the present invention is to provide genset, which provides required electricity from said converted natural gas to the Cryo pump at the time of grid power is not available.

One of the embodiments of the present invention is to provide a method, which does not require pipeline network.

One of the embodiments of the present invention is to provide a method wherein gas compressor may provide to increase pressure of boil off natural gas & present venting of the same in air.

One of the embodiments of the present invention is to provide a method wherein genset provide 30-100 KW electricity to the system for operation of the station when grid power is not available.

Another embodiment of the present invention wherein LNG is used which is compact and is used as main source at mother and daughter stations.

To supply Low Pressure PNG to nearby users and ensure Zero Loss System:
This invention also enables supply of odorized low pressure Piped Natural Gas to the potential users near the LCNG Dispensing Stations (provide separate vehicle for this). LNG from the tanker is vaporized with the help of low-pressure atmospheric vaporizers and odorized before delivering to Pressure Regulation Skid specifically designed to maintain Piped Natural Gas Pressure on the downstream piping. Major advantage of this invention is supply of Piped natural Gas to the commercial, industrial and residential localities and enable use of high-pressure natural Gas and replace the polluting and expensive fuels like diesel, petrol, propane, Furnace Oil, LPG, Butane, coal, wood, brickets, etc. Specifically, designed LNG tanker with required number of nozzle connections with piping and auto pressure building systems ensure refilling of downstream low-pressure PNG pipeline network in fully automatic mode. Specific P&ID of such LNG Tanker is shown in Diagram-D1. During the actual operation reverse feedback system is put into use to ensure trouble free, automatic and most reliable supply of PNG for consumers to replace heavy fuel as mentioned above.

Based on the consumption at different times of the day by the number of end users either at home, restaurants, hotels, hospitals, small industries or high way eateries connected to the LNG based LCNG station, the pressure in the PNG pipe network reduces. The present invention ensures that proportionate to the consumption and the pressure reduction, which happens in the pipe network is replenished with the help of re-gasified LNG. This ensures maintain constant pressure in the pipeline. The main advantage of such facilities are as below:

(a) Additional boil off gas is directly supplied to the Piped Natural Gas (PNG) Network thereby ensuring zero loss from the tanker
(b) Once the boil off gas is consumed, the tanker is kept at pre-determined regulated pressure, which ensures supply of cold LNG to the high-pressure reciprocating pump.
(c) Since it is ensured that the reciprocating pump operates at pre-designed sub-cold LNG at pre-determined pressure, the pump operation becomes extremely reliable, wear and tear reduces and as the differential temperature is eliminated, it which ensures long life of the pump.
(d) The above system also ensures that the mean time between the system maintenance and the reciprocating pump increases significantly.

Advantages of using liquefied natural gas are LNG is compact, easy to transport, has the highest safety record in the industry and considered to be the purest form of Natural Gas with high calorific value and potential to eliminate pollution related problems at large and the fact that when handled accurately, LNG based landed cost of LCNG is most economical.

Figure 1 of the present invention discloses principal embodiment, wherein a transportable LNG container / tanker 01 which is detachable is attached with dispensing site. Said container 01 is vacuum jacketed double walled construction of suitable capacity and working pressure. Said tanker consist of stainless-steel inner vessel and Carbon Steel / Stainless Steel outer vessel with high vacuum and in perlite or multi-layer super insulation in the annular space. The transportable LNG container 01 has top and bottom filling connections as usual so that LNG can be filled like any other tanker at the terminal. The tanker shall have various valves and instruments as shown located inside a steel valve box at rear end or any side end. The tanker shall be parked suitably and it has connection which is variable as per requirement; for an example in the present invention, A transportable LNG container 01 consisting of 5 connection which is listed as:
i. Boil off Gas recovery connection A;
ii. Connection of Vapor return from Pump B;
iii. LNG Liquid Line connection C;
iv. LPNG dispensing connection D;
v. Pressure maintenance connection E.

All the connection said A, B, C, D and E are made by means of vacuum jacketed or low heat loss piping 2, Vacuum jacketed flexible hose 3 and other hoses. Further, an instrument air supply from dispensing station is connected so that the LNG tanker ESD valve [Emergency Shut Down Valve] can be actuated from ground in case of emergency and LNG supplies shut off at source.

The tanker shall arrive at dispensing station and parked inside safety enclosure. The process connections A to E are made and also the instrument air supply connected to the truck from ground with the selector valve positioned accordingly. Normally LNG shall be delivered to the dispensing system by means of connection C and vapor return is accepted by means of connection B. Connection D shall ensure transportable LNG supplies to PNG vaporizers of PNG system. Connection A connects BOG compressor suction so that whenever required the BOG compressor of BOG system can suck gas from said tanker 1 to maintain the pressure, eliminate boil-off venting & zero-down losses.

The connection A is connected with boil off gas recovery system 5 and recovered gas is transferred to the PNG line or storage cascade. The connection B is connected with high-pressure LNG pump 4 wherein vapor natural gas generated into pump is transferred again into said transportable LNG container 01. The connection C is connected with high-pressure cryo pump 4 wherein LNG is pumped and pressure is increased and further LNG is transferred through vaporizers 06 wherein, LNG is converted into LCNG. Said Liquefied Compressed Natural Gas and dispensed as per requirement by means of dispenser 11. The connection D is connected with vaporizers 16 wherein transportable LNG is converted into LPNG. Said Liquefied Pipe Natural Gas, which is transferred to the users by means of pipe 100. Figure 1A of the present invention discloses an embodiment wherein major 4 connection are easily seen which are located at the back/side of the transportable LNG trailer or container 01.

Figure 1B discloses top view of the present invention wherein, LCNG dispensing system 200 which comprises of high-pressure cryo pump 04, Vaporizers 06, storage cascades 09 and other important components used to transfer LCNG to the dispenser 11. And LPNG dispensing system 300 which comprises of vaporizers 16 and other important components used to transfer LPNG to the users by means of main dispense pipe 100.

Figure 1C of the present invention discloses an embodiment wherein LCNG dispensing system 200 is provided with connection B and C wherein the connection B is connected with high-pressure LNG pump 4 wherein vapor natural gas generated into pump is transferred again into said transportable LNG container 01. The connection C is connected with high-pressure cryo pump 4 wherein LNG is pumped and pressure is increased and further LNG is travelled through vaporizers 06 wherein, LNG is converted into LCNG said Liquefied Compressed Natural Gas and dispensed as per requirement by means of dispenser 11.

Figure 1D of the present invention discloses an embodiment wherein LPNG dispensing system 300 is provided with connection D only wherein the connection D is connected with vaporizers 16 wherein transportable LNG is converted into LPNG said liquefied Pipe natural Gas which is transferred to the users by means of pipe 100.

Figure 2 and Figure 2A of the present invention discloses P&ID of LCNG and LPNG dispensing station wherein transportable LNG container 01 is parked at dispensing station for the purpose of supply LNG wherein said container 01 is provided with Boil off Gas recovery connection A; Connection of Vapor return from Pump B; LCNG dispensing connection C; LPNG dispensing connection D; and Pressure maintenance connection E wherein Said connection are made by means of vacuum jacketed low heat loss piping 2, Vacuum jacketed flexible hose 3 and other hoses. Further, an instrument air supply from dispensing station is connected so that the LNG tanker ESD valve [Emergency Shut down Valve] can be actuated from ground in case of emergency and LNG supplies shut off at source. Further, a system is integrated on the ground to accept specially built LNG tanker and get connected. The system shall ensure PNG at appx. 5 bar (g) and LCNG at 250 bar (g) at a time. Flow of PNG and LCNG can be varied using different capacities of equipment in the system and also by means of suitable VFD.

The system consists of ground mounted high-pressure LNG pump 4 which is connected to LNG tanker 1. The pump shall boost LNG pressure and deliver high pressure LNG at more than 250 bar (g) pressure. The pump is provided with all required safety instrumentation for safe operation. The high-pressure LNG is delivered to S.S lined atmospheric vaporizers, which converts into high pressure oil free LCNG. Each vaporizer has a duty cycle of 6-8 hours and when required switch over is done based on PLC signal from the PLC control room. The pump and vaporizers are located on skid 19.

Further, the LCNG is delivered to station LCNG storage cascade 9 via sequencing panel 8. The sequencing panel 8 is programmed to decide which flow shall be prioritized for economic operation. The station LCNG cascade shall have three banks to cater to LCNG dispenser for filling commercial vehicles. The priority panel 8 shall deliver LCNG to the dispensers 11 which shall be refilling LCNG absolutely oil free in commercial vehicles.

The purpose-built transportable LNG tanker also delivers LNG to low pressure LNG re-gasification vaporizers called as PNG vaporizers 16 via connection D. said vaporizers 16 are designed for appx. 8 hours duty cycle and changeover take place automatically after the duty cycle is complete or in case when outlet RLNG gas temperature is lower than pre-specified limit.

Moreover, said atmospheric LNG vaporizers utilize energy in air to regasify LNG. During the process of LNG to PNG conversion, the vaporizer gets ice/frost formed on its fin surface. This frost/ice melts during the idling period when the other unit is in operation.

The PNG vaporizer changeover valves, instruments, safety valves are located on a skid 17. Vaporizer and change over skid are located inside an impoundment dyke 14. The vaporized natural gas is then delivered to pressure regulation skid, which contains two parallel path pressure regulators, which controls the pressure to the required value. The regulators are provided with slam shut device, which control the pressure to the required value. The regulators are provided with slam shut device, which will physically close the regulator in case of its failure. The actuation of slam shut device is indicated by a limit switch provided. Due to difference in set pressure of the regulators it ensures an uninterrupted supply of PNG to localized pipe network such that even in case of failure of one regulator without any manual intervention gas supply is ensured. It shall also create an alarm in PLC in case of regulator failure, so repair is prompted and arranged. Isolation valve and pressure gauges are provided on both sides of the regulator. The regulated gas then flows to the flow meter, which shall measure the flow, totalize and the signal is then sent to PLC for logging. A bi-pass valve is provided to flow meter in case of any emergency. The PNG gas is then delivered to customer through local pipelines network. The temperature and pressure of gas is continuously monitored. Pressure reduction and metering instruments are located on the skid 17.

A common odorizing system 7 which consists of PLC controlled dozing pumps to inject the odorizer in required proportion to HP and LP stream both. The odorizer shall have suitable sized storage to inject sufficient quantity of odorant.

An automated BOG recovery unit 5 is installed in the ground system. When required it shall take gas from LNG tanker, heat by using atmospheric heater and feed it to boil-off gas compressor. Said BOG compressor shall compress the gas to the required pressure and can deliver the gas to PNG stream or fill stationary storage cascade 10. The gas from said cascade is dispensed to the commercial vehicles using standard CNG dispensers as required. This ensure that there is no loss of gas even when the system is not in use.

The integrated system on ground is provided with various safety arrangements 20, such as high/low temperature sensors located at strategic locations. Sensors can sense leakage of LNG or fire and accordingly the PLC is programmed to take action to raise alarm and shut down ESD valves and stop further LNG supply. Similarly, gas detection sensors 21 located at specific location would detect any gas leakage in the system and raise alarm accordingly. Emergency shut down push button 22 are also provided at important locations. In case the operator witnesses any emergency conditions then he can actuate the switch to create alarm and shut down the system.

Figure 3 of the present invention discloses P&ID of Boil off recovery system 05 wherein vaporized transportable LNG is supplied by means of connection A and recovered natural gas is supplied to LCNG by means of line L3 and to LPNG by means of line L2.

Figure 4 of the present invention discloses P&ID of LCNG dispensing system wherein the connection B is connected with high-pressure LNG pump 4 wherein vapor natural gas generated into pump is transferred again into said transportable LNG container 01. The connection C is connected with high-pressure cryo pump 4 wherein LNG is pumped and pressure is increased and further LNG is travelled through vaporizers 06 wherein, LNG is converted into LCNG said Liquefied Compressed Natural Gas and dispensed as per requirement by means of dispenser 11. Safety system 20 is installed within LCNG dispensing system which monitors all parameters and protects. Converted LCNG is supplied to the sequencing panel 8 and then stored into LCNG storage cascade 9 by means of line L6. Odorizing system 7 adds odorants into LCNG system.

Figure 5 of the present invention discloses P&ID of LPNG dispensing system wherein the connection D is provided from transportable LNG container 01 wherein transportable LNG tanker also delivers LNG to low pressure LNG re-gasification vaporizers called as PNG vaporizers 16 via connection D. said vaporizers 16 are designed for appx. 8 hours duty cycle and changeover take place automatically after the duty cycle is complete or the gas temperature is lower than specified. PNG gas is delivered by means of line 100.

Figure 6 of the present invention discloses Connection E would actuate pressure building valve automatically whenever required to maintain the tank pressure constant. The tanker 01 is provided with analogue pressure and level indication. LNG tanker has emergency shut down valve [ESD 1 and ESD 2] on liquid line, which can cut off LNG flow at source in case of any emergency. With instrument air supply connection, dispensing station safety system is synchronized with LNG tanker ESD valves to isolate supply of LNG in case of any eventuality. The tanker has safety valves [4 x 100%] designed to take care of any eventuality and avoid excessive pressure rise in tanker.

The control room which houses programmable logic controller 12 along with SCADA system is located in a safe area as per relevant codes and standards. The SCADA system shall take care of all alarms as well as it shall store all parameters fed into it. The Natural gas driven generator set 15 is also located near the control room, which runs on the PNG supplied by the system and provide power for operation & safety system. An instrument air compressor 13 with dryer is provided to take care of instrument air supply for valve operations. The total system ensures effective use of LNG in the tanker and work with minimum manual intervention, oil free production of LCNG using very low power/no grid power.

Figure 7 of the present invention discloses P&ID of sequencing panel 8 is programmed to decide which flow shall be prioritized for economic operation. The station LCNG cascade shall have three banks to cater to LCNG dispenser for filling commercial vehicles. The priority panel shall deliver LCNG to LNG dispensers 11 which shall be refilling LCNG absolutely oil free in commercial vehicles. Moreover, recovered gas comes by means of line L6 from boil off gas recovery system 05 and then stored into LCNG storage cascade 9 by means of low pressure line L1, medium pressure line L8 and high pressure line L9.

Figure 8 of the present invention discloses station LCNG storage cascade 9 wherein recovered natural gas, converted CNG gas from LCNG is stored into said station LCNG storage cascade 9 and dispense by means of dispenser 11 to vehicles.

Many a times, LNG is transported over extremely long distances of more than 1000 to 1500 Kms or even more and during this transportation LNG heats up and pressure in LNG Tanker rises. This increase of LNG temperature increases pressure and LNG gets saturated. This saturated LNG flashes more than sub-cooled LNG in the H.P. Reciprocating pump system. Such LNG is likely to create problem for High Pressure Reciprocating Pump, its priming and functionality of the Pump; therefore, Automated Vapor Recovery Unit 4 is provided to recover such excess heat and cool down the LNG in the Tanker.

Also, frequent start-stop of HP results into damage to H.P. Reciprocating Pump parts and reduces life of the pump piston. The vapor recovery system absorbs the excess heat from LNG in the tanker and converts this saturated-hot LNG into sub-cooled LNG.

This feature improves the life of the Pump and increases meantime between the maintenance required for High Pressure Reciprocating Pumping system 5. Fully Automated PLC SCADA System is provided in the Control Room 12. This PLC SCADA is pre-fed with Logic, I/Os for automated operation of the Station.

The present invention also improves the life of the Pump and increases meantime between the maintenance required for High Pressure Reciprocating Pumping system 5. Fully Automated PLC SCADA System is provided in the Control Room 12. This PLC SCADA is pre-fed with Logic, I/Os for automated operation of the station.

Natural Gas based Genset of appropriate capacity is also provided to run the safety system and Reciprocating Pumping system to ensure that CNG Station is always operational even when grid power is not available.

This Natural Gas based Genset is provided with automatic switch over and selection panel to enable the Station Operator use grid/generated power as per requirement.

Main advantages of the present invention over conventional Online Booster Stations and CNG Cascade based Daughter Stations are provided below in Table-2.

? Table – 2 Advantages of the present invention:
Main Advantages of this Invention over conventional CNG System assuming a moderately populated city / area estimated to consume 300 MT/day. 300 TPD
Considered as daily CNG sales value Conventional CNG System Present LCNG
Invention
Volume of CNG / LCNG considered in a Typical GA TPD 300 300
No of Online/Main stations considered for conventional Value chain System Nos 15 15
Capacity of the Online Station considered with Compression capacity 1200 SCMH TPD/SCMH 20 10
Average Length of Pipeline that needs to be installed for 300 TPD dispensing KM 750 0
No of Booster based Daughter stations considered dependent on Online Stations Nos 24 Not Required
Capacity of the Daughter Stations considered with Compression capacity 600 SCMH TPD/SCMH 5 Not Required
Reduction in CAPEX from Online Station & Daughter Station conventional model INR LAKHS 12210 6350
Reduction in Cost of Land Compared to conventional model INR LAKHS 7200 0
Reduction in cost of Laying Pipeline including all related troubles in laying pipeline INR LAKHS 75000 0
Reduction in OPEX in terms of Total Power required for dispensing 300 TPD in 1 year INR LAKHS / Year 2951 461
Reduction in Consumption of oil during Compression Lit / Year 24000 0
Reduction in Cost of Transportation for CNG sold at Daughter Stations only INR LAKHS / Year 1542 44
Reduction in the overall cost of Comprehensive maintenance & Spares INR LAKHS / Year 542 193
Reduction in cost of Manpower for Transportation of Gas for Daughter Stations INR LAKHS / Year 14 5
Reduction in Pollution using the LCNG from Invention which is attributed to Oil Proportionate proportionate to Oil 0
Carbon Deposition on the Engine Block and Piston Not Applicable Heavy and Damaging Not observed
Increased Safety from 250 Bar CNG Storage to 4 Bar LNG Storage Rating Severe & Critical safe & Automated

Table-3 discloses safety table which consisting of comparison between the present invention and conventional CNG system:

? Table-3: Safety Comparison Table
Sr.
No. Main points considered for safety ratings & comparison Conventional CNG System Present LCNG
Invention
1. CNG Cascade rea-filling at Online Mother Stations High risk due to elevated pressures Not required
2 High Pressure of >220 Bar filled steel cylinders used for transport of extremely small volume of CNG for remote dispensing High public safety risk Not applicable. In fact, low pressure LNG in double walled LNG tanker is extremely safe
3 Number of CNC Cascades generally required for Daughter Station remote dispensing 3 to 4 per Station & all at more than 235 Bar pressure. Typically, more than one Cascades are parked at Station. Very high potential hazard. Only one LNG tanker at pressure of 4 to 5 Bar (g) as compared to 235 Bar (g) in conventional station
4 Risk to public with respect to High Pressure CNG Cascades located at dispensing stations located inside existing dispensing station of petrol & diesel Extremely high risk as any incident may lead to trouble with other fuels as well Not applicable as main storage LNG in the LNG tanker is at a pressure of <5 Bar (g).
5 ESD system (Emergency Shut Down System) on the LNG tanker/Container/Trailer Synchronized with and automatically operated by PLC-SCADA central safety system logic located at the dispensing station will immediately shut down the flow of liquid LNG from the tanker thereby ensure highest safety considerations. Not applicable for ESD system
,CLAIMS:[CLAIM 1] A LCNG and LPNG dispensing system from transportable Liquified Natural Gas container comprises a method wherein,
A. a transportable LNG container 01 consisting of:
i. boil-off gas recovery connection A;
ii. connection of vapor return B is connected with pump 4 for recover excess vapor during priming of said cryo pump 4;
iii. LCNG dispensing connection C;
iv. LPNG dispensing connection D;
v. pressure maintenance connection E;

B. a high-pressure pump priming system:
i. connection of vapor return B is connected with cryo pump 04 wherein collected vapor is again transferred towards said container 01;
ii. said cryo pump 04 is authorized by PLC to start pumping of LNG after the installed temperature detector confirms to have reached present cryogenic temperature and priming is established;

C. LCNG production and dispensing system 200:

i. cryo pump 04 is connected with LCNG dispensing connection C wherein LNG from said container is pressurised;
ii. pressurised Liquefied Natural Gas enters into heat exchangers 06;
iii. heat exchangers 06 converts LNG into LCNG;
iv. converted LCNG is stored into LCNG station cascades 09;

D. LNG vapour recovery system 05:
i. recovers boil-off Natural gas occurred into transportable LNG container 01 is collected by means of boil-off gas recovery connection A;
ii. recovers flash gases at the time of priming of pump 04;
iii. recovered Natural Gas is transferred to LCNG dispenser 11 and LPNG dispensing system;

E. LPNG production and dispensing system 300:
i. Liquefied Natural Gas enters into heat exchangers 16 by means of LPNG dispensing connection D;
ii. heat exchanger 16 converts LNG into LPNG;
iii. converted LPNG is transferred to users;

F. odorizing system 07 adds odorant into high-pressure LCNG and LPNG stream for detecting potential gas leakage at the point of usage;

G. power generation system comprises a genset 15 based on converted natural gas and provides required electricity to the entire LCNG and LPNG station and pumps;

H. control unit 12 consisting of:
i. safety control system wherein gas leakage and pressure relief valves are controlled;
ii. data logging system;
iii. control Unit controls the rate of Liquefied Natural Gas from tanker, flow rate of natural gas to be dispensed, measures amount of vapor gas into tanker, controls amount of odorant to be inserted into high-pressure natural gas and control above said systems by means of providing feedback signals.

[CLAIM 2] A LCNG and LPNG dispensing system from transportable Liquified Natural Gas container as claimed in claim 1, Wherein, transportable LNG container is detachably attached with LCNG and LPNG dispensing station;

[CLAIM 3] A LCNG and LPNG dispensing system from transportable Liquified Natural Gas container as claimed in claim 1, wherein a dispensing method of oil free CNG using transportable liquefied natural gas (LNG) and produce compressed natural gas (LCNG), which is dispensed to vehicles.

[CLAIM 4] A LCNG and LPNG dispensing system from transportable Liquified Natural Gas container as claimed in claim 1, wherein low pressure re-gasified LNG to pipe network to carter to other nearby users and replace heavy fuels.

[CLAIM 5] A LCNG and LPNG dispensing system from transportable Liquified Natural Gas container as claimed in claim 1, wherein High Vacuum Multi-layered Vacuum Jacketed Cryogenic grade Pipelines are used for priming of High Pressure Reciprocating Pumps, referred to as Priming System.

[CLAIM 6] A LCNG and LPNG dispensing system from transportable Liquified Natural Gas container as claimed in claim 1, wherein high-pressure pump priming system Reduces flashing and evaporation of LNG while priming and operation of the LCNG system.

[CLAIM 7] A LCNG and LPNG dispensing system from transportable Liquified Natural Gas container as claimed in claim 1, wherein Small amount of Boil-off produced during priming is diverted to PNG network to attain loss free system.

[CLAIM 8] A LCNG and LPNG dispensing system from transportable Liquified Natural Gas container as claimed in claim 1, wherein temperature sensors, pressure sensors and gas leakage detectors are installed in the dispensing system.

[CLAIM 9] A LCNG and LPNG dispensing system from transportable Liquified Natural Gas container as claimed in claim 1, wherein low-pressure PNG to nearby users and ensure zero loss system wherein odorized Natural Gas supplied into low pressure Piped natural Gas which provides gas to the potential users near the LCNG dispensing station.

[CLAIM 10] A LCNG and LPNG dispensing system from transportable Liquified Natural Gas container as claimed in claim 1, wherein a method for dispensing highly pure oil free LCNG converted from Liquefied Natural Gas (LNG), using very little grid power.

[CLAIM 11] A LCNG and LPNG dispensing system from transportable Liquified Natural Gas container as claimed in claim 1, wherein losses are completely eliminated as BOG generated in the tanker due to natural evaporation and LNG, which, flashes during priming of the H.P. Pump is compressed and transferred to the Dispensing system or transferred in low pressure Natural gas pipeline for use by nearby users.

[CLAIM 12] A LCNG and LPNG dispensing system from transportable Liquified Natural Gas container as claimed in claim 1, wherein temperature sensors are provided on high pressure pumping system such that in case the high pressure pump loses its priming for any reason, the automatic system will activate automatic gas recovery system gas compression such that small amount of gas vent from the High Pressure Compression is heated and compressed into the station cylinder bank thereby ensuring good priming of the High Pressure Cryogenic Reciprocating Pump and also eliminate venting of LNG.

[CLAIM 13] A LCNG and LPNG dispensing system from transportable Liquified Natural Gas container as claimed in claim 1, wherein said dispensing method does not use oil lubricated booster compressor and provide clean high-pressure natural gas.

[CLAIM 14] A LCNG and LPNG dispensing system from transportable Liquified Natural Gas container as claimed in claim 1, wherein Genset provides required electricity from said converted natural gas to the Cryo pump at the time of grid power is not available.

[CLAIM 15] A LCNG and LPNG dispensing system from transportable Liquified Natural Gas container as claimed in claim 1, wherein said method does not require pipeline network.

[CLAIM 16] A LCNG and LPNG dispensing system from transportable Liquified Natural Gas container as claimed in claim 1, wherein Dedicated PLC and SCADA system for operation, safety and data logging at the LCNG Dispensing Station.

[CLAIM 17] A LCNG and LPNG dispensing system from transportable Liquified Natural Gas container as claimed in claim 1, wherein Once refilled tanker is properly connected, pressure check tested for the hose connections, operator enables automatic operation.

[CLAIM 18] A LCNG and LPNG dispensing system from transportable Liquified Natural Gas container as claimed in claim 1, wherein the forward flow happens when LNG from tanker is fed to high pressure reciprocating pump, which boosts LNG pressure from 4-5 bar/g to 255 bar/g.

[CLAIM 19] A LCNG and LPNG dispensing system from transportable Liquified Natural Gas container as claimed in claim 18, wherein high-pressure LNG is vaporized with the help of atmospheric H.P. Vaporizers. This high pressure LCNG is dozed with required odorant, which is also controlled by PLC system and the odorized LCNG is stored in the station LCNG cascade bank, which is dispensed into incoming onboard CNG cylinders.

[CLAIM 20] A LCNG and LPNG dispensing system from transportable Liquified Natural Gas container as claimed in claim 1, wherein once the pressure on the LCNG station cascade reduces the PLC system enable power to the pre-primed H.P. Reciprocating Pump, which sucks required amount of liquid from the LNG Tanker and with due atmospheric vaporization and odorization refills the station CNG cascade for extremely efficient operations.

[CLAIM 21] A LCNG and LPNG dispensing system from transportable Liquified Natural Gas container as claimed in claim 1, wherein each incoming vehicle will be refilled with maximum allowed fill pressure which ensures that the vehicle will have longer mean time between two refilling and vehicle utilization rate will increase.

[CLAIM 22] A LCNG and LPNG dispensing system from transportable Liquified Natural Gas container as claimed in claim 1, wherein genset provide 30-40kw electricity to the system.

[CLAIM 23] A LCNG and LPNG dispensing system from transportable Liquified Natural Gas container as claimed in claim 1, wherein LNG is used which is compact and is used as main source at mother and daughter stations.