Patent Application
20220290919
This disclosure relates to a precooling process using liquid nitrogen in hydrogen or helium liquefaction. More specifically, the disclosure relates to a method of precooling hydrogen or helium gas using a process based on a supply of liquid nitrogen, incorporating at least one turboexpander and one or more heat exchangers, together which reduce the amount of nitrogen required for precooling and reduce the energy consumed in the precooling process.
Liquefaction of hydrogen and helium requires a large expenditure of energy. Hydrogen has the second lowest boiling point of all substances, with a boiling temperature of −253° C. at atmospheric pressure. Only helium has a lower boiling point. The liquefaction process is divided into several stages, such as: hydrogen compression, pre-cooling, and liquefaction. In the pre-cooling stage of hydrogen liquefaction, the hydrogen gas may be cooled from ambient temperature to approximately −191° C. Large scale hydrogen liquefiers utilize liquid nitrogen supplied from an associated nitrogen/air liquefaction plant. Processes for the liquefaction of hydrogen and helium frequently use liquid nitrogen for precooling purposes in the liquefaction process. The use of liquid nitrogen reduces the overall energy requirement for production of liquid hydrogen or liquid helium. In turn, the liquid nitrogen derived for this employment is produced separately with a substantial expenditure of energy. As a means for precooling hydrogen or helium prior to liquefaction, the direct evaporation of liquid nitrogen, which is conventionally supplied at low pressure and at a cold temperature for vaporization and superheating, entails large temperature differences between the hydrogen or helium warm fluids and the cold nitrogen fluid.
The precooling process directly effects the total energy required for hydrogen or helium liquefaction. The energy required for precooling, as represented by the energy to produce the required liquid nitrogen, is a substantial part of the total energy to liquefy liquid hydrogen or helium. Recent work has concentrated on means to reduce the total energy required to liquefy hydrogen or helium by different means for supplying precooling refrigeration, and means for reduction of the liquid nitrogen requirement.
A method for precooling hydrogen or helium gas prior to liquefaction using a liquid nitrogen stream is disclosed. That method includes: a.) providing a pressurized liquid nitrogen stream containing liquid nitrogen at a pressure between about 15 bar(a) and about 70 bar(a); b.) passing the pressurized liquid nitrogen stream and a partially-cooled hydrogen or helium gas stream through a first heat exchanger that exchanges heat between the pressurized liquid nitrogen stream and the partially-cooled hydrogen or helium gas stream to provide a first partially-warmed nitrogen stream and a precooled hydrogen or helium gas stream; c.) passing the first partially-warmed nitrogen stream through one or more turboexpanders that lowers the temperature and pressure of the partially-warmed nitrogen stream to provide a cold nitrogen stream; and d.) passing the cold nitrogen stream through the first heat exchanger and through a second heat exchanger to provide the precooled hydrogen or helium gas stream, and a fully-warmed nitrogen gas stream. Step (d) may include: passing the cold nitrogen stream through the first heat exchanger that exchanges heat between the cold nitrogen stream and the partially-cooled hydrogen or helium gas stream to provide a second partially-warmed nitrogen gas stream and the precooled hydrogen or helium gas stream; and passing the second partially-warmed nitrogen gas stream through the second heat exchanger that exchanges heat between the second partially-warmed nitrogen gas stream and a warm hydrogen or helium gas stream to provide a fully-warmed nitrogen gas stream and the partially-cooled hydrogen or helium gas stream. The first heat exchanger and the second heat exchanger may be separate devices, or two parts within a single heat exchanger. The method may further include applying an auxiliary refrigeration system coupled to the second heat exchanger.
Step (a) may include: supplying a liquid nitrogen stream produced at a saturation pressure of less than about 10 bar(a); followed by increasing the pressure of the liquid nitrogen stream to provide the pressurized liquid nitrogen stream. Step (a) may include: supplying a liquid nitrogen stream produced at a saturation pressure of less than about 10 bar(a); splitting the liquid nitrogen stream into a first portion of the liquid nitrogen stream and a second portion of the liquid nitrogen stream; and increasing a pressure of the first portion of the liquid nitrogen stream to provide the pressurized liquid nitrogen stream. The second portion of the liquid nitrogen stream may pass through the first heat exchanger to provide a third partially-warmed nitrogen stream. The third partially-warmed nitrogen stream may pass through the second heat exchanger to provide a second fully-warmed nitrogen gas stream. The pressurized liquid nitrogen has a pressure between about 15 bar(a) and about 70 bar(a), or about 20 bar(a) and about 55 bar(a).
The pressurized liquid nitrogen stream may be split into a first pressurized liquid nitrogen stream and a second pressurized liquid nitrogen stream, and the first pressurized liquid nitrogen stream and the second pressurized liquid nitrogen stream passed separately through the first heat exchanger to exchange heat between the first and the second pressurized liquid nitrogen streams and the partially-cooled hydrogen or helium gas stream.
Another method for precooling hydrogen or helium gas using a liquid nitrogen stream is disclosed that includes: a.) supplying a liquid nitrogen stream produced at a saturation pressure of less than about 10 bar(a); b.) directing a first portion of the liquid nitrogen stream to a first heat exchanger to provide a first partially-warmed nitrogen stream; c.) directing the first partially-warmed nitrogen stream to a second heat exchanger to provide a first fully-warmed nitrogen gas stream; c.) increasing a pressure of a second portion of the liquid nitrogen stream to provide a pressurized liquid nitrogen stream at a pressure between about 15 bar(a) and about 70 bar(a); d.) passing the pressurized liquid nitrogen stream and a partially-cooled hydrogen or helium gas stream through the first heat exchanger in countercurrent to provide a second partially-warmed nitrogen gas stream and a precooled hydrogen or helium gas stream; e.) passing the second partially-warmed nitrogen gas stream through the second heat exchanger that exchanges heat between the second partially-warmed nitrogen gas stream and a warm hydrogen or helium gas stream to provide a second fully-warmed nitrogen gas stream and the partially-cooled hydrogen or helium gas stream; f.) passing the second fully-warmed nitrogen gas stream through one or more turboexpanders that lower the temperature and pressure of the second fully-warmed nitrogen gas stream to provide a cold nitrogen stream; e.) passing the cold nitrogen stream through the first heat exchanger that exchanges heat between the cold nitrogen stream and the partially-cooled hydrogen or helium gas stream to provide a third partially-warmed nitrogen gas stream and the precooled hydrogen or helium gas stream; and f) passing the third partially-warmed nitrogen gas stream through the second heat exchanger that exchanges heat between the third partially-warmed nitrogen gas stream and a warm hydrogen or helium gas stream to provide a third fully-warmed warm nitrogen gas stream and the partially-cooled hydrogen or helium gas stream. Step (g) may include: routing the second fully-warmed nitrogen stream through one or more compressors and one or more coolers before passing the second fully-warmed nitrogen stream through the one or more turboexpanders. Step (g) may include: passing the second fully-warmed nitrogen stream through two turboexpanders connected in series. The method may further include applying an auxiliary refrigeration system coupled to the second heat exchanger.
The pressurized liquid nitrogen stream may be split into a first pressurized liquid nitrogen stream and a second pressurized liquid nitrogen stream; and the first pressurized liquid nitrogen stream and the second pressurized liquid nitrogen stream routed separately through the first heat exchanger, and optionally, the second heat exchanger.
The method may include a system of recooling the second or third fully-warmed nitrogen gas stream, the system of recooling comprising: i.) passing the second or third fully-warmed nitrogen gas stream through a first compressor and a first cooler to obtain a compressed and cooled nitrogen gas stream, wherein the first compressor is coupled to the second heat exchanger and to the first cooler; ii.) passing the compressed and cooled nitrogen gas stream through one or more turboexpanders; and iii). passing the turboexpanded nitrogen gas stream through the second heat exchanger to provide a fourth fully-warmed nitrogen gas stream. Step (ii) includes passing the compressed and cooled nitrogen gas stream through two turboexpanders connected in series.
A precooling system using liquid nitrogen for hydrogen or helium liquefaction is also disclosed. The system may include: a warm hydrogen or helium gas stream; a pressurized liquefied nitrogen stream from a supply of liquefied nitrogen; a heat exchanger; and at least one turboexpander coupled to the heat exchanger and configured to lower a temperature of a partially-warmed nitrogen gas stream discharged from the heat exchanger. The heat exchanger may be configured to exchange heat between the pressurized liquefied nitrogen stream and a warm hydrogen or helium gas stream to increase a temperature of the pressurized liquefied nitrogen stream and decrease a temperature of the warm hydrogen or helium gas stream to provide a precooled hydrogen or helium gas stream, and a warm nitrogen gas stream,. In another aspect, the system includes a first heat exchanger configured to exchange heat between the pressurized liquefied nitrogen stream and a partially-cooled hydrogen or helium gas stream to increase a temperature of the pressurized liquefied nitrogen stream to provide a partially-warmed nitrogen gas stream, and decrease a temperature of the partially-cooled hydrogen or helium gas stream; at least one turboexpander configured to lower the temperature of the partially-warmed nitrogen gas stream; and a second heat exchanger configured to exchange heat between the partially-warmed nitrogen gas stream and the warm hydrogen or helium gas stream to increase a temperature of the partially-warmed nitrogen gas stream to provide a fully-warmed nitrogen gas stream, and to decrease a temperature of the warm hydrogen or helium gas stream.
The system may also include at least one compressor and at least one cooler configured to receive the warm nitrogen gas stream discharged from the heat exchanger, at least one turboexpander configured to receive the warm nitrogen gas stream after passage through the at least one compressor and the at least one cooler, and/or optionally, a valve coupled to the turboexpander.
The processes disclosed herein have been developed, in part, to reduce the amount of liquid nitrogen required for precooling hydrogen or helium gas in the process of liquefaction. These processes and precooling systems employ additional steps and equipment to more fully utilize the amount of liquid nitrogen supplied into the precooling system. That is, the externally derived liquid nitrogen is consumed at a reduced rate compared to conventional precooling systems. It is also understood that where liquid nitrogen has also been used for precooling other hydrogen or helium streams employed in the liquefaction process (the so-called recycle streams), the means for reducing the liquid nitrogen consumption therein are also applicable.
In a method for precooling hydrogen or helium gas using a liquid nitrogen stream disclosed herein, a liquid nitrogen supply is pressurized and supplies most of its cooling capacity in heat exchange with the hydrogen or helium gas, which warms the nitrogen; the warmed nitrogen is then machine-expanded to a cold temperature and re-introduced for heat exchange with hydrogen or helium. In effect, the supplied liquid nitrogen is passed through the same heat exchanger a second time (in a loop), thus reducing the liquid nitrogen requirement and the attendant energy required for its own production. The energy costs to produce this reduced quantity of liquid nitrogen are thereby reduced. Since this cost is a significant component of the energy cost for producing liquid hydrogen or liquid helium, the overall cost of liquefaction is reduced, which is of commercial importance. The costs of precooling may be reduced by about 20% to about 50%.
The term “machine-expanded,” as used herein, includes any device utilized to produce work by reducing the enthalpy of the fluid expanded, such as a turboexpander or a reciprocating expansion engine.
Conventional liquid nitrogen precooling processes for hydrogen have a liquid nitrogen expenditure of about 7 to about 10 kg liquid nitrogen per kg liquefied hydrogen. The precooling process disclosed herein may have a liquid nitrogen expenditure of about 4 to about 6 kg liquid nitrogen per kg liquefied hydrogen, or about 4.30 to about 5.35 kg liquid nitrogen per kg liquefied hydrogen. This is a significant reduction in liquid nitrogen expenditure over the conventional process.
A method for precooling hydrogen or helium gas using a liquid nitrogen stream is disclosed, whereby an overall reduction of the amount of liquid nitrogen is used compared to conventional precooling.
That method includes providing a pressurized liquid nitrogen stream that may have a pressure of about 15 bar(a) to about 70 bar(a), about 20 bar(a) to about 60 bar(a), or 20 bar(a) to about 50 bar(a). The pressurized liquid nitrogen may have a temperature of about −147° C. to about −196° C., about −169° C. to about −195° C., or about −189° C. to about −194° C.
Pressurized liquid nitrogen may be supplied directly into the method disclosed herein. Alternatively liquid nitrogen may be supplied from an external source having a saturation pressure of about 1 bar(a) to about 10 bar(a), which may then be pressurized by any means known in the art. The liquid nitrogen may be pressurized by utilizing a pump or by compression to increase the pressure.
In an embodiment, the pressurized liquid nitrogen stream may be split into a first pressurized liquid nitrogen stream and a second pressurized liquid nitrogen stream, and each of the first pressurized liquid nitrogen stream and the second pressurized liquid nitrogen stream may be directed through a first heat exchanger to exchange heat between each of the first and second pressurized liquid nitrogen streams and the partially-cooled hydrogen or helium gas stream. The two partially-warmed nitrogen streams having passed separately through the first heat exchanger may be combined into one stream before being directed through at least one turboexpander.
In an embodiment, a liquid nitrogen stream produced at a saturation temperature at less than about 10 bar(a) is supplied into the system and split into a first portion of the liquid nitrogen stream and a second (or remaining) portion of the liquid nitrogen stream. The first portion of the liquid nitrogen stream may have the pressure increased by any means known in the art, e.g., by pump or compression, to provide a pressurized liquid nitrogen stream, and the second portion of the liquid nitrogen stream may be directed into the first heat exchanger, and then optionally into the second heat exchanger, separately from the routing of the pressurized liquid nitrogen stream.
A “pump” as used herein means a mechanical device to increase the pressure of a liquid.
A warm hydrogen or helium gas stream is supplied for precooling and may be supplied from one or more hydrogen or helium feed streams or cycle hydrogen or helium feed streams. The warm hydrogen gas stream may be produced from natural gas, electrolysis of water, or other chemical methods. A warm hydrogen or helium gas stream may be supplied from a source outside of the liquefaction process or it may be a recycle stream from elsewhere in the process. The warm hydrogen gas stream may be at any pressure suitable for its eventual liquefaction. The warm hydrogen gas stream may have a pressure between about 20 bar(a) and about 80 bar(a), or about 20 bar(a) and about 40 bar(a) and/or have a temperature of about 25° C. to about 35° C. The warm hydrogen gas stream may have a composition of about 75% ortho and about 25% para spin isomers.
Ortho-para conversion of the hydrogen gas may be incorporated as the hydrogen gas is cooled. Ortho-para conversion may occur in the first heat exchanger and in the second heat exchanger, with the passages of the heat exchanger(s) optionally packed with a catalyst for the feed hydrogen. The catalyst may be any known for use in the art for this purpose. This may improve the overall energy efficiency of the liquefaction process. The precooled hydrogen gas stream may have a temperature of about −173° C. to about −196° C., about −180° C. to about −196° C., or about −190° C. to about −192° C., and/or a pressure of about 15 bar(a) to about 100 bar(a), or about 20 bar(a) to about 80 bar(a). The precooled hydrogen gas stream may be about 53% ortho and about 47% para.
A “heat exchanger,” as used herein, means any device capable of transferring heat energy or cold energy from one medium to another medium, such as between at least two distinct fluids. Heat exchangers include “direct heat exchangers” and “indirect heat exchangers.” Thus, a heat exchanger may be of any suitable design, such as a co-current or counter-current heat exchanger, an indirect heat exchanger (e.g. a spiral wound heat exchanger or a plate-fin heat exchanger such as a brazed aluminum plate fin type), direct contact heat exchanger, shell-and-tube heat exchanger, spiral, hairpin, core, core-and-kettle, printed-circuit, double-pipe or any other type of known heat exchanger.
As used herein a first heat exchanger transfers energy between counter current streams in the colder steps of the process, while a second heat exchanger transfers energy between counter current streams in the warmer part of the process. The precooled hydrogen or helium gas stream exits from the first heat exchanger, while the fully-warmed nitrogen gas stream exits from the second heat exchanger. The first and second heat exchangers may be two parts of one heat exchanger, or they may be two separate heat exchangers. When the first and second heat exchangers are two parts of one heat exchanger, the heat exchanger includes multiple outputs for streams passing therethrough, including, but not limited to exit points for valves at different locations on the unit.
As used herein, the term “indirect heat exchange” means the bringing of two fluids into heat exchange relation without any physical contact or intermixing of the fluids with each other. Core-in-kettle heat exchangers and brazed aluminum plate-fin heat exchangers are examples of equipment that facilitate indirect heat exchange.
A next step includes passing the partially-warmed nitrogen stream through at least one turboexpander that lowers the temperature and pressure of the partially-warmed nitrogen stream to provide a cold nitrogen stream. The turboexpander may be coupled to the first heat exchanger by any means known in the art. The turboexpander exhaust may flow to the first heat exchanger. The turboexpander may include a brake, such as a blower, fan or an oil pump that circulates and cools, to dissipate energy. The turboexpander may be coupled to a compressor for capturing the energy generated by the turboexpander.
By passing through one turboexpander, the warm nitrogen stream may be cooled by about 30 degrees to about 130 degrees, or about 50 to about 100 degrees, and/or the pressure may be reduced by about 2 bar to about 100 bar, 4 bar to about 60 bar, or about 30 bar to about 50 bar. By passing the stream through a second turboexpander connected in series to the first turboexpander, the temperature and pressure of the stream may be further reduced. The first turboexpander may be coupled to the second turboexpander.
A “turboexpander” as used herein means any device employed to achieve a reduction in temperature by effecting a reduction in pressure, while generating useful energy which can be either removed from or captured to assist in the required cooling process by the performance of work, such as but not limited to, radial inward flow machines typically used in cryogenic processing. The turboexpander uses energy in an expanded gas to generate mechanical energy through a rotation. The turboexpander turns at high speed and then the energy may be transferred via a shaft to a compressor, which recovers the energy by compressing a separate feed gas stream. This process elevates the pressure feed gas stream to the compressor, enabling it to supply useful energy back into the system.
Optionally, the method includes passing the partially-warmed nitrogen stream through at least one compressor and at least one turboexpander, in any order, to provide a cold nitrogen stream that is routed back through the first heat exchanger or second heat exchanger. The method may include passing the partially-warmed nitrogen stream through two to five compressors and two to five turboexpanders to provide a cold nitrogen stream that is routed back through the first heat exchanger or second heat exchanger. The method may include passing the partially-warmed nitrogen stream through two to five compressors, two to five turboexpanders, and two to five coolers to provide a cold nitrogen stream that is routed back through the first heat exchanger. An equal number of coolers may be used in the process as the number of compressors. One or more of the turboexpanders may be connected by a shaft to one compressor.
A “cooler” as used herein means any water or air cooler known in the art that removes heat from the system, such as, a fin-fan unit for cooling process streams by ambient air, a shell-and-tube unit, or a plate cooler which uses a water or brine system for cooling process streams from elevated temperatures to near-ambient temperatures. Passing a stream through a cooler may lower the temperature of the stream by about 40° C. to about 100° C.
When passing the cold nitrogen stream through the first heat exchanger, this creates a loop in the process of precooling which is a second passage of the nitrogen stream though the first heat exchanger. This allows for the same originally supplied nitrogen to be recycled and used in countercurrent for cooling the hydrogen or helium gas stream a second time in the first heat exchanger. The cold nitrogen stream may be routed through a valve before passing through the first heat exchanger for the second time in the process of precooling. Turboexpanders have a limited range of pressure ratios (inlet pressure/outlet pressure), so a valve may be added to the system to further lower the pressure, for example, instead of adding a second turboexpander, if needed. Accordingly, when a valve is used, there is a pressure drop in the nitrogen stream across the valve. The valve may decrease the temperature and pressure, and increase the % gas in the nitrogen stream.
After passing through the second heat exchanger, the fully-warmed nitrogen gas stream may have a temperature of about 15° C. to about 30° C., or about 20° C. to about 28° C., and a pressure of about 0.5 bar(a) to about 2 bar(a), or about 1 bar(a) to about 2 bar(a). The fully-warmed nitrogen gas stream may be routed through another processing loop comprised of at least one turboexpander, and optionally at least one compressor, for pressurizing and cooling and then reintroduced into the second heat exchanger. The fully-warmed nitrogen gas stream may be routed through another processing loop comprised of at least one turboexpander, and optionally at least one compressor, for pressurizing and cooling and then reintroduced into the first heat exchanger and then into second heat exchanger.
Also disclosed is a precooling system using liquid nitrogen for hydrogen or helium liquefaction. The system may comprise: a warm hydrogen or helium gas stream; a pressurized liquefied nitrogen stream from a supply of liquefied nitrogen; a first heat exchanger configured to exchange heat between the pressurized liquefied nitrogen stream and a partially-cooled hydrogen or helium gas stream to increase a temperature of the pressurized liquefied nitrogen stream to provide a partially-warmed nitrogen gas stream, and decrease a temperature of the partially-cooled hydrogen or helium gas stream; at least one turboexpander configured to lower the temperature of the partially-warmed nitrogen gas stream; and a second heat exchanger configured to exchange heat between the partially-warmed nitrogen gas stream and the warm hydrogen or helium gas stream to increase a temperature of the partially-warmed nitrogen gas stream and decrease a temperature of the warm hydrogen or helium gas stream. The first heat exchanger or the second heat exchanger may be coupled to one turboexpander. The precooling system may comprise a valve coupled to one turboexpander. The valve may configured to reduce the pressure of the nitrogen gas stream.
The precooling system may comprise at least one compressor and at least one cooler, and optionally at least one turboexpander, configured to receive the fully-warmed nitrogen gas stream after passage through the second heat exchanger. The precooling system may comprise at least one turboexpander configured to receive the warm nitrogen gas stream after passage through the at least one compressor and the at least one cooler. The precooling system may comprise one to four compressors, one to four coolers, and one to four turboexpanders configured to receive the fully-warmed nitrogen gas stream after passage through the second heat exchanger, with each compressor being coupled to a cooler, and the one to four turboexpanders being connected after the compressors and coolers in the system.
Also disclosed is a precooling system using liquid nitrogen for hydrogen or helium liquefaction, the system comprising: a warm hydrogen or helium gas stream; a pressurized liquefied nitrogen stream from a supply of liquefied nitrogen; a heat exchanger configured to exchange heat between the pressurized liquefied nitrogen stream and a warm hydrogen or helium gas stream to increase a temperature of the pressurized liquefied nitrogen stream to provide a warm nitrogen gas stream, and decrease a temperature of the warm hydrogen or helium gas stream to provide a precooled hydrogen or helium gas stream; and at least one turboexpander coupled to the heat exchanger and configured to lower a temperature of a partially-warmed nitrogen gas stream discharged from the heat exchanger. The precooling system may also include at least one compressor and at least one cooler configured to receive the warm nitrogen gas stream after passage through the heat exchanger, and optionally, at least one turboexpander configured to receive the warm nitrogen gas stream after passage through the at least one compressor and the at least one cooler. The precooling system may also include a valve coupled to the turboexpander configured to reduce the pressure of the nitrogen gas stream.
Described herein are systems and processes relating to precooling hydrogen or helium gas using a liquid nitrogen stream. Specific embodiments of the disclosure include those set forth in the following paragraphs as described with reference to the Figures. While some features are described with particular reference to only one Figure (such as
The cold nitrogen gas stream 107 is then routed through the first heat exchanger to complete the loop, and for a second pass of the nitrogen gas stream through the first heat exchanger, in which energy is transferred between the partially-cooled hydrogen or helium gas stream 102 and the cold nitrogen stream 107, to provide a partially-warmed nitrogen gas stream 108 and a precooled hydrogen or helium gas stream 103.
The partially-warmed nitrogen gas stream 108 is then routed through a second heat exchanger 130 in which energy is transferred between the warm hydrogen or helium gas stream 101 and the partially-warmed nitrogen gas stream 108, to provide a fully-warmed nitrogen gas stream 109 and a partially-cooled hydrogen or helium gas stream 102, which is then routed through the first heat exchanger 131.
The second heat exchanger 130 may include auxiliary refrigeration, here shown as propene streams 114, 115. Liquid propene stream 114 passes through the second heat exchanger which exchanges heat between the auxiliary refrigeration and the warm hydrogen or helium gas stream 101, and exits as a gas propene stream 115. The second heat exchanger may include auxiliary refrigeration coupled to the second heat exchanger. Auxiliary refrigeration supplements coolant in the precooling process and may be supplied from any other known sources of refrigeration. Auxiliary refrigeration may be a vapor compression refrigeration, absorption refrigeration, mixed refrigerant refrigeration, or any other means known to extract heat from the warm hydrogen or helium gas stream. Auxiliary refrigeration may comprise of one refrigeration stream, or two refrigeration streams, being the same or different. Auxiliary refrigeration may be a propene refrigeration stream which supplies a liquid stream at a temperature of about −20° C. to −50° C., and exits the system as a gas stream.
Having described an embodiment of the disclosure, additional aspects will now be described.
The system of
In
Table 3 includes a listing of the streams and equipment shown in FIG. 3 and the properties of each of the streams. The liquid nitrogen consumption, calculated by dividing the LIN supply flow rate by precooled hydrogen flow rate, is 4.30 kg LIN/kg LH2
Table 4 includes a listing of the streams and equipment shown in
A conventional precooling process is shown in
While there have been described what are presently believed to be various aspects and certain desirable embodiments of the disclosure, those skilled in the art will recognize that changes and modifications may be made thereto without departing from the spirit of the disclosure, and it is intended to include all such changes and modifications as fall within the true scope of the disclosure.
This application claims priority benefit under 35 U.S.C. §119(e) to U.S. Provisional Application No. 63/207,684, filed Mar. 15, 2021, the contents of which is incorporated by reference herein in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63207684 | Mar 2021 | US |
