阅读说明：本技术 一种采用钯合金膜纯化制取高纯氢工艺 (Process for preparing high-purity hydrogen by adopting palladium alloy membrane purification ) 是由 江洋洋 张楚璠 孔京 黄伟 贺向坡 于 2019-03-15 设计创作，主要内容包括：本发明涉及一种采用钯合金膜纯化制取高纯氢工艺,将粗氢通过脱硫吸附床,颗粒过滤器,加热器,增压泵,接着粗氢进入金属钯合金膜分离器中,一级分离器的出口气经换热器把热量交换到入口处。一级分离器的截流气通入二次分离器中提纯到一定纯度,再汇入到一级分离器进口气管路。另外,利用蓄热式加热炉回收废气热量进一步提高能量利用率。本发明过程较简单、清洁、节能,所得氢气适用于燃料电池、半导体器件和精密仪器等。同时,对原料气要求不高,所用撬装式设备方便移动,可以直接以工业化产氢为原料实现现场提纯得到高纯氢气。(The invention relates to a process for preparing high-purity hydrogen by adopting palladium alloy membrane purification, which comprises the steps of passing crude hydrogen through a desulfurization adsorption bed, a particle filter, a heater and a booster pump, then feeding the crude hydrogen into a metal palladium alloy membrane separator, and exchanging heat to an inlet through an outlet gas of a primary separator by a heat exchanger. The cut-off gas of the first separator is introduced into the second separator to be purified to a certain purity and then is gathered into an inlet gas pipeline of the first separator. In addition, the regenerative heating furnace is used for recovering the heat of the waste gas, so that the energy utilization rate is further improved. The process of the invention is simple, clean and energy-saving, and the obtained hydrogen is suitable for fuel cells, semiconductor devices, precise instruments and the like. Meanwhile, the requirement on the raw material gas is not high, the skid-mounted equipment is convenient to move, and the industrial hydrogen production can be directly used as the raw material to realize on-site purification to obtain the high-purity hydrogen.)

1. A process for preparing high-purity hydrogen by adopting palladium alloy membrane purification is characterized in that a skid-mounted device comprising two stages of metal palladium alloy membrane separation is adopted for hydrogen purification.

2. The process for preparing high-purity hydrogen by adopting palladium alloy membrane purification as claimed in claim 1, wherein the skid-mounted device for hydrogen purification comprises: the device comprises a desulfurization adsorption bed, a particle filter, a primary metal palladium alloy membrane separator, a secondary metal palladium alloy membrane separator, a primary heater, a secondary heater, a primary booster pump, a secondary booster pump, a first gas storage tank, a second gas storage tank, a third gas storage tank, a fourth gas storage tank, a heat exchanger and a heat accumulating type heating furnace, wherein crude hydrogen is connected with all the devices through pipelines.

3. The process for preparing high-purity hydrogen by adopting palladium alloy membrane purification as claimed in claim 2, which is characterized by comprising the following steps:

step S1: passing the crude hydrogen through a desulfurization adsorption bed and a particle filter to remove sulfide and particle impurities in the raw material crude hydrogen;

step S2: the filtered crude hydrogen enters a first gas storage tank, is pressurized by a primary booster pump, and is stored in a second gas storage tank, wherein the gas pressure is increased to 1-3 MPa;

step S3: the pressurized gas enters a primary heater from a second gas storage tank, and the gas is heated to 250-400 ℃ in the primary heater;

step S4: the pressurized and heated gas enters a primary metal palladium alloy membrane separator, one part of the pressurized and heated gas passes through the palladium alloy membrane separator to become a high-purity hydrogen product, and the other part of the intercepted gas enters a third gas storage tank;

step S5: the high-purity hydrogen flowing out of the outlet of the primary metal palladium alloy membrane separator exchanges heat to the inlet gas of the primary metal palladium alloy membrane separator through the heat exchanger to supplement heat for recycling;

step S6: the gas in the third gas storage tank enters a fourth gas storage tank after being pressurized by a secondary booster pump, is heated to 250-450 ℃ by a secondary heater, is purified to 85-95% by introducing a secondary metal palladium alloy membrane separator and is converged into the first gas storage tank; the trapped air of the secondary metal palladium alloy membrane separator is combusted to reuse heat.

4. The process for preparing high-purity hydrogen by adopting palladium alloy membrane purification as claimed in claim 2 or 3, wherein the pipeline is provided with a flow regulating valve and a flow display for displaying the gas flow in the pipeline.

5. The process for preparing high-purity hydrogen by adopting palladium alloy membrane purification as claimed in claim 2 or 3, wherein a pressure gauge and a pressure alarm device are connected to the gas storage tank, the pressure in the gas storage tank is displayed, and an alarm is given when the pressure is too high.

6. The process for preparing high-purity hydrogen by adopting palladium alloy membrane purification as claimed in claim 2 or 3, wherein the palladium alloy membrane is organized on the surface of the pipe in one or two of a winding type and a flat type inside the primary metal palladium alloy membrane separator and the secondary metal palladium alloy membrane separator.

7. The process for preparing high-purity hydrogen by adopting palladium alloy membrane purification as claimed in claim 2 or 3, wherein in the primary metal palladium alloy membrane separator and the secondary metal palladium alloy membrane separator, the palladium alloy membrane is composed of palladium and other metals, and the other metals are selected from one or more of silver, gold, copper, nickel, zirconium, gallium, aluminum and titanium.

8. The process for preparing high-purity hydrogen by adopting palladium alloy membrane purification as claimed in claim 2 or 3, wherein the crude hydrogen is one or more of hydrogen production by water electrolysis, methanol cracking gas, coal gas production and water gas conversion, and the purity is 65-95%.

9. The process for preparing high-purity hydrogen by adopting palladium alloy membrane purification according to claim 2 or 3, wherein the step of primary heat exchanger and secondary heat exchanger is one or more of a double-pipe type, a plate type, a tube type or a shell-and-tube type heat exchanger.

10. The process of claim 3, wherein the trapped gas in step S6 is introduced into a regenerative furnace to heat the heat exchange medium with the trapped gas.

Technical Field

The invention belongs to the field of hydrogen membrane separation and purification, and particularly relates to a hydrogen membrane separation and purification process method.

Background

With the reduction of fossil energy and the development bottleneck of power battery energy, and the excellent characteristics of hydrogen as secondary energy, such as good combustion performance, high efficiency, cleanness, no pollution, no greenhouse effect and the like, governments and research institutions have shifted attention to hydrogen energy. Recently, the national reform committee and the national energy agency have issued "innovation action plan of energy technology revolution (2016-.

The research on hydrogen production technology based on renewable energy and advanced nuclear energy, new generation coal catalytic gasification hydrogen production and methane reforming/partial oxidation hydrogen production technology, distributed hydrogen production technology and hydrogen purification technology develops key materials and technical equipment for hydrogen storage and transportation, realizes the integration of preparation, storage, transportation and application of large-scale and low-cost hydrogen, the standardization, popularization and application of hydrogen storage and hydrogen production modes in a hydrogenation station on site, and the like, and is a key task of hydrogen energy and fuel cell technology. The conventional process for producing hydrogen often produces a plurality of byproducts, such as CO and CO₂、O₂、H₂O、CH₄And the like, and most application fields of hydrogen have high requirements on the purity of the hydrogen. According to the national standard hydrogen fuel quality requirement part 1: the requirement in the proton exchange membrane fuel cell automobile fuel is that the purity standard of hydrogen used for the fuel cell at least reaches 99.999 percent. Meanwhile, in the last decade, the semiconductor industry such as large-scale integrated circuits, liquid crystal displays and optical fiber communication devices in China has increased explosively, and the quality requirement on high-purity gas (99.999% -99.9999%) is also very strict. Therefore, at present, the quantity and quality of the demand of the market for high-purity hydrogen are gradually improved, and the market prospect is better.

The low consumption and high efficiency separation method is always a difficult problem in the field of gas separation, and the traditional hydrogen separation and purification mainly uses a pressure swing adsorption technology, has higher requirements on equipment and has large investment. With the development of technology, the cost problem becomes a key link for the relation between the hydrogen energy cost and the application. The membrane separation method is a method for separating gas according to the selective permeability of a membrane to a specific gas, and the target gas is obtained by separating the gas through the selective permeability of the membrane under the pressure driving by means of the adsorption capacity of each component in the gas on the surface of the membrane or the difference of dissolution-diffusion in the membrane. The membrane separation method has the characteristics of no phase change, investment saving, low energy consumption, small occupied area, simple equipment, convenient operation, high running reliability and the like. Metallic palladium and its alloy membranes were the first metallic membranes used in hydrogen separation studies due to their excellent permeability and selectivity for hydrogen.

Patents CN201710568915.6 and CN201720903241.6 disclose a process, a mechanical device, a control system and a separation process for preparing high-purity and ultra-high-purity hydrogen by purifying hydrogen from coal gas. The low-grade coal mixed gas is purified to high-purity hydrogen by combining PSA pressure swing adsorption and membrane separation hydrogen, which is also a mixing means for purifying hydrogen conventionally used at present. The PSA equipment has large investment, small operation elasticity, large operation pressure and unobvious advantages in the aspects of re-investment and safety. In the metal membrane separation process without PSA, in order to obtain a larger hydrogen recovery rate, a larger operation pressure is generally selected, and the trapped gas is directly discharged or combusted (with open fire), so that the safety is questioned and the energy cannot be fully utilized.

Disclosure of Invention

The invention aims to provide a process method for purifying hydrogen by adopting a pilot-scale skid-mounted device, which integrates equipment such as pretreatment, gas separation and purification, tail gas recycling and the like. The hydrogen-gas hydrogen production device has the advantages of small occupied area, high hydrogen utilization rate, small operation pressure, high safety and large operation elasticity, and is suitable for various application scenes.

By adopting the process method of palladium alloy membrane separation, high-purity gas and closure gas obtained after separation and purification can be extracted out of the reaction system, the effect of promoting chemical equilibrium movement can be achieved, and the separation is facilitated to obtain hydrogen with higher purity; the first-stage intercepted gas is concentrated by adopting two-stage separation and then returned to the feeding pipeline, so that the operating pressure is reduced while the hydrogen utilization rate is kept; the finally intercepted low-concentration hydrogen is fully utilized, and the heat of the outlet hydrogen is collected through the heat accumulating type heating furnace and used for heating a heat exchange medium, so that the energy utilization rate and the safety are improved.

The main technical scheme of the invention is as follows: the process for preparing high-purity hydrogen by adopting palladium alloy membrane purification is characterized in that a skid-mounted device comprising two stages of metal palladium alloy membrane separation is adopted for hydrogen purification.

The basic process of the invention is that crude hydrogen passes through a desulfurization adsorption bed, a particle filter, a heater and a booster pump, then enters a metal palladium alloy membrane separator, and the outlet gas of a primary separator exchanges heat to an inlet through a heat exchanger. In addition, the cut-off gas of the first-stage separator is introduced into a second-stage separator to be purified to a certain purity and then is gathered into an inlet gas pipeline of the first-stage separator.

The skid-mounted high-purity hydrogen purification device comprises: the device comprises a desulfurization adsorption bed, a particle filter, a primary metal palladium alloy membrane separator, a secondary metal palladium alloy membrane separator, a primary heater, a secondary heater, a primary booster pump, a secondary booster pump, a first gas storage tank, a second gas storage tank, a third gas storage tank, a fourth gas storage tank, a heat exchanger, a heat accumulating type heating furnace and the like, wherein the crude hydrogen is connected with all the devices through pipelines.

The invention discloses a typical technical scheme: the process for preparing high-purity hydrogen by adopting palladium alloy membrane purification comprises the following specific steps:

(1) passing the crude hydrogen through a desulfurization adsorption bed and a particle filter to remove sulfides such as hydrogen sulfide and particle impurities in the raw material crude hydrogen;

(2) the filtered crude hydrogen enters a first gas storage tank through a pipeline, is pressurized through a primary booster pump, and is stored in a second gas storage tank, wherein the gas pressure is increased to 1-3 MPa;

(3) the pressurized gas enters a primary heater from a second gas storage tank, and the gas is heated to 250-400 ℃ in the primary heater;

(4) the pressurized and heated gas enters a primary metal palladium alloy membrane separator, one part of the pressurized and heated gas passes through the palladium alloy membrane separator to become a high-purity hydrogen product, and the other part of the intercepted gas enters a third gas storage tank;

(5) the high-purity hydrogen flowing out of the outlet of the primary metal palladium alloy membrane separator exchanges heat to the inlet gas of the primary metal palladium alloy membrane separator through a heat exchanger, and is recycled as supplementary heat;

(6) the gas in the third gas storage tank enters a fourth gas storage tank after being pressurized by a secondary booster pump, is heated to 250-450 ℃ by a secondary heater, is purified to 85-95% by introducing a secondary metal palladium alloy membrane separator and is converged into the first gas storage tank. The trapped air of the secondary metal palladium alloy membrane separator is combusted to reuse heat.

Furthermore, a flow regulating valve is arranged on the pipeline and is provided with a flow display to display the gas flow in the pipeline.

Further, a pressure gauge and a pressure alarm device are connected to the gas storage tank, the pressure in the gas storage tank is displayed, and an alarm is given when the pressure is too high.

Furthermore, inside the primary metal palladium alloy membrane separator and the secondary metal palladium alloy membrane separator, the structure mode of the palladium alloy membrane on the surface of the pipe fitting is one or more of a winding type and a flat type.

Further, in the primary metal palladium alloy membrane separator and the secondary metal palladium alloy membrane separator, the palladium alloy membrane is composed of palladium and other metals, and the other metals are one or more of silver, gold, copper, nickel, zirconium, gallium, aluminum and titanium.

Further, the purity of the crude hydrogen of the inlet gas is 65-95%.

Further, the primary heat exchanger and the secondary heat exchanger are one or more of a double-pipe type heat exchanger, a plate type heat exchanger, a shell-and-tube type heat exchanger or a shell-and-tube type heat exchanger.

Further, the intercepted gas in the step (6) enters a regenerative heating furnace, and the heat is utilized to heat the heat exchange medium.

When the invention adopts the palladium alloy membrane separator to separate and obtain the purified high-purity hydrogen from the crude hydrogen (the source can be hydrogen production by water electrolysis, methanol cracking gas, coal gas, water gas conversion and the like), the elasticity, the economy and the safety of the operation are comprehensively considered, the loss of the hydrogen in the crude hydrogen is reduced as much as possible by secondary separation and purification, the heat of the waste gas is recovered by a regenerative heating furnace, the temperature of the outlet gas is exchanged to the inlet gas by a heat exchanger, and the temperature of the inlet device is improved while the energy utilization rate is improved.

The invention has the advantages of simple and convenient process operation, small operation pressure, large elasticity, good safety, high efficiency of separating hydrogen by the palladium alloy membrane and good economic benefit, fully utilizes the intercepted gas of the primary separator and provides a more optimized method for efficiently producing high-purity hydrogen.

Drawings

FIG. 1 is a schematic diagram of an apparatus for purifying hydrogen to obtain high-purity hydrogen by using a palladium alloy membrane according to an embodiment of the present invention.

In the figure, 1 is a desulfurization adsorption bed, 2 is a particle filter, 3 is a first gas storage tank, 4 is a primary booster pump, 5 is a second gas storage tank, 6 is a primary heater, 7 is a primary metal palladium alloy membrane separator, 8 is a heat exchanger, 9 is a third gas storage tank, 10 is a secondary booster pump, 11 is a fourth gas storage tank, 12 is a secondary heater, 13 is a secondary metal palladium alloy membrane separator, and 14 is a regenerative heating furnace.

Detailed Description

In order to better understand the technical scheme of the invention, the invention is further described in the following with reference to the embodiment and the accompanying drawings, which need to be noted that the embodiment does not constitute a limitation to the protection scope of the invention.