CN101284646B

CN101284646B - Hydrogen preparing process by reacting pure alminuim powder with water

Info

Publication number: CN101284646B
Application number: CN2008100340900A
Authority: CN
Inventors: 邓振炎
Original assignee: University of Shanghai for Science and Technology
Current assignee: University of Shanghai for Science and Technology
Priority date: 2008-02-29
Filing date: 2008-02-29
Publication date: 2011-07-20
Anticipated expiration: 2028-02-29
Also published as: CN101284646A

Abstract

The invention provides a method for producing hydrogen through continuous reaction between pure aluminum powder body and water under the conditions of low vacuum and warm water. The main content of the method is as follows: putting a certain amount of fine A1 powder body into a closed vessel with a certain amount of water (the weight ratio of aluminum to water is 1:2-2.5), heating the water mixed with the Al powder body in the vessel to a certain temperature (such as 40 DEG C), and then vacuumizing to a certain low vacuum state (such as 3kPa, namely, the gas pressure of 0.03atm). The Al powder body can react with the water continuously and generate the hydrogen under the conditions of the temperature and the low vacuum. The speed for producing hydrogen by the reaction of the Al powder body and the water can be further increased if the reaction temperature is increased successively (shown in the attached figure 1). The hydrogen-producing method is mainly used for supplying hydrogen to fuel cells carried by fuel cell cars and other medium-sized and small-sized vehicles or appliances.

Description

Produce the processing method of hydrogen with fine aluminium powder and water reaction

Technical field

The present invention relates to a kind ofly produce the processing method of hydrogen with the reaction of fine aluminium powder and water, it is a kind of method of simple portable product hydrogen newly, can be directly provides hydrogen source for fuel cell car and other middle-size and small-size transportation means or the entrained fuel cell of device.The invention belongs to technical field of chemistry and chemical engineering.

Background technology

Along with going from bad to worse of global warming, environment, people more and more pay attention to the research and development of clean energy technology.Fuel cell is the core of clean energy technology, because fuel cell directly changes chemical energy into electric energy thereby has high efficient and low pollution.Hydrogen is the ideal fuels of fuel cell, be benign because the oxidation products of hydrogen is a water to environment, and hydrogen has characteristics in light weight, that energy density is high.Because the exhaustion day by day of fossil energies such as oil sees the bottom, the hydrogen fuel cell automobile is considered to people's ideal vehicles in the future.

The significant obstacle that influences the fuel cell car industrialized development is the transportation and the storage of hydrogen.Because liquefying hydrogen needs-252 ℃ low temperature, at normal temperatures hydrogen-pressure is reduced to about about 700 normal atmosphere of weight ratio needs of the hydrogen that can satisfy the commercialization requirement.For the commerce operation, these technology all do not have competitive power on cost.So people invest hydrogen storage material with attention.USDOE to the business-like target of hydrogen storage material is, the weight ratio of hydrogen in hydrogen storage material is 6.5wt% under 0～100 ℃ and 1～10 atmospheric condition.Though the various countries scientist seeking good hydrogen storage material, comprises metal hydride, organic-inorganic material and nano material etc., the development of hydrogen storage material does not at present also relatively slowly break through, and does not have to satisfy the material that USDOE requires.Under above working conditions, at present the storage hydrogen level of hydrogen storage material is far from reaching target call about～1wt%.

For solving the problem of fuel cell hydrogen source, people turn to attention and produce the hydrogen material recently.Produce characteristics of hydrogen material and can produce hydrogen with the water direct reaction, thereby saved complicated additional unit for them.The present metal hydride that mainly contains as research object is as LiH, NaH, MgH ₂, NaAlH ₄, LiBH ₄, NaBH ₄And KBH ₄Deng.Consider stability, price and other various factors of metal hydride, be easy to the business-like NaBH of having only at present ₄Therefore, as the product hydrogen material of portable use, NaBH ₄Study at most.Use NaBH ₄As the problem of producing the existence of hydrogen material is to use NaOH to make solution stabilizer thereby have the highly basic pollution problem.Simultaneously, use NaBH ₄Must use catalytic unit and catalyzer to produce hydrogen as producing the hydrogen material, this will increase the volume and the cost of system greatly, and in fact the cost of catalytic unit and catalyzer and fuel cell are suitable.Another present problem is NaBH ₄Cost an arm and a leg, be about US$55/kg, the cost that influence is used.

Producing the another kind of of hydrogen material is metal.Though metal Li, Na and K can be directly with the water reaction and produce hydrogen, the cost an arm and a leg product of reaction simultaneously of these basic metal is that highly basic produces environment and pollutes, so does not have commercial application value.But cheaply and on earth content is abundant for other metal such as prices such as Fe and Al, thereby attractive to people as producing the hydrogen material.Particularly not only atomic mass is light for metal A l, and the electron density height, with the hydrogen amount height of water reaction generation.But at normal temperatures and pressures, the reaction of metal Fe and Al and water is all very slowly limited.Metal A l particularly, its surface can form dense oxide protective membrane of a passivation when being exposed to well-oxygenated environment, and therefore, the direct reaction of metal A l and water is difficult.

Summary of the invention

The purpose of this invention is to provide a kind of new easy, inexpensive hydrogen manufacturing technique, reaching Al and water under certain condition can direct complete reaction and produce the target of hydrogen.

The present invention is a kind of processing method with fine aluminium powder and water reaction generation hydrogen, it is characterized in that having following process and step:

A. the meticulous aluminium powder body that with a certain amount of particle diameter is several microns to tens microns is put into the closed container (weight ratio of aluminium and water is 1: 2～2.5) that certain water gaging is housed, aluminium powder in the container is mixed with water, be heated to 40 ℃, be evacuated to low vacuum state then, its vacuum absolute pressure is≤i.e.≤0.03 normal atmosphere of 3KPa, and make aluminium powder body and water successive reaction under these conditions and produce hydrogen; Its reaction equation is:

More than reaction can produce the hydrogen (weight of the hydrogen of generation compares with the gross weight of aluminium and water) of 3.7mass%.The by product Al (OH) of reaction ₃Be the chemically neutral environmentally safe, and Al (OH) ₃Can be reduced into metal A l by the fusion electrolysis technology recycles.

The advantage of the inventive method is as follows:

(1) the present invention need not special and exacting terms, only needs certain rough vacuum and gentle temperature condition can make hydrogen.

(2) have higher hydrogen output, hydrogen output can be up to the hydrogen of 3.7mass%.

(3) just can make hydrogen without any need for soda acid and catalyzer, and byproduct of reaction is chemically neutral, non-environmental-pollution; And reducible time metal A l recycles.

(4) the metallic aluminium price is relatively cheap, and the aluminium source is abundant to be obtained easily; The cost that produces 1kg hydrogen with the Al powder is about NaBH ₄Sixth.

Therefore use aluminium powder system hydrogen to fuel cell car and other running tools or the entrained fuel cell hydrogen-feeding of device, tangible price advantage is arranged, and have the simple advantage of processing unit.

Description of drawings

Fig. 1 be the hydrogen amount that under rough vacuum and room temperature (18 ℃), 40 ℃ and 50 ℃ of conditions, produces respectively of the pure Al powder of 0.5 gram with the water reaction over time, wherein (b) be with (a) middle corresponding container of experimental data in air pressure.

Fig. 2 is that the X-ray diffraction pattern shows: the original Al powder surface of a. has complicated phase composition; The phase composition of b.Al powder and water 23 hours rear surface complexity of reaction under room temperature (18 ℃) and 0.03 normal atmosphere vacuum condition disappears; C.Al powder and the water reactant of reaction after 8 hours under 40 ℃ and 0.03 normal atmosphere vacuum condition is Bayerite (Al (OH) ₃).

Fig. 3 is the perspective Electronic Speculum shape appearance figure of (a) original Al powder, (b) Al powder and the water side reaction thing Bayerite (Al (OH) of reaction after 8 hours under 40 ℃ and 0.03 normal atmosphere vacuum condition ₃) perspective Electronic Speculum shape appearance figure.

Embodiment

After now specific embodiments of the invention being described in.

Embodiment one: the pure aluminium powder of getting 0.5 gram particle and directly be 3 μ m is put into the closed container that a certain amount of water is housed, aluminium powder body in the container is mixed with water, be heated to 40 ℃, be evacuated to low vacuum state then, its vacuum absolute pressure is 3KPa, promptly 0.03 normal atmosphere makes aluminium powder body and water successive reaction under this condition, and produces hydrogen; Its reaction equation is:

(1) under room temperature (18 ℃), 40 ℃ and 50 ℃ of conditions, the amounts of hydrogen that Al powder and water reaction produce over time.Referring to Fig. 1, Al powder and almost not reaction of water under the visible room temperature among the figure; But Al powder and water successive reaction and produce hydrogen under 40 ℃ of conditions.Temperature is increased to 50 ℃, and the speed that hydrogen is produced in reaction obviously improves.

(2) X-ray diffraction (XRD) detects, and shown by the X-ray diffracting spectrum of Fig. 2: the original Al powder surface of a. has complicated phase composition; The phase composition of b.Al powder and water 23 hours rear surface complexity of reaction under room temperature (18 ℃) and 0.03 normal atmosphere vacuum condition disappears; C.Al powder and the water reactant of reaction after 8 hours under 40 ℃ and 0.03 normal atmosphere vacuum condition is Bayerite (Al (OH) ₃).

(3) perspective electron microscope (SEM) detects, perspective Electronic Speculum shape appearance figure by Fig. 3 can be seen: (a) the fine and close smooth pattern of original Al powder, (b) Al powder and the water side reaction thing Bayerite (Al (OH) of reaction after 8 hours under 40 ℃ and 0.03 normal atmosphere vacuum condition ₃) the loose pattern of cotton shape.

Claims

1. processing method that produces hydrogen with the reaction of fine aluminium powder and water, it is characterized in that having following process and step: with a certain amount of particle diameter is that several microns to tens microns meticulous aluminium powder body is put into the closed container that certain water gaging is housed, the weight ratio of aluminium and water is 1: 2～2.5, aluminium powder in the container is mixed with water, be heated to 40 ℃, be evacuated to low vacuum state then, its vacuum absolute pressure is≤3kPa to make aluminium powder body and water successive reaction under these conditions and produce hydrogen; Its reaction equation is: