GB2580864A

GB2580864A - Apparatus to generate hydrogen from water splitting

Info

Publication number: GB2580864A
Application number: GB1817152.0A
Authority: GB
Inventors: Ouadi Miloud
Original assignee: Individual
Current assignee: Individual
Priority date: 2018-10-22
Filing date: 2018-10-22
Publication date: 2020-08-05
Also published as: GB201817152D0

Abstract

An apparatus for the production of hydrogen via water splitting or dissociation by the reaction between water 22 and an alkali metal 11 and/or alkali metal alloy such as lithium, sodium, potassium, rubidium, caesium or francium, mixed with a base catalyst at a temperature up to 1000 °C to produce hydrogen gas 23 and other by-products which may be used to generate electricity via a fuel cell, gas engine 25 or a sterling engine, may be drained and pumped away via a pump 49, or collected. The apparatus may comprise metal alkali identification equipment or detector 13, which rejects non-alaki materials and carries it out of the box 15 and may comprise an integrated metal shredder 17 or other milling mechanism to pre-treat the metal, an air lock 18 to isolate the main reaction chamber from the outside environment, and may comprise mechanical agitation.

Description

Hydrogen generation apparatus The invention relates to a new apparatus that generates hydrogen from the reaction between water and alkali metal and/or metal alloy whereby at least one metal within the matrix is an alkali metal.

The present innovation relates to a device known as the EcoPower Box, in which alkali metal and/or alkali metal alloys (feedstock) or combinations thereof are placed in the device. A detector identifies the material and a shredder/milling mechanism reduces the material size and increases the material surface area, the material is subsequently transported to the main reaction chamber. Air from the external atmosphere is prevented from entering the main reaction chamber by using an air lock system whereby only feedstock material can enter the main reactor chamber excluding air from the external atmosphere. In the main reaction chamber the alkali metal and/or alkali metal alloy come into a direct contact with a source of water, including waste water, fresh water, river water, salt water, sea water, or brackish water and reacts to produce hydrogen gas, the mixture can be mechanically agitated by use of an agitator, the reaction can also happen with the addition of a base catalyst added to the mixture and occurs between ambient temperature up to 1000 °C.

Hydrogen can be generated through different pathways. At current age, the state of art is to produce hydrogen via hydrocarbon reforming, especially trough thermolysis. Hydrogen is manly obtained from natural gas, from a fossil fuel source. Alternatively, hydrogen can be produced by electrolysis of water, without emissions of greenhouse gases (GHGs), providing that the electricity used in the process is derived from a renewable source. However, electrolysis demands high amount of energy to split the water. New techniques to produce hydrogen include: fermentation (microbial biomass conversion), biomass derived liquid reforming, thermochemical water splitting, photobiological, photoelectrochemical water splitting. Other methods include the gasification of biomass to produce a synthesis gas which then needs to be separated to extract hydrogen. This involves expensive gas cleaning equipment to remove tars, and other non-condensable gases such as CO2 and CO. Furthermore gasification processes require an abundant supply of biomass which is readily available as a feedstock. Once biomass is used in the reactor, it needs to be regrown sustainably in order to be classed as carbon neutral. This can take months or even years before any carbon savings are achieved.

In prior art reference, the authors of patent US 9780398B1 disclosed a device that generates heat, hydrogen and metal hydroxide by water splitting due to aluminium and water reaction to power a fuel cell unit. The authors of patent US2005/0232837A1 disclosed a new method and apparatus to split the water and produce hydrogen. Although these approaches are efficient towards hydrogen production, the drawback is that these reactors can only operate in batch mode because they do not include a detection mechanism for aluminium identification and do not include an integrated pretreatment shredding/milling system and do not include a method to prevent air from entering the reactor via an airlock system, whereby only selected feedstock material can pass into the main reaction chamber and air from the atmosphere is excluded. Consequently, the reactors cannot be operated on a continuous basis or semi continuous basis. In addition these previous patents do not integrate a pre-treatment system for preparation of metal or metal alloy before reaction.

Accordingly, it is an objective of the present invention to propose a new device for the generation of hydrogen from water splitting with the reaction between alkali metal and/or alkali metal alloys and water. This embodiment consists of a box or chamber integrated with a belt conveying system and a spectrometer or any other detection mechanism which identifies the material as alkali metal and/or alkali metal alloy and then via a control mechanism either sends the metal forwards to a shredding/milling compartment or rejects the material. After shredding/milling the material falls by gravity into an air lock system, whereby shredded material passes and air from the atmosphere is prevented from entering the system. The material falls into a storage hopper and a screw or any other conveying system carries the shredded material into the main reaction chamber, where there is either water and/or water pre mixed with a base catalyst. Water and base catalyst are fed into the reactor separately from their own independent storage hoppers which are close coupled to the reactor. Feeding of water and catalyst is performed by a controlled mechanism. The water splitting reaction temperature range is from ambient temperature to 1000 °C. The reaction is exothermic and generates heat. Therefore an integrated heat exchanger using water or any other heat exchange medium is necessary to remove waste heat from the process. This heat can be recovered and used to generate additional electricity by using a Stirling engine. Waste heat from the process can also be used for any other application whereby heat is required as a necessary input.

The hydrogen from water splitting is collected, filtered and cleaned, and supplies a gas engine or a fuel cell to generate electricity.

Figure 1 is a schematic diagram of a new apparatus (EcoPower Box) to produce hydrogen from alkali metals and or alkali metal alloys via water splitting reactions.

Figure 2 illustrates the embodiment descripted in Figure 1 route to produce hydrogen from alkali metals and or alkali metal alloys via water splitting reactions.

The new invention relates to a new apparatus to generate hydrogen by the reaction of alkali metal and or alkali metal alloy with water or water mixed with a strong base catalyst.

The alkali metal reacts with water and or water mixed with a strong base catalyst with or without mechanical agitation between ambient temperature up to 1000 °C. The reaction occurs by three different routes (A, B and C) as follows.

2Me + 2ROH + 2H20 4 R2Me2O4 + 3H2 (A) 2Me + 6ROH + xH2O 4 R5Me2O5 + xH2O + 3H2 (B) 2Me + 2ROH + 6H20 4 2RMe(OH)4 + 3H2 (C) 2RMe(OH)4 4 2ROH + 2Me(OH)3 (D) The metal oxide on the surface of the alkali metal or alkali metal alloy reacts with water and/or water catalyst mixtures, the use of base catalyst in the system encourages promotes the cleavage of the oxide layer which it chemically bound to the metal. After, the metal oxide layer is broken the metal is exposed to water and the passive surface reacts with water, generating hydrogen, heat and metal hydroxide with the radical R from the base catalyst. Thus, the residue can undergo further treatment, separating the base catalyst from the metal hydroxide (D). Following an extra step, the metal hydroxide is heated generating metal oxide which is a high value end product.

The reaction generates hydrogen gas, which is collected by a pipeline; the gas is filtered and cleaned. A bypass line connects a flare to the pipeline for safety. The hydrogen gas is carried on a continuous basis to a gas engine or fuel cell, which generates electricity. The hydrogen can also be transported to a storage vessel to be used at a later time or sold as hydrogen gas.

An anti-oxidant lining covers the internal surface from the main chamber to avoid corrosion.

The agitator blades are corrosion resistant.

The reaction is exothermic. Thus, the invention comprises a heat recovery mechanism the waste heat after recovery can be used in a Stirling engine to generate heat to recover additional electricity or the heat can be anywhere else where heat is required as an input.

Shown in Figures 1 and 2, is the alkali metal 11, which is the feedstock material.

The embodiment comprises an entrance 12 in which the feedstock material 11 is deposited. A detector 13 analyses which material is entering the reactor. If the material is not an alkali metal 14, the object is carried out of the box 15.

The apparatus comprises a belt conveying system 16 to carry the feedstock to a shredder/mill 17 to reduce the particles size and increase the superficial area. The shredded/milled material is transport though an air lock system 18 towards a hopper 19, reaching the screw or conveyor 20.

The screw or conveyor 20 transports the material from the hopper 19 to the main reaction chamber 21.

In the main reaction chamber 21, the alkali metal and or alkali metal alloy 11 reacts with water 22 or water mixed with metal hydroxide (base catalyst) to generate hydrogen gas 23. A filtering system 24(a and b) cleans the gas 23, which is delivered for a fuel cell or gas engine 25.

The reaction 22 generates metal hydroxide 26 and heat 27.

The heat 27 can be used in a Stirling engine 28 or for as useful heat in any other application which requires heat as an input source.

The air lock system 18 comprises a level indicator 29(a and b).

A water tank 30 is connect to the main chamber 21 to feed the reactor with water. The main chamber comprises a mechanical agitator 31, connected to a motor 32, and a cooling system 33. The level indicators 34a and 34b measure the level of materials in the main chamber, while the level indicator 35 measures the level of water in the water tank 30. The valve 36 controls the water feeding the main chamber.

The liquid in the main chamber is water either with or without metal hydroxide added as a base catalyst 37, which reacts with the alkali metal and/or alkali metal alloy 11 to generate hydrogen 23, metal hydroxide 26 and heat 27.

The embodiment comprises a pressure relief valve 38 with a pressure indicator 39, and comprises a temperature indicator 40.

The generated gas is carried out from the main chamber through the pipeline 41a, 41b and 41c. This pipeline passes through the filtering system 24a and 24b, reaching the fuel cell or gas engine 25. The valve 42a controls the gas feeding the pipeline toward filtering system, and the valve 42b controls the gas feeding the flare 43. The valve 44 controls the gas feeding the fuel cell or gas engine that generates electricity 45. The temperature indicator 46 in connected to the pipeline.

The valve 47 controls the drainage system, which comprises a filter 48 and a pump plus vessel 49.

There is a feeding tank 50 for the metal hydroxide (base catalyst) connected to the main chamber 21 and controlled by the valve 51.

The main chamber 21 comprises a heater 52.

The cooling system 33 is connected to a cooling medium 53.

Claims

CLAIMS1. A new apparatus to produce hydrogen through the reaction between water and alkali metal and/or metal alloy whereby at least one metal is an alkali.
2. A new apparatus to produce hydrogen through the reaction between alkali metal and/or alkali metal alloy with water and strong base catalyst.
3. An apparatus according to claims 1 and 2, which comprises a method to identify the initial material (alkali metal or alkali metal alloy) and allows only the correct material to continue to the main reaction chamber.
4. An apparatus according to claim 1, 2 and 3, which comprises a method to shred or mill the initial material to increase its surface area (alkali metal and/or alkali metal alloy), and after transport the material to the main reaction chamber.
5. Claim according to 1, 2, 3 and 4 whereby air from the external atmosphere is prevented from entering the main reaction chamber by using an air lock system.
6. A method according to claim 1 and 2 wherein the reaction temperature is from ambient up to 1000 °C.
7. An apparatus according to claim 1 and 2, which is connected to a fuel cell or gas engine which generates electricity.
8. An apparatus according to any of the preceding claims which uses a mechanical agitator.
9. An apparatus according to any of the preceding claims wherein a drainage system, with filters and pump, is connected to remove the liquid and solid by-products.
10. An integrated system according to any of the preceding claims wherein the waste material starts as entire part, and it is identified, shredded/milled and reacts with other components and is expelled as gas plus by-products.
11. An apparatus whereby the water and catalyst is contained in separate storage containers situated close to the main reaction chamber and enters the main reaction chamber by a controlled mechanism.
12. An apparatus according to any of the preceding claims wherein a sterling engine can be connected and used to generate electricity from waste heat.