US20090214987A1

US20090214987A1 - Method of preforming hydrocarbon by oxyhydrogen flame using two burners

Info

Publication number: US20090214987A1
Application number: US12/153,129
Authority: US
Inventors: Tomoki Yamasaki
Original assignee: Japan Hydrogen Co Ltd
Current assignee: Japan Hydrogen Co Ltd
Priority date: 2008-02-25
Filing date: 2008-05-14
Publication date: 2009-08-27
Also published as: JP2009196869A

Abstract

An object is to improve low fuel efficiency due to heating that is necessary continually during operation in order to continuously produce hydrogen without generating CO₂from methane, and to reduce a heat loss.

It is a method of reforming hydrocarbon by an oxyhydrogen flame, in which the oxyhydrogen flame is made from mixed gas of hydrogen and oxygen in a container sealed with an insulating material using a two-tube burner that supplies hydrogen and oxygen, methane pre-heated to 200 to 400° C. is injected into the above-described oxyhydrogen flame from a separate burner, methane is heat-decomposed into hydrogen and carbon powders by rapidly heating to 500 to 1000° C., and a two-tube burner using the oxyhydrogen flame is used so that hydrogen is continuously manufactured without generating CO₂as a byproduct by removing the carbon powders from the heat-decomposed mixed gas.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to a method of reforming hydrocarbon by an oxyhydrogen flame using two burners that is a method of continuously producing hydrogen without generating CO₂using only hydrocarbon and oxygen.
2. Description of the Related Art
The present invention relates to a method of obtaining hydrogen by heat-decomposing hydrocarbon (hereinafter referred to as methane) into hydrogen and carbon.
When methane is heated to 500 to 1000° C. in the state that no oxygen is present, it decomposes into nC and ₂nH₂(CnH₂n⁺ ₂→nC+₂nH₂). However, this is an endothermic reaction, and there is a necessity of heating continually during the operation in order to heat methane and to make up for the heat loss of a reactor. The larger the difference between the heat capacity for this heating and the heat capacity of hydrogen produced on the hydrogen side, the more useful a reforming device of methane becomes.
Therefore, important technical problems are the issues of what method is used for performing heat decomposition of methane, how the heat loss of a heating furnace can be made small, and whether heat loss quantity can be collected and used or not.
In a conventional method, a tubular furnace filled with a catalyst is heated from the outside to thereby heat the inside of the furnace to 700 to 1000° C., methane is then introduced into the tube and the methane is brought into contact with the heated catalyst to be decomposed, thereby extracting hydrogen and carbon from a discharge opening (Journal of The Japan Petroleum Institute, vol. 40, No. 1, 2 and 3, 1977).
However, since methane is externally heated in this method, fuel efficiency is poor, a large amount of LPG and electric power are used and the method thus could not be put to practical use.
Non-Patent Document 1: Journal of The Japan Petroleum Institute, vol. 40, No. 1, 2 and 3, 1977.
The problems are to improve low fuel efficiency due to heating that is to be necessary continually during operation in order to produce hydrogen continuously without generating CO₂from methane gas, and how to reduce the heat loss.

SUMMARY OF THE INVENTION

In view of the above-described circumstances, the present invention provides a method of reforming hydrocarbon by an oxyhydrogen flame, in which the oxyhydrogen flame is made from mixed gas of hydrogen and oxygen in a container sealed with an insulating material using a two-tube burner that supplies hydrogen and oxygen, methane pre-heated to 200 to 400° C. is injected into the above-described oxyhydrogen flame from a separate burner, methane is heat-decomposed into hydrogen and carbon powders by rapidly heating to 500 to 1000° C., and a two-tube burner using the oxyhydrogen flame is used so that hydrogen is continuously manufactured without generating CO₂as a byproduct by removing the carbon powders from the heat-decomposed mixed gas in order to improve the low fuel efficiency due to heating that is necessary continually during operation to produce hydrogen continuously without generating CO₂from methane, and to reduce a heat loss.
In the present invention, methane is directly heated to thermally decomposed, using an oxyhydrogen flame in a sealed container in order to produce hydrogen continuously without generating CO₂from methane. In this method, there is no generation of CO₂by using oxygen and hydrogen in heating, a high temperature of 700° C. or more for the heat decomposition can be expected, which also enables to have outstanding heat efficiency because of the inside heating.
The hydrogen that is necessary to produce hydrogen by such direct heat decomposition by the oxyhydrogen flame in a sealed container is about one third of the hydrogen that can be produced.
The device of the present invention is equipped with an oxyhydrogen two-tube burner in which a mesh or wire-shaped metal catalyst is provided at the tip, a heating part is covered with an insulating material such as ceramic, and the entire body is loaded in a sealed container.
When methane that is preheated to 200 to 400° C. with exhaust gas from another methane burner is blown into the oxyhydrogen flame of the above-described oxyhydrogen two-tube burner, methane is further heated rapidly by the oxyhydrogen flame to be 500 to 1000° C., and is decomposed into carbon and hydrogen.
The metal catalyst is to lower a reaction temperature and to improve the fuel efficiency, is an alloy of nickel with palladium, cobalt, chromium, platinum, etc., and as one example, a hydrogen reductant of a nickel alloy containing 1 to 5% of palladium, cobalt, chromium, and platinum is effective.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a vertical cross-sectional view showing a decomposition furnace decomposing methane into hydrogen and carbon in the present invention; and

FIG. 2 is a drawing of the entire device for producing hydrogen in the present invention.

EXAMPLES

FIG. 1 is a vertical cross-sectional view of the decomposition furnace decomposing methane into hydrogen and carbon in the present invention, and FIG. 2 is a drawing showing the entire device for producing hydrogen in the present invention.
The present invention employs an internal heating system as a heating method of methane.
It is a method in which an oxyhydrogen flame is blown out from the tip of a burner covered thick with insulating material 12 and into this flame, methane preheated to 200 to 400° C. is blown from the tip of the separate burner to thereby directly heat methane inside a decomposition furnace 39 and at the same time with action of a catalyst 14 provided into the flame of the burner, methane is decomposed into hydrogen and oxygen. The method has an advantage not only that heat efficiency is good, but also that the device is a small size and the heat loss is small without generating CO₂as a byproduct.
The present invention is to economically produce hydrogen without generating CO₂as byproduct using only methane and oxygen. The operation is divided into the following three steps.
First step: an operation of excluding air from the entire device
Second step: an operation of decomposing methane into hydrogen and carbon by heating methane to have a high temperature with an oxyhydrogen flame made from hydrogen and oxygen
Third step: an operation of removing and refining the produced carbon powders from hydrogen
The first step that initiates the device of the present invention is to exclude air from the entire device shown in FIG. 2. The air in the device is excluded using an inert gas such as argon and nitrogen.
In the operation of the second step, hydrogen stored in a float type hydrogen tank 33 is sent to a hydrogen throwing port 31 in FIG. 1 with an operation of a valve 34 in the upper part of the tank. On the other hand, a valve 24 of an oxygen throwing port 22 and a valve 43 are gradually opened, mixed gas of hydrogen and oxygen is made in a gas mixing chamber 26, it is passed through a blow tube 7 and ignited at a blow tube tip 19, and an oxyhydrogen flame is injected out as an arrow 10. Reference numerals 51 and 52 are a trap.
Additionally, methane is sent from a methane throwing port 13 located at a summit part of a blow tube 2 of a methane burner 3 through a valve 30 and through an arrow 17 to an arrow 16. Methane that is pressurized into a heat exchanger 15 by a valve 18 and heated to 200 to 400° C. is blown into the oxyhydrogen flame of the arrow 10 as an arrow 27 from the top part of the methane burner 3 through a heat methane pipe 5, heated to 500 to 1000° C. in an instant, decomposed into hydrogen and carbon, and sent into a cyclone tower 38 as an arrow 49. Reference numeral 53 is a trap.
In the operation of the third step, a decomposed gas of methane coming into cyclone tower 38 is stored in float type hydrogen tank 33 by the carbon powders being separated in cyclone tower 38, cooled in a jacket of an inner wall of cyclone tower 38, passed through a washing tank 37 by sucking and compressing with a pump 36, and then being sucked with a pump 35 through a valve 41. Reference numeral 32 is a valve for exhausting inert gas.
Note that an inside a metal outer configuration part 11 of decomposition furnace 39 is covered with a ceramic insulating material 22, and a high temperature can be kept in decomposition furnace 39. This metal outer configuration part 11 is installed on an outer wall plate 21 of cyclone tower 38.
Also, it is equipped with water cooling type jackets 28 and 29 to prevent over heating of the burner.
A plurality of decomposition furnaces 39 installed with the burner can be installed in cyclone tower 38.
Heat in the jacket for cooling in cyclone tower 38 is utilized in an air conditioner/heater, and it can be utilized in power generation and a water vapor boiler utilizing the high heat of the exhaust gas and a flow of high temperature in decomposition furnace 39. Note that reference numeral 40 in the fugure is the carbon powders.
A valve 25 is at an open position when heat exchanger 15 is not used, when carbon is attached to its heat methane pipe 5, etc.
The present invention is to decompose methane through every step and manufacture hydrogen. However, the steps are continuous, every step can be performed with the operation of an electromagnetic valve, and a centralized control by a computer is possible.
The present invention is to heat-decompose methane by directly heating making heat loss small in order to continuously produce hydrogen from hydrocarbon gas without generating CO₂, and is utilized in power generation and a boiler that is free of CO₂.
Since the present invention is a method of reforming hydrocarbon by an oxyhydrogen flame, in which the oxyhydrogen flame is made from mixed gas of hydrogen and oxygen in a container sealed with an insulating material using a two-tube burner that supplies hydrogen and oxygen, methane pre-heated to 200 to 400° C. is injected into the above-described oxyhydrogen flame from a separate burner, methane is heat-decomposed into hydrogen and carbon powders by heating rapidly to 500 to 1000° C., and a two-tube burner using the oxyhydrogen flame is used so that hydrogen is continuously manufactured without generating CO₂as a byproduct by removing the carbon powders from the heat-decomposed mixed gas, the low fuel efficiency due to heating that is necessary continually during operation in order to continuously produce hydrogen without generating CO₂from methane is improved, and the heat loss can be made less.

Claims

1. A method of reforming hydrocarbon by an oxyhydrogen flame, wherein the oxyhydrogen flame is made from mixed gas of hydrogen and oxygen in a container sealed with an insulating material using a two-tube burner that supplies hydrogen and oxygen, methane pre-heated to 200 to 400° C. is injected into the oxyhydrogen flame from a separate burner, methane is heat-decomposed into hydrogen and carbon powders by rapidly heating to 500 to 1000° C., and a two-tube burner using the oxyhydrogen flame is used so that hydrogen is continuously manufactured without generating CO₂as a byproduct by removing the carbon powders from the heat-decomposed mixed gas.