WO1999058627A2

WO1999058627A2 - Method for utilisation of a basis material

Info

Publication number: WO1999058627A2
Application number: PCT/NO1999/000158
Authority: WO
Inventors: Steinar Lynum; Jan Hugdahl; Ketil Hox; Ragne Hildrum
Original assignee: Kvaerner Technology And Research Ltd.
Priority date: 1998-05-14
Filing date: 1999-05-14
Publication date: 1999-11-18
Also published as: AU5537099A; WO1999058627A3; NO982245D0; NO982245L

Abstract

The invention comprises a method for utilisation of a basis material comprising at least one carbon compound, characterized in that the method comprises: decomposing the material in a processing chamber as a first step to obtain a carbon component and other components, utilising the carbon component for: a) fuel storage and/or; b) energy production and/or c) production of special products and/or d) further production processes, e.g. as reduction means and/or; e) development of means for energy production, recirculating the remaining carbon compounds to the processing chamber, and preferably utilising some of the produced energy to operate the processing chamber, and in that it provides for complete and pollution free utilisation of the basis material. The invention relates also to a carbon black material produced according to this method and a gas storage device comprising said carbon black material.

Description

Method for utilisation of a basis material

The present invention is related to a method of utilisation of a basis material comprising at least one carbon compound, a carbon black material produced by means of this method, a gas storage device comprising said carbon black material, and use of said gas storage device for fuel storage.

A typical example of utilisation of a basis material comprising carbon is hydrogen production based on fossil fuels, where natural gas or petroleum are used as a basis material. This process leads to production of carbon, and from the environmental point of view the main question concerning this process is what to do with the associated carbon. Conventional steam reforming or partial oxidation processes on their part discharge great quantities of carbon dioxide to the atmosphere. Hence this process is not appropriate for high scale hydrogen production, as will be necessary when hydrogen becomes the most current fuel replacing the actual fuels. A truly viable hydrogen production process should in terms of emissions have the lowest possible influence on the local and global environment. A viable process must thus further compete or surpass conventional processes in terms of thermal efficiency, energy comsumption and economical requirements. There are two known processes for hydrogen production that can be considered as environmentally friendly, that is, which lead to no emission of CO2. These methods are the PyroArc® and the carbon black (CB&H) process, both processes developed and commercialised by the Kvasrner company. In the PyroArc process, biomass and any type of waste (except radioactive waste) are converted into regenerate products and hydrogen in a highly efficient process. In the carbon black process, which may utilise a wide spectra of hydrocarbons as feedstock, the carbon fraction is converted to carbon black or to a pure carbon material, which are valuable products within the chemical and metallurgical industry. The aim of the invention is to combine these process with environmentally friendly methods of energy production to create a novel cycle where a basis material comprising carbon compounds is used completely and pollution free. We will now refer to the PyroArc and carbon black processes in greater detail, to show how these are vital parts of said cycle for complete and pollution free utilisation of a basis material.

The PyroArc process utilises waste and hydrocarbons as feedstock. This process is a two-stage gasification and decomposition process wich converts the feedstock into pure fuel gas, steam, slag and metals. The fuel gas, which mostly consists of hydrogen and carbon monoxide can be separated, utilising the hydrogen within the process industry, while the carbon monoxide might be used as a fuel gas. The advantages of the PyroArc process are as follows: * Complete decomposition of the waste

* Emissions close to zero due to complete decomposition in a two-stage process. This process satisfies the most stringent requirements to emissions.

* Recovery of waste as valuable products.

* High flexibility concerning feedstock. All kinds of waste (municipal, industrial and hazardous) with exception of radioactive waste can be treated. Conventional hydrocarbons may also be used as raw materials.

* High enery recovery from waste (90%), i.e. 70% as clean fuel gas and 20% as steam. * Independent evaluations of the process show that a net electric power production efficiency of 26,4% can be achieved. The highest corresponding value of the remaining four processes evaluated was 19,8%.

* Easy gas handling system, since the PyroArc gas volume represents only 30-40%) of the volume from an incinerator.

* Easy scale-up of plants due to the modular concept.

* Compact design, needs a small area.

A PyroArc plant can be equipped for continuous operation and have both dry and wet gas cleaning systems. Examples of waste which is successfully treated in a PyroArc plant are among others spent tyres, mixtures of wood and plastic, household waste, chlorinated solvents, paint, batteries and hospital waste. In addition the pilot plant can of course be operated on biomass and coal.

In the carbon black process, hydrocarbons are decomposed into carbon black and hydrogen by use of a high-temperature plasma process. The energy necessary for decomposition of the hydrocarbons is provided by a plasma generator, which converts electrical power into heat. The products of the process, carbon black and hydrogen, are both highly demanded in the commodity market. The advantages of the carbon black process are as follows: * Very low emissions due to nearly 100% conversion of the feedstock into carbon black and hydrogen.

* No catalyst is needed for the conversion process.

* High flexibility concerning feedstocks. All hydrocarbons ranging from light gases to heavy oil residues can be used.

* Higher energy efficiency and lower energy consumption per unit hydrogen produced compared to conventional hydrogen producing processes as steam reforming and water electrolysis.

* High flexibility concerning carbon black qualities, this leading to the possibility of producing different qualities of carbon black in the same reactor by varying the process parameters.

* Two valuable products result from this process, which leads to a highly competitive process.

* Easy scale-up of plants due to a modular concept.

Table 1 shows the characteristics regarding the carbon black process. The carbon black material produced according to this process is highly suitable within the following areas:

* Rubber and plastic industry, for use as a reinforcing material as well as other conventional uses in this field. * Metallurgical industry, which is in need of a clean, reactive carbon material, i.e. as carbon additive/carburiser in the steel and foundry industry, or reduction material for production og SiC, Si, FeSi.

The hydrogen produced by this process is attractive as a consequence of the very low emissions associated with its production process. This is due to the fact that the carbon content of the feedstock is converted to carbon black at high efficiency. Hence a hydrogen gas purity of at least 98% is common when utilising natural gas as a feedstock. The hydrogen gas can further be purified to the customer's requirements if high purity is needed.

The PyroArc and carbon black processes are flexible in use because they have a modular concept. The amount and purity of the produced hydrogen will depend on the feedstock. For the PyroArc process, the purity after the membrane separation will be up to 95%, which often is adequate for a refiner's need. For the carbon black process, the hydrogen purity as produced will commonly be about 98% or higher when utilising natural gas as a feedstock. By utilisation of a purification unit a purity of 99,9998%) can be achieved for both processes, which will be sufficient for all practical applications of hydrogen.

The carbon black production process as described enables production of both traditional as well as novel grades of carbon black (we hereby refer to S. Lynum, J. Hugdahl and R. Hildrun, "The Kvserner CB&H Process", presented at Carbon Black World, Nice, France, 4-6 March 1996). By varying the process parameters in the pyrolisis reactor it is possible to produce either conventional amorphous carbon black, graphitic carbon black for use in the metallurgical industry or graphitic carbon black in form of cones and platelets (we hereby refer to A. Krishnan, E. Dujardin, M.M.J. Treacy, J. Hugdahl, S. Lynum and T. W. Ebbesen "Graphitic Cones and Nucleation of Curved Carbon Surfaces", Nature, vol. 388, July 1997). The carbon black can thus be used e.g. as additive/carburiser in the steel and foundry industry. The metallurgical carbon black produced by use of the CB&H process is characterised by its cleanliness and reactivity. In metallurgical processes this can be beneficial, for example used as a reduction material in the production of silicon metal of solar grade. Solar grade silicon metal produced more cost efficiently by use of this plasma carbon might contribute to a break-through for a solar energy system. The above mentioned carbon black production method permits production of a carbon black material with a high gas absorption capacity (up to approximately 75wt%). Said high absorption capacity material can be used to implement a gas storage device, and especially for storage of hydrogen. Storage is the main problem related to implementing hydrogen as a fuel in the transportation sector, as liquid hydrogen is expensive to manufacture, gaseous hydrogen requires large containers and storage of hydrogen in metal hydrides results in high weight units due to their low energy density. A gas storage device based on a carbon black material with the above mentioned properties can efficiently store hydrogen and thus lead to transport means with an autonomy range of up to approximately 8000km.

Based on the advantages provided by the above mentioned processes, one aspect of the invention consists of a method for utilisation of a basis material comprising at least one carbon compound. This method is characterised in that it comprises:

-decomposing the material in a processing chamber as a first step to obtain a carbon component and other components,

-utilizing the carbon component for: a) fuel storage and/or; b) energy production and/or; c) production of special products; and/or d) further production processes, e.g. as reduction means; and/or e) development of means for energy production,

-recirculating the remaining carbon compounds to the processing chamber, and preferably

-utilising some of the produced energy to operate the processing chamber, and in that it provides for complete and pollution free utilisation of the basis material.

In a preferred embodiment of the invention, the decomposing process, if necessary followed by a separation step, results in a hydrogen component.

In a further preferred embodiment of the invention, the basis material is biomass, the carbon component is clean synthesis gas, and the other components are steam, slag and metals.

In another preferred embodiment of the invention, the basis material is a hydrocarbon, the decomposition process is a high-temperature plasma process, the hydrogen component which results of the decomposition is H2, and the carbon component is carbon black. This process leads to a carbon black material also according to the invention, having high gas absorption capacity, and to a gas storage device comprising a cassette or container housing such a carbon black material with high gas absorption properties.

The invention will now be described with reference to the attached drawing that shows an energy cycle based on the method according to the invention.

The energy cycle can be described as follows:

Renewable energy sources as solar energy SE, hydropower HE or wind energy WE produce electric power P. Electric power P can be distributed to the grid 1 , utilised for hydrogen (H2) production by use of electrolysis 2, used to feed a carbon black process 3 or used to feed a PyroArc process 4. In the PyroArc process 4, biomass B is processed and hydrogen H2 together with Electric power P are produced. In the carbon black process 3, petroleum can be used as a feedstock, and hydrogen H2, and carbon black CB can be produced with no CO2 emission. This is a significant difference between the Kvasrner carbon black process and conventional carbon black production technologies. Carbon clack CB produced in 3 can be used in the metallurgical industry 5 to produce among others solar cell silicon (Si-metal). This solar cell silicon permits utilisation of solar energy SE. Carbon black can also be used for gas storage, especially storage of H2 in fuel cassette 6. In this way, the H2 produced by the above mentioned methods can be utilised as a no emission fuel.

This shows that by use of the method according to the invention, a basis material comprising a carbon compound can be utilised completely and with no polluting emissions.

Another aspect of the invention comprises a carbon black material and a gas storage device based on said material.

As mentioned before, hydrogen is used as an energy source in many applications, and the difficulties related to hydrogen storage and transport have represented an obstacle for a more general use, although use of hydrogen will lead to clear advantages, among others because it will be completely pollution free. A special use of a storage device of this type will be as fuel for transport means, and more specifically for cars. One object of the gas storage device according to the invention is to provide an improved storage device for hydrogen, where the hydrogen can be safely stored and where the necessary space is strongly reduced compared to the prior art storage devices. Another object is to provide a storage device that can be designed as transportable unit so that hydrogen can be used in applications where the prior art solutions were not viable due to reduced storage space possibilities.

These and other objects are achieved by a gas storage device according to the invention, which is characterized in that it comprises a cassette or a container housing a carbon black material with high absorption capacity. In a preferred embodiment such gas is hydrogen. Carbon black absorbs and desorbs hydrogen, and it can thus be used for hydrogen storage and delivery. The storage capacity of carbon black can be controlled by changing parameters in its production method, and further by adding a catalyser. Using appropriate methods, the absorption capacity of the carbon black can be varied approximately between 15we% and 75we%. Material having said high storage capacity permits storage of hydrogen in smaller volumes.

The cassette in the device according to the invention can be produced from a tight material, e.g. metal or plastic. The invention can besides be used in many different applications, that is connected to different user units and the cassette's dimensions will vary accordingly. Used in relation to a fixed user unit (e.g. a plant), the cassette can be big and it can be refilled in location or replaced by a full cassette. For other applications the cassette can be designed to meet local requirements, it can e.g. be flat or have other adequate designs. In a preferred embodiment of the invention the cassette is equipped with a nozzle device for connection to a gas supply system and/or to a user unit. For special applications, the cassette can be designed as a module.

To start hydrogen delivery from the cassette to the user unit, the whole cassette or parts of it are heated. Heating can be achieved by any appropriate means, e.g. electrical, fuel cells or gas heating. Once delivery has started heat produced by the user unit itself can be used for the same purpose. Pressure can also be applied to the cassette for gas delivery, if necessary combined with heating. This aspect of the invention will now be illustrated by means of an example. As example a motor vehicle will be used. The vehicle's fuel tank is replaced by a cassette according to the invention that can be placed in the fuel tank location, in a compartment under the trunk or in other location in the vehicle where it is possible to pull it out for replacement by a new cassette. During insertion of the cassette a coupling device will connect the cassette to the vehicle's fuel system. As an alternative, the cassette can have a connection nozzle, but a replaceable cassette is envisaged as a faster system. To allow delivery of the gas out of the carbon black structure, a heating device is provided, which device is driven by the vehicle's battery or by a fuel cell. When the motor is running motor heat can be used for further heating of the cassette. The cassette according to the invention can thus successfully replace the vehicle's fuel tank since a cassette with a volume of 251 can give sufficient fuel to drive 8000km. The above mentioned example of use illustrates how the method, material and device according to the invention provide complete and pollution free utilisation of a basis material comprising carbon, and how this can lead to complete and viable solutions.

Claims

1. Method for utilisation of a basis material comprising at least one carbon compound, characterized in that the method comprises: -decomposing the material in a processing chamber as a first step to obtain a carbon component and other components, -utilising the carbon component for: a) fuel storage and/or b) energy production and/or c) production of special products and/or d) further production processes, e.g. as reduction means and/or e) development of means for energy production,

-recirculating the remaining carbon compounds to the processing chamber, and preferably -utilising some of the produced energy to operate the processing chamber, and in that it provides for complete and pollution free utilisation of the basis material.

2. Method according to claim 1, characterized in that the decomposing process, if necessary followed by a separation step, results in a hydrogen component.

3. Method according to claim 2, i n that the basis material is biomass, the carbon component is clean synthesis gas, and the other components are steam, slag and metals.

4. Method according to claim 3, characterized in that the second separation step comprises separation of the pure fuel gas in hydrogen and carbon monoxide, where the carbon monoxide is utilised as fuel gas.

5. Method according to claim 3 or 4 together with b) in claim 1, characterized in that the fuel gas is partly utilised for energy production that can operate the processing chamber.

6. Method according to claim 2, characterized in that the basis material is a hydrocarbon, the decomposition process is a high-temperature plasma process, the hydrogen component which results of the decomposition is H2, and the carbon component is carbon black.

7. Method according to claim 6 together with alternative c) in claim 1, characterized in utilising carbon black as carbon additive/carburiser in the steel and foundry industry.

8. Method according to claim 6 together with alternative d) in claim 1, characterized in that the carbon black is used as reduction material in production of high purity metals.

9. Method according to claim 8, characterized in that the carbon black is used as reduction material in production of silicon.

10. Method according to claim 9, characterized in that the produced silicon is used in production of solar cells, and energy from at least some of the solar cells is used to operate the burning chamber.

11. Method according to claim 6 together with alternative a) in claim 1 , characterized in utilising carbon black for storage of H2.

12. Method according to one of claims 1-11, characterized in utilising the hydrogen as a fuel.

13. Carbon black material produced according to the method described in claim 6, characterized in that it has high gas absorption capacity.

14. Carbon black material according to claim 12, characterized in that it has an absorption capacity of between 5wt%and 15wt%.

15. Carbon black material according to claim 12, characterized in has an absorption capacity of between 15wt% and 75wt%.

16. Gas storage device based on a carbon black material according to any of claims 12-14, characterized in that it comprises a cassette or a container housing a carbon black material with high gas absorption capacity.

17. Storage device according to claim 16, characterized in that the gas is hydrogen.

18. Storage device according to any of claims 16-17, characterized in that the cassette is equipped with a connection nozzle for connection to a gas supply system and/or to a user unit.

19. Storage device according to any of claims 16-18, characterized in that the cassette is arranged in contact and/or comprises a heating system , a pressure system if necessary or a combination of these for gas delivery to a user unit.

20. Use of a storage device according to any of claims 16-19 for storage of fuel in a car.