U.S. patent application number 10/502633 was filed with the patent office on 2006-08-24 for novel production method of gaseous fuels.
Invention is credited to Ki Chul Park, Hiroshi Tomiyasu.
Application Number | 20060185244 10/502633 |
Document ID | / |
Family ID | 27677874 |
Filed Date | 2006-08-24 |
United States Patent
Application |
20060185244 |
Kind Code |
A1 |
Park; Ki Chul ; et
al. |
August 24, 2006 |
Novel production method of gaseous fuels
Abstract
A novel process of producing gas fuel is provided, in which low
quality fuel such as coal and various kinds of plastics and resins
(polymeric compounds) collected as flame retardant waste are
decomposed to gas in supercritical water, so that the resultant gas
is effectively utilized as fuel. That is, polymeric compounds and
aromatic/condensed-aromatic hydrocarbons are decomposed in
supercritical water with ruthenium oxide (IV) as a catalyst. The
resultant gas components through the decomposition are collected as
gas fuel.
Inventors: |
Park; Ki Chul; (Nagano-shi,
JP) ; Tomiyasu; Hiroshi; (Nagano-shi, JP) |
Correspondence
Address: |
KANESAKA BERNER AND PARTNERS LLP
SUITE 300, 1700 DIAGONAL RD
ALEXANDRIA
VA
22314-2848
US
|
Family ID: |
27677874 |
Appl. No.: |
10/502633 |
Filed: |
February 4, 2004 |
PCT Filed: |
February 4, 2004 |
PCT NO: |
PCT/JP03/01105 |
371 Date: |
July 26, 2004 |
Current U.S.
Class: |
48/197R |
Current CPC
Class: |
Y02P 20/54 20151101;
C10J 2300/093 20130101; B01J 3/008 20130101; Y02P 20/52 20151101;
C10L 3/08 20130101; C10J 2300/0983 20130101; C10J 3/00 20130101;
C10J 2300/0946 20130101; Y02P 20/544 20151101; C10J 2300/0979
20130101 |
Class at
Publication: |
048/197.00R |
International
Class: |
C10J 3/46 20060101
C10J003/46 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 6, 2002 |
JP |
2002028957 |
Claims
1. A method of producing gas fuel, comprising: decomposing a
polymeric compound or an aromatic/condensed-aromatic compound in
supercritical water with ruthenium oxide (IV) as a catalyst, and
collecting gas generated from the decomposition as the gas
fuel.
2. A method of producing gas fuel, comprising: immersing a
polymeric compound or an aromatic/condensed-aromatic compound in
supercritical water as a material to be processed for obtaining the
gas fuel, reacting the material to be processed in the
supercritical water with ruthenium oxide (IV) as a catalyst to
decompose the material to be processed into a gas component and an
organic residue, and collecting the gas component as the gas
fuel.
3. A method of producing gas fuel according to claim 1, wherein
said polymeric compound is a compound having a polymeric structure
including polyvinylchloride (PVC), fiber reinforced plastics (FRP),
Teflon resins (PTFE), polypropylene (PP), polyethylene (PE),
polystyrene (PS), and Daiflon (PFA), and said
aromatic/condensed-aromatic compound is a compound having an
aromatic ring structure including naphthalene and coal.
Description
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention is related to a method of producing
gas fuel, in which low quality fuel such as coal and flame
retardant waste such as various plastics and resins are decomposed
in supercritical water with a catalyst, so that resultant gas can
be utilized as gas fuel.
BACKGROUND TECHNOLOGY
[0002] Conventionally, it has been known that some types of
plastics (for example, foamed polystyrene) are decomposed in
supercritical water without a catalyst. Generally, however, a great
majority of plastics and resins (polymeric compounds) are stable
even in supercritical water at 500.degree. C. In order to process
such compounds in supercritical water, it is necessary to apply an
oxidant such as oxygen into water to facilitate the combustion.
[0003] When a compound to be processed is burned with the critical
water oxidization, only carbon dioxide and water are obtained.
Further, depending on an amount of the oxidant, a large amount of
carbon may be produced due to imperfect combustion.
[0004] While coal is very stable in supercritical water, it is
known to be possible to extract oily components depending on a type
of coal. However, the extracted oily components have a composition
containing a large amount of oxygen, thereby making it difficult to
use as fuel.
DISCLOSURE OF THE INVENTION
[0005] As described above, it is difficult to decompose a great
majority of plastics and synthetic resins, which stays in a stable
state, through a simple process in supercritical water. It is also
difficult to convert coal to fuel. According to the present
invention, such polymeric compounds and aromatic/condensed
hydrocarbons are decomposed with ruthenium oxide (IV) as a catalyst
to produce gas through the decomposition, so that the gas can be
utilized as fuel.
[0006] That is, according to the present invention, a novel process
of producing gas fuel is provided, in which low quality fuel such
as coal and various kinds of plastics and resins (polymeric
compounds) collected as waste are decomposed to gas in
supercritical water, so that the resultant gas is effectively
utilized as fuel.
[0007] In the present invention, polymeric compounds and
aromatic/condensed hydrocarbons are decomposed in supercritical
water with ruthenium oxide (IV) as a catalyst. The resultant gas
components through the decomposition are collected as gas fuel.
[0008] In the present invention, polymeric compounds and
aromatic/condensed hydrocarbons, i.e. materials to be decomposed to
obtain gas fuel, are immerged in supercritical water. A reaction
occurs in the materials to be decomposed in supercritical water
with ruthenium oxide (IV) as a catalyst. As a result, the materials
are composed into gas components and organic residue, and the gas
component is collected as gas fuel.
[0009] In the present invention, the novel method of producing gas
fuel includes the following steps. According to a first aspect of
the present invention, polymeric compounds and aromatic/condensed
hydrocarbons are decomposed in supercritical water with ruthenium
oxide (IV) as a catalyst to produce gas components as a result of
the decomposition. The gas components, which are produced through
the decomposition of the polymeric compounds and aromatic/condensed
hydrocarbons, are collected to use as gas fuel.
[0010] As described above, conventionally, it is very difficult to
decompose various plastics (polystyrene, polyvinylchloride, etc.)
and synthetic resins, and low quality fuel such as coal. It is
possible to decompose such materials in supercritical water with
ruthenium oxide (IV) as a catalyst to generate gas. The resultant
gas is combustible gas, and can be collected and stored for the use
as fuel. When ruthenium oxide (IV) is used as a catalyst, compounds
are decomposed in reductive and oxidative environment. The
resultant gas produced through the reductive decomposition is
combustible low molecular weight hydrocarbons (mostly methane and a
trace amount of ethane and propane) and hydrogen, thereby obtaining
high quality gas fuel through the present invention.
[0011] Furthermore, as the material to be decomposed, it is
possible to decompose industrial waste such as polymeric compounds
as well as aromatic/condensed hydrocarbons. For example, it is
possible to decompose up to 92% of naphthalene to obtain flammable
gas as described above. In addition, the present invention is
similarly applicable to coal, which is very stable in supercritical
water, and it is possible to convert coal into flammable gas with
ruthenium oxide (IV) as a catalyst. In other words, it is possible
to modify coal into high quality fuel (low molecular weight
hydrocarbons such as methane and hydrogen) without containing
harmful metal, and nitrogen and sulfur components.
[0012] In the present invention, as the material for obtaining
fuel, it is possible to use industrial waste such as plastics and
resins, thereby producing gas fuel with low cost and contributing
to industrial waste treatment.
[0013] According to a second aspect of the present invention,
polymeric compounds and aromatic/condensed hydrocarbons, i.e.
materials to be decomposed for obtaining gas fuel, are immerged in
supercritical water. A reaction occurs in the materials to be
decomposed in supercritical water with ruthenium oxide as a
catalyst. As a result, the materials are composed into gas
components and organic residue, and the gas components are
collected as gas fuel. Accordingly, similar to the first aspect of
the present invention, it is possible to utilize the resultant gas
generated through the decomposition of polymeric compounds and
aromatic/condensed hydrocarbons as gas fuel.
[0014] Conventionally, it is very difficult to decompose various
plastics (polystyrene, polyvinylchloride, etc.) and synthetic
resins, and low quality fuel such as coal. It is possible to
decompose such materials in supercritical water with ruthenium
oxide (IV) as a catalyst to generate gas. The resultant gas is
combustible gas, and can be collected and stored for the use as
fuel.
[0015] According to a third aspect of the present invention, the
materials to be processed for obtaining gas fuel include a compound
having a polymeric structure such as polyvinylchloride (PVC), fiber
reinforced plastics (FRP), Teflon resins (PTFE), polypropylene
(PP), polyethylene (PE), polystyrene (PS), and Daiflon (PFA); and a
compound having an aromatic ring structure such as naphthalene and
coal. That is, such flame retardant materials and low quality fuel
are used as the materials to be processed, thereby effectively
utilizing materials.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a gas chromatogram showing low molecular weight
hydrocarbons obtained through decomposition of polystyrene;
[0017] FIG. 2 is a gas chromatogram showing hydrogen obtained
through decomposition of polystyrene;
[0018] FIG. 3 is a gas chromatogram showing carbon dioxide obtained
through decomposition of polystyrene;
[0019] FIG. 4 is a gas chromatogram showing low molecular weight
hydrocarbons obtained through decomposition of naphthalene;
[0020] FIG. 5 is a gas chromatogram showing hydrogen obtained
through decomposition of naphthalene;
[0021] FIG. 6 is a gas chromatogram showing carbon dioxide obtained
through decomposition of naphthalene;
[0022] FIG. 7 is a gas chromatogram showing low molecular weight
hydrocarbons obtained through decomposition of Taiheiyo coal;
[0023] FIG. 8 is a gas chromatogram showing hydrogen obtained
through decomposition of Taiheiyo coal; and
[0024] FIG. 9 is a gas chromatogram showing carbon dioxide obtained
through decomposition of Taiheiyo coal.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0025] According to the present invention, a novel process of
producing gas fuel is provided, in which polymeric compounds and
aromatics/condensed hydrocarbons are decomposed in supercritical
water with ruthenium oxide (IV) RuO.sub.2 as a catalyst, and the
resultant gas is collected as gas fuel.
[0026] In a critical state, water is heated to 374.degree. C., i.e.
a critical temperature, at 22.1 MPa, i.e. a critical pressure. When
water is filled in a reactor and heated above 374.degree. C., a
pressure is controlled by an amount of water and reaches 22.1 MPa
or higher. Water in such a state is called supercritical water. It
has been known that decomposition is facilitated in supercritical
water.
[0027] In the present invention, ruthenium oxide (IV) is used as a
catalyst. It has been experimentally confirmed that ruthenium oxide
(IV) efficiently decomposes organic compounds in any states of
liquid, solid, linear structures and cyclic structures to produce
gas in supercritical water. Accordingly, in the present invention,
ruthenium oxide (IV) is used as a catalyst for decomposing organic
compounds in supercritical water.
[0028] Materials to be processed for obtaining gas fuel include a
compound having an aromatic ring structure such as naphthalene and
coal; and a compound having a polymeric structure such as
polyvinylchloride (PVC), fiber reinforced plastics (FRP), Teflon
resins (PTFE), polypropylene (PP), polyethylene (PE), polystyrene
(PS), and Daiflon (PFA) as flame retardant materials.
[0029] As an embodiment, polystyrene as the polymeric compound was
decomposed in an experiment, as follows: 100 mg of polystyrene
(apparent quantity; 0.960 mmol with --C.sub.8H.sub.8-- as a unit),
20 mg of ruthenium oxide (IV), and 3 ml of water were placed in a
batch-type supercritical water reactor. After the reactor was
sealed, the reactor was heated to conduct a reaction at 450.degree.
C. for 2 hours. After cooling, the reactor was connected with a
vacuum glass line, and produced gas components were analyzed with
on-line gas chromatography. An oily organic residue was extracted
using chloroform and collected from a water phase. As a result, 99%
of polypropylene was decomposed into gas components, and a trace
amount (1.1 mg) of the organic residue remained.
[0030] As shown in a gas chromatogram (detector: FID, separation
column: PorapakQ, carrier gas: Ar) in FIG. 1, it is confirmed that
61% of polystyrene was converted into methane (4.69 mmol), 0.20%
thereof was converted into ethane (0.00756 mmol), and 0.091%
thereof was converted into propane (0.00234 mmol). The conversion
rates were calculated from a total amount of carbon contained in
polystyrene and total amounts of carbon contained in hydrocarbon
gases. As shown in a gas chromatogram (detector: FID, separation
column: molecular sieve 5A, carrier gas: Ar) in FIG. 1, it is
confirmed that a large amount of hydrogen (1.04 mmol) was produced.
As shown in a gas chromatogram (detector: TCD, separation column:
PorapakQ, carrier gas: Ar) in FIG. 3, it is also confirmed that
other gas component was carbon dioxide.
[0031] The obtained gases are flammable gases (methane, ethane,
propane, hydrogen) and carbon dioxide. Carbon dioxide can be
selectively collected through calcium hydroxide solution, thereby
imposing no influence on the environment. The organic residue has a
trace amount, and it was confirmed that there is no influence on
the environment upon processing.
[0032] As another embodiment, naphthalene as the
aromatic/condensed-aromatic compound was decomposed in an
experiment, as follows:
[0033] 100 mg of naphthalene (0.780 mmol), 20 mg of ruthenium oxide
(IV) (RuO.sub.2), and 3 ml of water were placed in a batch-type
supercritical water reactor. After the reactor was sealed, the
reactor was heated to conduct a reaction at 450.degree. C. for 3
hours. After cooling, the reactor was connected with a vacuum glass
line, and produced gas components were analyzed with on-line gas
chromatography. An organic residue was extracted using chloroform
and collected from a water phase. As a result, 92% of naphthalene
was decomposed into gas components, and a trace amount (8.5 mg) of
the organic residue remained.
[0034] As shown in a gas chromatogram (detector: FID, separation
column: PorapakQ, carrier gas: Ar) in FIG. 4, it is confirmed that
47% of naphthalene was converted into methane (3.67 mmol), 0.24%
thereof was converted into ethane (0.00946 mmol), and 0.074%
thereof was converted into propane (0.00192 mmol). The conversion
rates were calculated from a total amount of carbon contained in
naphthalene and total amounts of carbon contained in hydrocarbon
gases. As shown in a gas chromatogram (detector: FID, separation
column: molecular sieve, carrier gas: Ar) in FIG. 5, it is
confirmed that a large amount of hydrogen (1.61 mmol) was produced.
As shown in a gas chromatogram (detector: TCD, separation column:
PorapakQ, carrier gas: Ar) in FIG. 6, it is also confirmed that
other gas component was carbon dioxide.
[0035] The obtained gases are flammable gases (methane, a trace
amount of ethane, a trace amount of propane, hydrogen) and carbon
dioxide. Carbon dioxide can be selectively collected through
calcium hydroxide solution, thereby imposing no influence on the
environment. A trace amount of the organic residue was mainly
unreacted naphthalene, and it was confirmed that the organic
residue can be used again as the material to be processed.
[0036] As a further embodiment, Taiheiyo coal as the low quality
fuel was decomposed in an experiment, as follows:
[0037] 100 mg of Taiheiyo coal, 20 mg of ruthenium oxide (IV)
(RuO.sub.2), and 3 ml of water were placed in a batch-type
supercritical water reactor. After the reactor was sealed, the
reactor was heated to conduct a reaction at 450.degree. C. for 2
hours. After cooling, the reactor was connected with a vacuum glass
line, and produced gas components were analyzed with on-line gas
chromatography. An organic residue produced from Taiheiyo coal was
extracted using chloroform and collected from a water phase.
[0038] As shown in a gas chromatogram (detector: FID, separation
column: PorapakQ, carrier gas: Ar) in FIG. 7, it is confirmed that
0.609 mmol of methane, 0.0343 mmol of ethane, and 0.0170 mmol of
propane were produced from 100 mg of Taiheiyo coal. As shown in a
gas chromatogram (detector: FID, separation column: molecular
sieve, carrier gas: Ar) in FIG. 8, it is confirmed that a large
amount of hydrogen (1.23 mmol) was produced. As shown in a gas
chromatogram (detector: TCD, separation column: PorapakQ, carrier
gas: Ar) in FIG. 9, it is also confirmed that 1.55 mmol of carbon
dioxide was produced. A trace amount (4.4 mg) of an oily organic
material was extracted.
[0039] The obtained gases are flammable gases (methane, a trace
amount of ethane, a trace amount of propane, hydrogen) with no
harmful components (nitrogen component, sulfur component or heavy
metal). Carbon dioxide can be selectively collected through calcium
hydroxide solution, thereby imposing no influence on the
environment. A trace amount of the organic residue can be stored in
a glass bottle, thereby imposing no negative influence on the
environment.
[0040] As described above, polystyrene (polymeric compound) and
naphthalene (aromatic/condensed-aromatic compound) are converted
into low molecular weight hydrocarbons (methane, ethane, propane),
and hydrogen is produced. The results indicate that ruthenium oxide
(IV) functions as a catalyst of reductive decomposition. Further,
the conversion into carbon dioxide indicates that ruthenium oxide
(IV) functions as a catalyst of oxidative decomposition. Such
conversion of a polymeric compound and an aromatic/condensed into
low molecular weight hydrocarbons and generation of hydrogen are
quite different characteristics from supercritical water oxidation,
in which an organic compound is decomposed through oxidation.
[0041] The result of the decomposition of polystyrene indicates
that ruthenium oxide (IV) decomposes a polymeric compound, i.e.
large linear macromolecules, into low molecular hydrocarbons
through reduction and oxidation. Furthermore, the result of the
decomposition of naphthalene indicates that an aromatic compound
having a stable conjugated ring structure is oxidized, and at the
same time, is opened reductively to produce low molecular
hydrocarbons. Accordingly, ruthenium oxide (IV) functions as a
catalyst for decomposing many organic compounds in supercritical
water through reduction and oxidation.
* * * * *