U.S. patent application number 14/373542 was filed with the patent office on 2014-12-25 for reformed coal production equipment.
This patent application is currently assigned to MITSUBISHI HEAVY INDUSTRIES, LTD.. The applicant listed for this patent is MITSUBISHI HEAVY INDUSTRIES, LTD.. Invention is credited to Keiichi Nakagawa, Setsuo Omoto, Fumiaki Sato, Jun Satou.
Application Number | 20140373436 14/373542 |
Document ID | / |
Family ID | 49005788 |
Filed Date | 2014-12-25 |
United States Patent
Application |
20140373436 |
Kind Code |
A1 |
Nakagawa; Keiichi ; et
al. |
December 25, 2014 |
REFORMED COAL PRODUCTION EQUIPMENT
Abstract
Reformed coal production equipment includes: a combustion
furnace (124) for generating heated gas (11); a dry distillation
gas supply pipe (101) for supplying dry distillation gas (14)
generated at a dry distillation device to the combustion furnace; a
vapor generator (125) to which a portion of the heated gas
generated at the combustion furnace is supplied and which generates
waste heat gas (13) by subjecting the heated gas to heat exchange;
and a discharge pipe (52), a waste heat gas delivery pipe (54), a
mixed gas delivery pipe (55), a blower (126), a mixed gas supply
pipe (56), a mixed gas branching pipe (102), a flow rate adjustment
valve (103), and a mixed gas communication pipe (104) supplying, to
the dry distillation gas supply pipe, the waste heat gas and
low-temperature heated gas (12) formed by indirectly heating dried
coal by the heated gas at the dry distillation device (121).
Inventors: |
Nakagawa; Keiichi; (Tokyo,
JP) ; Omoto; Setsuo; (Tokyo, JP) ; Sato;
Fumiaki; (Tokyo, JP) ; Satou; Jun; (Tokyo,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MITSUBISHI HEAVY INDUSTRIES, LTD. |
Tokyo |
|
JP |
|
|
Assignee: |
MITSUBISHI HEAVY INDUSTRIES,
LTD.
Tokyo
JP
|
Family ID: |
49005788 |
Appl. No.: |
14/373542 |
Filed: |
February 21, 2013 |
PCT Filed: |
February 21, 2013 |
PCT NO: |
PCT/JP2013/054251 |
371 Date: |
July 21, 2014 |
Current U.S.
Class: |
44/629 |
Current CPC
Class: |
C10L 9/08 20130101; C10L
5/28 20130101; Y02P 20/129 20151101; C10B 47/30 20130101 |
Class at
Publication: |
44/629 |
International
Class: |
C10L 5/28 20060101
C10L005/28 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 24, 2012 |
JP |
2012-038514 |
Claims
1. Upgraded coal production equipment including drying means for
drying coal, indirect-heating pyrolysis means for performing
pyrolysis on the dried coal by indirectly heating the dried coal by
use of a heating gas, and cooling means for cooling the coal
subjected to the pyrolysis, characterized in that the equipment
comprises: heating gas generation means for generating the heating
gas; pyrolysis gas supply means for supplying the heating gas
generation means with a pyrolysis gas generated in the
indirect-heating pyrolysis means; waste-heat gas generation means
for receiving supply of part of the heating gas generated in the
heating gas generation means and generating a waste-heat gas by
subjecting the heating gas to heat exchange; and mixed gas supply
means for supplying the pyrolysis gas supply means with the
waste-heat gas and a low-temperature heating gas generated when the
heating gas heats the coal indirectly in the indirect-heating
pyrolysis means.
2. The upgraded coal production equipment according to claim 1,
characterized in that p1 the equipment further comprises gas
temperature measurement means, provided at the pyrolysis gas supply
means, for measuring a gas temperature, and the mixed gas supply
means includes gas flow rate adjustment means for adjusting a flow
rate of the waste-heat gas and the low-temperature heating gas
supplied to the pyrolysis gas supply means, and control means for
controlling the gas flow rate adjustment means based on the gas
temperature measured by the gas temperature measurement means.
Description
TECHNICAL FIELD
[0001] The present invention relates to upgraded coal production
equipment, and is particularly useful when used to upgrade coal of
low rank (low-rank coal), such as brown coal or subbituminous coal,
which is porous and has a high water content.
BACKGROUND ART
[0002] Coal of low rank (low-rank coal), such as brown coal or
subbituminous coal, which is porous and has a high water content
generates a low amount of heat per unit weight, and is therefore
dried through a heating treatment to have improved amount of heat
generation per unit weight.
[0003] As upgraded coal production equipment configured to perform
such upgrade of low-rank coal, there is, for example, equipment
including: an indirect-heating pyrolysis device which performs
pyrolysis on low-rank coal by heating the low-rank coal indirectly
by use of a heating gas; and a combustion furnace which generates
the heating gas by combusting a pyrolysis gas generated in the
pyrolysis device and supplied to the combustion furnace through a
pyrolysis gas supply pipe.
[0004] The pyrolysis gas described above is composed of a
low-boiling component. However, since the low-rank coal is
processed under a relatively high temperature, the pyrolysis gas is
accompanied by tar (pyrolysis oil) which is a high-boiling
component. When the pyrolysis gas is cooled, the tar is attached to
a wall surface of a duct or the like through which the pyrolysis
gas flows. When a large amount of tar is attached, a problem might
occur, such as clogging the duct. Hence, various techniques have
been developed to remove the tar.
[0005] For example, Patent Document 1 given below discloses a
decoking method for combusting and removing coke attached to the
inside of a pipe by use of a gas which is obtained by adjusting air
to have an oxygen concentration of 3 vol % to 21 vol % through
dilution with water vapor or an inert gas, and which is also
adjusted to have a temperature of 350.degree. C. to 500.degree.
C.
[0006] Patent Document 2 given below discloses a method for
performing a pyrolysis treatment on a processed object by using an
external heating kiln. In this method, an oxygen-containing gas is
supplied into an inner cylinder of the external heating kiln to
combust a carbide of organic matter in the processed object and/or
a combustible gas, which are produced by pyrolysis. Thereby, the
temperature of a pyrolysis gas increases, so that liquefaction or
solidification is prevented.
PRIOR ART DOCUMENTS
Patent Documents
[0007] Patent Document 1: Japanese Patent Application Publication
No. Hei 5-188653 (see, e.g., paragraphs [0013], [0017], and the
like)
[0008] Patent Document 2: Japanese Patent Application Publication
No. 2004-3738 (see, e.g., paragraphs [0011], [0014], [0015], and
the like)
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
[0009] To apply the decoking method described in Patent Document 1
to the upgraded coal production equipment described earlier, the
decoking has to be performed with the pyrolysis device itself being
stopped. Alternatively, two systems of ducts through which the
pyrolysis device supplies the combustion furnace with a pyrolysis
gas are provided, and the decoking has to be performed while
stopping one of the systems. This entails decrease in operating
rate of the equipment, size increase, and the like, causing
increase in costs for producing upgraded coal. In other words, the
tar cannot be removed efficiently.
[0010] By directly supplying the oxygen-concentration adjusted gas
adjusted for its oxygen concentration to the pyrolysis gas supply
pipe described earlier, tar produced during operation is combusted,
so that attachment of the tar to the pyrolysis gas supply pipe can
be suppressed. However, generating the oxygen-concentration
adjusted gas from air or from an inert gas (nitrogen or water
vapor) requires an apparatus specialized for that, and this
increases costs for producing upgraded coal. Moreover, the
oxygen-concentration adjusted gas has to be increased in
temperature in advance in order for it to react with the tar. Thus,
additional energy is needed. In sum, the tar cannot be removed
efficiently.
[0011] In the method for performing a pyrolysis treatment on a
processed object by using an external heating kiln described in
Patent Document 2, the carbide itself of organic matter in the
processed object produced by the pyrolysis is combusted. Thus, when
this method is applied to the pyrolysis device of the upgraded coal
production equipment, the production volume of the upgraded coal is
lowered.
[0012] In view of the above, the present invention has been made to
solve the problems described above, and has an objective of
providing upgraded coal production equipment capable of efficient
tar removal without lowering the production volume of upgraded
coal.
Means for Solving the Problems
[0013] Upgraded coal production equipment according to a first
aspect of the invention for solving the above problems is upgraded
coal production equipment which includes drying means for drying
coal, indirect-heating pyrolysis means for performing pyrolysis on
the dried coal by indirectly heating the dried coal by use of a
heating gas, and cooling means for cooling the coal subjected to
the pyrolysis, and which is characterized in that the equipment
comprises: heating gas generation means for generating the heating
gas; pyrolysis gas supply means for supplying the heating gas
generation means with a pyrolysis gas generated in the
indirect-heating pyrolysis means; waste-heat gas generation means
for receiving supply of part of the heating gas generated in the
heating gas generation means and generating a waste-heat gas by
subjecting the heating gas to heat exchange; and mixed gas supply
means for supplying the pyrolysis gas supply means with the
waste-heat gas and a low-temperature heating gas generated when the
heating gas heats the coal indirectly in the indirect-heating
pyrolysis means.
[0014] Upgraded coal production equipment according to a second
aspect of the invention for solving the above problems is the
upgraded coal production equipment according to the first aspect of
the invention described above, characterized in that the equipment
further comprises gas temperature measurement means, provided at
the pyrolysis gas supply means, for measuring a gas temperature,
and the mixed gas supply means includes gas flow rate adjustment
means for adjusting a flow rate of the waste-heat gas and the
low-temperature heating gas supplied to the pyrolysis gas supply
means, and control means for controlling the gas flow rate
adjustment means based on the gas temperature measured by the gas
temperature measurement means.
EFFECT OF THE INVENTION
[0015] According to the upgraded coal production equipment of the
present invention, the low-temperature heating gas and the
waste-heat gas can be supplied to the pyrolysis gas supply means.
Thereby, even if the pyrolysis gas is cooled in the pyrolysis gas
supply means to face possible liquefaction or solidification of tar
(pyrolysis oil), the low-temperature heating gas and the waste-heat
gas make the oxygen concentration about 1 to 2%, and thereby the
tar is oxidatively decomposed. As a result, the tar becomes light
in weight and is thereby prevented from being attached to a wall
surface of a duct or the like forming the pyrolysis gas supply
means. Further, since a light gas generated when the tar becomes
light in weight is combusted, the temperature of the pyrolysis gas
rises, which can prevent attachment of tar to a wall surface of the
duct or the like forming the pyrolysis gas supply means. The
oxidative decomposition of the tar can be performed without
stopping the device, and therefore the operating rate of the
equipment can be improved compared to equipment which has to stop
the device in order for the tar to be oxidatively decomposed. In
other words, tar can be removed efficiently. Since the pyrolysis
gas has almost the same temperature as the low-temperature heating
gas and the waste-heat gas, preheating of the low-temperature
heating gas and the waste-heat gas is unnecessary, which is
energy-saving.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a schematic diagram showing the overall
configuration of a main embodiment of upgraded coal production
equipment according to the present invention.
MODE FOR CARRYING OUT THE INVENTION
[0017] An embodiment of upgraded coal production equipment
according to the present invention is described.
Main Embodiment
[0018] Based on FIG. 1, a main embodiment of upgraded coal
production equipment according to the present invention is
described.
[0019] First, as shown in FIG. 1, low-rank coal 1 such as brown
coal or subbituminous coal is supplied to a drying device 111 by a
hopper or the like (not shown), the drying device 111 being drying
means for drying the low-rank coal 1. An outlet opening of the
drying device 111 communicates with an inlet opening 122a of a
pyrolysis device 121 configured to perform pyrolysis on dried coal
2. An outlet opening 122b of the pyrolysis device 121 communicates
with an inlet opening of a cooling device 131 being cooling means
for cooling pyrolysis coal 3.
[0020] The pyrolysis device 121 has an inner cylinder 122 and an
outer cylinder 123 surrounding the inner cylinder 122. The outer
cylinder 123 is supplied with a heating gas 11 to be described
later. Thereby, the dried coal 2 supplied into the inner cylinder
122 is indirectly heated and is subjected to pyrolysis, to generate
the pyrolysis coal 3. In other words, the pyrolysis device 121 is
an indirect-heating device, such as, e.g., an external heating
kiln, in which a hot gas (heating gas) being a heat source does not
come into direct contact with the low-rank coal 1. The pyrolysis
device 121 forms indirect-heating pyrolysis means.
[0021] A gas exhaust port of the inner cylinder 122 of the
pyrolysis device 121 communicates with a gas intake port of a
combustion furnace 124 via a pyrolysis gas supply pipe 101.
Thereby, a pyrolysis gas 14 containing gaseous tar (pyrolysis oil)
generated by the pyrolysis is supplied to the gas intake port of
the combustion furnace 124. The gas intake port of the combustion
furnace 124 is also supplied with a fuel (not shown) such as a
natural gas. The combustion furnace 124 generates the heating gas
11 by combusting the pyrolysis gas 14 and the fuel such as a
natural gas. In other words, the combustion furnace 124 forms
heating gas generation means. A gas exhaust port of the combustion
furnace 124 communicates with a gas intake port of the outer
cylinder 123 of the pyrolysis device 121 via a heating gas feed
pipe 51.
[0022] The heating gas feed pipe 51 communicates with a gas intake
port of a steam generator 125 via a heating gas branch pipe 53. The
steam generator 125 forms waste-heat gas generation means for
generating a waste-heat gas 13 through heat exchange between the
heating gas 11 and water to thereby generate steam. A gas exhaust
port of the steam generator 125 communicates with an exhaust pipe
52 to be described later via a waste-heat gas feed pipe 54.
[0023] A gas exhaust port of the outer cylinder 123 of the
pyrolysis device 121 communicates with a gas intake port of an
exhaust-gas treatment device 127 via the exhaust pipe 52, the
exhaust-gas treatment device 127 being exhaust-gas purification
means for purifying the waste-heat gas 13 and a low-temperature
heating gas 12 which is generated when the heating gas 11 heats the
inner cylinder 122. The low-temperature heating gas 12 and the
waste-heat gas 13 are discharged to the outside of the system after
undergoing the purification treatment in the exhaust-gas treatment
device 127.
[0024] The exhaust pipe 52 communicates with a gas intake port of a
blower 126 via a mixed gas feed pipe 55. A gas exhaust port of the
blower 126 communicates with a gas intake port of the combustion
furnace 124 via a mixed gas supply pipe 56. The mixed gas supply
pipe 56 communicates with a mixed gas branch pipe 102. The mixed
gas branch pipe 102 communicates with a mixed gas communication
pipe 104 via a flow rate adjustment valve 103. The mixed gas
communication pipe 104 communicates with the pyrolysis gas supply
pipe 101.
[0025] The pyrolysis gas supply pipe 101 is provided with a gas
temperature measurement instrument 105 which is gas temperature
measurement means for measuring the temperature of a gas inside the
pipe. The gas temperature measurement instrument 105 is connected
to a control device 106 such that the measured gas temperature can
be sent to the control device 106, the control device 106 being
control means for controlling the valve position of the flow rate
adjustment valve 103.
[0026] The exhaust pipe 52, the waste-heat gas feed pipe 54, the
mixed gas feed pipe 55, the blower 126, the mixed gas supply pipe
56, the mixed gas branch pipe 102, the flow rate adjustment valve
103, the mixed gas communication pipe 104, and the like form mixed
gas supply means.
[0027] In the upgraded coal production equipment according to this
embodiment thus configured, when the low-rank coal 1 is charged
into the hopper, the hopper supplies the low-rank coal 1 at a room
temperature to the drying device 111 a predetermined amount at a
time. The low-rank coal 1 supplied to the drying device 111 is
removed of water and becomes the dried coal 2 by being heated up to
about 200.degree. C. by a drying combustion gas (about 150 to
300.degree. C.) from a drying combustor (not shown). Then, the
dried coal 2 is transferred into the inner cylinder 122 of the
pyrolysis device 121. The dried coal 2 transferred to the pyrolysis
device 121 is subjected to pyrolysis by being indirectly heated by
the heating gas 11 (gas temperature: about 1050.degree. C., oxygen
concentration: about 2 to 3%) from the combustion furnace 124.
Thereby, the dried coal 2 becomes the pyrolysis coal 3 as a result
of removal of components such as the pyrolysis gas 14 containing
gaseous tar, and the pyrolysis coal 3 is fed to the cooling device
131. The pyrolysis coal 3 fed to the cooling device 131 becomes
upgraded coal 4 by being cooled down to about 50.degree. C.
[0028] Meanwhile, the heating gas 11 (gas temperature: about
1050.degree. C., oxygen concentration: about 2 to 3%) generated in
the combustion furnace 124 is fed to the outer cylinder 123 of the
pyrolysis device 121 via the heating gas feed pipe 51. The heating
gas 11 used inside the outer cylinder 123 to heat the inner
cylinder 122 becomes the low-temperature heating gas 12 (gas
temperature: about 350.degree. C., oxygen concentration: about 2 to
3%). The low-temperature heating gas 12 is fed to the exhaust pipe
52. Meanwhile, the heating gas 11 is also fed to the steam
generator 125 via the heating gas feed pipe 51 and the heating gas
branch pipe 53. The heating gas 11 used in the steam generator 125
for generation of water vapor becomes the waste-heat gas 13 (gas
temperature: about 350.degree. C., oxygen concentration: about 2 to
3%). The waste-heat gas 13 is fed to the exhaust pipe 52 via the
waste-heat gas feed pipe 54.
[0029] Part of the low-temperature heating gas 12 and the
waste-heat gas 13 is supplied to the exhaust-gas treatment device
127. The low-temperature heating gas 12 and the waste-heat gas 13
undergo the purification treatment in the exhaust-gas treatment
device 127 and are then discharged to the outside of the system.
The rest of the low-temperature heating gas 12 and the waste-heat
gas 13 (gas temperature: about 350.degree. C., oxygen
concentration: about 2 to 3%) is fed to the blower 126 via the
mixed gas feed pipe 55.
[0030] Part of the low-temperature heating gas 12 and the
waste-heat gas 13 fed to the blower 126 is supplied to the
combustion furnace 124 via the mixed gas supply pipe 56. The rest
of the low-temperature heating gas 12 and the waste-heat gas 13
(gas temperature: about 350.degree. C., oxygen concentration: about
2 to 3%) fed to the blower 126 is supplied to the pyrolysis gas
supply pipe 101 via the mixed gas branch pipe 102, the flow rate
adjustment valve 103, and the mixed gas communication pipe 104.
[0031] The valve position of the flow rate adjustment valve 103 is
controlled by the control device 106 based on the gas temperature
measured by the gas temperature measurement instrument 105. For
example, the control device 106 adjusts the flow rate adjustment
valve 103 by opening it to increase the aperture when the gas
temperature measured by the gas temperature measurement instrument
105 is equal to or higher than 400.degree. C., and adjusts the flow
rate adjustment valve 103 by narrowing it when the gas temperature
exceeds 550.degree. C. Thereby, the low-temperature heating gas 12
and the waste-heat gas 13 (oxygen concentration: about 2 to 3%) are
mixed with the pyrolysis gas 14 (gas temperature: about 400.degree.
C., oxygen concentration: about 0%), and this mixed gas has an
oxygen concentration adjusted to about 1 to 2%. As a result,
gaseous tar (pyrolysis oil) is oxidatively decomposed (decoking) to
become light in weight, and thereby attachment of the tar to the
pyrolysis gas supply pipe 101 can be prevented. The tar is reduced
in weight to become a light gas, and this light gas is combusted.
Thus, decrease in the gas temperature is prevented. Thereby,
attachment of the tar to the pyrolysis gas supply pipe 101 can be
prevented. Specifically, the decoking is performed just when the
tar is about to be attached to the inner wall surface of the
pyrolysis gas supply pipe 101 by adjustment of the amount of the
low-temperature heating gas 12 and the waste-heat gas 13 supplied
to the pyrolysis gas supply pipe 101 based on the gas temperature
inside the pyrolysis gas supply pipe 101. Hence, the tar can be
efficiently removed.
[0032] Thus, according to the upgraded coal production equipment
according to this embodiment, by supplying the low-temperature
heating gas 12 and the waste-heat gas 13 into the pyrolysis gas
supply pipe 101, the oxygen concentration of the gases 12, 13, 14
in the pyrolysis gas supply pipe 101 is adjusted to about 1 to 2%,
so that tar contained in the pyrolysis gas 14 (pyrolysis oil) is
oxidatively decomposed (decoking) to become light in weight.
Thereby, attachment of the tar to the pyrolysis gas supply pipe 101
can be prevented.
[0033] Moreover, since a light gas generated when the tar becomes
light in weight is combusted, the temperature of the pyrolysis gas
14 rises, which can prevent attachment of the pyrolysis oil to a
wall surface of the pyrolysis gas supply pipe 101 and the like.
Since the pyrolysis gas 14 has almost the same temperature as the
low-temperature heating gas 12 and the waste-heat gas 13,
preheating of the low-temperature heating gas 12 and the waste-heat
gas 13 is unnecessary, which is energy-saving. Furthermore, since
decoking can be performed to remove tar without stopping the
device, the operating rate of the equipment can be improved
compared to equipment which has to stop the device to decoke the
device for tar removal. In other words, tar can be removed
efficiently.
INDUSTRIAL APPLICABILITY
[0034] The upgraded coal production equipment according to the
present invention can remove tar efficiently without lowering the
production volume of upgraded coal, and can therefore be utilized
significantly beneficially in various industries.
EXPLANATION OF REFERENCE NUMERALS
[0035] 1 low-rank coal
[0036] 2 dried coal
[0037] 3 pyrolysis coal
[0038] 4 upgraded coal
[0039] 11 heating gas
[0040] 12 low-temperature heating gas
[0041] 13 waste-heat gas
[0042] 14 pyrolysis gas
[0043] 51 heating gas feed pipe
[0044] 52 exhaust pipe
[0045] 53 heating gas branch pipe
[0046] 54 waste-heat gas feed pipe
[0047] 55 mixed gas feed pipe
[0048] 56 mixed gas supply pipe
[0049] 101 pyrolysis gas supply pipe
[0050] 102 mixed gas branch pipe
[0051] 103 flow rate adjustment valve
[0052] 104 mixed gas communication pipe
[0053] 105 gas temperature measurement instrument
[0054] 106 control device
[0055] 111 drying device
[0056] 121 pyrolysis device
[0057] 122 inner cylinder
[0058] 123 outer cylinder
[0059] 124 combustion furnace
[0060] 125 steam generator
[0061] 126 blower
[0062] 127 exhaust-gas treatment device
[0063] 131 cooling device
* * * * *