JPS60217291A - Gasification of polymeric compound - Google Patents

Abstract

PURPOSE:To maximize the gasification ratio of a biopolymer compound or an organic polymer compound, by thermally carbonizing the compound, and contacting with a catalyst in the presence of steam to effect the cracking and gasification of the compound. CONSTITUTION:A polymer compound such as wood, plastics, etc. is charged through the inlet 7 into the gasification zone 3 of the furnace, partially burnt with combustion oxygen (air or O2-containing gas) introduced through the inlet 5, and made to contact with steam introduced through the inlet 6 at 700-1,000 deg.C to effect the carbonization simultaneous to the water-gas reaction. The tar produced by the reaction is gasified, transferred upward, made to contact with the catalyst layer 4 heated at about >=700 deg.C, and gasified to form H2, CO, CO2, etc.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a gasification method for carbonizing biopolymer compounds such as wood and organic polymer compounds such as plastics to decompose and gasify them. The present invention relates to a method for gasifying a polymer compound that can improve gasification efficiency as much as possible.

[Technical background of the invention and its problems] Generally, from the viewpoint of resource efficiency, biopolymer compounds such as wood and organic polymer compounds such as plastics are decomposed and gasified by carbonization to produce H2 and Co.

A method for gasifying a polymer compound to obtain a raw material gas for the chemical industry, such as CO2, is already known.

For example, as a method for decomposing and gasifying biopolymer compounds (generally referred to as biomass), 70% of wood, etc.
A conventional method has been known in which dry gasification is performed at a relatively low temperature range of 00 to 1000°C, but in this case, the tar content, that is, the polymer polycondensate, is removed from the raw material such as wood.
As about 20% of the tar is produced as a by-product, it not only significantly reduces the gasification rate, but also causes inconveniences such as the generated tar adhering to the piping and equipment after the gasification furnace and potentially clogging them. .

For this reason, attempts have been made to improve gasification efficiency by impregnating or mixing catalysts for decomposing tar into raw materials such as wood, and suppressing the generation of tar as much as possible during carbonization. In this case, there is a problem that it becomes difficult to recover the catalyst and the operating cost increases.

[Object of the Invention] The present invention has been devised to address the above-mentioned problems and to effectively solve them.

The object of the present invention is to decompose and gasify a gas containing a polymer polycondensate (tar component) generated by heating and carbonizing a polymer compound by contacting it with a separately provided catalyst in the presence of water vapor. The object of the present invention is to provide a method for gasifying a polymer compound that can improve gasification efficiency.

[Summary of the invention] The present invention involves first carbonizing a polymer compound such as wood or plastic, and then contacting the generated gas containing the polymer polycondensate with a catalyst in the presence of water vapor to decompose the polymer polycondensate. This is the gist of this article.

[Embodiments of the Invention] A preferred embodiment of the method of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a schematic plan view showing an example of a polymer compound gasification apparatus for carrying out the method of the present invention.

As shown in the figure, this apparatus has a gasification furnace 1 in the shape of a cylindrical body. A heating gasification section 3 is formed in the lower part of the gasification furnace 1 so as to cross the perforated plate 2, etc., and is configured to heat and carbonize raw materials (wood, etc.) fed into the gasification section 3. ing. A catalyst layer 4 filled with a catalyst is formed above the heating gasification section 3 at an appropriate interval, and is designed to decompose the polymer polycondensate produced by carbonization and subjected to TR. The catalyst to be filled is preferably an oxide of an alkali metal or an alkaline earth metal, such as poly77 potassium luminate (K2O-Ap20) or calcium oxide (Cab), but is not limited thereto. In addition, in order to prevent the catalyst layer 4 from being blocked by dust such as ash and unreacted substances accompanying the gas containing the polymer polycondensate, the catalyst layer 4 may be a fixed bed using a honeycomb type catalyst or a fixed bed using a pellet catalyst. It is preferable to configure it as a moving bed or a fluidized bed using a powder catalyst.

At the bottom of the gasifier 1, there is oxygen for combustion (air, etc.) inside the furnace.
A combustion oxygen introduction section 5 for introducing oxygen and a water vapor introduction section 6 for introducing water vapor are provided, respectively, and the above-mentioned heating gasification 8I! A raw material input section 7 into which raw materials are inputted is formed on the side of 3.

Further, a generated gas discharge section 8 is provided at the upper end of the gasification furnace 1 to discharge generated cracked gas to the outside of the furnace.

The method of the present invention will be described in detail based on an example of the apparatus configured as described above.

The high molecular compound such as wood or plastic fed into the furnace heating gasification section 3 from the raw material input section 7 is partially heated by the combustion oxygen (air or oxygen-containing gas) introduced from the combustion oxygen introduction section 5. Burns, 700-1000℃
Under this temperature condition, the water vapor is introduced from the water vapor introducing section 6, contacts the repelled water vapor, and undergoes a water gas reaction while being carbonized. At this time, temperature control in the heating gasification section is performed by controlling the amount of oxygen to be supplied and changing the amount of partial combustion.

This gasification reaction generates about 10 to 20% of the tar content of the raw material, i.e., a polymer polycondensate, which in a vaporized state rises together with the polymer polycondensate-containing gas and comes into contact with the catalyst layer 4. let This catalyst layer 4 is maintained at approximately 700° C. or higher, and the polymer polycondensate (Cn Hm ) in contact with the catalyst is combined with unreacted water vapor that was not subjected to the gasification reaction of the raw material as shown in the following formula (1).

As shown in (2), it is decomposed and gasified to produce gases such as H2, Go, and Go2.

CnHIn+nH2O→ncO+(-!!!-+n)H
2'-(1)CnHIT,'+2nH20-+nCO
2+(-'+2n)H2----'-(2) The amount of catalyst filled in the catalyst layer 4 is appropriately increased or decreased depending on the processing capacity of the polymer compound.

The gas generated by decomposition in the catalyst layer 4 is then discharged to the outside of the furnace from a generated gas discharge section 8, and after its heat is recovered by a heat exchanger (not shown) or the like, it is transferred to a subsequent process.

In this manner, the polymer polycondensate generated during carbonization of the polymer compound can be reliably gasified by bringing it into contact with the heating gasification section 3 and the catalyst layer 4 provided separately.

In addition, as mentioned above, the catalyst layer 4 has a helical cam structure that is difficult to block due to dust etc., but if it becomes necessary to replace it with a new catalyst layer due to blockage or due to a decrease in activity, etc. Since the catalyst layer 4 itself has an integral structure, replacement work can be easily performed, and recovery of the catalyst is not difficult as in the conventional example.

On the other hand, in the heating gasification section 3, the remaining ash or unreacted substances (unreacted carbon, etc.) are appropriately discharged υ1 from the ash discharge section 9 to the outside of the furnace.

In the above embodiment, the polymer polycondensate-containing gas generated in the heating gasification section 3 is directly guided to the catalyst layer 4, but the amount of dust generated in the heating gasification section 3 is particularly large. In some cases, a method as shown in FIG. 2 may be used. That is, the heating gasification section 3 and the catalyst layer 4 are housed in separate containers, and the cyclone 10 is provided between them to transfer the polymer polycondensate-containing gas generated in the heating gasification section 3 to the cyclone 10. After dust removal, the polymer polycondensate may be gasified in the catalyst layer 4. In this case, the transfer system from the heating gasification section 3 to the catalyst layer 4 may be appropriately heated. to prevent condensation of the gaseous polymer polycondensate. Components that are the same as those in FIG. 1 are designated by the same reference numerals and their description will be omitted.

Comparison of the tar production rate, wood gasification rate, and produced gas composition when the method of the present invention is carried out using wood as a raw material using the above-mentioned apparatus, and with a conventional method that does not perform gasification treatment of polymer polycondensates. are shown in the table below.

Table [Effects of the Invention] To summarize, according to the method of the present invention, the following excellent effects can be exhibited.

(1) *+A""5"7 f-y 9 "0 high" conversion 8
The polymer polycondensate (tar component) produced as a by-product during low-temperature carbonization gasification is decomposed by a catalyst to produce H2, CO, CO2'J
Since the gas can be converted into any gas, the gasification efficiency can be improved as much as possible.

(2) Since all of the by-product polymer polycondensate (tar content) can be gasified, it is possible to prevent clogging of piping, equipment, etc. caused by this.

(3) Since the exhaust gas from the furnace does not contain polymer polycondensates, heat can be easily recovered on the downstream side.

(4) Since the catalyst layer and the heating gasification section are provided separately, the catalyst layer can be easily replaced.

[Brief explanation of drawings]

FIG. 1 is a schematic plan view showing an example of a polymer compound gasification apparatus for carrying out the method of the present invention, and FIG. 2 is a schematic plan view showing another example of the apparatus. Note that 1. 3 is a gasification furnace, 3 is a heating gasification section, 4 is a catalyst layer, 5 is an oxygen introduction section for combustion, 6 is an air introduction section, and 8 is a produced gas discharge section. Patent applicant: Patent attorney representing Ishikawajima-Harima Heavy Industries Co., Ltd.
Nobuo Kinutani 10-

Claims (1)

[Claims] Biopolymer compounds such as wood and organic polymer compounds such as plastics are heated and carbonized, and the resulting gas containing the polymer polycondensate is brought into contact with a catalyst/media in the presence of water vapor to contain it. A method for gasifying a polymer compound, characterized in that the polymer polycondensate is decomposed and gasified.