JP3787616B2 - Hydrogenation gasification method for coal and hydrocarbon polymers - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hydrogenation gasification method for converting coal and plastics into an energy source such as light hydrocarbons. More specifically, the present invention efficiently converts plastics such as coal and polyethylene or wastes containing them into hydrogen-based fuels such as methane by reacting with hydrogen under high temperature and pressure, thereby converting environmental pollutants and Remove harmful metals and effectively use them as various energy sources for next-generation distributed power generation fuels such as city gas, fuel for power generation, micro gas turbines and fuel cells, and treat waste such as waste plastic The present invention relates to a hydrogenation gasification method that converts energy sources.
[0002]
[Prior art]
There are two methods for converting coal into methane, which has been established with clean and advanced technology: hydrogenation gasification, which directly produces methane from coal, and gasification of coal with oxygen and steam to carbon monoxide and hydrogen. After conversion, a method of synthesizing into methane using a catalyst such as nickel is known.
In general, the hydrogenation gasification method can produce methane with a smaller exothermic process than the methane synthesis method, so that it is expected to be able to constitute a process with low heat loss and high thermal efficiency, and development research has been continued for many years.
[0003]
The hydrogenation gasification of coal is known to have a lower reaction rate than the partial oxidation method using oxygen as a gasifying agent, and the hydrogenation gasification of coal is an exothermic reaction. Is also known to be smaller than partial oxidation. At the beginning of the development of this hydrogenation gasification process, attempts have been made using a reactor similar to the partial oxidation method, but most of the attempts have failed because the reaction mechanism between the two is different.
[0004]
In recent years, basic analysis of the hydrogenation gasification reaction process of coal has progressed, and it has become clear that the initial pyrolysis process has a significant effect on the subsequent secondary hydrogenation cracking. It was found that the decomposition reaction was completed in a short time when mixed with hydrogen at the reaction temperature. In addition, since the secondary hydrogenation proceeds relatively slowly, the conversion rate to methane and the selectivity can be increased if the reaction product is kept at the reaction temperature for a long time after the conversion from coal to gas is completed. It turns out that it improves. Based on these findings, a reactor having the structure shown in FIG. 1 has been proposed, and further research and development has been carried out. This reactor disperses finely pulverized coal with a high-speed hydrogen flow at the top of the reactor for rapid pyrolysis, and then puts the reaction products on a stream circulating in the reactor to perform secondary hydrogenolysis. It is what makes you do.
[0005]
In the hydrogenation gasification process, the retained energy (internal energy) of raw coal and hydrogen is distributed to the retained energy of the product gas and the reaction heat after the reaction. A part of the reaction heat is dissipated and lost from the reactor wall, and the rest heats the product gas and flows out of the reactor as sensible heat of the gas. The temperature of the resulting product gas depends on the reaction heat, the heat radiation from the reactor wall, and the heat capacity of the gas. The product gas temperature and the reaction temperature when the reactor accepts the raw material are equal, and the reactor is thermally It becomes stable state. Therefore, the reaction heat constitutes a heat loss of the process, and the lower the reaction heat, the higher the thermal efficiency of the process in calculation. However, the product gas temperature falls below the reaction temperature, and the reaction temperature cannot be maintained.
The reactor shown in FIG. 1 has a double-pipe structure in which a lift pipe is provided, and coal and hydrogen are blown in the direction of descending the center of the lift pipe. The lift pipe serves to circulate the hot product gas after the reaction to the upper part of the lift pipe, and sensible heat of the hot product gas is imparted to the coal and hydrogen to be blown to cause thermal decomposition. However, since it is assumed that the reaction temperature cannot be maintained even if the product gas is internally circulated, a method in which a part of hydrogen is burned with oxygen and mixed with coal is employed.
[0006]
[Problems to be solved by the invention]
By the way, the hydrogenation gasification method that gasifies coal with hydrogen can produce methane that can be used cleanly in existing utilization systems as city gas and power generation fuel in a small exothermic process. However, there are two main issues to be solved.
The first challenge is to establish thermal independence of the reactor based on a simplified principle. Since the hydrogenation gasification reaction of coal is a weak exothermic reaction, a device for maintaining the reaction temperature is required. Conventionally, a reactor structure that recirculates high-temperature product gas to the coal / hydrogen supply section has been adopted, and oxygen is mixed into the supplied hydrogen to partially burn the hydrogen to maintain the reaction temperature. However, in this method, the structure of the reactor is complicated and the addition of oxygen causes a decrease in the operational stability and thermal efficiency of the process. It is necessary to establish it.
The second issue is the establishment of a reaction acceleration method that improves the economics of the process. In hydrogenated gasification, it is estimated that 60% of the gas price is plant construction costs, and it is pointed out that it is necessary to reduce the plant cost by reducing the reactor size. In order to realize this, it is necessary to improve the reaction rate between coal and hydrogen, and a reactor capable of operating at 900 to 1000 ° C. and 7 MPa is currently under development. However, it is speculated that the use of expensive heat-resistant materials and the thickening of the reactor will be indispensable for the reaction at higher temperatures and higher pressures, which will increase the plant construction cost. Has reached. For this reason, establishment of the method of promoting reaction by methods other than high temperature / high pressure conditions is calculated | required.
[0007]
In general, when coal is supplied to a hydrogenation gasification reactor, heat (sensible heat of coal), which is obtained by multiplying the heat capacity of solid coal by the increase from room temperature to the reaction temperature, is absorbed first, followed by a pyrolysis reaction. The heat of reaction required for is absorbed. Therefore, under adiabatic conditions, the reaction temperature decreases due to the sensible heat of coal and the heat required for pyrolysis. Thereafter, a secondary hydrogenation process (exothermic reaction) of the thermal decomposition product occurs, and the reaction temperature rises accordingly. The details of the heat transfer and mass transfer phenomenon between the coal during the reaction and the surrounding atmospheric gas have not yet been elucidated.
However, the reaction temperature decreases due to the endothermic reaction that occurs immediately after the coal is fed into the reactor, which delays the progress of the secondary hydrogenation cracking and ultimately reduces the overall achievement rate of the hydrogenation gasification reaction. It is clear from the data accumulated in the past that a chain phenomenon occurs.
Therefore, oxygen is supplied to the reactor and a part of hydrogen is combusted to suppress this chain phenomenon. However, the addition of oxygen inevitably causes a decrease in thermal efficiency. Measures to compensate for the lack of heat of reaction by the method are required.
[0008]
At present, attempts have been made to install lift pipes in internal circulation reactors. However, there is a support structure that can select materials that can be used in a high-temperature hydrogen atmosphere of 800 to 1050 ° C and maintain mechanical strength. This is a big problem considering future scale-up. Further, carbon deposition is expected in the reactor due to fluctuations in reaction conditions, and particularly when the reactor structure and internal gas flow are complicated, there is a concern that the carbon deposition may adversely affect the process.
[0009]
This invention is made | formed in view of the above-mentioned actual condition in a prior art. That is, the object of the present invention is to maintain the desired reaction temperature without circulating the product gas or adding oxygen by combining the hydrocracking reaction of coal and the cracking reaction of hydrocarbon-based polymer, and is simple. An object of the present invention is to provide a hydrogenation gasification method capable of promoting a cracking reaction using a small reactor, achieving a good cracking reaction rate, and producing a high-concentration hydrocarbon fuel gas with high efficiency.
Another object of the present invention is to apply the decomposition of the waste hydrocarbon polymer to the hydrocracking reaction of coal so as to efficiently use the heat of reaction and to reduce the hydrocarbon polymer that is difficult to dispose of. It is an object of the present invention to provide a hydrogenation gasification method that can be effectively used as a good fuel gas.
[0010]
[Means for Solving the Problems]
  As a result of intensive studies to solve the above-described problems in the hydrogenation gasification process for coal and the like, the present inventors have completed the present invention.
  That is, in the method for hydrogenating gas of coal and hydrocarbon polymer in the present invention, after mixing finely pulverized coal and hydrocarbon polymer, the obtained raw material mixture and hydrogen are mixed.Under high temperature and pressure conditions exceeding 700 ° CIntroduced into hydrogenated gasification reactor,TheIt is characterized in that it is converted into a hydrocarbon mixed gas through a hydropyrolysis reaction under high temperature and pressure conditions.
  Further, in the hydrogenation gasification method of other coal and hydrocarbon polymer in the present invention, after the finely pulverized coal and hydrocarbon polymer are mixed, the obtained raw material mixture and hydrogen are mixed.Under high temperature and pressure exceeding 700 ° CIntroduced into hydrogenated gasification reactor,TheHydrogenated pyrolysis reaction under high temperature and pressure conditions to convert to hydrocarbon mixed gas, hydrogen produced by the gasification reactor and hydrogen obtained by partially oxidizing the generated char with oxygen, the hydrogenated gas It supplies to a chemical reactor.
[0011]
In the hydrogenation gasification method of the present invention, the raw material mixture preferably contains a hydrocarbon polymer amount of 10 to 120% by weight with respect to the amount of carbon contained in the coal. The obtained hydrocarbon mixed gas is preferably a lower hydrocarbon fraction mainly composed of methane and an aromatic hydrocarbon fraction mainly composed of benzene, toluene and xylene. Furthermore, as the high temperature pressurization conditions, it is preferable that they are 700-1200 degreeC and the range of 2-10 MPa.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail.
First, the present inventors examined the hydrogenation gasification reaction under practical reaction conditions and clarified the following reaction process in order to solve the above-described problems.
That is, with coal alone, when coal is set to predetermined reaction temperature and pressure conditions and supplied to a hydrogenated gasification reactor filled with hydrogen, it is first pyrolyzed to produce gas, volatile matter and char. Further, each product reacts with hydrogen to be converted into a final product mainly composed of methane. The initial pyrolysis reaction is completed within a few seconds, but since it is an endothermic process, a rapid temperature drop occurs during this time. Since the subsequent secondary decomposition process is accompanied by heat generation, the temperature is reversed and rises. On the other hand, in the case of plastics such as polyethylene alone, the endothermic phenomenon in the pyrolysis stage is milder than in the case of coal alone, but the exothermic heat in the subsequent secondary decomposition process is intense.
Based on the results of these basic studies, the characteristics of the hydrogenation gasification reaction process
(1) In the progress of hydrogenation gasification of coal, the process in which the sensible heat of the reaction gas, hydrogen, is distributed and transmitted to the coal dominates the progress of the reaction.
(2) In the hydrogenation gasification of plastics, after a certain induction period in which thermal decomposition proceeds, rapid secondary decomposition occurs.
(3) Some plastics have an endotherm that is so small that the endotherm in the first stage of pyrolysis is hardly observable in a hydrogen atmosphere, and the exothermic heat of the subsequent secondary decomposition is large.
The three points were confirmed.
[0013]
Next, when the hydrogenation gasification test was conducted by mixing the plastic having the above property (3) with coal, the thermal decomposition of both, the hydrogenated secondary decomposition of the thermal decomposition product proceeded rapidly, The desired reaction rate was achieved within a short time. Therefore, since hydrogenation gasification of plastics is an exothermic reaction, if this exothermic reaction coexists with hydrogenation gasification of coal, a constant reaction temperature is maintained without lowering the gasification reaction temperature of coal. Expect to get.
Therefore, in the present invention, by combining the coal and plastic mixing, the reaction temperature is maintained without circulating the product gas or adding oxygen, and the reactor is simplified and miniaturized. is there.
[0014]
When pyrolysis gasification of coal in the presence of hydrogen, the reaction process is affected by the chemical properties of the raw materials.For example, even if the same coal is used, the product gas composition and product It has been confirmed that the yields are different. In addition, the present inventors have confirmed that the initial process of the reaction in which the raw material is changed from coal to another organic substance such as plastic changes significantly. In particular, it has been found that an aliphatic polymer substance has a small endothermic phenomenon due to thermal decomposition at the initial stage of the reaction, and a large amount of heat generated by the subsequent hydrogenolysis.
FIG. 2 shows a comparison of changes over time in the respective reactor temperatures when coal and polyethylene are hydrogenated and gasified in a reactor filled with hydrogen under predetermined reaction temperature and pressure conditions. . When coal is blown into the reactor, the temperature immediately decreases, and after 3 to 5 seconds, it reverses and rises rapidly, and then gradually returns to the external heat temperature of the reactor. The temperature drop peak seen after 80 seconds in FIG. 2 is caused by the hydrogen that stayed in the low temperature portion in the apparatus passing through the reactor when the product gas is exhausted.
On the other hand, in polyethylene, a rapid exothermic reaction starts about 1 second after being injected into the reactor, and then the temperature gradually decreases toward the external heat temperature of the reactor. In this way, the reaction immediately after being injected into the reactor follows an opposite thermal process, in which coal is endothermic while polyethylene is exothermic.
[0015]
  Therefore, in the present invention, if coal and a hydrocarbon polymer such as polyethylene (PE) are mixed and used as a raw material to be injected into the reactor, the heat of reaction when the hydrocarbon polymer is hydrogenated is transferred to the coal. As a result of conducting a test in which a mixture of coal and hydrocarbon polymer was introduced into a hydrogenation gasification reactor under high temperature and pressure, it was conceived that thermal decomposition of coal could be promoted to achieve a high reaction achievement rate. A hydrocracking reaction took place over time, and a product composed mainly of a hydrocarbon mixed gas was obtained. Figure 3 shows coal alone (△), PE alone (□), And when the mixture of the two (circle mark, supply weight ratio 1: 1) is hydrogenated and gasified at 800 ° C. and 70 atm. The results are shown by plotting the logarithm of the reaction time on the horizontal axis and the amount of methane produced per gram of the sample on the vertical axis. In addition, a wavy line shows the average production | generation value which calculated | required the amount of methane obtained by coal single and PE single by calculation.
[0016]
In these series of tests, the feed ratio is selected so that the hydrogen / coal ratio of coal alone is 0.3 g / g, so that the weight ratio is the same on an ashless basis for polyethylene alone and a mixture of coal and polyethylene. The sample supply amount was determined. This hydrogen / coal supply ratio of 0.3 g / g when only coal is used is a supply ratio assumed when the hydrogenation gasification process is put to practical use. The amount of methane produced from coal increases over time at 190 ml / g after 1 second of reaction time and 650 ml / g after 80 seconds.
On the other hand, with polyethylene alone, the amount of methane produced increases rapidly after an initial induction period of about 2 seconds. The amount of methane produced after 1 second was 120 ml / g and reached 1390 ml / g after 80 seconds. If it is assumed that there is no mixing effect between coal and polyethylene and the methane production amount of the mixed sample is the arithmetic average value of both, it is expected that the production amount change shown by the dotted line in FIG.
[0017]
However, in the reaction using the mixed sample, the measured value of the amount of methane produced showed a tendency that was significantly different from the calculated value expected by the dotted line in FIG. In particular, focusing on the reaction time, the amount of methane produced markedly increased within 5 seconds, and in particular, about 3 times the arithmetic average value was produced within 2 seconds of the reaction time. On the other hand, when the reaction time was 5 to 80 seconds, the amount of methane produced changed while maintaining a value approximately 120 ml / g larger than the arithmetic mean value of the dotted line. In other words, it is clear that the mixing reaction of the raw materials accelerated the methane production reaction in a short time, and it is assumed that the reaction rate required for a practical process can be achieved in a short time within 2 seconds. Is done.
[0018]
When coal and hydrocarbon polymers are mixed and the raw materials are combined, the decomposition reaction accelerates because the reaction heat generated when the hydrocarbon polymer is hydrogenated is given to the thermal decomposition of the coal and endothermic reaction. As the process proceeds, the subsequent hydrogenation reaction is assumed to be the result of starting at a higher temperature. As can be seen from FIG. 3, the amount of methane produced when coal and polyethylene are reacted with hydrogen alone is hardly changed within 2 seconds, but when both are used in a mixture, the amount of methane produced is within 2 seconds. The amount of methane produced increases to about 3 times. This increase in the amount of production cannot be explained simply by promoting the thermal decomposition of coal, and it is presumed that the hydrogenation gasification reaction of polyethylene was also accelerated by the combination.
Moreover, the char obtained as a gasification residue of coal was mixed with polyethylene and subjected to hydrogenation gasification for confirmation. When this char is added to polyethylene, the amount of methane produced increases, so it is believed that char has catalytic activity for the hydrogenation gasification of polyethylene.
That is, coal is given reaction heat during hydrogenation gasification of polyethylene, the degree of progress of the thermal decomposition reaction is deepened, and the interaction that polyethylene undergoes hydrogenation gasification reaction by the catalytic effect of the produced char works. It was found that the amount of methane produced increased about 3 times in 0 to 2 seconds.
[0019]
The present invention is a hydrogenation gasification method that utilizes the reaction acceleration effect of the above-mentioned composite of raw materials, and the hydrogenation gasification process involves adding oxygen to a mixture of coal and a hydrocarbon-based polymer and hydrogen. In addition, a hydrogenation gasification step for obtaining a fuel gas mainly composed of methane by performing a hydrogenation gasification reaction under high temperature and pressure is indispensable. In addition, the hydrogenation gasification stage, a char gasification stage in which char of unreacted residue generated in this stage is partially oxidized with oxygen to produce hydrogen, and a process of circulating the hydrogen as a hydrogen source in the hydrogenation gasification stage Consists of In this case, the reaction achievement rate in the hydrogenation gasification stage must be balanced with an amount of char that is commensurate with the hydrogen consumed in the production of methane at this stage.
In the process of the present invention, oxygen is not added to the hydrogenation gasification step, so there is no temperature drop in the reactor, a constant reaction temperature can be maintained, and the decomposition reaction of the raw material mixture can be promoted. .
[0020]
As shown in FIG. 3, the carbon conversion rate from the mixed sample to the gas reached 77.05% after 1 second and 81.2% after 2 seconds, and there was not enough char even after 1 second to configure the process. It is in the state to do. Therefore, since the hydrogenation gasification reactor can be configured in a reaction time of 1 second or less in actual operation, compared with the conventional design with a reaction time of 5 to 10 seconds, Combining raw materials to obtain fuel gas by mixing coal and hydrocarbon polymer is an extremely effective means.
[0021]
In the hydrogenation gasification method of the present invention, lignite, subbituminous coal, bituminous coal, etc. having a carbon content of 70 to 80% can be used as the raw material coal. Since bituminous coal has a low reactivity between the generated char and hydrogen, if bituminous coal is hydrogenated gas alone, the char becomes surplus and its disposal becomes a problem. However, when a hydrocarbon-based polymer is mixed with bituminous coal, the reaction in the hydrogenation gasification stage can proceed excessively, and sub-bituminous coal can be fully utilized if a large amount of coal is supplemented in the partial oxidation process. Thus, in the present invention, since the coal type that could not be used conventionally can be supplied as a raw material for the hydrogenation gasification process, there is an advantage that the range of usable coal types can be expanded.
[0022]
In addition, as the hydrocarbon-based polymer raw material, if it is made of a solid hydrocarbon-based polymer product that can quickly shift to an exothermic reaction process without exhibiting an endothermic phenomenon like coal when hydrogenating gasification, These wastes can also be used, and aliphatic polymer compounds such as polyethylene and polypropylene that can obtain lower hydrocarbon fuel gas mainly composed of methane are desirable, and benzene (B), toluene (T ) And xylene (X) can be obtained in high yield, aromatic polymer compounds such as polystyrene can be used. If polyethylene, polypropylene, or the like to be discarded is used as these hydrocarbon-based polymers, the waste is effectively used, and resource saving is a useful treatment method, and it is extremely effective from the viewpoint of cost.
[0023]
The raw material mixing ratio of coal and hydrocarbon polymer is desirably blended in a range of 10 to 120% by weight of hydrocarbon polymer with respect to the amount of carbon in the coal. In addition, coal and hydrocarbon-based polymers are used by mixing finely pulverized ones with a mixer immediately before the hydrogenation gasification reactor. It is preferable.
Furthermore, it is preferable to introduce into the hydrogenation gasification reactor at a rate of 0.2 to 0.6 kg of hydrogen with respect to 1 kg of the mixture of coal and hydrocarbon-based polymer.
[0024]
The temperature and pressure conditions for operating the hydrogenated gasification reactor are 700 to 1200 ° C., preferably 800 to 1050 ° C., and 2 to 10 MPa, preferably 2.5 to 7. It is performed in a pressure range of 0 MPa. Furthermore, the reaction time is 2 seconds or less, preferably 1 second or less.
[0025]
As a specific example of the present invention, a process example in which a mixture of coal and polyethylene (PE) is used as a raw material will be described according to the flow of FIG. In this process, coal and polyethylene are mixed into gas and converted to methane and BTX, and the by-product char is gasified with oxygen, then shift-converted to synthesize hydrogen and circulate to the hydrogenation gasification reactor. It is.
[0026]
Coal (1) and polyethylene (2) finely pulverized in advance are cut out from each hopper and supplied to the mixer (11). Hydrogenation gasification reactor of coal and polyethylene so that the heat of reaction when hydrogenating hydrogenated polyethylene is transferred to coal well and polyethylene is well hydrogenated by the catalytic effect of char surface It is desirable that the components be mixed well immediately before the transfer to prevent one component from segregating during transportation and producing a concentration distribution.
[0027]
Next, the mixture of coal and polyethylene is reacted by being injected from the mixer (11) into the hydrogenation gasification reactor (12) together with hydrogen (4). Since the gasification proceeds to the target conversion rate within 2 seconds due to the reaction promotion effect already explained, it is sufficient that the reactor volume is smaller than that of the conventional method (reaction time: 7 to 10 seconds). There is no need to install a pipe or other structure for circulating gas in the reactor as in the conventional method. As the reactor (12), a simple reactor of a tube type in which the residence time of gas and coal is about 2 seconds is used.
[0028]
The gas flowing out from the hydrogenation gasification reactor (12) passes through the dust remover (13), undergoes a gas purification process of cooling in the cooling tower (14), and recovers the BTX fraction from the lower part of the tower. Thereafter, the gas fraction is introduced into the shift reactor (15) and converted into hydrogen, and then the carbon dioxide gas is recovered in the decarbonation tower (16) and subjected to sufficient desulfurization, etc. In 17), methane and ethane are recovered as product gases. Hydrogen is separated from the product gas and circulated to the hydrogenation gasification reactor (12). The residual gas excluding methane, ethane and hydrogen is used as fuel for process heat and process steam production. Further, the char (3) discharged from the hydrogenation gasification reactor is sent to the char gasification furnace (18) to be partially oxidized with oxygen to synthesize carbon monoxide and hydrogen, and then to the monoxide in the shift converter. After the carbon is converted to hydrogen, it is introduced into the hydrogenation gasification reactor together with the circulating hydrogen. In order to produce a larger amount of methane, the gas after gas purification is sent to a methane synthesis process using Ni or the like as a catalyst, and CO + 3H₂→ CH₄+ H₂It is also possible to recover the carbon monoxide remaining by the methanation reaction represented by O by changing it to methane.
[0029]
In order to better understand the content of the present invention, FIG. 5 is based on experimental data (800 ° C., 7.1 MPa, reaction time 2 seconds) by another example process using a mixture of coal and polyethylene. The material balance was calculated and illustrated. In this process, coal was supplied to a partial oxidation furnace for hydrogen production to replenish necessary hydrogen.
In the example shown in FIG. 5, the ratio of polyethylene to the whole raw material is 36.7%. The heat efficiency obtained by dividing the calorific value of the entire product gas by the calorific value of the supplied coal and polyethylene is 86.2%. When limited to the production of methane and ethane, which are product gases, 77.9% and 5.2% for BTX production, the combined thermal efficiency reaches 83.1%. On the other hand, when coal is gasified alone, the efficiency when limited to methane and ethane is about 70%. Therefore, an efficient process configuration can be realized by combining fuels. In this example, the ethane concentration in the product gas is 14.4%, and the calorific value of the gas is 10526 kcal / m.^Three It has achieved a high calorific value close to the standard value of city gas currently used in Japan, and can be used as city gas with slight adjustment.
[0030]
【The invention's effect】
According to the present invention, since the raw material in which the hydrocarbon-based polymer is mixed with coal is used, the reaction time when hydrogenating the coal is shortened, and thereby the reactor can be downsized and simplified, and the plant construction cost can be reduced. This contributes to the stabilization of operations.
The present invention can accelerate the thermal decomposition of coal using the reaction heat generated during the hydrogenation gasification of hydrocarbon-based polymer, so that the hydrogenation gasification reactor does not need to be an internal circulation type, There is an advantage that the hydrogen combustion mechanism by oxygen can be reduced. Moreover, in this invention, since reaction time can be shortened by the effective utilization of reaction heat, a reactor structure can be simplified and reduced in size.
[0031]
The raw material hydrocarbon polymers are polyethylene, polypropylene, polystyrene products, etc., which are conventionally treated as waste. In the present invention, these waste plastics can be used effectively, saving resources and protecting the environment. It can contribute greatly. The resulting fuel gas not only increases the amount of methane produced, but also increases the concentration of methane in the produced gas, improving the productivity per reactor, and separating methane into cold. Can reduce power costs.
Moreover, since the fuel gas obtained by the present invention has a high calorific value including a saturated hydrocarbon gas at a high concentration, it can be supplied as a city gas with a slight adjustment.
[Brief description of the drawings]
FIG. 1 Conventional coalHydrogenatedIt is a cross-sectional block diagram of the reactor used for gasification.
FIG. 2 is a graph showing changes over time in reactor temperature when coal and polyethylene are hydrogenated and gasified, respectively.
[Figure 3] Coal alone (△), PE alone (□), And a mixture of the two (circle), each is a graph showing changes in the amount of methane produced by hydrogenation gasification reaction.
FIG. 4 is a schematic configuration diagram showing an example of a flow of a gasification process using a mixture of coal and PE of the present invention as a raw material.
FIG. 5 is a schematic configuration diagram showing an example of another flow of a gasification process using a mixture of coal and PE of the present invention as a raw material.
[Explanation of symbols]
  1 ... Coal
  2. Polyethylene
  3 ... Char
  4 ... Hydrogen
  5 ... Methane
  6 ... BTX
  7 ... water vapor
  8 ... carbon dioxide
  9 ... oxygen
10 ... ash
11 ... Mixingvessel
12 ... Hydrogenated gasification reactor
13 ... Dust remover
14 ... CoolingTower
15 ... Shift reactor
16 ... decarboxylation tower
17 ... Cryogenic separator
18 ... Char gasifier (partial oxidation furnace)

Claims (5)

After mixing the finely powdered coal and hydrocarbon-based polymer, the resulting feed mixture and hydrogen were introduced into hydrogenation gasification reactor the hot pressure exceeding 700 ° C., hydrogenated to the high temperature pressurized condition A hydrogenation gasification method for coal and hydrocarbon-based polymer, characterized in that it is converted into a hydrocarbon mixed gas by a thermal decomposition reaction. After mixing the finely powdered coal and hydrocarbon-based polymer, the resulting feed mixture and hydrogen were introduced into hydrogenation gasification reactor the hot pressure exceeding 700 ° C., hydrogenated to the high temperature pressurized condition Supplying the hydrogenated gasification reactor with hydrogen produced by the pyrolysis reaction to convert to a hydrocarbon mixed gas, and hydrogen produced by the gasification reactor and partial oxidation of the generated char with oxygen. A hydrogenation gasification method for coal and hydrocarbon polymers.   The hydrogenation of coal and hydrocarbon polymer according to claim 1 or 2, wherein the raw material mixture contains a hydrocarbon polymer amount of 10 to 120% by weight with respect to the carbon amount contained in the coal. Gasification method.   The hydrocarbon mixed gas is a lower hydrocarbon fraction mainly composed of methane and an aromatic hydrocarbon fraction mainly composed of benzene, toluene and xylene. The hydrogenation gasification method of the coal and hydrocarbon polymer as described in the paragraph. The method for hydrogenating gasification of coal and hydrocarbon polymer according to claim 1 or 2, wherein the high-temperature pressurization condition is 1200 ° C or lower and in the range of 2 to 10 MPa.

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