JPH0417998B2 - - Google Patents

Description

[Detailed description of the invention]

Industrial Application Field The present invention deals with soot, coke-like substances, heavy hydrocarbons, etc. that are generated when gas, liquid, or solid fuels are combusted in a heating furnace or engine or reacted in a chemical reaction device. The present invention relates to a combustion aid for promoting combustion when burning and removing deposits attached to metal walls, etc. Prior art Carbonaceous substances adhering to the surfaces of the piping systems and heat exchangers of heating furnaces and exhaust gas boilers, inside the hydrocarbon heating pipes of heating furnaces, hydrocarbon pyrolysis reactors and kilns, etc. are soot, coke, polymerized etc. It consists of deposits or deposits such as hydrocarbons (hereinafter referred to as coke-like hydrocarbon materials). Conventionally, methods such as hammering, scraping, blasting, or combustion have been employed to remove this coke-like hydrocarbon material, but it is difficult to remove it in practice. In particular, since it is desirable to remove coke-like hydrocarbons deposited in flues, exhaust systems, and heat exchangers during operation, there is a need for the development of a method that can effectively remove them by using additives. Under these circumstances, various additives have been proposed for lowering the ignition temperature of coke-like hydrocarbons such as soot. For example, Japanese Patent Application Laid-open No. 52-59331 discloses that NaClO ₃ 50 to 70% by weight, wood pulp 8%
A soot ignition temperature lowering agent is disclosed comprising a formulation of ~30% by weight, 1-10% by weight of metal soap, and 12-20% by weight of iron or lead oxide powder. In other words, the publication states that the above additives can increase the ignition temperature of soot to 600%.
It teaches that as the temperature decreases from ~650°C to 260~315°C, the combustion of soot is promoted and auxiliary combustion is performed. Canadian Patent No. 99007 discloses an additive consisting of a mixture of ammonium nitrate and at least one alkali or alkaline earth metal nitrate, sulfur or a sulfur compound, and British Patent No. 1249371 The publication states that in order to clean soots, carbon, or cinder that has adhered to the surface of pipes such as boilers, a mixture of alkali metal nitrate and oxidizing substance is transported by a combustion gas flow and adhered to the target part. A method is disclosed in which the portion is burned by heating. However, the method disclosed above uses an agent containing a chloric acid compound or nitrate, which poses a problem in that it is dangerous to handle. Therefore, there is a need for an additive that is safe to handle and that can burn off coke-like hydrocarbons at relatively low temperatures. Problems to be Solved by the Invention The present invention has been made in view of the above-mentioned circumstances, and provides a method for burning and removing coke-like hydrocarbon substances generated in the above-mentioned combustion equipment and related equipment. deposited by pneumatic conveyance, mixing, or direct application to the area where the hydrocarbon material is deposited to effectively remove said coke-like hydrocarbon material by combustion at relatively low temperatures; The objective is to provide a combustion improver that is safe to handle and economically inexpensive. The present invention will be explained in detail below. Structure of the Invention The present invention is characterized by mixing 5 to 50 weight percent of a hydrocarbon having a boiling point of 350°C or higher to a mixed powder of 5:95 to 90:10 weight percent of copper chloride powder and potassium chloride powder. It is a combustion aid for the combustion of coke-like hydrocarbon substances. The term "coke-like hydrocarbon material" as used herein refers to a carbonaceous material consisting of soot, coke, polymerized hydrocarbons, etc. that accumulates and adheres to the various combustion equipment and related equipment described above. Means for Solving the Problems The combustion improver for combustion of coke-like hydrocarbon substances according to the present invention has a boiling point of 350°C or more added to a mixture of 5 to 95% by weight of copper chloride powder and 95 to 10% by weight of potassium chloride powder. 5 hydrocarbons with respect to the total amount of the mixture
It is mixed in a proportion of ~50% by weight. In the present invention, copper chloride powder and potassium chloride powder are mixed at the above blending ratio, preferably 20:80 to 80:20 (weight ratio), more preferably 30:70 to 70:30 (weight ratio). It is important to use potassium chloride alone, as no effect has been observed.
In addition, although copper chloride alone exhibits catalytic action,
The above-mentioned combustion promoting effect is low, and only when used in combination with potassium chloride does a remarkable combustion promoting effect, ie, the effect of lowering the ignition temperature of coke-like hydrocarbon substances such as soot, occur. Copper chloride may be either CuCl or CuCl ₂ , but CuCl ₂ is hygroscopic and difficult to handle.
Practically speaking, it is preferable to use CuCl. Copper chloride and potassium chloride are used in powder form or in the form of particles supported on a porous powder carrier so that they can be easily transported by air current. When supported on porous powder, alumina,
It is supported on powder particles such as silica, silica alumina, zeolite, graphite, or carbon black, preferably with a surface area of 30 to 300 m ² /g and a particle size of 20 to 300 μ, and baked at a temperature of 200 to 300°C to form particles. It is better to make it . Among these porous carriers, carbon black and the like are particularly advantageous because they can themselves be used as fuel. In addition, regarding the above support,
Only either copper chloride or potassium chloride may be supported. Next, the hydrocarbon to be mixed with the above copper chloride and potassium chloride has a boiling point of 350°C or higher, preferably 380°C or higher, particularly preferably 400°C or higher, and a melting point of 200°C or lower and is solid or solid at room temperature. Preferably, it is semi-solid and has excellent combustibility. Such hydrocarbons have a viscosity of 20 to 150 cSt (30℃)
Mineral oil-based lubricating oil fractions (e.g. neutral oil, bright oil, etc.), crude wax and paraffin wax obtained in the lubricating oil refining process, and liquid polypropylene, polyisobutylene, polybutene, adipine used in synthetic lubricating oils, etc. Examples include higher alcohol ester oils of dibasic acids such as acids. On the other hand, materials with high carbon content and asphaltene content such as asphalt, materials that generate toxic gas such as polyvinyl chloride, and hard polyolefins with a high degree of crystallinity are not preferred. Note that hydrocarbons with a boiling point lower than 350° C., such as gasoline, light oil, or light lubricating base oil, have a low effect of promoting the ignitability of coke-like hydrocarbons and are therefore not practical. In the present invention, the above-mentioned hydrocarbons are mixed at a blending ratio of 5 to 50% by weight with respect to the total amount of copper chloride and potassium chloride, and if the above-mentioned blending ratio of hydrocarbons is less than 5% by weight, combustion will occur. No promoting effect can be expected, and on the other hand, even if the content exceeds 50% by weight, no further improvement in combustion promotion can be expected. The mode of mixing hydrocarbons with copper chloride powder and potassium chloride powder is to support hydrocarbons in one or both of these powders, or to impregnate and support hydrocarbons in porous powder. are mixed with the above mixed powder. Furthermore, the hydrocarbon supported on this porous powder may be mixed with a mixed powder of one or both of copper chloride powder and potassium chloride powder supported on the porous powder described above. Therefore, it is also possible to support copper chloride powder, potassium chloride powder, and hydrocarbon on the same porous carrier. As the porous powder for impregnating and supporting the hydrocarbon, those mentioned above can be used, but powders of wood chips, cotton, rice bran, pulp, rice, etc. can also be mixed and used. In addition, when the hydrocarbon is supported on the porous powder, the amount of hydrocarbon supported is such that the surface of the powder carrier does not become sticky. Since the porous powder adsorbs hydrocarbons well, the powder may take on a granular shape after being supported. Incidentally, when using a powdered catalyst used for fluid catalytic cracking of heavy oil as a porous carrier, for example, and adsorbing and supporting circulating oil base oil as a hydrocarbon, the surface becomes smooth and easy to handle. . In order to burn and remove coke-like hydrocarbons using a combustion improver made of a mixture of copper chloride powder, potassium chloride powder, and hydrocarbons as described above, in the form of powder particles or granules, The coke-like hydrocarbon material is transported by an air current and deposited on the deposited area, or it is suspended in water, alcohol, ketone, or other volatile dispersant to form a slurry, preferably containing a vinyl acetate-based A small amount of adhesive is added, applied directly to the coke-like hydrocarbon deposits, dried, and then heated to ignite the coke-like hydrocarbon material. When the coke-like hydrocarbon material to which the combustion improver according to the present invention is attached or coated as described above is heated in the presence of oxygen-containing gas,
It ignites and starts combustion at a relatively low temperature of 350℃. Incidentally, coke-like hydrocarbon substances alone require heating at a temperature of about 500 to 650°C for ignition.
Therefore, it can be said that the combustion promoting effect of the coke-like hydrocarbon substance of the combustion improver according to the present invention is remarkable. As mentioned above, since the combustion improver according to the present invention can be transported by airflow, in practice, the combustion improver can be blown into the exhaust gas line of a heating furnace or diesel engine to transport the coke-like hydrocarbon substances by airflow. It can be attached to the deposited area, and combustion can be continued by circulating air. Furthermore, when hydrocarbons are supported on a porous carrier such as rice bran or sawdust, the ignition starts at a lower temperature and ensures stable ignition and continued combustion of the coke-like hydrocarbon material. Furthermore, by using the combustion improver according to the present invention, it is possible to effectively remove coke-like substances from economizers of large ships equipped with diesel engines during operation, and it is also possible to effectively remove coke-like substances that adhere to the inner walls of kilns, etc. For coke-like substances, when a slurry of this combustion improver is applied, dried, and then heated, ignition occurs at a temperature of 250 to 350℃, combustion begins, and a coke-like substance is formed in a short time. Burning of substances will now end. EXAMPLES AND EFFECTS The present invention and its effects will be specifically explained below using examples. Example 1 A coke-like substance (56.2 wt% carbon content, 4.0 wt% hydrogen content, 80 wt% total combustible content) adhering to the exhaust valve of a large diesel engine was treated with each of the formulations shown in Table 1. Combustion aid for combustion (both
(adjusted to 200 mesh or less) was mixed well and placed on the balance of a differential thermal analyzer as a sample.
The measuring section of the analyzer was heated at a rate of 20°C/min, air was passed through at 70ml/min, and the weight of the sample and temperature changes were recorded. The results are shown in Table 1.

[Table] A...Petroleum paraffin wax (melting point 60~
The above wax was heated to 80°C and diluted with heptane, and the CuCl/KCl mixed powder was added to the wax liquid, and after stirring and mixing, the heptane was distilled off to make it supported. . C... An aqueous solution of CuCl and KCl (19: 1 weight ratio)
Add FCC catalyst powder and stir to impregnate.
The powder obtained by drying and calcining at 200° C. is added to lubricating oil to adsorb the oil, and the amounts of the three components supported on the FCC catalyst are as follows. C
Adjusted using the same procedure. E: Combustion improver A prepared in the same manner as A except that CuCl ₂ powder was used instead of CuCl powder. F: Combustion aid C was prepared in the same manner as C except that CuCl ₂ was used instead of CuCl. G: Combustion improver prepared in the same manner as C except that light oil (boiling point range 230-360°C) was used instead of lubricating oil. In addition, Ti, Tm, and Tf in the table are as follows. Ti...Temperature at which coke starts to burn as the temperature rises. Tm...Temperature when the degree of weight loss of coke reaches 1/2. Tf...Temperature at which coke combustion ends and weight loss stops. Example 2 1 g of coke-like substance (suit) used in Example 1
was collected in a flat state on a magnetic plate, and 0.5 g of each of the combustion improvers used in Example 1 was sprinkled thereon. Next, the magnetic dish is heated to a certain temperature (300℃, 350℃, 400℃
The sample was placed in an electric furnace kept at a temperature of 450°C) and left for 10 minutes, and the combustion rate was determined from the change in weight before and after placing it in the electric furnace. The results are shown in Table 2.

[Table] As shown in Table 2, it is recognized that the combustion promoting effect of the suit is high when the combustion improver according to the present invention is used.

Claims (1)

[Claims] 1. 5:95~ of copper chloride powder and potassium chloride powder
Boiling point 350 for mixed powder consisting of 90:10% by weight
A combustion aid for combustion of coke-like hydrocarbon substances, which is a mixture of 5 to 50% by weight of hydrocarbons having a temperature of ℃ or higher. 2. The combustion improver according to claim 1, comprising a mixture of hydrocarbons supported on one or both of copper chloride powder and potassium chloride powder. 3. The combustion improver according to claim 1, comprising a mixture of hydrocarbons supported on porous powder. 4. The combustion improver according to claim 1, which is a mixture of copper chloride and potassium chloride, one or both of which are supported on a porous powder, and a hydrocarbon that is supported on a porous powder. 5 Hydrocarbons include mineral oil-based lubricating oil, synthetic lubricating oil,
The combustion improver according to any one of claims 1 to 4, which is one or more selected from the group consisting of liquid paraffin, coarse wax, and paraffin wax. 6. The combustion improver according to claim 5, wherein the paraffin wax is a petroleum wax with a melting point of 50 to 150°C. 7. The combustion improver according to claim 3 or 4, wherein the porous powder is one or more selected from the group consisting of alumina, silica, silica-alumina, zeolite, graphite, and carbon black. .