JPS59501163A - Finely divided carbon water dispersion system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Coal-water dispersion system The present invention provides a coal-water dispersion that is highly suitable for storage and suitable for transportation and energy production. Related to the system. More particularly, the present invention comprises water, pulverized coal and additives; It concerns a dispersion in which the coal content is between 60 and 80% by weight.

Dispersed coal is considerably less polluting and easier to handle than solid coal; It also eliminates the risks associated with transportation and storage. In addition, such a distributed system is an economical point. It is also preferable.

The reason for using coal dispersion is that it can be used on a large scale as a basic energy source, and also because it can produce sleepiness and heat. This is because small factories are reluctant to increase their use of coal. related to this However, solid coal is difficult to handle for several reasons, and therefore liquid coal is generally Conversion to a physical state is considered to be the preferred method. Chemically converting coal into a liquid product The so-called liquefaction method is unable to compete with oil. The stone roast is chemically transformed into a gaseous product. The so-called vaporization method for coal exchange appears to be the preferred method for total utilization of coal. but However, even though this method cost a considerable amount of money to develop the technology, However, there are still considerable technical difficulties.

Another method of converting coal to a liquid state is physical conversion, and the present invention! Fi-ko Regarding the method. It uses some kind of heating oil, methanol, etc. Ariiso fuel, Alternatively, it is carried out by completely dispersing the coal in a liquid consisting of water.

The problem with aqueous dispersions of pulverized coal is primarily to stabilize the dispersion at low viscosities. It is to make it. Coal particles should not settle during storage or transportation of the coal dispersion. No. Additionally, coal dispersions are optionally burned using slightly modified conventional techniques. The pump should have a customized rheology to suit the pump and have high pump operability. It is Tsuheki.

Among the earlier proposals for stabilizing coal-water dispersions are the Federal publication Khim, Pereab, Topl, 1975, 30(2).

Pages 19-29, and Chemi cal Abstracts 87 There is a proposal summarized in :555326. In this case, polycarboxylic acid salts and polyphosphates and others have been used as stabilizers. optimal mix The viscosity of the product is about 5P at a coal content of 57-63, so this dispersion is Not satisfied with demand. Furthermore, the stability of the precipitate is insufficient.

Swedish Publication No. 7805632-2 (Stabilization against precipitation) Polyelectrolytes with durable action, especially polyphosphates (as described in the above-mentioned Soviet publications) A coal-water dispersion system is disclosed which is achieved (according to the same principles as those described). . In this case as well, stabilization against precipitation is insufficient.

U.S. Pat. No. 4,242.098 describes several water-soluble polymers (polyethylene Coal-water stabilization achieved by the addition of (ren oxide, polyacrylamide, etc.) Describes a dispersed system. This dispersion is an improvement over the previously described dispersion.

The theory of stability of dispersion systems has recently been considerably refined. The theory suggests a more enviable system. It has evolved to include, but among other things, new types of interactions have been validated.

Electrostatic stabilization by surfactants and polyelectrolytes and steric stabilization by polymers In addition to the conventionally known effects such as stabilization, there is a further central effect, the so-called irrigation power.

This water availability has recently been verified and explained theoretically. This irrigation power is optionally used by other water sources. The present invention provides a long-term stable coal-water dispersion of the type described above with It will form the main foundation of the Ming Dynasty. This coal-water basin dispersion rate may vary slightly depending on available technology. It is well suited to be used in the form and directly combusted. According to the invention, this dispersion The system has the characteristics described in claim 1.

This dispersion system has significantly reduced frictional force? was manipulated, and e-brine was imported. It has rheological properties that allow it to transport and, inter alia, to prevent flocculation and It has a much improved stability score for...

If the coal-water dispersion system, which is naturally thermodynamically unstable, is stabilized, The rate of sludge and flocculation is reduced by the creation of a barrier that acts against particle attraction. It will be lowered. This repulsive action has three main principles: electrostatic stabilization, steric stability ratio, This is achieved through stabilization through water use. Stabilization reduces the energy of particles change and/or create a barrier that prevents the inhalation of particles. Konera no Hara Based on the theory, high-content coal particles can be reduced to 7 by adding a small amount of organic additives. @It is possible to have a stable 1 h during vN and release 0 new colloid X k mlJ In order to It is necessary to give the system a special feature that develops a barrier that repels the tongue. . Certain forms of steric stabilization by hydrophilic polymers1 provide long-term stability in coal-water dispersions. Provide favorable conditions for stability.

Studies of lamellar liquid crystal phases in ionic surfactant systems have shown that these phases swell and It was found that large amounts of water can be taken up. This occurs between adjacent layers of surfactant. This may be explained by the repulsion force in the water layer and may also be related to the force of an electrostatic double layer.

phospholipid 5 (Phospholipids) Zwitterionic substances such as lecithin do not cause significant swelling, but Very clear. This jr-4 has considerable repulsion even in the absence of pure charge indicates the existence of This repulsive force, or so-called hydration force, has a deviation of 2 to 3 years over the distance. It changes almost exponentially with distance. This force is of a general nature and It varies depending on the length of the kill chain and the physical state of the alkyl chain (liquid or solid). First, a quantity charged surfactant is included in the system. It also exists in cases where Irrigation forces act between surfaces several angstroms apart from each other It was also verified by directly measuring the total force. A theoretical model of water utilization has recently been devised. 1, thereby increasing the hydration force to the so-called at the interface where the effective dielectric constant is changing. It became possible to link it to the existence of Miracciano. Due to the zwitterionic group Such mirror charges are common in micro-2 and macro-heterogeneous systems. this is a book In the invention, it is used to impart a desired special effect to a low-intensity suspension.

However, zwitterionic surfactants such as lecithin can be adsorbed onto the surface of all-solid particles. Ru. Then, there is a strong repulsive force between the particles or they exist at a short distance. Therefore, this principle i71 1 is particularly useful for thick dispersions.

The invention will be explained in more detail with reference to the following examples.

example ■Lecithin or (non-micelle-forming zwitterionic surface such as rl alkyl betaine) The active agent (therefore it is relatively insoluble in water) is first dissolved in the aqueous solvent. Ru. The solvent may, for example, consist of octatool, hexadecane or methanol, and It can be recovered in a proper way, or even just a little bit of the dispersant can be removed.

2. Add the prepared surfactant to the dispersion of pulverized coal and water. coal powder The suitable size is 1-200 μm (polydisperse coal powder) with a wide particle size distribution. Ru. The particle size and particle size distribution are selected depending on the desired stability. The smaller the particle size , Stable: C: When large coal is crushed to ultra-micrometer particle size: Q: Expensive. It is. Particle concentration can vary over a wide range.

Considering technical aspects, the particle concentration should be optimized depending on the situation. It is. Coal-water dispersions with a dry matter content of 65-75% by weight (e.g. Particularly useful as it has good rheological properties (for transport in lines) It is. In order to achieve the maximum coal content (70-80% by weight), the particle size distribution must be taken into particular consideration. In the normal case Kj4, which is A simple geometric calculation to ensure the least free space when packing particles It can be done based on.

After the adsorption step, to provide some form of steric barrier: (also to reduce friction between particles) In order to reduce the - into a distributed system. For example, polyether, polysaratosudo, polya Lecole, 7f! One can choose from lJ acrylates. Relying on the present invention (c) Suitable materials are polyethylene oxide and polyethylene oxide polyester. Propylene oxide type copolymer, carboquine methylcellulose, xantha I have a hard time. Polymer concentration I'io in parts by weight based on total weight, which can be from 1 to 5% However, from an economical point of view, the optimum value is about 05.

To make the dispersion attractive as a non-contaminant of oil: Potassium salts or alkaline earth metal salts may be added to the dispersion. Salt is hydroxy acid [Hikarushi] Dolomite powder is preferred. Generated by natural oxidation of salt The acid gas component is completely neutralized, and the particle separator (particle percipita Collect it with tor).

Auxiliary agent that forms a monolayer at the interface to prevent water from evaporating from the dispersion. may be added to the dispersion. Such adjuvants include cetyl alcohol and hexadecano. There is a le.

The present invention has substantial advantages over prior art techniques for stabilizing coal particles in aqueous solutions.

Due to excellent sedimentation stability combined with rheoconotic properties suitable for pump operation The resulting dispersion can be used for example in the chemical industry for direct energy generation. 1 (well suited for transport in a suitable manner in conduits or lines) There is.

Combustion tests in boilers designed for heavy oil are conducted when the dispersion system absorbs all or part of the heavy oil. It was shown that it is very suitable for replacing parts.

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Claims (1)

[Claims] 1. A small amount of water that is adsorbed on the surface of coal particles and causes repulsion between the coal particles due to the water utilization force. at least one type of O amphipathic substance; cooperating with said amphipathic substance and at least one type 2 polymers with hydrophobic: polymers with hydrophilic and hydrophilic properties; characterized by water, pulverized coal and additives with a coal content of 60 to 80% by weight. A distributed system containing 2 The amphipathic substance is lecithin or other O zwitterionic surfactant. The dispersion system according to claim 1, characterized by: 3 One of the polymers has a predominant amount of polyethylene oxide Characterized by being a copolymer of polyethylene oxide and polyethylene oxide The dispersion system according to claim 1. 4. A claim characterized in that the molecular weight of the copolymer is 5000 to 50,000. The dispersion system according to item 3 of the desired scope. 5. The copolymer contains at least 70% by weight of polyethylene oxide; Claim 4, characterized in that the molecular weight is 8,000 to 15,000. Distributed system. 6. A claim characterized in that one of the polymers is polysaccharide. Item 7 as described in Range 1: The polysaccharide is xanthan gum or guarco. 6. The dispersion system according to item 6, characterized in that the dispersion system is 8 Shima 1 for claim i, characterized in that the total amount of additives is less than 2 parts by weight Dispersion system described in section.