JPS61218693A - Additive for solid fuel-water slurry - Google Patents

Abstract

PURPOSE:The titled additive that contains a salt of a graft polymer resultant from reaction of an (alkyl-substituted)naphthalenesulfonic acid with (meth)acrylic acid in the presence of a polymerization initiator, thus improving slurry stability for a long period of time. CONSTITUTION:The objective composition contains, as an active ingredient, a salt (preferably sodium, potassium, ammonium or lower amine salt) of a graft polymer which is prepared by reaction of (A) an (alkyl-substituted) naphthalenesulfonic acid with (B) acrylic or methacrylic acid or a mixture thereof, preferably in the presence of (C) a peroxide polymerization initiator. The amount of component (A) employed is 0.1-50pts.wt. per 1pt.wt. of component B. The solid fuel is preferably coal (dry-distilled coke) or petroleum coke.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to an additive for solid fuel water slurry useful as a fuel made by dispersing solid fuel powder such as coal, carbonized coal coke, petroleum coke, etc. in water. .

[Conventional technology]

Solid fuels, of which coal is a representative example, have for a long time lost their place as fuel to petroleum due to their solid shape.
In the wake of the oil crisis, solid fuels were reviewed, and there have been many attempts to treat solid fuels as fluids by mixing solid fuel powder with a medium, as exemplified by coal-oil mixed fuel (COM). is being carried out.

However, in the case of coal-oil mixed fuel, it is impossible to avoid the disadvantage that about half of the fuel is oil, and there is a desire to develop another slurry fuel.

In recent years, slurry, a fluid made by using water as a medium and dispersing solid fuel such as coal or petroleum coke at high concentrations, has become suitable for transportation by pipeline or oil tanker, and it has also become suitable for transporting oil in various boilers. Attempts are being made to use it as an alternative fuel or raw material for gasification. In the case of this slurry, since the medium is water, it is preferable that the slurry has the following properties.

That is, it must have a high solid fuel powder concentration, a low viscosity, and excellent long-term stability without causing agglomeration or sedimentation of the solid fuel powder.

By the way, it is already known that various additives such as rust preventive agents, antioxidants, and dispersants are added to the slurry in order to modify the characteristics of the coal-water slurry. However, among these known additives, very few have been found that give very good results on the solid fuel powder concentration or viscosity and also satisfy both this property and the stability of the slurry. For example, U.S. Patent No. 2.346.151,
Japanese Patent Publication No. 55-45600 and Japanese Patent Publication No. 54-16
Additives such as phosphoric acid esters disclosed in Publication No. 511, various amines, reaction products of alkylene oxide with alkylphenols, naphthols, and other acidic phosphates, and salts of polycarboxylic acids such as polymethacrylic acid reduce viscosity. It has poor functionality and is difficult to obtain high concentration slurry.

Also, JP-A-52-71506 and JP-A-53-5
Lignosulfonate salts proposed in JP-A No. 81, naphthalene sulfonate salts and formaldehyde condensate salts of naphthalene sulfonic acid proposed in JP-A No. 56-57889, For example, copolymers such as the sodium salt of octene-maleic anhydride copolymer have a viscosity lowering function compared to the above-mentioned additives and contribute to the stability of the slurry to some extent, but these properties still need to be improved. There is still room for this, and it cannot be said to be sufficient.

[Problem that the invention seeks to solve]

The purpose of this invention is to obtain an industrially useful additive for solid fuel water slurry that has a better viscosity reducing function than the above-mentioned conventional additives and also provides good results in terms of long-term stability of the slurry. It is said that

[Means for solving problems]

As a result of intensive studies to achieve the above object, the inventors discovered that naphthalene sulfonic acid, which may have an alkyl substituent, is reacted with acrylic acid, methacrylic acid, or a mixture thereof in the presence of a polymerization initiator. The inventors have discovered that the resulting graft polymer salt provides good results in both the viscosity-reducing function of solid fuel water slurry and the stability of the slurry, leading to the completion of this invention.

That is, the present invention relates to converting naphthalenesulfonic acid (hereinafter referred to as (alkyl)naphthalenesulfonic acid), which may have an alkyl group, to acrylic acid, methacrylic acid, or a mixture thereof (hereinafter referred to as (meth)acrylic acid) in the presence of a polymerization initiator.
The present invention relates to an additive for solid fuel water slurry that contains as an active ingredient a salt of a graft polymer obtained by reacting with acrylic acid (acrylic acid).

[Structure and operation of the invention]

The additive of this invention is obtained by sulfonating naphthalene and/or naphthalene having an alkyl substituent having usually up to 22 carbon atoms with sulfuric acid or the like (alkyl).
The active ingredient is a salt of a graft polymer obtained by reacting naphthalene sulfonic acid with (meth)acrylic acid in the presence of a polymerization initiator, generally in water.

When graft polymerizing (alkyl)naphthalenesulfonic acid with (meth)acrylic acid, the ratio of the former [(alkyl)naphthalenesulfonic acid] to 1 part by weight of the latter [(meth)acrylic acid] is 0.
．． The amount is preferably 1 to 50 parts by weight, preferably 0.2 to 20 parts by weight. When the dispersant is set within these ranges, a dispersant particularly suitable for achieving the objects of the present invention can be obtained.

As the polymerization initiator, peroxides are preferred, and organic peroxides such as hydrogen peroxide, persulfates, and cumene hydroperoxide are particularly preferred. Of course, it is not limited to these peroxides.

The amount of the polymerization initiator to be added to (alkyl)naphthalenesulfonic acid and (meth)acrylic acid may be any amount that is used in a normal polymerization reaction, and the degree of polymerization may be changed as appropriate depending on the amount. It is usually used in a range of 0.1 to 5% by weight.

The reactants obtained by such graft polymerization include a graft polymer in which (meth)acrylic acid is grafted onto (alkyl)naphthalenesulfonic acid, and some unreacted (alkyl)naphthalenesulfonic acid and ( Homopolymers of meth)acrylic acid may be included, but in the present invention there is no particular need to separate and remove these unreacted substances and homopolymers.

In the additive of this invention, such a graft polymer is used in the form of a salt. The means for forming this salt may be arbitrary. For example, when the graft polymerization reaction is carried out in water, the necessary alkali may be added before the reaction, or after or before or after the reaction to neutralize it. Examples of salts include potassium salts, sodium salts, ammonium salts, and lower amine salts. Examples of lower amine salts include methylamine,
Lower alkylamine salts such as ethylamine and propylamine, and alkanolamine salts such as monoethanolamine and triethanolamine are preferably used.

In addition to the active ingredient consisting of the salt of the graft polymer described above, the additive of this invention may contain surfactants that have been proposed in the past, and if necessary, gelling agents, rust preventives, and preservatives. If foaming is observed, an antifoaming agent such as a fatty acid alcohol or a silicone compound may be used in combination.

The amount of the additive of the present invention configured as described above added to the solid fuel water slurry varies depending on the characteristics of the slurry, that is, the particle size and concentration of the solid fuel powder, the type of the active ingredient itself, etc., but it is generally The active ingredient is 0.01 to 5% by weight in the slurry, particularly preferably 0.05 to 0.
．． It is preferable to adjust the amount to 5% by weight. As the amount added increases, the viscosity lowering effect becomes greater and good results are obtained in terms of stationary stability. However, if the amount exceeds a certain level, no further effect can be expected, which is economically disadvantageous.

The method of adding the additive is arbitrary, and an appropriate method may be selected depending on whether the solid fuel powder is obtained by dry pulverization or wet pulverization. For example, in the dry pulverization method, it is preferable to add and mix the additive of the present invention in advance into water in which the pulverized powder is to be dispersed, and then add and mix the pulverized powder thereto.

On the other hand, in the wet pulverization method, it may be added in advance to the water used for wet pulverization, or it may be added during or after wet pulverization.

In addition, if it is difficult to obtain stable slurry properties by using additives and using only underwater pulverization or normal impeller stirring, it is better to mix using a stirrer with strong shearing force, such as a homogenizer or line mixer. .

Solid fuels to which the additive of this invention is applied include coal,
There are petroleum coke and coal carbonized coke, and the coal may be subbituminous coal, bituminous coal, anthracite coal, etc., and there are no particular restrictions. These solid fuels are pulverized by a dry pulverization method or a wet pulverization method to form a powder for water slurry, but the particle size of this powder is not particularly specified. However, in order to avoid problems such as abrasion and clogging during pipeline transportation and burner combustion, it is usually preferable that the 200 mesh bath has a content of 50% by weight or more.

〔Effect of the invention〕

The additive for solid fuel water slurry of this invention exhibits an excellent viscosity reducing function, and usually contains 65 to 75% by weight of solid fuel.
This makes it possible to prepare a slurry that exhibits a relatively high concentration and low viscosity. Furthermore, the resulting slurry not only has excellent static stability, but also no increase in the viscosity of the slurry is observed even when stirred, and a slurry with no problems in handling the slurry can be obtained.

As described above, the additive for solid fuel water slurry of the present invention is an extremely industrially advantageous solid that can be easily and economically transported by vibrine transportation or other methods, and can be easily supplied to combustion equipment. A fuel water slurry can be provided.

〔Example〕

EXAMPLES Below, examples of the present invention will be described in more detail.

The industrial analysis values of coal (Nilmero coal) and petroleum coke used as solid fuels in the following Examples and Comparative Examples are shown in Table 1 below.

Table 1 Furthermore, in the following Examples, additives synthesized according to Synthesis Examples 1 to 5 below were used as additives of the present invention, but as long as they are defined in the claims, the additives of the present invention may be used. It goes without saying that the additives are not limited to those obtained by these synthesis examples.

Synthesis Example 1> 100 parts by weight of naphthalene sulfonic acid, 150 parts by weight of water and 60 parts by weight of acrylic acid were mixed in a stirrer.

The mixture was placed in a reactor equipped with a thermometer and a condenser, the neutralization value of the mixture was measured, and a neutralization equivalent of 48% by weight aqueous sodium hydroxide solution was added and stirred for neutralization.

After the mixture was heated to 30°C, 2 parts by weight of a 10% by volume hydrogen peroxide solution was added with stirring, and an exothermic reaction occurred and the temperature reached 75°C. The reaction was continued at this temperature for 5 minutes, further heated and maintained at 95° C. for 10 minutes to complete the reaction, yielding Additive A of the present invention containing a salt of the graft polymer.

Synthesis Example 2 100 parts by weight of naphthalenesulfonic acid, 200 parts by weight of water and 100 parts by weight of acrylic acid were placed in a reactor similar to that in Synthesis Example 1, and the mixture was neutralized with an aqueous sodium hydroxide solution. After the mixture had been brought to 30° C., 2 parts by weight of cumene hydroperoxide were processed.

An exothermic reaction occurred and the temperature reached 80°C. The temperature was further increased and maintained at 95° C. for 15 minutes to complete the reaction, thereby obtaining Additive B of the present invention containing a salt of the graft polymer.

Synthesis Example 3 100 parts by weight of naphthalene sulfonic acid, 150 parts by weight of water and 30 parts by weight of methacrylic acid were placed in the same reactor as in Synthesis Example 1, and 0.5 part by weight of cumene hydroperoxide was added. An exothermic reaction occurred and the temperature reached 78°C. After holding at this temperature for 5 minutes, the temperature was further raised and held at 95°C for 10 minutes. Measure the neutralization value of the resulting mixture,
A neutralization equivalent of 28% by weight aqueous ammonia solution was added for neutralization to obtain Additive C of the present invention containing a salt of a graft polymer.

<Synthesis Example 4> 50 parts by weight of naphthalene sulfonic acid, 200 parts by weight of water, and 80 parts by weight of acrylic acid were placed in the same reactor as in Synthesis Example 1, and the neutralization value of the mixture was measured. 1/2 neutralization was performed with a 48% by weight aqueous sodium hydroxide solution equivalent to 2 equivalents. When 3 parts by weight of sodium persulfate was added and stirred, an exothermic reaction occurred and the temperature of the reaction product reached 80°C. Furthermore, 1/2 of the neutralization equivalent of an aqueous sodium hydroxide solution was added for complete neutralization, thereby obtaining the additive of the present invention containing the salt of the graft polymer.

Synthesis Example 5> 100 parts by weight of naphthalene sulfonic acid, 150 parts by weight of water,
20 parts by weight of acrylic acid and 20 parts by weight of methacrylic acid were placed in the same reactor as in Synthesis Example 1, and 4 parts by weight of a 10% by volume hydrogen peroxide aqueous solution was added. The exothermic reaction caused the reaction mixture to reach 70°C. After maintaining this temperature for 5 minutes, it was heated to 95°C and maintained at this temperature for 10 minutes to complete the reaction. Neutralization with 28% by weight aqueous ammonia yielded additive E of the invention containing a salt of the graft polymer.

The effective concentration of each of the additive aqueous solutions obtained in Synthesis Examples 1 to 5 above was determined from the loss on drying after drying at 105°C, and based on this, solid fuel water was used in the following examples. The concentration of the effective additive component in the slurry was set to a predetermined value.

Furthermore, the viscosity and static stability of the solid fuel water slurries obtained in the following Examples and Comparative Examples were measured as follows. First, the viscosity of the obtained solid fuel water slurry (25℃
) was measured using a B-type viscometer, and the stationary stability was examined using the following method. That is, a stainless steel cylinder with a diameter of 5 aa and a height of 20 cI11 was provided with outlets with stoppers at positions 6 cm and 12 am from the bottom, and the obtained solid fuel water slurry was poured into the cylinder to a height of 18 cm from the bottom, and the cylinder was heated at room temperature for 30 minutes. I let it sit for a week. Next, the cylinder bottom is divided into an upper layer above 12ca+, a middle layer between 6 and 12aa, and a lower layer below 6cm, and the solid content of each layer is left in a dryer at 105°C for 2 hours using a loss-on-drying method. It was measured.

Example 1 Nilmelo coal was dry-pulverized to obtain coal powder containing 75% by weight of 200 mesh passes. Using this powder and the inventive and comparative additives shown in Table 2 below and the required water,
By thoroughly stirring and mixing these, a coal water slurry composition having a solid content of 70% by weight was obtained. Each sura obtained 17
The viscosity and static stability of the -m parabolite were as shown in Table 2. In addition, the concentration of each additive's effective content in the slurry is also listed in the same table.

Example 2 Petroleum coke powder was obtained by pulverizing petroleum coke and having 200 mesh passes of 80% by weight. This powder, the additives shown in Table 3 below, and water were thoroughly mixed to obtain a petroleum coke water slurry composition with a solid content of 75% by weight. Table 3 shows the results of measuring the viscosity and standing stability of each of the obtained slurry compositions. In addition, the concentration of each additive's effective content in the slurry is also listed in the same table.

From the results in Tables 2 and 3 above, it is clear that the additive for solid fuel water slurry of the present invention has low viscosity and excellent static stability despite the high solid fuel powder concentration. It is clear that a solid fuel water slurry is obtained.

Claims (5)

[Claims] (1) The active ingredient is a salt of a graft polymer obtained by reacting naphthalene sulfonic acid, which may contain an alkyl substituent, with acrylic acid, methacrylic acid, or a mixture thereof in the presence of a polymerization initiator. Additive for solid fuel water slurry. (2) The amount of naphthalene sulfonic acid, which may have an alkyl substituent, for acrylic acid, methacrylic acid, or a mixture thereof is 1 part by weight for the former and 0.1 part by weight for the latter.
50 parts by weight of the additive for solid fuel water slurry according to claim (1). (3) The polymerization initiator is a peroxide (
The additive for solid fuel water slurry according to item 1) or item (2). (4) The additive for solid fuel water slurry according to any one of claims (1) to (3), wherein the salt of the graft polymer is a sodium salt, potassium salt, ammonium salt, or lower amine salt. (5) The additive for solid fuel water slurry according to any one of claims (1) to (4), wherein the solid fuel is coal, carbonized coal coke, or petroleum coke.