JPS60166390A - Pitch-water slurry composition - Google Patents

Abstract

PURPOSE:A pitch-water slurry composition, obtained by dispersing fine pitch powder stably in water with a specific nonionic surfactant and a specific water- soluble high polymer, and having improved fluidity. CONSTITUTION:A pitch-water slurry composition obtained by dispersing fine pitch powder having 50-180 deg.C softening point uniformly in water with (A) a nonionic surfactant expressed by the formula (R is 1-30C alkyl or aryl; n is >=10) and (B) one or more water-soluble high polymers selected from the group consisting of hydroxyethyl cellulose, guar gum, polyethylene oxide and carboxylmethyl cellulose (CMC) salts. The preferred amounts of the components (A) and (B) to be incorporated in the slurry based on the pitch are as follows; 0.1-1wt% component (A) and 0.01-1wt% component (B).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pitch-water slurry composition stably dispersed in fine pitch powder and having good fluidity. More particularly, the present invention relates to a pitch-water slurry composition in which fine pitch powder is dispersed in water, which enables pipeline transportation and is suitable for supply to combustion equipment.

In recent years, the problem of energy supply and demand based on 1 petroleum has become a problem due to the high price of 1 petroleum and supply instability, and there is an urgent need to ensure a stable supply of energy by diversifying energy sources. For this reason, the effective use of solid fuels such as coal as an alternative to petroleum energy is being reconsidered.

However, unlike liquid fuels such as 1 petroleum, solid fuels cannot be transported by pipeline and are extremely disadvantageous in dispersion and handling. In order to improve the handling disadvantages of such solid fuels.

A method of pulverizing solid fuel and dispersing it in water to form a slurry has been studied, but this method has various problems. That is, when the solid fuel concentration is increased, the solid fuel particles in the slurry coagulate in water, resulting in an increase in the viscosity of the slurry and a decrease in fluidity.
-If the concentration is lowered, the efficiency of transportation and combustion will decrease, making it impractical. Furthermore, if the finely powdered solid fuel aggregates or settles during storage of the solid fuel-water slurry, transportation and combustion will be hindered, so the slurry must be kept stable.

Various types of coal, which have large reserves and are not unevenly distributed, have been studied as a solid fuel.

However, coal generally contains a large amount of ash, and there are problems in the treatment of the ash. Moisture in coal makes it difficult to increase the concentration of slurry, resulting in a decrease in calorific value. The present inventors have arrived at the present invention as a result of intensive research to improve the two drawbacks of the solid fuel-water slurry.

That is, 1. The gist of the present invention is (a) a nonionic compound represented by the general formula [I] (wherein R represents an alkyl group or an aryl group having 1 to 3 carbon atoms, and n represents a number of 70 or more); softening point! and (b) at least one water-soluble polymer compound selected from the group consisting of hydroxyethyl cellulose, guar gum, polyethylene oxide, or carboxymethyl cellulose salt.
rθ~/FrO°C A pitch-water slurry composition is obtained by uniformly dispersing pitch fine powder in water.

To explain the present invention below, the pitch used in the present invention is preferably go-igo'c, a heavy residue from petroleum distillation, and if the pitch is lower than s□℃, it is difficult to grind.
- 1,000,000 g It is practically difficult to manufacture a product with a temperature higher than 0°C. Unlike coal, pitch contains almost no ash or moisture and becomes a slurry fuel with a high calorific value.

Pitch can be ground by either a dry method or a wet method carried out in water, but if the wet method is used, a single powder clump will ignite.

There are no problems such as pitch melting and adhesion due to frictional heat.

preferable.

In the case of the dry method, a 5-shot type crusher such as a hammer mill or an atomizer is preferred since it is less likely to cause the problem of pitch melting and adhesion due to frictional heat than a compression type such as a ball mill or rod mill.

The smaller the pitch particle size, the better the dispersion stability and combustibility, but as the degree of pulverization increases, the cost of pulverization,
The viscosity of the slurry increases. Therefore, it is preferable to use a particle size that can pass through a 200-mesh sieve seven times through a 70-mesh sieve, which is about the same particle size as the pulverized coal being burned in the pulverized coal boiler.

Since the surface of pitch is highly hydrophobic, it is difficult to produce a stable and highly concentrated slurry in a system containing only pinch fine powder and water, even with strong stirring. When a surfactant, which is a dispersant, is added to the pitch-water slurry, it forms at the interface between pitch particles and water.

The surfactant adsorbs and causes the pitch particles to break apart and prevent them from agglomerating together.

It is expected to create a good dispersion state.

However, depending on the type of surfactant.

The viscosity of the slurry exhibits dilatancy (a phenomenon in which the viscosity increases when shearing force is applied), and the stability of the slurry is extremely poor (which is inconvenient for pipeline transportation, etc.).

Therefore, it is necessary to disperse the slurry with a surfactant that imparts chicken-tropic properties.

In the present invention, as such a surfactant.

A nonionic surfactant represented by the general formula [■] is used.

In the formula, R represents an alkyl group or an aryl group having 7 to 30 carbon atoms, preferably an alkyl group having 7 to 7 g of carbon atoms, particularly preferably an alkyl group of g%/2, and n is an average of ethylene oxide. The number of moles added is 19 or more, preferably.

20 to ioo is shown.

Although it is possible to obtain a pitch-water slurry composition with a good viscosity-reducing effect by using only the nonionic surfactant of the present invention, hydroxyethyl cellulose, guar gum, polyethylene oxide or carboxymethyl cellulose salt may also be used.

For example, if a water-soluble polymer compound having a molecular weight of 000 or more, such as an alkali metal salt such as a sodium salt of carboxymethyl cellulose, is used in combination, a pitch-water slurry composition with higher stability can be obtained.

The nonionic surfactant represented by the general formula [■] is used in an amount of 0.7 to 1% by weight based on the pitch in the slurry. O,
Under OS gravimetric conditions, the sla IJ-stabilizing effect is small, and r
Even if the weight percentage is exceeded, the effect will not be so great, which is economically disadvantageous. The water-soluble polymer compound is contained in an amount of o, oos-s by weight based on the pitch in the slurry.

It is preferably used within the range of Q and Q/-/wt%.

If it is less than 0.0 OS weight-i%, the effect is small.

If the S weight i exceeds 1%, the effect will not be so great, which is economically disadvantageous, and the slurry will thicken too much, making it difficult to handle.

To prepare the pitch-water slurry composition of the present invention,
The mixing order of pitch, water, surfactant, and water-soluble polymer compound is arbitrary.

Usually, after dissolving or dispersing the surfactant in water,
Pitch is added to obtain a slurry using a suitable mixing device or grinding device.Next, a water-soluble polymer compound is added as a powder or dissolved or dispersed in a small amount of water, and pitch is prepared using a suitable mixing device. - Producing a water slurry composition.

If the pitch concentration constituting the pitch-water slurry is too low, the efficiency of transportation and combustion will decrease.

Also, if it is too large, the viscosity will become too high.

It varies depending on the type of pitch and grain size, but generally 30 to 3 g
% by weight, preferably 50-75% by weight.

The pitch-water slurry composition of the present invention has a high slurry concentration (good fluidity and stability, does not cause agglomeration or sedimentation, and has little foaming, so it is easy to transport by pipeline and does not require ash treatment when burned. Because it produces a high calorific value and contains moisture, the generation of soot and NOx is reduced.

Next, the present invention will be explained by examples. The raw material pitches used in the following examples are coal pitches A (softening point g~9/'CJ) and B (softening point g~97), which have different softening points.
℃J,C (softening point iiz~/ko0℃) was dry-pulverized using a sample mill, and its particle size is as shown in Table 7.

Table 7 Examples/-/Q and Reference Examples/~IQ Water solution 9. 1 g of water or a predetermined amount of the surfactant listed in Table C was dissolved in a stainless steel beaker of aoocc.
2/g was introduced, and while stirring with a stirrer, gradually added Kobitsu B59f/, and then s, oo with a homomixer.

A slurry was prepared by stirring at rpm for 5 minutes. Add the water-soluble polymer compound in the amount shown in Table C to this and mix with a stirrer at GO rpm for 40 minutes until the solid content is about 6.
A pitch-water slurry containing % S heavy yellow was prepared.

The viscosity of the obtained pitch-water slurry was measured using a B-type viscometer.
．． Measurement was performed at t° C. and rotational speed A Orpm.

The results are shown in Table 1. In addition, as an evaluation of the stability of the slurry, the inner diameter 3α height/2
．． Pour the prepared slurry into a glass tube of jCm from the bottom.
After putting it to a height of 7 m and leaving it for 1 day at a temperature of 7 m, a glass rod of j * tx 96° OI was allowed to fall naturally into the slurry in the glass tube with its lower end in contact with the liquid surface.
Sedimentation (caking) of fine pitch powder: By tracking the height from the bottom of the glass rod to the bottom of the glass tube, the number of days for fine pitch powder to settle was measured, and those with no sedimentation were evaluated as stable. . The results are shown in Table 1. Results 5 It can be seen that the pitch-water slurry composition of the present invention has low viscosity, good fluidity, and stability.

Examples//~/ko

Claims (1)

[Claims] (1) (a) A nonionic compound represented by the general formula [I] (wherein, R represents an alkyl group or an alkyl group having a carbon number/-JO, and n represents a number of 70 or more) The softening point Z
A pitch-water slurry composition obtained by uniformly dispersing fine pitch powder at O-igo°C in water.