JPS6341593A - Viscosity lowering agent of aqueous mixture of coals - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to aqueous carbonaceous mixtures containing poly(oxyalkylene) nonionic surfactants as viscosity reducing agents.

US Pat. No. 4,358,295 describes a carbon-aqueous mixture with a high solids content.

This solid is dispersed in water using a selected poly(oxyalkylene) nonionic surfactant.

The surfactants include block copolymers of ethylene oxide and propylene oxide derived from bifunctional or higher functional initiators.

Particularly preferred are block copolymers of ethylene diamine and propylene oxide derived from nitrogen-containing compounds such as ethylene diamine and having a molecular weight of 14[100 or more], as described in column 6, lines 35-50 of that specification.

However, while these products are effective for dispersing granular charcoal into aqueous charcoal mixtures, they also have drawbacks. The high ethylene oxide content of most effective viscosity reducing agents causes gel formation when it comes into contact with water. Detailed reports on the gel regions of various block copolymers of ethylene oxide and propylene oxide can be found in the Pluronic Polyols and Tetronic Polyols technical data collection published by Basf.

For example, Tetronic surfactant 1307, which is specifically described in the above specification, forms a permanent gel when attempting to prepare a 60% aqueous solution. When this compound comes into contact with water, it immediately forms gel particles, which are slow to dissolve and
Moreover, it is difficult to prepare a low concentration aqueous solution because it does not dissolve unless strongly stirred.

Because of the solubility problems mentioned above, it is difficult to prepare aqueous solutions of these additives for mixing with the aqueous slurry components in producing commercial products of charcoal-water mixtures.

The long time required to dissolve, as well as the preparation of relatively low concentration stock solutions of various viscosity reducing agents,
This will increase the price of the final product. Furthermore, the solid nature of the heated products requires that they be transported and stored in heated containers, which further increases production costs.

The liquid additive used in the present invention dissolves rapidly in water and has a carbon-water content equivalent to or better than the selected poly(oxyalkylene) nonionic surfactants described in U.S. Pat. No. 4,658,295. It shows the effect of reducing the viscosity of the mixture.

The present invention comprises granular charcoal (a) dispersed as a solid, water (b) as a dispersion medium, and a mixture of ethylene oxide and a higher epoxide having 6 to 4 carbon atoms.
It is a carbon aqueous mixture containing a viscosity reducing agent (c) obtained by reacting with a hydrophobic initiator.

The viscosity reducing agent used in the present invention is a poly(oxyalkylene) nonionic surfactant, comprising a hydrophobic part and a hydrophilic part consisting of a mixture of ethylene oxide and a higher epoxide having 6 to 4 carbon atoms. Contains. The weight ratio of ethylene oxide and higher epoxide is 5:1 to 2:1, and the average molecular weight of the nonionic surfactant is about 10.
000 to 50,000 is preferable.

Furthermore, the present invention provides a method of adding to water a viscosity reducing agent obtained by reacting a mixture of (a) ethylene oxide and a higher epoxide having 5 to 4 carbon atoms using a hydrophobic initiator; (b) The resulting solution is added to a mixture of granular charcoal and water so that the weight ratio of the charcoal-water mixture to the viscosity reducing agent is 10.
00:1 to 10:1, and (c) stirring the resulting mixture at high speed.

The content of granular charcoal is 40 to 90% based on the total weight of the slurry.
Weight percent is preferred.

The charcoal aqueous mixture of the present invention includes the viscosity reducing agent solution of (a) in a ratio of water to viscosity reducing agent of 1000:1 to 10.
:1 by mixing with water and then mixing this solution with granulated charcoal while stirring vigorously.

It is particularly advantageous in the present invention that the viscosity-lowering agent can be dissolved in water at ambient temperature in a short time.

This is important because it allows the viscosity reducing agent to be mixed with the water before adding the granulated charcoal. Uniform mixing of the viscosity reducing agent and water is important to obtain uniform viscosity.

Granular coal used in the present invention includes bituminous coal, anthracite coal,
Examples include subbituminous coal, lignite, charcoal and petroleum coke.

The particle size of granular charcoal is 0.1~! 150μm preferably 1-2
It is 50 μm. Best results are obtained with particle sizes below 200 μm. The amount of granular charcoal is usually 40 to 90% by weight, preferably 70 to 80% by weight, based on the total weight of the charcoal-water mixture.
Weight%.

The viscosity reducing agent is liquid at room temperature and has a viscosity of 10,000 to 500
00 is preferably a poly(oxyalkylene) nonionic surfactant having an average molecular weight of 15,000 to 60,000. The viscosity reducing agent is a mixture of ethylene oxide and a higher epoxide having 6 to 4 carbon atoms, such as polypropylene or butylene oxide, and a hydrophobic initiator, preferably an aliphatic diamine such as ethylenediamine. The one obtained by reacting with a higher epoxide having 4 carbon atoms and the ratio of ethylene oxide to higher epoxide in the hydrophilic part is 10:1
-1:1, preferably 5:1-1:1.

Poly(oxyalkylene) nonionic surfactants can be produced by known methods. Essentially, the initiator is reacted with a mixture of ethylene oxide and a higher epoxide having 3 to 4 carbon atoms, such as propylene oxide or butylene oxide, at elevated temperature in the presence of an oxyalkylation catalyst.

The amount of liquid viscosity reducing agent used is usually 0.1 to 10.0% by weight, preferably 0.6% by weight, based on the total weight of the aqueous charcoal mixture.
~6.0% by weight.

Water is another component of the charcoal-aqueous system, and the amount used is 60-10% by weight, preferably 50-25% by weight, based on the total weight of the charcoal-aqueous system.

The aqueous carbon mixture may contain additional ingredients such as defoamers, thickeners,
Salts, bases, other flow modifiers or mixtures thereof may also be added.

As antifoaming agents, customary antifoaming agents are generally used, and silicone-containing or silicone-free compositions are used.

The thickeners added to the mixture may also be conventional. Thickeners are added to increase the non-gelling properties of the composition.

The thickener is preferably xanthan gum, guar gum, glue or a mixture thereof, and the amount thereof used is about 0.01 to 3.0% by weight based on the total weight of the mixture.

In preparing the composition, a poly(oxyalkylene) nonionic surfactant is mixed with water at or near room temperature and normal pressure to form a concentrated solution, which is then mixed with powdered coal and water. It is preferable to use a fluid liquid material. Defoamers can be added to the water to aid mixing. If necessary, a thickener may be added to prevent gelation. Other additives such as salts or bases can also be added to aid in dispersion.

In order for the viscosity reducing agent to work effectively, it should be quickly dissolved in water. Viscosity reducing agents that are readily soluble in water can save time and money. In the following examples, the nonionic surfactant Tetronic 130, which is a block copolymer described in U.S. Pat. No. 4,658,296, was used.
7 (hereinafter referred to as BC8) and Tetronic 15, a nonionic surfactant derived from ethylenediamine.
The solubility was compared with that of a 170 similar compound (hereinafter referred to as HC8).

Table 1 shows the dissolution time of BO2 at various concentrations in water.

1st Surface surfactant Concentration in water (%) Dissolution time (hours) BO2 (melting) 10
2.5N 20)8
．． 0//30)24.
0EC3 (thin section) 10
0.7N 20
2.4〃30 >24.
0 From this result, it is known that the dissolution time of flaky BC8 at a concentration of 10% is the shortest.

Table 2 HC8/20 20.0 10.0 1.1// 2
0.0 20.0 1.4 〃20.0 30.0 )8.0 HC8/25 25.0 10.0 1.2# 25
．． 0 20.0 1.9 〃25.0 30.0 )24.0 ucs/30 30. [+ 1 [+, 1 0.6N
30.0 20.0 0.6 〃30.0 30.0 1.00 HC3/40' 4o, o 1o, o 1.1/
/ 40.0 20.0 1.25〃40.0 30
．． 0)24.0 The dissolution times at various concentrations of HO2 containing various proportions of propylene oxide in the heterologous chain are shown in Table 2.

The molecular weight of all HC'S products is approximately 15,000.

Comparing Tables 1 and 2, it can be seen that all HC8 products show better results at the corresponding concentrations compared to the molten BC8 products. The flaky BC3 product contains H containing 60% propylene oxide at a concentration of 10%.
It showed better results than HC8 products other than C8 products.

All HC3 products showed good results at 20% concentration. Among the surfactants tested, the one with the shortest dissolution time was HC8/30 containing 60% propylene oxide.
Met.

In the examples below, HCB/3 for various charcoal-water mixtures
The viscosity reducing effects of 0 and BO2 were compared.

Charcoal-water mixtures were prepared by dissolving the surfactant in water at a concentration of 30% and adding this solution to the mixture of water and various charcoals. As for charcoal, 90% of the particles have a diameter of 160 μm or less, and 100% have a diameter of 25 μm or less.
A material with a diameter of 0 μm or less was used. The coal content in the mixture is
Measurements were made by repeatedly heating the mixture in a microwave oven for 15 minutes or until it no longer lost weight. The viscosity was measured using a Haake viscometer (model xv100) and an MV 2 P spindle. Viscosity was measured by increasing the shear rate from 0 to 12 rpm over 4 minutes. After holding the viscometer at this speed for 1 minute, the shear rate was reduced to 0 for 4 minutes. The same cycle was repeated and the viscosity at 100 seconds was measured from the second drop curve. The results are shown in Table 6.

Table 6 BO264, 7161, 722
6,0u BO264,2101,594,0 Darton Charcoal HC8/30 64.9 24
4.5 2445〃BC865,1394,9479
,5 Boland charcoal HC6/30 64.2
101.5'112.8〃BC865,24
51,3479,5 As is clear from Table 3, ■(c
s/6o showed a viscosity-lowering effect on all the coals tested, and in some cases (Darton coal and Boland coal) it showed a better effect than BO2, which is known as a viscosity-lowering agent for coal-water systems. HC3/3[+, like other types of I-[C8 products, dissolves rapidly in water and does not require melting or flaking. This saves time and money and makes operations more efficient.

Claims (1)

[Scope of Claims] 1. Granular charcoal (a) dispersed as a solid, water (b) as a dispersion medium, and a mixture of ethylene oxide and a higher epoxide having 3 to 4 carbon atoms are combined into a hydrophobic starting material. A charcoal aqueous mixture containing a viscosity reducing agent (c) obtained by reacting with a viscosity reducing agent (c). 2. The charcoal aqueous mixture according to claim 1, wherein the viscosity reducing agent has an average molecular weight of 10,000 to 50,000. 3. Claims characterized in that the hydrophobic initiator for the viscosity reducing agent is a compound obtained by reacting an aliphatic diamine with a higher epoxide having 3 to 4 carbon atoms. The charcoal aqueous mixture according to item 2. 4. (a) Granular charcoal of 45 to 90% by weight based on the total weight of the charcoal aqueous mixture, (b) 1% of the total weight of the charcoal aqueous mixture
Claim 2, characterized in that it contains 5 to 60% by weight of water, and (c) 0.1 to 5.0% by weight of a viscosity reducing agent, based on the total weight of the aqueous carbon mixture. Charcoal aqueous mixture as described in. 5. Claim 4, characterized in that the weight ratio of ethylene oxide to higher epoxide in the hydrophilic part of the viscosity reducing agent is 10:1 to 1:1, preferably 5:1 to 2:1. Charcoal aqueous mixture as described in. 6. The aqueous charcoal mixture according to claim 5, wherein the higher epoxide is propylene oxide. 7. (a) A viscosity reducing agent obtained by reacting a mixture of ethylene oxide and a higher epoxide having 3 to 4 carbon atoms with a hydrophobic initiator is added to water, and the viscosity reducing agent is (b) Add the resulting solution to a mixture of granular charcoal and water such that the weight ratio of the charcoal-water mixture to the viscosity reducing agent is 1000:1 to 10:1. and (c) stirring the resulting mixture at high speed. 8. The method according to claim 7, characterized in that the viscosity-lowering agent has an average molecular weight of 10,000 to 50,000. 9. Granular charcoal (a) of 45 to 90% by weight based on the total weight of the charcoal aqueous mixture, 15 to 6% of the total weight of the charcoal aqueous mixture
Claim 7, characterized in that 0% by weight of water (b) and 0.1 to 5.0% by weight of viscosity reducing agent, based on the total weight of the aqueous charcoal mixture, are used. the method of. 10, characterized in that the weight ratio of ethylene oxide to higher epoxide in the hydrophilic part of the viscosity reducing agent is 10:1 to 1:1, preferably 5:1 to 1:1;
A method according to claim 9. 11. The method according to claim 10, wherein the higher epoxide is propylene oxide.