JPH0157640B2 - - Google Patents

Description

[Detailed description of the invention] Natural organic substances, such as peat, lignite, pulverized coal,
Pulp waste liquid sludge, activated sludge, sewage sludge, oil sand, etc., in their natural state of existence or generation, often contain various contaminants in addition to the main natural organic matter. In order to utilize the desired natural organic matter, it is necessary to separate these impurities simply and economically.

The present invention relates to a method for easily and economically separating impurities from these natural organic substances and producing fuels and various other useful compositions based on these natural substances.

Peat and lignite have a moisture content of about 70 to 50% in their natural state, and further contain impurities such as uncarbonized long fibrous materials and earth and sand, depending on the coal mining conditions. Even powdered coal still contains impurities such as sand.

Pulp waste liquid, activated sludge, and sewage sludge similarly contain impurities such as earth and sand and long fibrous substances.

Furthermore, for oil sands, 20 to 30%
The situation appears to be that ultra-heavy oil is involved.

The current situation regarding the removal of impurities that coexist with these natural organic substances is generally as follows.

In peat and lignite, only the moisture is evaporated and impurities are not removed.

When powdered coal is crushed, some impurities may come out of the system, but they are not actively removed.

Currently, pulp waste liquid sludge, activated sludge, and sewage sludge are burned using combustion improvers in a state where even their own coagulation cannot reduce the moisture content to below 80%. Nothing is being done.

For ultra-heavy oils such as oil sands and oil shells where oil is impregnated between inorganic substances, current methods are to wash them with steam, water, etc. and separate the oil and water, or to partially burn them underground to improve their fluidity. They are extracting oil. When separating water and very heavy oil, generally
Heavy oil with an API of 6° to 12° has a specific gravity that is almost the same as water, so separation requires a large amount of cost.

However, the above-mentioned natural organic substances are very important resources, and if the impurities therein could be easily and economically removed, their value would be enormous.

Currently, the fuels commonly used are: (1) liquid fuel;
It can be roughly divided into three categories: (2) solid fuel, and (3) extra-heavy oil, and the trend is that (1) and (3) are more important, while (2) is gradually decreasing.

In terms of technology, (1) and (3) are aimed at reducing the size of the combustion chamber and complete combustion (no suit or coke) to reduce SOx and NOx, and (2) is reducing the ash content and improving the combustion of biomass, etc. when mixed combustion. It lies in the homogenization of gender.

Next, from a user-oriented point of view, (1) and (3) mean that there is no prospect of a stable supply of liquid fuel at low prices for the foreseeable future, and that the amount of ultra-heavy oil that is four times the ultimate extractable amount of crude oil is The number of places that consider the future prospects to be advantageous has also increased.

On the other hand, regarding (2), in Japan, the effective use of biomass, and in the Soviet Union and Scandinavia, the use of peat as fuel has been actively promoted.

In order to meet these two needs, for the former, it is appropriate to stably exist micro-particle water in the fuel and micro-atomize the fuel oil by micro-explosion, and at the same time use heavy oil. It would be best if we could lower the temperature of the frame and reduce thermal noise.

Regarding the latter, when burning biomass, the greatest need is for the combustion rate to be constant, whether it is single combustion or mixed combustion with coal.

In order to achieve the above object, it is preferable to reduce the calorific value of the fuel, control it to a constant value, and perform complete combustion. In order to control the calorific value of a viscoelastic material with a high calorific value such as asphalt, coal tar pitch, or atactic polypropylene, and to completely burn it, a natural organic material with a low calorific value that contains an appropriate amount of water is finely divided. Uniform dispersion is appropriate. Further, it is preferable if a commonly used combustion device can be used as a liquid fuel without changing the dispersion state of the dispersed composition.

This is where the value of the method for producing a fuel composition containing natural organic substances of the present invention lies.

The present invention solves the above problems and provides a simple and economical method for removing impurities from natural products, which can be achieved through the following steps.

First, a dilute aqueous suspension of these natural organic substances is made. These dilute suspended aqueous solutions are suitable for 0.1% to 20%, and there are no restrictions on concentration or temperature, and impurities are separated from natural organic matter in the suspension, and natural organic matter remains suspended. Bye.

Contaminants are separated by flowing this dilute suspended aqueous solution in a laminar flow and settling, or by removing contaminants using a method such as a liquid cyclone, first removing inorganic contaminants with a heavy specific gravity based on the difference in specific gravity. . Thereafter, the dilute suspension from which impurities have been removed is passed through a relatively coarse wire mesh filter (gradient filter) to remove relatively large impurities such as light hair and uncarbonized cellulose. The diluted natural organic substance-containing suspension that has undergone these two purification steps is hereinafter referred to as a purified suspension.

The purified suspension obtained as above is put into the viscoelastic material being kneaded and kneaded together. The viscoelastic body and viscoelasticity in the present invention will be described as follows.

A substance with such high viscosity that it exhibits elasticity under normal conditions without any force deforms greatly when subjected to strong shearing force, such as during kneading (this is simply referred to as viscoelasticity in the present invention). ) will be referred to here as a viscoelastic body.

A mixture of suspended solids that have an affinity for the viscoelastic body, suspended solids that do not have an affinity for the viscoelastic body, and a suspending medium (hereinafter referred to as When adding and kneading suspensions (called suspensions), they become large and deform while exhibiting stringiness.
Suspended substances that have an affinity for the viscoelastic body are occluded in the viscoelastic body, and substances that have no affinity for the liquid or the viscoelastic body are expelled from the system by the kneading force acting on the system of the viscoelastic body containing the liquid. It is possible to selectively occlude turbid substances.

Therefore, the present invention is characterized in that a viscoelastic body is kneaded in a state exhibiting viscoelasticity, and a suspension is added, mixed, and kneaded to occlude an compatible suspended substance in the viscoelastic body. This is a method for producing a fuel composition. In this method, suspended matter that has an affinity for the viscoelastic body is occluded in the viscoelastic body, and water comes out of the system. (Japanese Patent Application No. 54-140974) In general, it is better to use a lipophilic viscoelastic material for lipophilic suspensions, and a hydrophilic highly viscoelastic material is suitable for hydrophilic suspensions, but the present invention As described below, the lipophilic viscoelastic material can be used not only for treating lipophilic suspensions, but also for other suspensions in systems using water as a medium.

As the suspension enters the viscoelastic body, the viscoelasticity may change. If the viscosity becomes too high, it is necessary to adjust the viscosity by increasing the temperature or adding a viscosity reducing agent. On the other hand, if the viscosity decreases too much, the opposite treatment is required (Japanese Patent Application No. 1983-63001) By the above treatment, it is possible to concentrate the purified natural product from the purified suspension into the viscoelastic body. Examples of viscoelastic materials include asphalt, pitch, tar, attacking polypropylene, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, polyvinyl alcohol aqueous solution, and starch aqueous solution, which exhibit viscoelasticity at a certain temperature. There is a substance.

The equipment used in this step is not particularly specified as long as it is capable of kneading under high shearing force, such as a kneader or vistar, but it is suitable if it has a jacket for the purpose of controlling the temperature.

The mechanism by which the purified natural product is concentrated and occluded in the viscoelastic body from the purified suspension in this manufacturing process is not necessarily clear. Also, it is surprising that the power consumed during this process is extremely small, but the reason for this is not clear at present.

In the former case, the suspension is probably first drawn into the viscoelastic body being kneaded, and then the suspension medium, which has poor affinity with the viscoelastic body, is removed from the system by kneading. Furthermore, in the latter case, the suspension gets caught up in the viscoelastic body being kneaded, and a suspending medium with poor affinity comes out. It is presumed that a suspending medium enters between the layers where it is stretched, and that this has an effect similar to that of a lubricant.

If you want to further strengthen the dehydration of this concentrated purified natural product and viscoelastic mixture, you can achieve your goal by changing the conditions in a direction that increases the viscosity of the viscoelastic (e.g., lowering the temperature) and kneading. .

A viscoelastic material that has an appropriate amount of moisture and contains purified organic matter is a plastic material that is suitable as a fuel in itself, and can be molded into pellets or sheets. It can also be mixed with oil-soluble liquids such as hydrocarbons and alcohols in any proportion, and can be easily made into a liquid form. Furthermore, in order to distribute an appropriate amount of water in this composition to a size of approximately 0.1 to 5 microns for the purpose of utilizing micro-explosive combustion, additives such as partially saponified polyvinyl acetate or anionic activator may be added during kneading. This is achieved by When a dispersion stabilizer such as partially saponified polyvinyl acetate or anionic activator is used, it is preferably added in an amount of 5 to 0.1%, preferably 4 to 0.5%, based on the organic substance including the viscoelastic material. Further, the composition prepared in this way can be easily made into a liquid by mixing it with an oil-soluble substance such as hydrocarbon or alcohol in any proportion.

The present invention will be explained below with reference to Examples.

Example 1 Sewage sludge (water content reduced using anionic coagulant)
The sludge (concentrated to 80%) is kneaded in asphalt, and 1 part of asphalt is mixed with 1 part of sludge with a moisture content of 50%.
A kneaded product of 30% was obtained. The equipment used was a kneader, and the temperature was 30°C to 38°C. The water that comes out of the system is clear. When 0.4 parts of kerosene was mixed with 1 part of this kneaded material, the sludge was evenly dispersed and became a high-quality fuel. However, in this case, the inorganic content was approximately 10%, including coarse particles of inorganic matter, which was expected to clog the burner nozzle.

Next, we will describe the purification of the sludge stock solution (99.3% water). The first tank is a feed tank for raw sludge, and this overflow liquid flows into the second tank, and a purification device was constructed in which a 20-mesh stainless steel wire mesh was attached to the outlet of the second tank. The undiluted sludge that is fed into the first tank little by little becomes a completely laminar flow in the first tank and the second tank due to the slight head difference between the first tank and the second tank, and flows to the bottom of the first tank and the second tank. Inorganic impurities such as pebbles and sand, and organic impurities such as long fibers such as hair and fiber waste were observed in the wire mesh at the exit of the second layer. The sludge did not float or settle in the first and second layers. The purified suspension obtained in this way was
The mixture was introduced into asphalt that had been kneaded in advance in a kneader, and kneaded. Water went out of the system and sludge was absorbed into the asphalt. The temperature of the sludge stock solution is 30°C to 38°C as described above. Moisture content in 1 part asphalt
One part of 50% sludge was mixed. 0.4 part of light oil was mixed with 1 part of this kneaded material. The sludge was completely evenly distributed and the inorganic content was reduced to 0.1%. Under a microscope, water droplets are distributed between 1 micron and 10 microns.

1 part of pre-kneaded asphalt with a moisture content of 50
0.01 part of partially saponified polyvinyl acetate (degree of saponification 75%, DP600) was added to a mixture of 1 part of sludge, and after kneading, 0.4 part of kerosene was added thereto. The sludge is completely uniformly dispersed, and the water is dispersed with particle sizes ranging from 0.1 microns to 5 microns.

This mixture is liquid and fluid.

Example 2 Crude oil tank sludge (paste) was collected,
A large amount of hot water was added to this to adjust the oil content in the sludge dispersion to 1%.

This liquid was passed through the two-tank laminar flow separation tank shown in Example 1. Impurities such as sand, pebbles, and rust settled to the bottom, but it was difficult to separate the oil and water. This oil/water mixture is pre-kneaded in a vistar at 30℃.60/80
It was placed in asphalt and kneading was continued. The oil completely entered the asphalt, and colorless, transparent, and odorless water came out of the system. As the amount of oil in the asphalt increased, the viscosity increased until it became impossible to continue kneading. When C heavy oil was added to this kneaded product in an amount of 10% by weight based on the asphalt, the viscosity was reduced again and kneading could be continued.
In this case, the sand taken out from the bottom of the first tank and the second tank was black and still had a large amount of oil attached to it.
Partially saponified polyvinyl acetate (0.1% in water)
Addition) is dissolved in the water used to dilute the paste.1
% sludge dispersion was made. This was treated in the same manner as in the previous method, but the wastewater was colorless, odorless, and transparent, and the oil content such as sand and pebbles that had accumulated at the bottom of the first and second tanks had disappeared. Partially saponified polyvinyl acetate was mixed into the paste in advance to make a 1% sludge dispersion, and the oil was recovered through the first and second tanks. This suggests that the oil adhering to sand, pebbles, etc. has a low affinity and can be easily separated by a surfactant added to water.

It is thought that the separated and emulsified oil was recovered.

Example 3 A suspension of Hokkaido peat (containing 70% volatile matter, 0.1% uncarbonized organic impurities and 25% inorganic impurities based on the same solid content) in 30°C water with a solid content of 1% was prepared. .

This suspension was purified by the method of Example 1. Uncarbonized fibrous impurities were trapped in the inclined filter (stainless wire mesh), and inorganic impurities such as pebbles and sand were settled at the bottoms of the first and second tanks.

This purified suspension was put into 100/200 asphalt that had been kneaded in advance at 30°C in a kneader and kneaded.
Water went out of the system, and organic matter was occluded in the asphalt. The water that came out of the system was clear, colorless, and odorless, and as shown in Example 2, as the amount of organic matter absorbed increases, the viscosity increases, and the composition finally reaches a solid content: asphalt ratio of 0.7 to 1.0:1.0. Then it became impossible to knead. By adding 10% C heavy oil (based on asphalt), it became possible to knead it again.

The ash content in this kneaded product (total solid content: asphalt = 1:1) was 0.3%.

Example 4 A kneaded product of the purified organic matter obtained in Example 1 and asphalt was prepared in the presence of water in an amount 100 times the amount of the kneaded product.
Kneaded in a kneader at 30°C for 10 minutes. After that, the kneader was tilted to let the water out of the system, but the water was colorless, odorless, and transparent, but very fine clay-like inorganic substances were observed at the bottom.

The thickness of this kneaded product was 0.1%.

The dehydration state of the kneaded product of the purified organic material obtained in Example 1 and asphalt was examined in the presence of water while tilting the kneader. It was observed that water was discharged from the part where it was being kneaded, but very fine sand had accumulated on the bottom side wall of the inclined kneader, and if you looked at the part where it was kneaded in more detail, it looked like water. It was confirmed that the particles were being expelled from the kneaded body.

Compared to Example 1, the ash content of Example 4 was reduced by 0.04%. This result shows that when the sludge-occluding asphalt is kneaded in a range where it exhibits viscoelasticity and a large amount of water is added to it, clay with poor affinity is discharged together with the water, resulting in the production of fuel, especially liquid fuel. Worth it if you do.

Example 5 Collagen wastewater containing large amounts of water-soluble collagen is produced during the manufacturing process of collagen casings for sausage applications.

Although the concentration of organic matter in this wastewater varies depending on the case, it generally contains about 0.1 to 1.0% of organic matter. This wastewater is generally sent to the biological treatment process through the second tank inclined filter shown in Example 1, but it is also a highly concentrated wastewater treatment and needs to be diluted with a large amount of water.

SAPRO-L is added to the wastewater after passing through the inclined filter in advance.
(manufactured by Shimanishi Kaken, flocculant) was added to wastewater at 100 ppm and mixed. The wastewater, which had been transparent, turned milky white and became suspended in a floc-like state.

This suspension was added to a kneader using 60/80 asphalt as a viscoelastic body and kneaded at 30° C. and 60 rpm. The amount of asphalt used was 2 kg, and the suspension was added 2 times. The kneading time was 10 minutes, and the treatment liquid became colorless and transparent. This operation was repeated until the collagen contained in the asphalt reached a ratio of 0.7 to 1.0 with respect to the asphalt, and the appearance of the obtained collagen-containing asphalt turned brown. When the water contained in organic matter (asphalt and collagen) is set to 0.5 to the organic matter, the hydrated organic matter is a W/O type emulsion with a brown surface, and the water particles are uniformly dispersed with a size of 1 to 10 microns. Ta. Furthermore, kerosene was mixed with this, and this W/O type emulsion is uniformly dispersed, can be mixed in any ratio, and has fuel suitability.

Example 6 A similar experiment was conducted by adding SAPRO-L to the collagen casing wastewater shown in Example 5 without using a gradient filter. Experimental conditions are as in Example 5.
is exactly the same.

The treatment time for this collagen casing wastewater containing undissolved collagen was slightly longer than in Example 5.
It required 30 minutes, and the collagen content in the asphalt was 0.5 to 0.7 relative to asphalt.

Under a microscope, the size of the water particles contained in the organic matter was 1 to 10 microns, and they were uniformly dispersed. From this phenomenon, it was considered that the water-insoluble collagen present in the gradient filter was finely and uniformly dispersed in the asphalt by kneading, similar to the water-soluble collagen.

The composition is also miscible with kerosene and has fuel suitability.

Example 7 At a canning factory that manufactures "Sea Chicken",
A concentrated waste liquid containing large amounts of fish oil, protein, and COD is produced.

Normally, suspended substances are removed from this waste liquid using the second gradient filter shown in Example 1.
The filtered water is a milky white viscous liquid containing 5000~10000ppm of fish oil and protein.

Asphalt 80 with a penetration of 60 to 80 is placed in a horizontal kneading machine with an internal volume of 150 liters, which has a two-shaft kneading device with internal stirring and mixing blades that rotate at 45 revolutions per minute.
While the mixture was being kneaded and maintained at 40°C, filtered water was added and kneaded at a rate of 320 kg/hour. The cloudy filtered water was treated, and water-insoluble, mainly suspended substances such as oil and protein were occluded in the asphalt, and the treated water became colorless, odorless, and transparent and flowed out. The KMnO ₄ method COD of the treated water was 1000 ppm. Also, the asphalt changed from black to a slightly grayish black.

Addition of wastewater was stopped when the amount of suspended solids mainly composed of fish oil and protein was 0.7 (weight ratio to asphalt containing suspended matter), and only kneading was performed to bring the water content to 0.5 (weight ratio to asphalt containing suspended matter). The asphalt containing the waste from the cannery was suitable as a fuel, but it had a foul odor.

This was diluted 2.5 times with low-sulfur C heavy oil, and a switching combustion test was conducted in a package boiler that was continuously running on C heavy oil.

As a result, compared to operating on C heavy oil,
The fuel obtained by diluting suspended matter-containing asphalt with C heavy oil had a whiter flame, stronger flame strength, and shorter flame length, and there was no bad odor during combustion.

Example 8 Short fiber agglomeration deposits are found in industrial waste from a pulp mill. That is, in the paper making process, short fibers,
Clay and the like are filtered together with water, and it is a suspended substance with a high water content consisting of cellulose, inorganic substances, and water that are coagulated and precipitated.

This substance is added to 60/80 asphalt which has been mixed in advance at 30℃ and 60rpm at a water content of 90%.
Kneaded. At the same time as kneading, the short fibers were occluded in the asphalt, and most of the water and inorganic substances were discharged out of the system. Abbreviation asphalt: Suspended solids = 1:
At 0.7, the addition of suspended solids was stopped, and kneading was continued under ventilation to adjust the water content to 0.3/1.0 in the weight ratio of asphalt to solids in the suspended solids. This mixed composition is moldable and can be easily made into briquettes. This briquette was co-fired with coal in a normal coal boiler, but no black smoke was emitted and the combustibility was good and showed uniform combustion.

Claims (1)

[Scope of Claims] 1. A natural organic material containing impurities is dispersed and suspended in water to separate the impurities, and then excess water is removed by kneading with a viscoelastic body in a state exhibiting viscoelasticity. A method for producing a fuel composition mainly composed of natural organic substances, which is produced by removing the substances. 2. In the method for producing a fuel composition based on a natural organic material as set forth in claim 1, a dispersion stabilizer such as partially saponified polyvinyl acetate or an anionic activator is added to a natural organic material including a viscoelastic material. Against 5
A method for producing a fuel composition, which comprises adding up to 0.1% of water and stably dispersing the water content into a size of 0.1 to 5 microns. 3. In the method for producing a fuel composition mainly composed of natural organic substances as set forth in claim 1, a liquid fuel composition is prepared by mixing the fuel composition and an oil-soluble liquid such as hydrocarbon or alcohol. Method for producing the composition. 4. In the method for producing a water-stable dispersion fuel composition containing natural organic substances as set forth in claim 2, the fuel composition is prepared by mixing a fuel composition and an oil-soluble liquid such as hydrocarbon or alcohol. Method for producing liquid composition.