CN1042041C

CN1042041C - Process for manufacturing composite solid fuel from coal and vegetable material, and composite solid fuel

Info

Publication number: CN1042041C
Application number: CN 93102572
Authority: CN
Inventors: 溝口中一; 山本裕; 萩野孝文
Original assignee: Taiyo Steel Co Ltd
Current assignee: Taiyo Steel Co Ltd
Priority date: 1992-04-16
Filing date: 1993-03-15
Publication date: 1999-02-10
Anticipated expiration: 2013-03-15
Also published as: JPH06184571A; CN1077735A

Abstract

In a process for producing a composite solid fuel through compression molding of a starting material mixture of a coal powder with 20-25wt.% vegetable matter powder, slaked lime as a desulfurizing agent is added in such an amt. that the molar ratio of calcium in slaked lime to sulfur contained in the coal powder in the starting material mixture is in the range of 1.0 to 1.8. The mixture is compressed with coal compressor to obtain composite solid fuel coal.

Description

The method and this composite solid fuel that prepare composite solid fuel by coal and plant material

The present invention relates to a kind of method for preparing composite solid fuel by fine coal and comminuted plants raw material such as timber, bagasse etc.The invention still further relates to this composite solid fuel.

For a long time, coal is used as the fuel of indoor process furnace, boiler etc. always.Generally, its size of the coal of such use is about 50-100mm (diameter), in order that be convenient to air infiltration.Fine coal has several millimeters particle size, and it is to mine, and forms in transportation and the coal separation process, and fine coal can be used for making said briquette through with a kind of suitable binding agent mold pressing.

Said grizzle such as brown coal and sedimentary brown coal, they are distributed in the whole world in large quantities, and are widely used as cheap fuel, and still, it comprises high ash oontent, and it is worth up to 30% weight, thereby it is difficult on the low side comparatively speaking with calorific value to ignite.In addition, these grizzles produce more ash and smog of cigarette and the more cinder that is formed by the fusion ash content.

As a countermeasure, people advised a fine coal especially the grizzle particle mix with dry and comminuted plants raw material such as timber, bagasse etc., and obtain composite solid fuel after passing through mold pressing.

The composite solid fuel of top indication is generally by following method preparation, coal and plant material are carried out drying independently of one another and be ground into the chip that size is no more than several millimeters, then they are mixed as much as possible, can add a kind of binding agent if desired, this mixture is relevant with a kind of raw material in the raw material, then this mixture is joined in the moulding press, such as a kind of like this coal cinder moulding press, at this machine intimate the two rollers of a pair of subtend are arranged, the mold pressing groove is arranged around roller, the briquette material is added on two rollers by rotary worm in the bucket-shaped sleeve or screw rod, and its middle sleeve is installed in two rollers top.

This composite solid fuel can and deposit brown coal by various coals, particularly grizzle such as brown coal and make as raw material.Each kind of plant comprises that bagasse and wood fragments material all can be used as plant material.

Though made composite solid fuel by grizzle, but, wherein comprise up to the ash oontent of 30% weight and the sulphur content of 5-8% weight, like this, the waste gas that comprises more oxysulfide will be discharged in the atmosphere with ash and smog of cigarette, thereby cause environmental pollution.

An object of the present invention is to provide a kind of method for preparing composite solid fuel by fine coal and comminuted plants raw material especially wood fragments material and bagasse effectively, so that this composite solid fuel reduces the amount at the waste gas sulphur oxide that produces significantly and to greatest extent when burning.

Above-mentioned purpose can be reached by the method that comprises the following steps, these steps are, dry this two kinds of raw materials of also thereupon pulverizing, the raw material of these pulverizing is mixed equably, so that the content of the contained plant material of mixture then, carries out mold pressing to this mixture at about 20% to 25% weight range, white lime is added in this mixture, and its consumption makes that the mol ratio of institute's calcium content and total sulphur content (mainly being included in the coal raw material) is about 1.0-1.8.

In the composite solid fuel (especially fine coal raw material) sulphur content with add white lime calcium in combustion processes, react, be present in the combust with the form of sulfurated lime.Because total sulphur content of about 80% weight (mainly is included in the coal raw material, and be included in the ash content) can therefore be fixed up, thereby not only can significantly reduce the amount of oxysulfide (especially sulfurous gas), otherwise it will be discharged in the atmosphere with ash and smog of cigarette and go; And, because there is considerable amount to be included in the coal ash content, just significantly reduced the content of cinder.

Below will provide one embodiment of the present of invention.

(1) preparation of composite solid fuel

At first, be used for preparing the coal and timber (white fir and the China fir) raw material of composite solid fuel according to this embodiment, its ultimate analysis the results are shown in table 1.

Table 1

The total S of ash amount C H N O ^*Coal 11.36 72.99 4.82 1.08 7.88 2.15 timber 0.81 52.10 6.14 0.10 40.82 0.04*S value comprises the sulphur in the ash oontent that is contained in the coal raw material.

Be 20% (weight), in the mixture of the wood raw material (particle size is no more than 2mm) pulverized, add the white lime of various amounts, to fine coal raw material (particle size is no more than 3mm) and content so that find out the amount of required adding.This uniform mixture is joined in the block-making machine (diameter of roller is 250mm), to carry out the mold pressing corresponding to about 300HPa pressure.

(2) effluent gas analysis

The one silica glass incendiary pencil (internal diameter 28mm) that is filled with the sample coal cinder is placed on temperature control pre-treatment in 300 ℃ electrothermal oven.Sample after heating 20 minutes, bubbling air (1.6 liters/minute) because burning sample, temperature was raised to 700 ℃ gradually in 40 minutes.Collect combustion gases and residual air,, measure the amount of sulfurous gas so that analyze.

(3) experimental result

According to a large amount of experiments, the amount that wherein joins the white lime in the mixture is different, this mixture comprises the plant material of 20% weight, have found that sulphur fixedly than with the relation of the mol ratio of calcium contents and total sulphur content shown in Fig. 1 (unique figure), can find out thus curve roughly straight line rise to Ca/S and be about 1 point.Fixedly than reach about 80% (mole) of maximum than the time, Ca/S is 1.2, and when calcium contents be that mol ratio with respect to total sulphur content is 1.8 or when higher, fixing than being substantially constant at about 78%.All these, its prerequisite is that the part by weight of employed two kinds of raw materials is noted earlier.

Should, when using white lime, use calcium contents when the mol ratio of total sulphur content is in the 1-1.8 scope at a certain consumption, then sulphur just can be effectively be fixed up with the form of sulfurated lime.About 28% the numerical value that obtains when not adding white lime is compared, and this numerical value of about 80% is beyond thought.

Can show, the invention provides very ideal composite solid fuel, its superior especially part, not only be significantly to reduce the amount that is included in the sulfurated lime that is discharged in the combustion fumes, (this combustion fumes is undesirable when considering environmental pollution, but up to now, when using coal fuel, when especially grizzle fuel or use comprised the compound fuel of this class coal fuel, people thought that this combustion fumes is inevitable); And be to have improved flammability, the ash and smog of cigarette that it discharged has reduced, and the cinder that produces when using grizzle or contain the fuel of this grizzle also reduced significantly, and is this, make this fuel can keep the perviousness of air, thereby cause the improvement of combustionproperty.

Claims

1. the method for preparing composite solid fuel by fine coal and plant material, it comprises the following steps: dry and pulverizes these two kinds of raw materials, the raw material that mixes these pulverizing equably, so that the scope of the plant material that is contained in the mixture is about 20% to 25% weight, then, this mixture is carried out mold pressing under the pressure that is equivalent to 300MPa approximately; Be characterised in that, white lime be added in this mixture that its consumption makes that the calcium and the mol ratio of the total sulfur content that is mainly contained are about 1.0-1.8 in the coal raw material.

2. according to the method for claim 1, it is characterized in that employed coal raw material is a kind of grizzle, it comprises the total sulphur content up to the ash oontent of 30% weight and 5-8% weight.

3. according to the method for claim 1 or 2, it is characterized in that, carry out mold pressing by a grinder, this grinder has the two rollers of a pair of subtend, in the roller circumferential surface many grooves is arranged, and each is used for the briquette of mold pressing compound fuel.

4. composite solid fuel, it comprises a kind of coal raw material, especially a kind of containing up to the ash content of 30% weight and grizzle raw material and a kind of plant material of 5-8% weight sulphur, especially the uniform mixture of timber or bagasse, wherein the plant material consumption is in 20-25% weight, wherein also be added with white lime, its content makes that institute's calcium content is about 1.0-1.8 with the mol ratio that mainly is included in the total sulphur content in the coal raw material in the white lime, and the uniform mixture that this is final carries out mold pressing at last and makes.