KR101621268B1 - Method for manufacturing solid fuel using coffee grounds - Google Patents

Abstract

The present invention relates to a method for producing a solid fuel using coffee grounds, and more particularly, to a method for producing a solid fuel using coffee grounds, comprising mixing a coffee grounds with lignin and an inorganic binder to prepare a coffee ground mixture, And a forming step of compressing and molding the resulting coffee ground mixture.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method for manufacturing solid fuel using coffee grounds,

The present invention relates to a method for producing a solid fuel using coffee grounds which is eco-friendly and harmless to the human body during combustion and which can also be used as a firing ball.

A method for producing a solid fuel having a high burning property and being used as an excellent heat source using a carbon powder obtained by a process of forming a hole or the like or a fracture caused by a friction or an impact between the formed products during transportation, The sawdust was carbonized and compressed to produce solid fuel.

However, since the fuel materials of low grade coal such as anthracite and lignite contain sulfur, nitrogen, and the like in addition to carbon as constituent components, a large amount of gases harmful to human body such as sulfur oxides and nitrogen oxides are generated. And when sufficient activation heat energy required for the oxidative exothermic reaction of the fuel after ignition is not supplied to the entire fuel within a short time, carbon monoxide gas is generated by incomplete combustion.

Accordingly, there has been a problem that the ignition operation is avoided by the user of the ignition step due to the toxic gas generated when the solid fuel of the coal-based fuel material produced in this way is used for charcoal grilling in a restaurant or the like.

In addition, the conventional solid fuel has a problem in that the chemical added to the solid fuel is a high price, which causes a rise in production cost. In recent years, solid fuels mainly made of wood and activated carbon have been introduced, but most of them have problems such that the initial ignition efficiency is high but the smoke is excessively generated, and the thermal efficiency is somewhat lowered.

Meanwhile, the charcoal used in the conventional roasting can be generally classified into charcoal and molded charcoal. The charcoal is produced by pyrolysis of the whole wood lumber in a charcoal kiln, and most of the charcoal is sold as an interior, a luxury restaurant, a hotel, etc. The above-mentioned briquettes are made of sawdust or plywood made of sawdust or plywood at the construction site for the purpose of recycling purpose, and formed by molding at high temperature and high pressure. In order to compensate for the low quality of the above-mentioned briquette, a chemical containing heavy metals or harmful substances is added . In Korea, low-priced molding coal imported from China or Indonesia is mainly used due to the restriction of supply of charcoal. In the case of imported molding shell, only the mark of origin of the importer is managed, and the management standard related to product quality is insufficient, And harmful heavy metals such as arsenic, lead, chromium, antimony, barium and organic volatile substances (VOCs) such as dioxins and benzo-pyrene contained in pulpwood and plywood are not even reflected in the quality standards Which is very low in human safety, has been circulating throughout the country.

Conventionally, coffee makers have produced coffee beverages and the like and have produced more than a few hundred thousand tons of coffee waste per year in Korea alone. The coffee grounds are excellent in air permeability due to the nature of plant cell tissues, uniform in particle size distribution, It contains 15 ~ 25% of coffee oil. Its solids are energy resources with high calorific value of 6000 kcal / kg or more, but only a part of it is used as raw material of organic fertilizer and most of it is incinerated or landfilled like general waste.

In recent years, attempts have been made to use coffee grounds as solid fuel, but solid fuels using coffee grounds, which are already known, still generate incomplete combustion when burned, resulting in harmful gases such as carbon monoxide. There is a limit to use.

It is an object of the present invention to provide a method of manufacturing a solid fuel which can recycle abandoned resources and is eco-friendly, while significantly reducing the product unit cost compared with existing products.

It is another object of the present invention to provide a solid fuel which is harmless to the human body even when it is used in the use of a crushing ball because the generation of harmful gas such as carbon monoxide and sulfur dioxide is minimized.

The present invention relates to a method for producing a solid fuel using coffee grounds, and more particularly, to a method for producing a solid fuel using coffee grounds, comprising mixing a coffee grounds with lignin and an inorganic binder to prepare a coffee ground mixture, And a forming step of compressing and molding the resulting coffee ground mixture.

In the present invention, the coffee grounds preferably have a particle size distribution of 100 μm to 5 mm.

In the present invention, it is preferable to use the lignin extracted from the black liquor, and the lignin is preferably mixed at 10 to 15 wt% with respect to the total weight of the coffee ground mixture in the mixing step.

In the present invention, it is preferable that the inorganic binder is a Ca series binder or a Si series binder. Examples of the Ca series binder include calcium carbonate (CaCO ₃ ), calcium hydroxide (Ca (OH) ₂ ), calcium oxide calcium (CaO _2), calcium silicate (Ca ₂ SiO _4), calcium phosphate _{(Ca 3 (PO 4) 2} ), calcium gluconate _{((CH 2 OH (CHOH)} 4 COO) 2 Ca), calcium formate (C ₂ H ₂ O ₄ Ca), calcium acetate (C ₄ H ₈ CaO ₅ ), or calcium propionate ((CH ₃ CH ₂ COO) ₂ Ca). The Si-based binder is preferably silica (SiO ₂ ). It is preferable that the inorganic binder is mixed in an amount of 1 to 5% by weight based on the total weight of the coffee ground mixture in the mixing step.

In the present invention, it is preferable to dry the coffee residue mixture at a moisture content of 5 to 10% by weight, and the molding step preferably compresses the dried coffee residue mixture at a pressure of 5 to 10 kg / cm ² Do.

Another aspect of the present invention relates to a solid fuel using coffee grounds produced by the above method.

According to the production method of the present invention, it is possible to produce environmentally friendly solid fuel by recycling discarded coffee grounds, extracting lignin from the black liquor generated in the kraft pulping process, and recycling the lignin. By recycling, the manufacturing cost of the solid fuel product can be remarkably lowered compared with the existing product of the equivalent specification.

In addition, the solid fuel produced by the production method of the present invention can minimize the generation of harmful gas such as carbon monoxide and sulfur dioxide during combustion, and can prevent harmful heavy metals such as arsenic, mercury, lead, and organic volatile substances such as dioxin and benzopyran ) Can be minimized and it is harmless to the human body even if it is used in the use of a ball.

1 shows a flowchart of a method for producing solid fuel using a coffee ground according to the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is capable of various modifications and various embodiments, and specific embodiments are illustrated in the drawings and will be described in detail in the detailed description. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

More particularly, the present invention relates to a method for producing a solid fuel using coffee grounds, comprising mixing a coffee grounds with lignin and an inorganic binder to prepare a coffee ground mixture, a drying step of drying the coffee ground mixture, And a forming step of compressing and molding the coffee ground mixture.

In the present invention, the coffee grounds are remnants obtained by processing coffee beans, and the coffee grounds are residual residues obtained by heating the coffee bean having a vegetable content to a predetermined temperature or above and extracting the coffee stock solution from the finely divided powder. Therefore, , Cellulose, and the like. That is, the coffee grounds are excellent in the air permeability due to the nature of the plant cell structure, and can be continuously heated for a predetermined time or more through a certain compression molding. The coffee grounds contain 15 to 25% of coffee oil. The solids are energy resources with a high calorific value of 6000 kcal or more per kg, or only a part of them are used as raw materials for organic fertilizer, and most of them are incinerated or buried like general waste. to be. In the present invention, since the above-mentioned discarded coffee residue is recycled as the main raw material of the solid fuel, the raw material can be obtained at an inexpensive price, and the cost of the solid fuel product can be remarkably lowered.

In the present invention, it is preferable to use a homogeneous particle size distribution of the coffee grounds so as to minimize incomplete combustion of solid fuel and to minimize the generation of harmful gases such as carbon monoxide. More specifically, To 5 mm.

The lignin is an essential component of wood together with cellulose and hemicellulose, and is contained in 25-30% of conifer and 20-25% of hardwood in terms of biomass production, kraft pulp process, etc. It is obtained as a large amount of by-products.

In the present invention, since the lignin has a calorific value of 6,100 kcal / kg, which is higher than the calorific value of cellulose, which is the main component of waste wood, of 4,200 kcal / kg, it improves the combustion efficiency of the solid fuel, Can be minimized and the generation of harmful gas such as carbon monoxide can be suppressed.

Generally, the method of extracting lignin from herbaceous plants, woody plants, etc. is widely known, but it is preferable to use lignin extracted from black liquor in the present invention. The black liquor is a strongly alkaline black waste produced in the step of delignification of wood during the kraft pulping process. The black liquor contains lignin residue, hemicellulose, inorganic compound, etc. in a liquid phase. Globally, about 100 million tonnes of black liquor is produced as a by-product, and the amount of lignin contained in the black liquor is estimated to be about 30 million tons per year. Currently, more than 99% of the lignin extracted from the world is burning. Only about 1% of lignin is used as carrier of pesticide, additive for concrete, surfactant, adsorbent, fertilizer, rubber additive, . The present invention relates to a method for recovering lignin from a black liquor, which is generated in the kraft pulping process, by using a coffee waste and recovering lignin from the black liquor, thereby recycling waste that is eco-friendly and discarded in terms of recycling of wastes. It is economically advantageous.

The method of extracting lignin from the black liquor may be a method of adding a acid to the black liquor to form a precipitate, neutralizing the formed precipitate, and drying to obtain lignin of the particulate lignin.

The acid may be any acid as long as it can form a precipitate by lowering the pH of the black solution, but it is preferably selected from the group consisting of sulfuric acid, hydrochloric acid, phosphoric acid, and mixtures thereof. The pH of the black solution to which the acid is added is preferably 2. This is because when the pH is lower or lower than 2 in the process of lowering the pH of the black solution, the yield of extracted lignin is lowered.

The precipitate formed by adding an acid to the black solution is filtered with a decompressor or the like, and the pH of the precipitate is neutralized to 5 to 6 by using distilled water or the like. The neutralized precipitate is dried at 40 ° C to 50 ° C for 1 day to 2 days to extract lignin.

In the present invention, the content of the lignin is not particularly limited, but is preferably 10 to 15% by weight based on the total weight of the coffee ground mixture. When the content of lignin is less than 10% by weight based on the total weight of the coffee ground mixture, the heat-generating performance of the solid fuel is excessively lowered and the meat is not ripe. Thus, there is a problem that the content of lignin is inadequate for application as a roasting fuel. If the content exceeds 15% by weight based on the total weight of the mixture, the burning rate is excessively high and the fuel is consumed in a short time, so that it is used as a fuel for burning, which needs to be continuously burned so that a certain quantity of meat can be burned by a single fuel injection The reason for this is that the production cost of the solid fuel is increased by mixing the content of lignin having a relatively high raw material cost among the constituent materials more than necessary.

In order to further improve the moldability of the solid fuel using the coffee grounds in the mixing step and to reduce the drying burden of the drying step, the inorganic binder is mixed with an inorganic binder in addition to lignin, and the inorganic binder is preferably a Ca series binder or a Si series binder Do. By adding the Ca series binder or the Si series binder to the coffee ground mixture, when the coffee ground mixture dried in the forming step is compression molded, the particles of the coffee ground mixture are more firmly fixed, And when the Ca-based binder or the Si-based binder is mixed with the coffee ground mixture, moisture and the Ca-based binder material or Si-based binder material undergo hydration-exothermic reaction in the coffee ground mixture, It has an effect of spontaneously evaporating some of the existing water, and has an advantage that the heat energy required in the drying step can be saved.

Further, the solid fuel using the coffee residue produced by mixing the Ca series binder or the Si series binder has a problem in that the Ca series binder or the Si series binder binds with the sulfur (S) component and remains as an inorganic substance Therefore, the emission amount of sulfur oxide (SO _x ) in the atmospheric state due to the use of solid fuel can be remarkably reduced.

The Ca-based binder is not particularly but not of those types are limited, and calcium carbonate (CaCO _3), calcium hydroxide (Ca (OH) _2), calcium (CaO), calcium peroxide oxide (CaO _2), calcium silicate (Ca ₂ SiO ₄ ), calcium phosphate _{(Ca 3 (PO 4) 2} ), calcium gluconate _{((CH 2 OH (CHOH)} 4 COO) 2 Ca), formic acid, calcium _{(C 2 H 2 O 4 Ca} ), calcium acetate (C ₄ H ₈ CaO ₅ ) or calcium propionate ((CH ₃ CH ₂ COO) ₂ Ca).

The Si-based binder is not particularly limited, but is preferably silica (SiO ₂ ).

In the present invention, the content of the inorganic binder is not limited, but it is preferable to mix the inorganic binder in an amount of 1 to 5% by weight based on the total weight of the coffee ground mixture. This is because when the content of the inorganic binder in the coffee ground mixture is less than 1% by weight, the content of the inorganic binder is too low, so that the particles of the coffee ground mixture can not be solidly fixed when the coffee ground mixture dried in the forming step is compression- When the content of the inorganic binder in the coffee residue mixture is higher than 5% by weight, the content of the inorganic binder is too high to inhibit the combustion efficiency The problem occurs.

In the present invention, the drying step is a step of removing moisture contained in the coffee ground mixture to a certain level prior to the molding step of the coffee ground mixture. The present invention is characterized in that the coffee grounds are not dried in advance, Moisture content of about 50%) to prepare a coffee ground mixture first, followed by drying the prepared coffee ground mixture. This is because the Ca-based binder or the Si-based binder added during the formation of the coffee residue mixture causes self-drying by the hydration heat due to the hydration reaction with the moisture contained in the coffee grounds and thus the energy required in the subsequent drying step Electricity) costs can be saved.

In the present invention, it is preferable to dry the coffee residue mixture at a moisture content of 5 to 10% by weight, more preferably 5% by weight. When the coffee ground mixture is dried at a moisture content of less than 5% by weight, excessive energy is injected into the drying process to cause an increase in manufacturing cost, and the content of moisture in the coffee ground mixture is too small, When the coffee ground mixture is dried at a water content higher than 10% by weight, the content of water in the coffee ground mixture is excessively large, so that when the solid fuel is converted into a solid fuel, the combustion performance Which leads to incomplete combustion, resulting in the generation of harmful gas such as carbon monoxide, which makes it unsuitable as a fuel for roasting.

In the present invention, the forming step is a step of forming a solid fuel that keeps a predetermined shape by compressing a coffee ground mixture that has undergone the drying step using a press device. The shape of the solid fuel of the present invention is And may be, for example, a cylindrical shape having a hole on the inner side or a disk-shaped one having a plurality of through holes.

The molding apparatus to be used in the molding step may be any molding apparatus that is commonly used, and the pressure required when the coffee residue mixture dried in the molding step is compression molded is 5 to 10 kg / cm ² . This is because when the compression molding is performed at a pressure of less than 5 kg / cm ² , the durability of the finally produced solid fuel is excessively reduced and it is easily broken. When compression molding is performed at a pressure higher than 10 kg / cm ² , The internal air permeability of the solid fuel is lowered and the internal combustion is not performed well, so that the combustion efficiency of the solid fuel is lowered because the uniform combustion is not generated in the solid fuel, and excessive energy input occurs in the compression molding step, There is.

Another aspect of the present invention relates to a solid fuel using the coffee grounds produced by the above method. When the solid fuel according to the present invention is used, incomplete combustion can be minimized during combustion, and even when used as a fuel for roasting, The generation of carbon monoxide can be minimized, so that the user can safely bake meat. In addition, there is a problem in that harmful heavy metals such as arsenic, mercury, lead, chromium, antimony, barium and organic volatile substances (VOCs) such as dioxins and benzopyrene are generated in the waste wood or plywood The solid fuel produced by the manufacturing method of the present invention is not harmful to human body even when it is used for the use of a fire fighting ball because harmful heavy metals such as arsenic, mercury, lead and the like, and organic volatile substances (VOCs) such as dioxins and benzo-pyrene are not generated.

The manufacturing method of the present invention will be described with reference to FIG. 1 is a flow chart of a method for manufacturing a solid fuel using coffee grounds according to the present invention. Referring to FIG. 1, the manufacturing method of the present invention first comprises preparing a coffee ground mixture by mixing lignin and an inorganic binder with prepared coffee grounds. (S10). Next, the coffee ground mixture is dried using a drying apparatus such as a vacuum drying apparatus to remove water present in the mixture to a certain level (S20). Then, the dried coffee ground mixture is pressed And the solid fuel is produced by compression molding (S30).

Hereinafter, the present invention will be described by way of examples. The following examples are only illustrative of the present invention, and the scope of the present invention is not limited thereby.

Example

A coffee ground mixture was prepared by mixing coffee grounds (using coffee grounds mixed with arabica and lobster paper in a ratio of 7: 3), lignin extracted from black liquor, calcium oxide (CaO), and the coffee grounds 85 wt%, lignin 11 wt%, and calcium oxide (CaO) 4 wt%.

Next, the coffee ground mixture prepared above was injected into a fine-powder fired boiler through a fine-powder nozzle to thermally dry the coffee ground mixture so that the water content of the coffee ground mixture was about 5% by weight.

Finally, the dried coffee ground mixture was compression-molded at a pressure of about 7 kg / cm ² using a press apparatus to produce a solid fuel using the coffee residue of the present invention.

As a result of using the solid fuel prepared as described above, no harmful gas such as carbon monoxide or sulfur dioxide was generated during combustion and harmful heavy metals such as arsenic, mercury and lead and organic volatile substances such as dioxins and benzopyran (VOCs) Did not occur.

As described above, those skilled in the art will understand that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. It will be understood by those skilled in the art that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention as defined by the appended claims and their equivalents. .

Claims (11)

Mixing the lignin extracted from the black liquor and the inorganic binder with the coffee grounds to prepare a coffee ground mixture, wherein the lignin is mixed at 10 to 15% by weight based on the total weight of the coffee ground mixture;
A drying step of drying the coffee ground mixture; And
And a shaping step of compressing and shaping the dried coffee ground mixture to produce a solid fuel using the coffee grounds.
The method according to claim 1,
Wherein the coffee grounds have a particle size distribution of 100 μm to 5 mm.
delete delete The method according to claim 1,
Wherein the inorganic binder is a Ca-based binder or a Si-based binder.
6. The method of claim 5,
The Ca-based binders include calcium carbonate (CaCO _3), calcium hydroxide (Ca (OH) _2), calcium (CaO), calcium peroxide oxide (CaO _2), calcium silicate (Ca ₂ SiO _4), calcium phosphate (Ca ₃ (PO ₄ ) ₂ ), calcium gluconate ((CH ₂ OH (CHOH) ₄ COO) ₂ Ca), calcium formate (C ₂ H ₂ O ₄ Ca), calcium acetate (C ₄ H ₈ CaO ₅ ) or calcium propionate CH ₃ CH ₂ COO) ₂ Ca).
6. The method of claim 5,
Wherein the Si-based binder is silica (SiO ₂ ).
The method according to claim 1,
Wherein the inorganic binder is mixed in an amount of 1 to 5% by weight based on the total weight of the coffee ground mixture in the mixing step.
The method according to claim 1,
Wherein the drying step comprises drying the coffee ground mixture at a water content of 5 to 10% by weight.
The method according to claim 1,
Wherein the forming step compresses the dried coffee ground mixture at a pressure of 5 to 10 kg / cm < ² > to form a solid residue.
A solid fuel using coffee grounds produced by the method of any one of claims 1, 2 and 5 to 10.

Images