KR101592937B1

KR101592937B1 - Fuel from sewage sludge

Info

Publication number: KR101592937B1
Application number: KR1020140028774A
Authority: KR
Inventors: 김장섭
Original assignee: 김장섭
Priority date: 2014-03-12
Filing date: 2014-03-12
Publication date: 2016-02-11
Also published as: KR20150106563A

Abstract

The present invention relates to a method for recovering waste water from sewage sludge as fuel by adding wood powder and rice hull powder to the sewage sludge and further adding waste oil to increase the amount of heat as fuel and to moisturize the sewage sludge before hot air drying, The present invention relates to a fuel cell including sewage sludge capable of removing the odor of the sewage sludge itself and reducing the water content through a hot air drying process.

Description

[0001] Fuel from sewage sludge [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a fuel cell including sewage sludge, which is used to convert sludge (hereinafter referred to as sewage sludge) generated in sewage into fuel and which reduces water content through addition of a compound and hot air drying, .

In order to produce a solid fueled product with sewage sludge, the water content of the sludge itself must be lowered. However, there is a limitation in the technology of the dehydration facility currently being operated in the sewage treatment plant. The water content of the sewage sludge cake itself is 80% by weight on average, and in order to convert it into fuel, it is necessary to reduce the water content to 10% by weight or less, which requires a great deal of cost. Sewage sludge organic solid sludge solidification fuel technology is largely divided into carbonization technology, dry-solidification technology, and dry-gasification technology.

Carbonization technology is an anaerobic or hypoxic state, that is, heat treatment of raw materials at a high temperature in a reducing state, oxygen atoms and hydrogen atoms are volatilized and oil content is extinguished. Carbonization and ashes are left behind. . The carbonization process proceeds in the order of drying, dry gas formation, and carbonization depending on the temperature. The dry-solidification technique is a technique in which additives are mixed in the sludge, the water is firstly removed from the drying-molding apparatus to form pellets, and the molded sludge is cured and solidified. In addition, the drying-gasification technology is a technique of first drying the sludge, gasifying the dried sludge at an appropriate temperature, and using the resulting sludge as an energy source through an intermediate process. So it is called energy utilization technology.

According to the above conventional methods, sludge having a moisture content of 70 to 80% by weight, which is primarily dehydrated, is dried to a moisture content of 10% by weight or less and then mixed with a caloric aid such as anthracite coal, wood, So that a solid fuel is produced. Most of these conventional solid fuel technologies are different depending on how the sludge is dried or molded in some way. The sludge is dried and then mixed with a heat assistant or a heat assistant and a molding agent, . The conventional solid fuel conversion technology has the following problems.

First, since the mixture of sludge and caloric aid is formed by compression at high pressure, there is a problem that the gap between the particles is too dense and there is almost no pore or the porosity is too low. These solid fuels are not easy to burn during combustion, take a long time to complete combustion, and generate harmful gas and odor due to incomplete combustion.

Secondly, energy is consumed primarily to dry the sludge in the past, and energy is secondarily consumed in the process of compressing the dried sludge to a high pressure. Therefore, there is a problem that a lot of energy is consumed in the process of manufacturing the solid fuel, thereby increasing the manufacturing cost. This discourages the idea of recycling sludge as renewable energy.

Thirdly, since the dried sludge is compression-molded at a high pressure, there is a problem that a separate molding agent or an adsorbent must be added in order to facilitate molding. This is not only a cause for further lowering the porosity of the solid fuel, but also may cause harmful components in the combustion.

Fourth, in order to uniformly mix the sludge after drying, the dried solid material must be pulverized into powder or dispersed to a maximum degree before drying, so that the facility is complicated and the facility cost is excessively used, resulting in a low economic efficiency .

Thus, the conventional solid fuel technology using sludge is difficult to apply as an effective alternative for recycling as renewable energy due to the above-mentioned problems.

Korean Patent Registration No. 0592918

Representative sewage sludge from organic wastes has been restricted from January 2012 due to the enactment of the London Convention 1996, and land disposal became inevitable. As an alternative thereto, conventional techniques exist for drying sewage sludge to solidify fuel (RDF). However, the success of sewage sludge as a solid fuel should lower the water content of the sludge having a high water content to a low water content, that is, at least 10% by weight, and must be an environmentally friendly method free from odor. In addition, insufficient calorific value as a fuel is required to be converted into a good alternative energy source by adding an inexpensive calorific value auxiliary agent.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a sludge sludge comprising 80 to 150 parts by weight of wood powder and 5 to 30 parts by weight of rice hull powder per 100 parts by weight of sewage sludge having a water content of 70 to 85% After the addition, the mixture of the above combination is hot-air dried at 100 to 400 ° C at normal pressure to produce a fuel including powdery or molded sewage sludge whose water content is reduced to 0.5 to 10% by weight.

The second step is to add 80 to 150 parts by weight of wood powder, 5 to 30 parts by weight of rice hull powder and 1 to 5 parts by weight of waste oil to 100 parts by weight of sewage sludge having a water content of 70 to 85% by weight, And dried by hot air at 400 ° C to reduce the water content to 0.5 to 10% by weight to produce a fuel including powdery or molded sewage sludge.

In the present invention, the mixture containing the sewage sludge is dried at a temperature of 300 ° C for 5 hours, and the low calorific value of the fuel can be 4310 kcal / kg or more.

First, by adding wood flour, rice husk powder and waste oil to sewage sludge, it is possible to suppress the spontaneous ignitability and to reduce the odor of the sewage sludge itself in an environmentally friendly manner, to increase the heating value as fuel, Thereby improving the drying efficiency.

Secondly, since the calcination is performed in a low temperature region (100 to 400 ° C) as compared with the conventional high temperature carbonization (carbonization temperature: 600 to 800 ° C), it is possible to increase the value of the coal as a substitute fuel.

1 is a table showing an embodiment of a fuel cell including sewage sludge of the present invention.

In the present invention, the term " process " means not only an independent process but also the term when the desired action of the process is achieved even if it can not be clearly distinguished from other processes.

Also, in this specification, the numerical range indicated by using " ~ " indicates a range including numerical values before and after "~" as a minimum value and a maximum value, respectively.

In the present specification, the amount of each component in the composition means the total amount of the plurality of substances present in the composition, unless otherwise specified, when a plurality of substances corresponding to each component in the composition are present.

1972 London Convention The definition of sewage sludge as defined in the 1996 Protocol is "organic matter-rich wastes generated from primary physical treatment as residues from municipal sewage treatment." Sewage is the source of topsoil and, in many cases, treated and untreated industrial effluents As well as water-soluble municipal waste. " . The process of producing the sludge as a final product resulting from the treatment of conventional constants, industrial wastes, industrial wastewater, sewage and manure, is a process in which the microorganisms take up the nutrients dissolved in the wastewater and propagate, Refers to a mass of microorganisms separated by sedimentation.

South Korea, which is a member of the London Convention, has abolished marine dumping since 2012. According to the statistics of the Ministry of Environment of Korea in 2011, the amount of sewage sludge recycled from 3023,829 tons of sewage treatment facilities in 433 places in Korea is 746 6005 Which is only 24.6% of the total.

Although many researches have been carried out in the field of recycling as building materials, landfill materials in residential land development area, fuel conversion, etc. However, no matter how much sewage sludge is recycled in any field or purpose, The first procedure to eliminate and reduce is essential.

The present invention relates to a fuel cell including sewage sludge, which is used for recycling sludge generated in sewage as fuel and which has a reduced moisture content and an increased heating value through addition of a compound and hot air drying. Hereinafter, the present invention will be described in detail with reference to preferred embodiments of the present invention.

In order to make sewage sludge, which has a high water content and is difficult to use as a bad odor fuel, as a fuel, the present invention is applied to 100 parts by weight of sewage sludge having a water content of 70 to 85% by weight collected in a sewage terminal treatment plant, And 5 to 30 parts by weight of horseshoe powder are added to the mixture, and the mixture of the combination is hot-air dried at 100 to 400 ° C under atmospheric pressure to reduce the water content to 0.5 to 10% by weight. It is possible to increase the amount of heat as fuel and to add moisture of the sewage sludge before drying the hot air, and to remove the odor of the sewage sludge itself by adding the above-mentioned wood and rice hull powder.

In addition, 1 to 5 parts by weight of waste oil is additionally added to the above-mentioned additives to further increase the calorific value, thereby making it possible to produce sewage sludge fuel with efficiency as a fuel, and this will be supported by the embodiments described later.

Hereinafter, the present invention will be described with reference to the results shown in FIG. Sewage sludge fuel carbon A was prepared by adding 100 parts by weight of wood powder and 20 parts by weight of rice hull powder to 100 parts by weight of sewage sludge. Sewage sludge fuel carbon B was prepared by adding 100 parts by weight of wood powder to 100 parts by weight of sewage sludge, , 20 parts by weight of rice hull powder and 3 parts by weight of waste oil, and dried at a temperature of 300 캜 for 5 hours.

According to this embodiment, as shown in FIG. 1, the lower calorific value of the sewage sludge fuel cell A with the addition of wood powder and rice husk powder was increased by about 3 times as compared with the case where only the drying process was performed without adding the additive to the sewage sludge And the amount of heat generated by sewage sludge fueled coal B, in which waste oil is added to wood and rice hulls, is increased by about 3.8 times.

Fuelization through conventional drying only has a high calorific value, but the smell of the product has become a problem. In the case of the high-temperature carbonization method, since the drying temperature is as high as 600 to 800 ° C, the smell is reduced, but the calorific value of the carbide is low. In the high temperature carbonization process, the relationship between the carbonization temperature and the fuel composition change and the calorific value with respect to the drying sludge decreases as the carbonization temperature rises, but the calorific value per kilogram of the fuel is hardly decreased until the carbonization temperature is about 400 ° C, It is possible to secure fuel water. This is because in the temperature range up to about 400 ° C, the rate of reduction of oxygen in the combustible components is small and the proportion of carbon having a high calorific value is relatively high.

On the other hand, the present invention provides a fuel including sewage sludge which is heated at a relatively low temperature range (100 to 400 ° C) to increase the heating value of the dried material and enhance the value as a coal alternative fuel.

It is a matter of course that the fuel coal containing sewage sludge of the present invention is discharged as powder having a water content of less than 10% by weight and can be used as a fuel for a thermal power plant or can be formed into a solid fuel through a subsequent molding process.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it should be understood that various changes and modifications will be apparent to those skilled in the art. Obviously, the invention is not limited to the embodiments described above. Accordingly, the scope of protection of the present invention should be construed according to the following claims, and all technical ideas which fall within the scope of equivalence by alteration, substitution, substitution and the like within the scope of the present invention, Range. In addition, it should be clarified that some configurations of the drawings are intended to explain the configuration more clearly and are provided in an exaggerated or reduced size than the actual configuration.

Claims

In a fuel containing sewage sludge,
80 to 150 parts by weight of wood powder and 5 to 30 parts by weight of rice hull powder are added to 100 parts by weight of sewage sludge having a water content of 70 to 85% by weight, and then the water content is 0.5 to 10%
Wherein the mixture containing the sewage sludge is hot-air dried at 100 to 400 ° C at normal pressure.

In a fuel containing sewage sludge,
80 to 150 parts by weight of wood powder, 5 to 30 parts by weight of rice hull powder and 1 to 5 parts by weight of waste oil are added to 100 parts by weight of sewage sludge having a moisture content of 70 to 85% by weight, Weight%
Wherein the mixture containing the sewage sludge is subjected to hot air drying at 100 to 400 ° C at normal pressure.

3. The method according to claim 1 or 2,
Wherein the mixture containing the sewage sludge is dried at a temperature of 300 ° C for 5 hours, and the low calorific value of the fuel is 4310 kcal / kg or more.

3. The method according to claim 1 or 2,
Wherein the fuel containing the sewage sludge is in powder form.

3. The method according to claim 1 or 2,
Characterized in that the fuel containing the sewage sludge is a solid state and a pellet molded into a predetermined shape.