PL197240B1 - Method of annihilating processed organic wastes by combusting them in rotary cement kilns - Google Patents

Abstract

The proposed liquidation method of treated organic waste, in particular meat and bone meals, waste fats and another treated veterinary waste of animal origin, by incineration thereof in rotary cement kiln when burning cement is carried out in such a manner that treated organic waste with maximum moisture content of 50 percent, minimum heating value of 11 MJ.kge-1 and with formation of 50 percent by weight of ash, at the most, is added in a rotary cement kiln as a portion of the total amount of fuel either directly into the flame via a main burner and/or via a calcining burner and/or via an auxiliary burner, and/or the treated organic waste is added into said rotary cement kiln hot portion with temperatures above 1400 degC, whereby such amount of the treated organic waste is added into the rotary cement kiln, which evolves by its burning up to 90 percent of heat energy needful for achieving effective temperature for cement burning and simultaneously the amount of the treated organic waste is controlled to maintain amount of phosphorus oxide, expressed as Pi2Oi5 in clinker below the level of 2 percent. This means that the added treated organic waste burns in the kiln under oxidation kiln atmosphere in excess of combustion air and under generation of non-toxic combustion products and ash. Heat energy evolved by this burning is thus employed for effective cement burning, whereby the non-toxic combustion products are partially caught during counter-current cement burning on the ground raw material mixture and on clinker being just formed, and ash arising by incineration of the treated organic waste containing bones reacts quantitatively with clinker mass. Phosphorus oxide, analytically expressed as Pi2Oi5 exhibits in amounts up to 2 percent a mineralizing effect on formation of clinker phases.

Description

REPUBLIC

POLAND

(12) PATENT DESCRIPTION (19) PL (11) 197240 (13) ^B1 (21) Application number: 350783.

(51) Int.Cl.

F23G 7/00 (2006.01) (22) Date of notification: 21.11.2001

Patent Office of the Republic of Poland

Method of liquidation of processed organic waste by incineration in a cement rotary kiln (73) The holder of the patent:

Povazska cementaren, a.s., Ladce, SK (30) Priority:

02/19/2001, SK, PV242-2001 (43) Application announced:

August 26, 2002 BUP 18/02 (45) The following was announced about the grant of the patent:

31.03.2008 WUP 03/08 (72) Inventor (s):

Pavel Martauz, Ladce, SK Julius Strigac, Halic, SK Zdeno Orsag, Trencin, SK Ivan Tiso, Trencianska, SK Ferdinand Gach, Ladce, SK Lubomir Jezo, Ladce, SK Vladimir Ivanka, Puchov, SK (74) Representative:

Rokicki Bogdan,

Kancelaria Prawnicza, Kancelaria Patentowa (57) 1. Method of liquidation of processed organic waste by combustion in a rotary cement kiln heated in the process of burning clinker with noble fuel or a mixture of noble fuels or a mixture containing precious and alternative fuels, in which organic waste is added to the cement kiln through the main burner and / or calcination burner directly into the flame, and / or through the auxiliary burner into the flame at a temperature of 1900 ° to 2000 ° C and / or into the hot part of the furnace at temperatures of 1400 ° to 1900 ° C, characterized in that a part of the calorific value of the noble fuel or a blend of noble fuels or a blend containing precious and alternative fuels is replaced with organic waste having a minimum calorific value of 11 MJ / kg, preferably more than 20 MJ / kg, and containing a maximum of 50% by weight of ash with a maximum moisture content of 50% , preferably less than 10%, preferably meat and bone meal, fat o waste and / or other processed animal waste which, at high temperatures and in an oxidizing atmosphere with an excess of combustion air, burn with the use of their thermal energy, with the non-toxic exhaust gases after thermal decomposition being captured by countercurrent burning through the ground mixture of raw materials and the resulting clinker, and the ash formed from bone minerals after combustion will react quantitatively to the mass of clinker, with the mineralizing effect of phosphorus oxide P2O5 on the formation of clinker phases, with the content of up to 2% of phosphorus oxide P2O5 in clinker, obtained from ash from meat-bone meal or organic waste containing bones on firing has a mineralizing effect on clinker formation, preferably keeping the phosphorus oxide P2O5 content in the clinker at up to 0.5%.

exhaust fumes

PL 197 240 B1

Description of the invention

The invention relates to a method for the disposal of processed organic waste by incineration in a cement rotary kiln, in particular for the disposal of meat and bone meals, fats and other processed animal veterinary waste.

The elimination of dangerous, biologically contaminated organic substrates, the introduction of which into the food circulation and food production is prohibited, is very topical nowadays. Animal waste is processed in sanitation plants, known as tilers, into meat and bone meal and animal fats, or other products. Large amounts of this waste in the form of bones and viscera are a product of the meat industry, as bones make up about one fifth of the weight of an animal. A significant group of risky waste is also created by dead animals infected with various diseases, including the currently problematic BSE disease, known as mad cow disease.

BSE disease (beef spongial encephalopathy) was caused by the feeding of infected meat and bone meal in compound feed containing pathological protein particles - prions, which was fed to cattle as an important source of protein, without prior high temperature treatment. Pathological prions cause severe degenerative diseases of the nervous system in humans, known as a new variant of Creutzfeldt-Jacob disease, and in animals known as BSE (Beat Type Spongial Encephalopathy) - Mad Cow Disease and TSE (Transmission Spongy Encephalopathy) known as sheep foot-and-mouth disease. Diseases caused by prion have been found in 20 animal species, including man. The immune system cannot recognize the pathogenic prions, and the disease uncontrollably spreads throughout the body, resulting in brain degeneration and death. In the case of farm animals, in the event of this disease being diagnosed, the entire herd must be liquidated.

Currently, there is no effective drug or vaccination against these diseases, prions are very resistant, survive in the environment and are difficult to neutralize with normal disinfectants. The only possible protection against the spread of these diseases is the elimination of meat and bone meals from risky animal waste by burning them.

Under normal conditions of municipal waste incineration plants, where temperatures of 700 ° - 900 ° C, max. 1200 ° C are obtained, there is a risk of imperfect combustion of organic carbon from meat and bone meals and the problem of using waste ash. The energy potential of meals during combustion in normal combustion chambers is not utilized. Elimination of meat and bone meal with improper technology may cause further environmental problems related to imperfect combustion, the result of which may be the formation of toxic exhaust gases with the content of CO, C soot, organic sulfur compounds, dioxins, furans, HCN, in the reducing atmosphere of H2S and the presence of organic additive compounds halogens, which are a significant environmental burden.

The result of perfect combustion of organic waste should be flue gases with CO2, SO2, NOx, H2O, hydrogen halides and ash that is harmless to health.

The problem of neutralizing hazardous biological waste by incineration in combustion chambers of various designs is solved by many patents. The waste is, for example, incinerated in grate furnaces according to the published international patent application WO 9500804, possibly in fluidized layers according to CS AO 214859, SK 278 599, DE 4414579, in the form of various pellets according to US 5 001 993, or as solid or liquid waste according to FR 2 661 734, in various design variants of incineration devices EP 0751347, WO 9626021, US 3782301. However, these patented solutions do not provide methods for the disposal of ashes resulting from the incineration of pathogenic animal waste and do not use the energy potential for the incineration of some types of waste.

The burning of animal bones in a suitably adapted device at temperatures of about 650 ° C solves US 4,000,705, with the formation of ash and volatile hydrocarbons that can be condensed, released into the atmosphere or burned.

The use of meat-and-bone meal as an additional fuel for fluidized combustion of mechanically dehydrated waste wastes at temperatures of 850 ° to 1150 ° C is disclosed in the published international patent application WO 9952830.

The high-temperature mass incineration of hazardous waste in blast furnaces with temperatures around 2000 ° C around the bottom of the kiln is described in patent CZ 284 954. Waste

They are added to the furnace charge and are thrown into the furnace from above, where, under the influence of high temperatures, they are heated in the opposite direction by the flowing blast furnace gas. In this process, partial melting of the charge occurs, formation of blast furnace gas, pyrolysis and formation of pyrolysis products. The blast furnace gas contaminated with pyrolysis products is discharged for incineration in a second blast furnace. The disadvantage of this solution is that the fine-grained contaminated material may contaminate the area from the charge, e.g. due to unfavorable weather conditions, in the event of a failure, pyrolysis products may enter the atmosphere, gaseous SO2, HCl, HF are not captured as waste, blast furnace slag is formed as a natural waste of iron production technology.

The incineration of pellet solid combustible waste as additional fuel in a rotary cement kiln is described in US Patent 5,724,899. The pellets are delivered to the kiln with a special device placed on the kiln shell and they burn practically before entering the sintering zone, thus creating a secondary furnace within the rotary cement kiln. In this way, however, there is a risk of contamination of the cement kiln dust in the form of imperfectly burned contaminated material resulting from the decomposition of the burning pellets, which is carried away by the flue gas at a high flow rate, since the pellets are not added to the kiln at the highest temperature zones. sintering zone in which addition to the furnace through the plating is practically not possible due to high temperatures and the formation of lumps.

The patent EP 0501944 solves the use of waste preheated air from industrial cooling devices, such as a cement clinker cooler, for the combustion of biological waste, but the problem of the ash generated is likewise not solved here.

The disadvantage of the prior art in the field of disposal of biological waste, especially such as meat and bone meal and other processed animal substrates, is generally insufficiently effective, ecological and economic disposal by combustion in ordinary combustion chambers, where there is a possibility of formation of toxic compounds as a result of imperfect combustion, without the economic use of calorific value, and problems related to the use or disposal of ash from incinerated waste.

The aim of the present invention is the safe, hygienic, ecological, waste-free and economical disposal of meat and bone meals and other processed animal wastes from the tiling with possible microbiological negative impact on living organisms, by burning as an alternative fuel in rotary cement kilns.

This goal has been achieved by the method of disposal, according to the invention, of processed organic waste, especially meat and bone meal, waste fats and other processed veterinary waste of animal origin by burning in a rotary cement kiln heated in the process of burning clinker with noble fuel, in which the waste is added. to the cement kiln through the main burner and / or calcination burner directly into the flame and / or through the auxiliary burner into the flame at 1900 ° to 2000 ° C and / or into the hot part of the rotary kiln at 1400 ° to 1900 ° C. The essence of the invention lies in the fact that part of the heating value of a noble fuel or a blend of noble fuels, or a blend containing noble and alternative fuels will be replaced with meat and bone meal, waste fat and / or other processed waste of animal origin, which at high temperatures and oxidizing atmosphere in a furnace with excess combustion air they will burn out using their heating value, while the non-toxic flue gases after perfect thermal destruction will be partially captured by countercurrent firing on the ground mixture of raw materials and the resulting clinker, and the ash resulting from bone minerals will react quantitatively to the mass after combustion clinker with the mineralizing effect of phosphorus oxide P2O5 on the formation of clinker phases.

It is preferable to use the mineralizing effect of phosphorus oxide from the meat and bone meal ash on clinker formation when calcined to a content of 2% phosphorus oxide P2O5 in the clinker, preferably up to 0.5% phosphorus oxide P2O5 in the clinker obtained.

It is also advantageous that the added processed organic waste has a minimum calorific value of 11 MJ / kg, preferably more than 20 MJ / kg and contains a maximum of 50% by weight of ash with a maximum moisture of 50%, preferably less than 10%.

The advantages also include the fact that part of the calorific value of the noble fuel or a blend of noble fuels, or a blend containing noble and alternative fuels, is replaced by meat meal4

40%, preferably up to 5%, or waste fat up to a maximum of 90%, preferably 30%, where appropriate.

It may also be advantageous that part of the calorific value of the noble fuel or a mixture of noble fuels, or a blend containing noble and alternative fuels, is replaced with a mixture of meat and bone meal and waste fat, or other organic waste of animal origin in any proportions up to max. 90%.

At high temperatures obtained during the burning of clinker in an oxidizing atmosphere with an excess of combustion air and a sufficiently long retention time of the flue gases and the fired material in the cement rotary kiln, complete thermal decomposition of all organic substances occurs without the possibility of the formation of toxic fumes.

The counter-current flow of material and exhaust gases and their sufficiently long retention time in the cement rotary kiln-heat exchanger system ensures the binding of gaseous acid chlorine, fluorine and sulfur compounds with the alkaline mixture of raw materials with the formation of alkaline compounds, which are then bound with the structure of the resulting clinker in the firing process .

The result of firing is non-toxic exhaust gas with carbon dioxide CO2, nitrogen oxides NOx, water vapor H2O and oxygen O2, and with a low content of sulfur oxide SO2 and hydrogen halides. High combustion temperatures, a sufficiently long exposure time, excellent decomposition of organic substances, their oxidation in excess O2 and the general technological solution of the cement rotary kiln do not allow the formation of toxic flue gases containing dangerous dioxins, furans and other organic compounds, as can be observed in conventional waste incineration plants .

An important advantage of burning organic substrates of animal origin, especially meat and bone meals and bone-containing waste, in cement rotary kilns is the immediate elimination of the ash formed by its quantitative reaction to the structure of the clinker phases as a result of chemical reactions and physical processes, whereby the waste becomes their inherent nature part.

One of the main advantages of burning meat and bone meal and other organic waste, especially processed animal waste with a minimum calorific value of 11 MJ / kg, with a maximum moisture content of 50% and an ash content of up to 50%, e.g. waste animal fats from the risky group animals, there is the saving of noble fuels normally used in cement technology (natural gas, heating oils, coal). These wastes are used as alternative fuels to a certain extent so that it does not have a negative impact on the technological process of clinker burning and the overall quality of the cement produced. In the case of meat-and-bone meal, it is a replacement of noble fuel in the range of up to 40%, usually up to 5%, in the case of waste fat, the range is wider, and in the case of appropriate burner changes, it is even possible to dose waste fat higher than 70% as a substitute fuel for sufficiently heated furnace, due to the fact that the fat has a calorific value comparable to the calorific value of noble fuels and practically zero ash content.

In the burning of the clinker, an alternative fuel is preferably used as an alternative fuel of a mixture of meat and bone meal and waste animal fat, which is an easily transportable slurry.

The factor limiting the amount of meat and bone meal used as an alternative fuel in the burning of cement clinker is the content of phosphorus oxide P2O5 in the ash and, consequently, in the clinker. The amount of phosphorus oxide P2O5 in the clinker ranges from a trace level to 1.5%, typically from 0.05 to 0.25%. A concentration above 0.5% can sometimes cause serious quality problems and reduce the strength of the cement, especially in the earlier stage of maturation. Additions of phosphorus oxide P2O5 above 0.5% stabilize C2S at the expense of C3S, which is the most important clinker material from the point of view of strength, or break down C3S into C2S dicalcius silicate and CaO calcium oxide. Concentration up to 0.5% phosphorus oxide P2O5 significantly increases the initial strength (due to the high hygroscopicity C3S), and the concentration to 2% of an oxide of phosphorus P 2 O ₅ is obtained sufficient strength cement, whereas at higher concentrations than 2%, the strength is lowered. The amount of phosphorus oxide P2O ₅ in clinker up to 2% mineralizes the overall clinker formation process and improves the clinker grinding properties.

The variability of the ash composition does not create any exceptional requirements for the homogenization of meat and bone meal or other processed organic waste of animal origin. The composition of the ash does not require chemical changes or minimal corrections of the chemical system in terms of the content of calcium oxide CaO during the preparation of the raw material mixture.

PL 197 240 B1

Perfect combustion of animal waste into non-toxic flue gases and quantitative binding of ash with clinker does not create the need for constant monitoring and control of the generated flue gases.

The subject of the invention in the embodiments is shown in the drawing schematically showing a cement rotary kiln adapted for the disposal of treated organic waste according to the invention on the basis of example 2.

P r z k ł a d 1

In the rotary cement kiln 1 with a capacity of 1700 t of clinker per day, meat and bone meal was burnt in an amount of up to 5% of the calorific value equivalent of noble fuel (natural gas with a calorific value of 33.5 MJ.m ³ ). Meat and bone meal was led through the main burner 4 to the flame, where it underwent complete thermal decomposition. In clinker, an increase in P2O5 content was observed from the original 0.15% to 0.4% P2O5. During firing, an increase in hourly productivity by approx. 3% was observed. The cement obtained after grinding the thus prepared clinker and the setting regulator did not show any deviation from the normal properties, the cement solutions did not contain higher amounts of heavy metals. The flue gas from the heat exchanger did not contain any toxic compounds, and no ash from the combusted organic substrates was detected in the dust.

P r z k ł a d 2

In a rotary cement kiln 1 with a pre-calcining channel 2 with a capacity of 1700 t of clinker per day, waste animal fat from tiling in an amount up to 30% of the calorific value equivalent of noble fuel (heavy fuel oil with a calorific value of 40 MJ.kg ¹ ) was burned. The preheated mixture of waste animal fat and heavy fuel oil was led through a burner 5 into the flame in the precalcining duct 2 between the heat exchanger 3 and the rotary kiln 1, where it underwent complete thermal decomposition. No performance degradation or any technological issues were observed. The cement obtained after grinding the thus prepared clinker and the setting regulator did not show any deviation from the normal properties, the cement solutions did not contain increased amounts of heavy metals. The exhaust gas from the heat exchanger did not contain any toxic compounds.

P r z k ł a d 3

In a rotary cement kiln 1 with a capacity of 1700 t of clinker per day, a mixture of waste meat and bone meal and waste animal fat in a weight ratio of 1: 1 in the amount of up to 200 kg per hour was burned. The preheated mix was fed through the auxiliary burner 6 to the hot portion of the rotary kiln sintering string 1 where it was completely thermally decomposed. In clinker, an increase in P2O5 content was observed from the original 0.15% to 0.18% P2O5. The cement obtained after grinding the clinker obtained in this way and the concentration regulator did not show any deviations from the normal properties, the cement solutions did not contain an increased amount of heavy metals. The exhaust gas with the heat exchanger did not contain any toxic compounds, and no ash from the combusted organic substrates was detected in the dust.

The given examples are only an illustration of the possibilities and do not exhaust all options for the disposal of processed organic waste, especially animal origin, as alternative fuels.

Claims (4)

Patent claims 1. Methods for the disposal of processed organic waste by burning in a rotary cement kiln heated in the process of burning clinker with noble fuel or a mixture of noble fuels or a mixture containing precious and alternative fuels, in which organic waste is added to the cement kiln through the main burner and / or calcination burner directly to the flame and / or through an auxiliary burner to a flame with a temperature of 1900 ° to 2000 ° C and / or to the hot part of the furnace with temperatures of 1400 ° to 1900 ° C, characterized in that part of the calorific value of the noble fuel or fuel mixture noble or a mixture containing precious and alternative fuels is replaced with organic waste, having a minimum calorific value of 11 MJ / kg, preferably more than 20 MJ / kg, and containing a maximum of 50% by weight of ash with a maximum moisture of 50%, preferably less than 10%, preferably with flour meat and bone, waste fat and / or other processed waste from believers that burn at high temperatures and in an oxidizing atmosphere with an excess of combustion air using After the thermal decomposition, non-toxic combustion gases are captured by the ground mixture of raw materials and the resulting clinker, and the ash formed from bone minerals after combustion will quantitatively react to the mass of clinker, with the mineralizing effect of phosphorus oxide P2O5 on the formation of clinker phases, with the content of up to 2% of phosphorus oxide P2O5 in clinker, obtained from ash from meat-and-bone meals or organic waste containing bone, during firing has a mineralizing effect on the formation of clinker, preferably while maintaining the content of phosphorus oxide P2O5 in the clinker at the level of 0.5%. 2. The method according to p. 1, in that a part of the value of noble pallwa or a blend of noble fuels or a blend containing noble and alternative fuels is replaced with meat and bone meal up to a maximum of 40%, preferably up to 5%. 3. The method according to napl. 1, zi ^ jami ^ i ^ i ^ Ą / the fact that part of the value o | ^^ ł <^ \ ^^ j pallwa εζ ^ οήβΐ ^ βοο or mixtures of precious and alternative fuels are replaced with waste fat up to a maximum of 90%, preferably 30%. 4. The method according to napl. 1, zi ^ jami ^ i ^ i ^ Ą / the fact that part of the value o | ^^ ł <^ \ ^^ j pallwa chiacet or a mixture of precious fuels or a mixture containing precious and alternative fuels is replaced with a mixture of meat and bone meal and Waste fat or other organic waste of animal origin in any proportion to a maximum of 90%.