Compressed fuel composed of renewable organic residues and/or raw materials and production thereof

Abstract

The invention relates to a compressed fuel composed of organic residues and/or raw materials having at least one additive for increasing the calorific value and for decreasing slag formation, which fuel consists of a fuel mixture which contains a) 72 to 83% by weight combustible organic residues and/or raw materials having a moisture of 8 to 20%, b) 15 to 25% by weight natural organic oils and/or fats for increasing the calorific value and c) 2 to 3% by weight sodium perborate for increasing the ash melting point and as oxygen supplier. As organic residues and/or raw materials, use is made of comminuted and naturally aged or artificially aged (by UV irradiation or by the addition of 0.1-0.3% by weight of age-promoting UV additives or UV absorbers) cereal straw of all types, sugar cane, bamboo, cotton plants, jute, sisal, hemp, ramie, rice straw, rice husks, Chinese silver grass, elephant grass, flax, coconut, kenaf, or esparto grass, into which, for improving penetrability, the oil and/or fat fraction with admixed surfactant fraction of 1-5% by weight based on the oil/fat fraction is added. In addition, the fuel mixture can contain 0.4-0.6% by weight of hexamethylenetetramine for supporting ignition and burning acceleration and soot reduction, and also 1.0-1.5 lignin for solidification. This fuel has scarcely any tendency to slag formation, has good burn-up behavior and a calorific value of 6.8 kWh/kg, wherein the exhaust gas is free of fine dust and contains scarcely any measurable pollutants.

1 . Compressed fuel composed of organic residues and/or raw materials, having at least one additive, to increase its heating value, and to reduce the formation of slag, wherein the fuel mixture consists of
 72 to 83 wt.- % combustible organic residues and/or raw materials, having a moisture of 8 to 20%,   15 to 25 wt.- % natural organic oils and/or fats,   to increase the heating value, and   2 to 3 wt.- % sodium perborate to increase the ash melting point and as an oxygen supplier.   
   
   
       2 . Compressed fuel according to  claim 1 , wherein the fuel mixture contains 0.4 to 0.6 wt.- % hexamenthylene tetramine, with reference to the total mass. 
   
   
       3 . Compressed fuel according to  claim 1 , wherein the fuel mixture contains 1.0 to 1.5% lignine, with reference to the total mass. 
   
   
       4 . Compressed fuel according to  claim 1 , wherein the fuel mixture contains up to 3%, with reference to the total mass, of another powdered additive or an additive dissolved in water, having a pH≧7, to raise the ash softening point. 
   
   
       5 . Compressed fuel according to  claim 4 , wherein the additive is borax or sodium metasilicate or trisodium octaborate or zinc borate or trisodium phosphate or ammonium sulfate. 
   
   
       6 . Compressed fuel according to  claim 1 , wherein the organic residues and/or raw materials used are grain straw of all kinds, sugar cane, bamboo, cotton bushes, jute, sisal, hemp, ramie, rice straw, rice shells, Chinese silver grass, elephant grass, flax, coconut, kenaf, or alfa grass. 
   
   
       7 . Compressed fuel according to  claim 1 , wherein the fuel mixture proportion of the organic residues and/or raw materials contains 50-58 wt.- % organic residues and/or raw materials and 22-25 wt.- % rapeseed cake. 
   
   
       8 . Compressed fuel according to  claim 1 , wherein the fuel mixture proportion of natural organic oils and/or fats contains 3-21 wt.- % of natural organic oils and/or fats and 2-4 wt.- % fusel oil. 
   
   
       9 . Compressed fuel according to  claim 8 , wherein the fusel oils are homologs of ethyl alcohol or higher alcohols, such as amyl alcohol. 
   
   
       10 . Compressed fuel according to  claim 1 , wherein the fuel mixture contains 1.5 to 3 wt.- % of an odor improving agent, with reference to the oil component. 
   
   
       11 . Compressed fuel according to  claim 10 , wherein the odor improving agent is an ether oil that is soluble in oil. 
   
   
       12 . Compressed fuel according to  claim 11 , wherein the ether oil is a pine needle oil or clove oil or citrus oil or forest fragrance oil. 
   
   
       13 . Compressed fuel according to  claim 1 , wherein the fuel mixture contains 1.5 to 3 wt.- % of an air pore forming agent, with reference to the total mass of the fuel mixture. 
   
   
       14 . Compressed fuel according to  claim 13 , wherein the air pore forming agent is a powdered sodium lauryl sulfate or sodium dodecyl sulfate, or a sodium lauryl sulfate or sodium dodecyl sulfate dissolved in water, having a pH≧7. 
   
   
       15 . Compressed fuel according to  claim 1 , wherein the organic residues and/or raw materials are naturally aged new raw materials or used raw materials, such as gray straw, for example, which have been stored appropriately for their use. 
   
   
       16 . Compressed fuel according to  claim 1 , wherein the organic residues and/or raw materials have been artificially aged, appropriately for their use. 
   
   
       17 . Compressed fuel according to  claim 16 , wherein for artificial aging, 0.1 to 3.0 wt.- %, with reference to the mass of the organic residues and/or raw materials, of a UV absorber, or a UV additive that promotes aging are added to the organic residues and/or raw materials. 
   
   
       18 . Compressed fuel according to  claim 16 , wherein for artificial aging, the organic residues and/or raw materials are pretreated with UV radiation. 
   
   
       19 . Compressed fuel according to  claim 1 , wherein the shredded residue and/or raw material component, from which the dust has been removed, was vacuum-impregnated with an oil and/or fat component that was metered in, or the finished, mixed fuel mixture was subjected to vacuum impregnation before pelleting. 
   
   
       20 . Compressed fuel according to  claim 1 , wherein the fuel mixture contains an additive of 1-5 wt.- %, with reference to the oil component, of surfactants having a pH≧7. 
   
   
       21 . Compressed fuel according to  claim 20 , wherein the surfactants mixed in are from the group of ampholytic or amphoteric surfactants. 
   
   
       22 . Compressed fuel according to  claim 21 , wherein a fatty acid base composed of coconut oil or palm oil or jatropha oil is preferably used as ampholytic or amphoteric surfactants. 
   
   
       23 . Compressed fuel according to  claim 1 , wherein the added oil and/or fat component has a temperature ≧60° C. 
   
   
       24 . Compressed fuel according to  claim 1 , wherein the fuel is preferably compressed into fuel bodies at a compressing pressure between 200 to 250 bar. 
   
   
       25 . Compressed fuel according to  claim 1 , wherein all the additives lie in an alkaline range (pH 7), are non-toxic and biodegradable. 
   
   
       26 . Method for the production of a compressed fuel composed of organic residues and raw materials, according to  claim 1 , wherein
 the organic residues and raw materials, by themselves or in a mixture, having a moisture of 8 to 20%, are cleaned of foreign bodies, dust, and waste, and are shredded,   the shredded residues and raw materials are freed of dust by way of an exhaust air filter, and metered into the components of the other substances to be mixed in, at a previously determined percentage ratio, in a mixing and metering device,   the oil and/or fat component is metered into the component of the residues and raw materials metered into the mixing and metering device, at a temperature of ≧60° C., and the liquid components of the air pore forming agents and/or fusel oils and/or substances that raise the ash melting point, in aqueous solution, are metered in, by themselves or mixed with the oil and fat component,   subsequently, the powdered and/or granulate components of the sodium perborate and/or hexamethylene tetramine and/or lignine and/or substances that raise the ash melting point and/or air pore forming agents are metered in, in powder form, by themselves or in a premixed batch, and   afterwards, the fuel components are mixed in the mixing and metering device, to form a homogeneous fuel mixture, and the homogeneous fuel mixture is passed to a pelleting press, in metered form, where it is compressed into fuel bodies, preferably at a compressing pressure of 200 to 250 bar.   
   
   
       27 . Method according to  claim 26 , wherein the residues and/or raw materials that have been shredded and freed of dust are put into intermediate storage in a metering silo, and passed to the mixing and metering unit in metered form. 
   
   
       28 . Method according to  claim 26 , wherein naturally aged organic residues and/or raw materials are used for production of the fuel. 
   
   
       29 . Method according to  claim 26 , wherein the shredded organic residues and/or raw materials are irradiated with UV radiation after the dust has been removed, and then stay in a silo for the aging period, or alternatively, wherein the shredded organic residues and/or raw materials are mixed with a UV additive that promotes aging, or a UV absorber, at 0.1-0.3 wt.- % with reference to the mass of the residue and/or raw material, after the dust has been removed, and then stay in a silo for the aging period. 
   
   
       30 . Method according to  claim 26 , wherein the metering silo is used for the artificial aging period, and the metering silo is designed to have a storage capacity that allows continuous implementation of the process, when adhering to the aging period. 
   
   
       31 . Method according to  claim 26 , wherein the oil and/or fat component is passed to the mixing and metering device with a component of 1-5 wt.- % surfactants, with reference to the oil and/or fat component, mixed in. 
   
   
       32 . Method according to  claim 26 , wherein the shredded residues and/or raw materials are vacuum-impregnated with the oil and/or fat component that is metered in, or the homogeneously mixed fuel mixture is vacuum-impregnated before pelleting. 
   
   
       33 . Method according to  claim 26 , wherein the air transport of the shredded residue and/or raw material to the exhaust air filter is carried out with heated air, for moisture equalization. 
   
   
       34 . Method according to  claim 26 , wherein in order to maintain the percentage composition of the fuel mixtures, the amount units of liquid and powdered or granulate substances metered into the mixing and metering unit are regulated volumetrically or gravimetrically, as a function of the mass of the residues and/or raw materials metered in.