DE3329771A1 - Immobilisation of pollutants in the preparation of briquettes from organic products or waste products such as, for example, domestic refuse, sewage sludge and industrial hazardous waste - Google Patents

Abstract

To reduce the emission of pollutants in the thermal treatment (incineration, gasification, pyrolysis) of briquettes of organic products and waste products and to reduce the leachability of the residues, inorganic additives are added in the preparation of the briquettes. With utilisation of exothermic heat of reaction and under pressure, chemical reactions are initiated and accelerated during the pressing step, so that chemical binding of pollutants takes place during pressing and during the pyrolysis and/or incineration to give sparingly soluble minerals, mixed oxides and natural or technical silicates.

Description

title

Binding of harmful substances in the production of briquettes from organic Products or waste products such as

Household waste, sewage sludge and special industrial waste.

Field of application The invention relates to the binding of pollutants (chlorine, Sulfur, fluorite, phosphate, heavy metals) in the manufacture of briquette any Shaping under high pressure from garbage, sewage sludge and other organic substances or waste products through the addition of suitable inorganic additives and initiation chemical reactions at elevated temperatures in the pressing process.

Purpose: For the universal use of such briquettes made from garbage (e.g. House fires, for industrial firing, for generating generators and synthesis gas, for Generation of methane or U1> ...) is next to setting a constant Helzwert above all ensures low pollutant emissions in the Use, as well as a firm binding of the existing pollutants in the residues necessary.

State of the art: The state of the art can be assumed to be known will.

Latest development of Mannesmann-Veba (research report T79-102 BMFT, VDI Nachrichten 31, from July 30/31, 1982) lead to a briquette with a chlorine content of 0.2 -6s6Z and a sulfur content of Q.2 - 0.45X. These procedures will be no inorganic additives were added to the starting substance, but the inorganic ones Components of the garbage are moreover 50 widespread. separated as possible.

Criticism of the state of the art: The relatively high levels of sulfur and especially of chlorine drastically increase the boiler corrosion and require for Keeping the air clean is usually a smoke gas scrubber.

At such high concentrations it is still not possible to do additional To use hazardous waste for the production of the briquettes without the limit values of the legal Exceeding regulations. With the relatively high proportion of heavy metals in the garbage, It is especially necessary in sewage sludge and in special industrial waste Substances insoluble in water as far as possible in the residues (ash, pyrolysis coke) to tie.

Task: The invention is based on the task of using suitable Surcharges for the production of briquettes from organic products or waste products to achieve a chemical bond of existing pollutants and thereby the emission of pollutants and the leachability of heavy metal salts from the residues to minimize.

Solution: This object is achieved according to the invention in that in Inorganic compounds are added to the product preparation after the comminution and a variety of chemical reactions utilizing exothermic heat of reaction and initiated under high pressure (more than 1000 bar). By adding inorganic compounds (CaO, MgO, MgCO3, silicates, Al203) finds a chemical Binding of harmful substances during the pressing process (> -1000 bar> 100 0C) and during the Pyrolysis or combustion to form sparingly soluble minerals, mixed oxides and natural ones respectively.

technical silicates instead.

Achievable advantages: The particular economic value of the invention is due to the fact that waste, sewage sludge, processed according to this process or industrial hazardous waste from thermal treatment without additional flue gas cleaning Can be supplied, This results in high investment costs and high operating costs saved for flue gas cleaning. Due to the presence of heavy metals in the residues they can be used in many ways or can be stored safely.

Claims (1)

Patent claims binding of harmful substances in the production of briquettes from organic products or waste products characterized in that by Adding inorganic compounds (CaO, MgO, MgCO3, silicates, Al2O3) a chemical Binding of pollutants during the pressing process or during pyrolysis / combustion takes place namely - through the formation of naturally occurring minerals and salts (e.g. CaSO4, MgSO4, CaCl2, CaF2, Ca-Phosphate), - through the formation of mixed oxides of Ca, Mg, Al with oxides (or salts) of other metals (e.g. Ni, Co> Fe, Pb, Cd), " through formation of silicate with metal salts (e.g. of Fe-, Mn-, Sn-, Cr-, Co-, Ba-, Zn-, Ni, Pb, Ti, Be, Li-Cd salts) to poorly soluble, naturally occurring or technical silicates. 2e characterized in that at very high pressure (> 1000 bar) and at temperatures of over 100 ° C due to friction and additional exothermic Heating the desired chemical reactions are initiated and accelerated expire; 3. characterized in that the addition described inorganic Compounds in the combustion gases achieved far lower concentrations of pollutants than in other fossil fuels and briquettes from household waste. Table total chlorine sulfur Bricollet from household 1) waste and 10% Sewage sludge (according to the above <0.1% 0.04% method) Table total chlorine Sulfur coal 1) 0.1% 0.8-1.5% heating oil EL 1) <0.1% 0.5% heating oil S 1) 0.1% 2.8X 2) Briquette according to the Mannesmann-Veba method 0.2-0.6 0.2-0.45 using Eco-Fuel II (USA) 0.1-0.7 0.1-0.6 1) Expert opinion of a publicly appointed and sworn trading scheme kers 2) VDI-Nachrichten 31, 30./31.7.1982 3) Research report T 79-102 of the BMFT 4. characterized in that an Auslau.gbarkeit the existing in the starting products Heavy metals from the residues of the thermal treatment are almost completely prevented is (<ppb range) and the residues are recycled without endangering the environment can be.