RU2326900C1 - Processing of organic carbonaceous waste and carbonaceous moulding - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention concerns obtaining of moulded fuel, particularly of carbonaceous mouldings in the briquette or pellet form made of organic carbonaceous waste. Additionally, carbonaceous mouldings can be used in agriculture as fertiliser and/or soil structure-forming agent. The process involves proportioning, activation mixing of the components, activated component moulding under the pressure of 120 MPa to obtain carbonaceous mouldings. Organic carbonaceous waste includes lignine and/or sewage treatment sediments, and/or animal manure, and/or bird droppings. The components or their mix are dried to 40% dampness before moulding, either by direct contact with drying medium containing up to 14 mass % of oxygen with the components or their mix; or without direct contact with the drying medium heated up to 500°C.

EFFECT: fast adhesion of organic carbonaceous component particles in mouldings and higher moulding solidity due to the optimal component dampness and moulding pressure.

4 cl, 1 tbl, 2 ex

Description

The invention relates to the production of molded fuel, and more specifically to the production of carbon-containing moldings in the form of briquettes or pellets from organic carbon-containing waste, which can be used as a substitute for natural solid fuel. In addition, these carbon-containing moldings can also be used as fertilizers and / or soil builders in agriculture.

Known solid solid fuel (briquetted, extruded or granular) that can be used for domestic purposes, as well as in industry, partially solving the problem of reducing environmental pollution by waste (RU 2131449 C1, 1998, IPC S10L 5/14) .

This molded fuel is based on a dried mixture of ground solid fuel and condensed sludge from wastewater treatment plants. Such a molded fuel contains condensed sludge with a water content of 5-14 wt.% And crushed solid fuel selected from the group consisting of wood, vegetable waste, lignin, peat, coke or coal fines, textile waste or mixtures thereof (RF patent No. 2131449) .

Such a molded fuel, to ensure mechanical strength, requires drying of the finished moldings (rather than finely divided components). This leads to high energy costs and higher cost of waste processing.

The closest to the claimed invention are carbonaceous molding used as a substitute for natural solid fuel for municipal and industrial needs, as well as fertilizers and / or soil structurant in agriculture (RU 2246530 C1, 2003, IPC ⁷ S10L 5/02 ) Carbon-containing moldings contain ground peat and / or lignin and woody plant components in the form of sawdust and / or wood chips and / or bark and / or straw and / or husk seeds and / or oilcake and / or stalks, and / or leaves of plants and / or animal components in the form of bird droppings and / or manure and a binder, which is used as quicklime or caustic soda or potassium hydroxide. The binder is introduced in an amount of 1-10 wt.%. Activation of peat and / or lignin and binders was understood to mean the achievement of such a combination of effects as an increase in the surface of solid particles due to their additional grinding in the activator, homogenization of the mixture, and partial drying of the mixture.

In carbon-containing moldings, additional chemicals are used to form an adhesive substance, and they also use the double mixing process, the aging process, which complicates the technology and increases the cost of waste processing.

A known method of producing a molded fuel, which includes dosing and mixing condensed activated sludge from wastewater treatment plants and ground solid fuel, molding the mixture and subsequent drying of the moldings (RF patent No. 2131449). For mixing using condensed activated sludge with a water content of 70-80 wt.%. The mixture is molded at a pressure of 0.1-25 MPa. Dry moldings at 50-180 ° C or at ambient temperature. Molded fuel contains condensed sludge with a water content of 5-14%.

This method leads to high energy costs, since the drying is carried out not of finely dispersed components, but of moldings, which leads to high energy and financial costs in waste processing.

Closest to the claimed is a method of manufacturing carbon-containing molds, which includes dosing, mixing, grinding and activating peat and / or lignin with a binder, then add wood-vegetable and / or animal components, re-mix and the resulting mixture is molded into moldings, which are then strengthened by aging them for 2-30 hours (patent RU 2246530 C1, 2003, IPC ⁷ C10L 5/02).

The binder additive, evenly distributed in the volume of peat and / or lignin, leads to an exothermic reaction, as a result of which the mixture is heated and adhesive humates are formed that stick together the particles of the mixture during molding. Then wood-vegetable and / or animal waste is introduced into this mixture.

For the formation of an adhesive substance, additional chemicals are used, the process of double mixing of the components and aging of the moldings, this complicates the technology and reduces the productivity of the technology and ultimately increases the cost of waste processing.

The basis of the invention is the task of simplifying the technology and reducing the cost of processing organic, carbon-containing waste having an energy potential, without losing the properties of organic waste burn and / or improve soil fertility and soil structure.

This task is especially relevant when there is a need for the speedy elimination of the accumulation of large quantities of various organic wastes, the decomposition products of which the environment is poisoned.

The technical result is the provision of strong adhesive adhesion of particles of organic carbon-containing components in the moldings, increasing the strength of the moldings due to the optimal moisture content of the components and molding pressure.

The problem is solved in that in a method for processing organic carbon-containing waste having an energy potential, to burn and / or improve soil fertility and its structure, without loss of the properties of organic waste, into carbon-containing moldings, including dosing of components in the form of organic carbon-containing waste, mixing-activation, molding of activated components to obtain carbon-containing moldings, organic carbon-containing biological waste products are used as components origin, such as sludge from wastewater treatment, and / or animal manure, and / or bird droppings, and / or lignin, or mixtures thereof in any combination, and to ensure the adhesion of particles in the obtained carbon-containing moldings before molding each component or their the mixture is dried to a moisture content of not more than 40%, and molding is carried out at a pressure of not more than 120 MPa, which ensures strong adhesive adhesion of the particles.

It is also advisable to carry out the drying by direct contact of the drying agent with the drained components or their mixture, while the drying agent should contain oxygen in an amount of not more than 14 wt.%, Which excludes spontaneous combustion of any of the drained components or their mixture during the drying process.

It is also advisable to carry out the drying without direct contact of the drying agent with the drained components at a temperature not exceeding 500 ° C, while the pressure in the drying chamber may be lower than atmospheric.

In addition, it is advisable that when mixing-activating the components, additives from solid combustible waste are additionally added with a moisture content of not more than 70% in an amount of not more than 70 wt.%. As solid combustible waste, it is advisable to use screenings of peat, sawdust, bark, straw, floor, husk of seeds, oilcake, leaves and stems of plants, the combustible part of municipal solid waste in any combination thereof.

The problem is also solved by obtaining carbon-containing moldings.

The method is as follows.

Organic waste of biological origin, including components such as lignin, and / or sewage sludge, and / or animal manure and / or bird droppings, is dried using a drying agent.

The drying agent in contact with the drained components or their mixture contains oxygen in an amount of not more than 14 wt.%, Such a concentration of oxygen in the drying agent does not allow spontaneous combustion of the drained components or their mixture during drying.

When drying the components or their mixtures without direct contact with the drying agent and air in the drying chamber at a temperature of no higher than 500 ° С, the oxygen content in the drying agent is not required to be limited, since in this case neither oxygen of the drying agent nor air oxygen in the drying zone does not come into contact with drained components or their mixtures, spontaneous combustion of components or their mixtures is impossible. It is possible to carry out more intensive drying by maintaining the pressure in the drying chamber below atmospheric.

Each component of organic waste or their mixture is dried to a moisture content of not more than 40%, molding is carried out at a pressure of up to 120 MPa, which provides strong adhesive adhesion of the particles of the components in the moldings.

It was experimentally established that to ensure strong adhesive adhesion of particles of components or mixtures of organic carbon-containing waste of biological origin, including components such as lignin, and / or sediment from wastewater treatment, and / or animal manure, and / or bird droppings, or mixtures thereof in any combination, the humidity of any of the components or their mixtures after drying should be no more than 40%, and the molding pressure not more than 120 MPa.

The components or mixtures thereof are also dried using a drying agent, which, in contact with the components to be dried or their mixture, contains oxygen in an amount of not more than 14 wt.%. This concentration of oxygen does not allow spontaneous combustion of components or their mixtures.

The components or mixtures thereof are dried to a moisture content of not more than 40%.

The resulting dried components or mixtures thereof in any combination and ratio are molded into carbon-containing moldings.

Molding can be carried out on roller, stamping, extruder, hydraulic presses and granulators, and moldings in the form of briquettes, granules or pellets are obtained.

The molding is carried out at ambient temperature and pressure up to 120 MPa.

The obtained carbon-containing moldings have high mechanical strength, and the cost of their production is relatively low.

Examples of specific implementation of the method.

Example 1. As an organic carbon-containing waste was taken hydrolysis lignin - waste Onega hydrolysis plant with a moisture content of 67%. The lignin was subjected to mixing - activation on a rotary vane crusher in order to homogenize and activate the surface of the particles. Activated lignin was dried in a fluidized bed dryer with flue gases produced in a heat generator, in the vortex furnace of which a part of dry lignin was used as fuel. At the same time, constant instrument control was carried out for the temperature of the flue gases supplied to the dryer by a smoke exhaust from a heat generator, for the oxygen content in these gases, and for the humidity of the dried lignin. The reduced oxygen content in the drying agent (flue gas) was maintained by recirculating 70% of the spent drying agent, which was fed from the dryer by a special exhaust fan to the heat generator mixer for heating and then fed back to the dryer. During drying, the temperature of the drying agent supplied to the dryer varied in the range of 200-220 ° C, the oxygen content in the drying agent varied in the range of 8-9%, and the moisture content of the dried lignin varied from 9 to 12%. Dried lignin was fed into a roller press, where dried lignin was formed into fuel briquettes at a pressure of 22 MPa. The resulting briquettes had a high mechanical strength - 89% (for dropping), a relatively high calorific value of the working fuel - 4400 kcal / kg and had a 30% lower cost compared to lignin briquettes, which were dried after molding.

Example 2. As the organic carbon-containing waste, a residue was taken from wastewater treatment from the treatment facilities of the city of Rostov with a humidity of 76%, and as an additive, the combustible part of the crushed solid household waste (MSW) from the installation for sorting solid waste with a humidity of 30% was used. The ratio of sludge and combustible part of solid waste was as follows: sludge from wastewater treatment - 80 wt.%; combustible part of solid waste - 20 wt.%.

The components were mixed - activated in a rotary vane crusher. The activated mixture was dried in a tube dryer, where the drying agent was steam. In this case, there was no contact of the drained mixture with steam and air, since the drained mixture was moved by a screw inside the inner pipe, and the steam was fed into the annular gap between the inner and outer pipe. Heat was transferred to the drained mixture through the walls of the inner pipe. The drying space of the inner pipe was isolated from the air. Therefore, restrictions on the oxygen content in the pair were not required and control over this parameter was not carried out. Constant instrument control was carried out over the temperature of the steam supplied to the dryer and the humidity of the dried mixture. During drying, the steam temperature varied in the range of 230-250 ° C, the moisture content of the dried mixture varied in the range of 10-14%. The dried mixture was fed into a hydraulic press, where briquettes were molded as a fuel for gasification at a pressure of 18.5-20 MPa. The obtained briquette moldings had high mechanical strength - 91% (for dropping), high calorific value of the working fuel - 3950 kcal / kg and had a cost price of 35% lower than moldings according to the known solution (prototype).

Other examples are tabulated.

Example No. The composition of the waste and the parameters of the method of processing Formings and their parameters The composition of the components and additives, wt.% The humidity of the components,% Type of drying, molding pressure The mechanical strength of the moldings,% Mold moisture, intended use, cost reduction effect, lower heat of combustion one 2 3 four 5 6 3 Pig Manure - 20 86 Drying with direct contact of the drying agent with the components to be dried, the oxygen content in the drying agent is 14%. The temperature of the drying agent is 215-230 ° C. The humidity of the dried mixture is 40%. The molding pressure is 15 MPa. 80 Mold moisture 40%; molding for fertilizer, the cost is lower than the prototype by 40% lignin - 10
Husk of seeds - 70 70
70 four Bird droppings - 30 60 Drying without contact of the drying agent with the mixture to be dried, with a pressure in the drying chamber below atmospheric (150 mmHg) The temperature of the drying agent is 210-240 ° C. Humidity of the dried mixture is 24%. The molding pressure is 120 MPa. 98 Mold moisture 24%; granules for fertilizing and structuring the soil, the cost is lower than the prototype, by 21% Cow Dung - 30
Sawdust - 20
Polova - 20 80
27
22 5 Sludge from wastewater treatment - 100 72 Drying with direct contact of the drying agent with the drained precipitate. The oxygen content in the drying agent is 8-10%. The temperature of the drying agent is 240-260 ° C. Humidity of the dried mixture is 21%. Molding Pressure 25 MPa. 91 Mold moisture 21%; fuel briquette, the cost price is lower than that of the prototype, by 24%, the calorific value of lower 3500 kcal / kg 6 Pig Manure - 60 82 Drying without contact of the drying agent with the drained mixture. The temperature of the drying agent 470-500 ° C. Humidity of the dried mixture is 18%. Molding Pressure 20 MPa. 89 Mold moisture 18%; fuel pellets, the cost is lower than the prototype, 32%; lower calorific value - 3600 kcal / kg Crushed Straw - 10
Crushed leaves and stalks of sunflower - 30 eighteen
35 7 Bird droppings - 40 74 Drying without direct contact of the drying agent with the drying mixture. The temperature of the drying agent is 215-225 ° C. Humidity of the dried mixture is 28%. The molding pressure is 22 MPa. 86 Mold moisture 28%; granules for fertilizer, the cost is lower than the prototype by 27% Lignin - 10 69 Crushed Bark - 20
Beet cake - 30 22
41 8 Pork manure -100 78 Drying with direct contact of the drying agent with drained manure. The oxygen content in the drying agent is 9-11%. The temperature of the drying agent 220-230 ° C. Humidity of dried manure 15%. Molding Pressure 20 MPa. 90 Mold moisture 15%; fuel briquette, the cost price is lower than by the prototype by 30%, the heat of combustion is lower than 3600 kcal / kg.

Claims (5)

1. A method of processing organic carbon-containing waste having an energy potential, without losing the properties of organic waste to burn and / or improve soil fertility and structure, into carbon-containing moldings, including dosing of components in the form of organic carbon-containing waste of biological origin, mixing-activation, molding of activated components under pressure to obtain carbon-containing moldings, characterized in that as carbon-containing waste biological origin They use sediments from wastewater treatment, and / or animal manure, and / or bird droppings, and / or lignin, before molding, each component or their mixture is dried to a moisture content of not more than 40%, and molding is carried out at a pressure of not more 120 MPa, while the drying of the components or their mixtures is carried out either by direct contact of the drying agent with the dried components or their mixture and the drying agent contains oxygen in an amount of not more than 14 wt.%, Or the drying is carried out without direct contact with the drying agent and ambient air at a pace the temperature of the drying agent is not higher than 500 ° C. 2. The method according to claim 1, characterized in that in the case of drying without direct contact with the drying agent and the surrounding air, it is carried out at a pressure in the drying chamber below atmospheric. 3. The method according to claim 1, characterized in that when mixing - activating the components, additives from solid combustible waste are additionally added with a moisture content of not more than 70% in an amount of not more than 70 wt.%. 4. The method according to claim 3, characterized in that as solid combustible waste, screenings of peat, sawdust, bark, straw, flooring, husks of seeds, cake, leaves and stems of plants, combustible part of municipal solid waste in any combination thereof are used. 5. Carbon-containing moldings obtained according to any one of claims 1 to 4.