DE3145066A1 - Process for producing a comparatively higher-energy, nitrogen-rich gas and equipment for carrying out the process - Google Patents

Abstract

The process and the equipment for producing a high-energy, nitrogen-rich gas in a tower-type chamber (combustion chamber), which is surrounded by an annular chamber and in the upper part of which fluid-bed units are arranged in accordance with Figure 1, from comminuted biomasses which may have been predried, utilises a number of different process steps. This starts initially with burning a minor part of the biomass in the central chamber, passing the resulting heat into the annular chamber, carrying out the partial combustion in a fluidised bed and then pyrolysing the predominant part of the biomass, oxygen being fed to the pyrolysis material and steam being fed via a grate in the annular chamber to the pyrolysis gas being formed. Subsequently, such a quantity of charcoal is fed in the upper part of the annular chamber via the fluid bed that an adequate cracking temperature is reached. <IMAGE>

Description

"Procedure ..."

It is already known to process biomass in order to convert these pyrolysis products, such as charcoal and pyrolysis gas.

Such systems can be operated stationary or mobile.

Both types of construction are difficult to control operationally because of the waste products. In addition, the resulting pyrolysis gas is a lean gas that is technically engineered gives little energy and also contains components that, if not sufficient removed, are detrimental to the company.

The inventive method and its device have the The task set to produce an energy-rich gas, free of harmful components, whereby a number of by-products are put to an industrial use.

The invention solves this problem by using shredded biomass al, the substance to be reprocessed, which may have been predried, runs out, and it characterizes: .lch in that a) a smaller compared to the total mass Part of the biomass, if necessary with the addition of preheated air, "Procedure ... "is burned in the combustion chamber (10), b) the resulting heat by conduction of heat through the partition (11) between the combustion chamber (10) and the annular chamber (20) is placed in the latter> c) the process stages a) and b) are reinforced by the introduction of preheated air, the amount and Pressure is dimensioned so that a fluidized bed in partial combustion is in the chamber (10) arises, d) the predominant part of the biomass in the annular chamber (20) is subjected to a pyrolysis process, e) the conversion of the pyrolysis material, if necessary takes place with the addition of small amounts of oxygen, f) the resulting Pyrolysis gas water vapor is added in an amount and a pressure that zXine Let the fluidized bed arise over the annular chamber grate (21), g) the temperature in the upper part (28) of the annular chamber (cracking chamber) by means of conscious proportion control is raised to at least 750 ° C (cracking temperature) by charcoal.

The procedure and the facility for its implementation the production of a comparatively high-energy, nitrogenous "Procedure ... "of free gas by means of a tower-like chamber, surrounded by a ring-like chamber is surrounded, and arranged in the upper part of fluidized bed fluidized bed internals are made from shredded, possibly pre-dried biomass. You go from a central, substantially circular combustion chamber 10 and this combustion chamber surrounding annular chamber 20, the annular chamber initially taking its heat from the central Combustion chamber 10 relates. In the upper part of the annular chamber 20 there are fluidized bed internals arranged, which help to reach high temperatures, for example around 800 C.

A thermal ring 30 serves both to guide the flue gases from the central Chamber 10 as well as the discharge of the smoke gases from the outlet 32.

L) he process presupposes a comminution of the resulting biomass to a piece size advantageously less than 2 cm. Between the shredding device 40 and storage container (silo) 50 are dryer 60, heat exchanger 61 and the 1 transport device 41 for <liu shredded biomass. The dried silage becomes cyclone cleaning via a discharge device (conveyor belt), downstream a heat exchanger 61,> transported. This transport is superimposed by In the upper part of the dryer 60, so-called vapors, which consist of air and steam, are withdrawn and stick on fine airborne particles. This share goes directly into the Zyklon 63. This Become vapors "Process ..." by means of the known cyclone effect, which is based on centrifugal forces, separated into two parts. The centrally ascending one Part goes into the heat exchanger 61, from which a return line of the warm air to the dryer 60 takes place via the shredder 40. The other solid tea migrates over a transport device to the fuel silo 50 and from this the stored Material in the actual facility for producing synthesis or enriched Gas is now conducted as the core of the facility, called reactor UO.

In the reactor 80 (combustion chamber 10 and annular chamber 20) there are a number of different options Procedural stages ahead. A part, for example 30% of the fuel is under Adding preheated air by a heat exchanger from the process cycle come karin, burned. The resulting heat is transferred by conduction the wall 11 delivered directly to the annular chamber 20. Since the preheated air is not difficult can be measured according to quantity and pressure so that a fluidized bed over the grate 12 entheht, the heat exhaustion is in the kiln itself and via the central surrounding Ring wall 11 is considerably larger than when the material to be fired is at rest.

The annular chamber 20 is with the remaining portion of about 7 ()% de. ' Material to be fired charged and is initially subject to a pyrolysis process, in the context of this Registration under pyrolysis a conversion of the processed goods in gaseous form adding lesser "Procedure ..

Means amounts of oxygen. According to a special feature of the invention steam can also be added, the amount and pressure of the gas or the Water vapor are measured so that a fluidized bed in the annular chamber 20 arises over the grate 21.

The resulting smoke gases in the central combustion chamber 1 0 to improve the thermal balance of the facility to the outer wall the annular chamber 20 and leave the so-called outer thermal ring 30 via the outlet 32 with operating direction to a further cyclone 72 in which dc.s flue gas is also cleaned in the usual way.

Eb s lies within the scope of the invention, in the third place also so-called Add purge gas. The purge gas can from the process, for example as Pyrolysis gas. It is advisable to use the gaseous components to be introduced under the pyrolysis grate 21 via injectors 26 known per se.

According to a further special feature of the invention can optionally the pyrolysis process can be controlled so that zein in part of the resulting charcoal is removed from the process via outlet 70 if their separate recovery it is asked for.

Purely economic considerations determine that.

But it is also possible to use all the charcoal in the ring chamber. " Procedure . .

mer 20 to gasify so that no residue remains.

Carrier materials in the fluidized bed can be used accordingly in a manner known per se sized granular quartz sand.

One focus of the invention is the design of the upper annular chamber space 20 by means of a special grate design with fluidized bed internals 28 (not shown) for the purpose of increasing the temperature in the cracking area, with a particular effect is caused by the fact that the fluidized bed extends over the entire annulus correspondingly large effective area extends. In terms of temperature arises on average a temperature of 700 to 750 ° C in the pyrolysis room. The temperature depends on the withdrawal of charcoal from this process stage or leaving the charcoal in the pyrolysis material.

It is in the nature of the process that the upper annular cracking chamber 23, the bottom of which consists of a grate, with time to Ashes tend to become constipated. In order to counter this risk, are according to the invention Shovel-shaped internals 31 are provided, which according to a special feature of the invention are designed radially curved so that the ash fractions on the outer wall the cracking chamber. This rotating centrifugal driving effect is created by means of the radial driving effect caused by the blades. The radial Drive blades 31 "Process ..." the ash components on the edge the end. They leave the reactor via a rotary valve.

It has been found within the scope of the invention that in the cracking room temperatures around 8000C are sufficient for the intended further digestion of pyrolysis gas, mainly heavy hydrocarbons, so that the increase in temperature occurring here corresponds to the calorific value according to the invention after is relatively small.

It is a special feature of the invention at this point below the upper grate 25 external oxygen generated in a manner known per se from a Add O2 generator. Because the temperature level that is necessary to the cracking temperature to generate with certainty, is relatively small, the oxygen supply can also to smaller volumes, for example compared to the gas volume generated, in limit this example to only about 8%.

To the CO2 share, which in the described process stages inevitably often as small as possible, can be in the upper part of the annular chamber 20 a part of the charcoal recovered can be added again. This reduced the CO ratio, which is harmful to heat, and part of it becomes 2 CO.

The annular chamber has two outlets. The upper outlet 22 from the cracking canister 23 is passed directly into another cyclone 71, in which by centrifugal action a separation of the so obtained "Process ..." of gas from solids takes place.

The gas flowing out of the outlet 24 from the pyrolysis chamber 20 can deii injectors 26 are added and serves as an additive for the flushing fluid.

The gases leave the upper reaches of the cyclones 71, 72 to enter a heat exchanger 73 to flow. This heat exchanger 73 can be used in the usual way as a tubular heat exchanger be trained. In the upstream of the heat exchanger, 79 H20 introduced. This creates steam and warm air, which in the manner described in the injectors 26 open. The result should come out of the heat exchanger Gas through a fine filter 74 advantageously also a filtration in a manner known per se Way to be subjected. It can then be sucked off by a piston blower 75.

Now in a power generator 77 (gas engine with generalor) this gas can be used directly or as Synthe @ egas for further processing are fed. It is then advisable to interpose a gas reservoir 76.

If one goes in the heat balance of 100% of the energy to be processed Biomass, with a moisture content of around 20% to be expected, then, in the example chosen, 70% of the biomass go into the fluidized bed pyrolysis chamber and about 30% in the central combustion chamber.

"Process ..." If one takes into account the heat loss occurring in these chambers off, then 10% go in the form of flue gas in the further process, and after the fluidized bed cracking chamber, with the deduction of the heat loss there, for example 52.J.5% as synthesis gas in the next process stage. Leave in the final stage about 41% the facility in the form of synthesis gas, if one considers the loss through smoke emission in the amount of 2% and for the electric drive in the amount of 5%, the cooling loss with 2%, the expenditure for fuel drying with 5.5% and for oxygen generation billed at about 5%.

The outflowing synthesis gas had been carried out in a practical Plant has a composition of about 35% H2, 43% CO, 18% C02 and 4% of the valuable CH4. These numbers refer to the total amount of gas produced.

The emitted gas had a calorific value of 2,600 Kcal / Nm3 = 10 920 Kjoule / Nm3 and is thus clearly several times as high as that shown here practical example the 2 1/2 times, compared to the calorific value, which was previously after State of the art could be achieved.

"Procedure..." 10 circular combustion chamber 11 ring wall of 10 12 grate of 10 13 flue gas from 10 20 ring chamber (pyrolysis chamber) 21 lower grate from 20 (pyrolysis) 22 upper Outlet of 23 for cracking gas 23 cracking chamber (annular) 24 lower outlet for purge gas (Pyrolysis gas) 25 grate of 23 26 injectors 27 fluidized bed in 23 28 fluidized bed internals (Radial blades) 30 thermal ring 31 radial blades 32 exhaust gas from 30 40 Crushing device for the biomass 41 conveyor belt to the dryer 42 conveyor belt to the silo 43 conveyor belt to the reactor 80 44 dust 45 ash 50 storage container 51 exhaust air Dryer 62 52 flue gas from 10 "Process ..." 60 Dryer 61 Heat exchanger 63 Cyclone for vapors 70 Outlet for charcoal (10 and 20) 71 Cyclone for cracked gas 72 Cyclone for flue gas 73 Heat exchanger 74 Fine filter 75 Piston fan 76 Gas storage tank 77 Gas engine with generator (power generation group) 78 O2 generator 79 H2O line t; 0 reactor L e r s e i t e

Claims (6)

"Procedure..." P a t e n t a n s p r ü c h e 1. Procedure for Production of a high-energy, nitrogen-free gas in a tower-like chamber (Combustion Chamber), which is surrounded by an elongated chamber, and in its Upper part of fluidized bed internals are arranged, from crushed, if necessary predried biomass, characterized in that a) a comparative to Total mass smaller part of the biomass, possibly with the addition of preheated Air is burned in the combustion chamber (10), b) the heat generated in this way by heat conduction via the partition (11) between the combustion chamber (10) and Annular chamber (20) is placed in the latter, c) the process stages a) and b) are reinforced by the introduction of preheated air, the amount and " Procedure . . . "Pressure is to be measured in such a way that one is in partial combustion Fluidized bed is created in the chamber (10), d) the major part of the biomass is subjected to a pyrolysis process in the annular chamber (20), e) the implementation of the The pyrolysis material is carried out with the addition of small amounts of oxygen, if necessary, f) the pyrolysis gas that is now produced is water vapor in an amount and a pressure is added, which create a fluidized bed above the annular chamber grate (21), g) the temperature in the upper part (23) of the annular chamber (cracking chamber) by means of conscious. Proportion of charcoal control raised to at least 750 ° C (cracking temperature) will. 2. The method according to claim 1, d a d u r c h g e k e n n z e i c h n e t, the flue gas is taken from the process as a purge gas and under the Grate (21) of the ring chamber (20) by blowing into the process via injectors (26) is reintroduced. : i. Method according to Claims 1 and 2, d a d u r c h g ekennz @ ic hti e t that narrowly classified quartz sand is used as a carrier in the fluidized bed (27) will. "Procedure ..." 4. Facility for carrying out the procedure according to -'en claims 1 to 3, by means of a circular, central combustion chamber (10), annular chamber (20) and their inlet and outlet for process materials, d a d u r c h gek ennze I n e t that the annular chamber (20) in the upper part is an annular l-bed (27) is assigned. 5. device according to claims 1 to 4, d a d u r c h g e -k e It is noted that the annular chamber (20) has an outlet (22) for cracked gas the cracking chamber (23) and an outlet (24) from the pyrolysis chamber (20) for the purge gas Has. 6. Device according to claims 1 to 5, d a d u r c h g e -k e n n z ei c h ne t that in the annular cracking chamber (23) fluidized bed internals (28) are arranged.