DE102006039622A1 - entry system - Google Patents

Abstract

Transport system for introducing biomass into a gasifier, comprising:
a plug screw (9) which pushes the biomass into the gasifier, the plug screw being designed to compress the biomass, on the one hand to promote pressure in the gasifier and, on the other hand, to leave gas and bed material in the gasifier,
- With a gate valve (16, 11), which adjoins the screw conveyor and which feeds at standstill of the screw conveyor, so that heat, steam and gas can not escape.

Description

The The invention relates to a system for the abandonment of biogenic starting materials in a carburetor in particular in a pulse carburetor after the Applications 10 2006 022 265.2, 10 2006 017 355.4, 10 2006 017 353.8.

Field of the invention:

The Development of thermal gasification processes has essentially produced three different carburetor types, the entrained flow gasifier, the fixed bed gasifier and the fluidized bed gasifier.

For the commercial Gasification of biomass were primarily the fixed bed gasifier and the fluidized bed gasifier further developed.

From the many different technical approaches in the field of fixed bed gasification is at this point the Carbo-V process exemplified.

Literature for fluidized bed gasification, which is part of this application, can be taken from the following literature: Wolfgang Adlhoch, Rheinbraun AG, Hisaaki Sumitomo Heavy Industries, Ltd., Joachim Wolff, Karsten Radtke (Speaker), Krupp Uhde GmbH, Gasification Technology Conference, San Francisco, California, USA, "High-Temperature Winkler Gasification of Municipal Solid Waste"; October 8-11, 2000; Conference Proceedings ,

Literature for circulating fluidized bed in the composite system, can be taken from the following sources: "Decentralized power and heat generation based on biomass gasification", R. Rauch, H. Hofbauer, lecture University of Leipzig 2004 , "Circulating Fluidized Bed, Gasification with Air, Operation Experience with CfB Technology for Waste, Utilization at a Cement Production Plant" R.Wirthwein, P. Scur, K.-F. Scharf-Ruedersferor Cement GmbH, H. Hirschfelder-Lurgi Energy and Entsorgungs GmbH, 7th International Conference on Circulating Fluidized Bed Technologies, Niagara Falls, May 2002 ,

Literature for combination fixed bed (rotary tube), can be taken from the following sources: 30 MV Carbo V Biomass Gasifier for Municipal CHP ; The CHP Project for the City of Aachen, Matthias Rudloff; Lecture Paris, October 2005

Literature for combination for the fixed bed gasification (slag deadening gasifier) can be taken from the following sources: Operation Results of the BGL Gasifier at Schwarze Pumpe, Dr. med. Hans-Joachim Sander SVZ, dr. Georg Daradimos, Hansjobst Hirschfelder, Envirotherm ; Gasification Technologies 2003; San Francisco California, October 12-15 2003; Conference Proceedings

at The Carbo-V process gasification takes place in two stages. First the biomass is at 500 ° C in their fleeting and solid components split. The result is a tar-containing Gas and additionally "charcoal". The gas is at temperatures of more than 1200 ° C burned, with the tars decaying into CO2 and H2. With the hot flue gas and the charcoal will follow produces a CO and H2-containing product gas.

by virtue of of high technical and economic Expenses caused by the high pressure level (up to 40 bar), are these carburettor types for the gasification of biomass (which accumulates regionally and has significant influence on the cost of Logistics and processing has) entirely not suitable.

The Fluidized bed gasifiers can be subdivided into two processes, which is in the warm-up of the fluidized bed, the circulating fluidized bed gasifier and the stationary fluidized bed gasifier.

Literature for desulfurization in a fluidized bed gasification can be taken from the following source: Gasification of Lignite and Wood in the Lurgi Circulating Fluidized Be Gasifier; Research Project 2656-3; Final Report, August 1988, P.Mehrling, H.Vierrath; LURGI GmbH; for Electric Power Research Institute, Palo Alto, California: ZWS Pressure Gasification in the Combiblock, Final Report BMFT FB 03 E 6384-A; P. Mehrling, LURGI GmbH; Bewag

In Güssing (Austria) At the beginning of 2002, it became an allothermal, circulating fluidized bed gasification plant put into operation. The biomass is in a fluidized bed with Gassing steam as an oxidizing agent. For heat supply for the gasification process Part of the charcoal produced in the fluidized bed burned a second fluidized bed. By the gasification under Steam, a product gas is generated. The disadvantages are the high ones Acquisition costs of the system technology and an excessive effort for the process control.

The management of the fluidized bed material requires a targeted control and regulation of the steam circulation in the sense of a mammoth pump movement to increase the heat and mass transfer and to improve the reaction conditions by increasing the effective reaction space. The mammoth pump is a conveying device in which solids / water mixtures with the help of compressed air (propellant or conveying gas), promoted by eg injection of this air by means of nozzles in pipes or a stirred tank becomes. The injected gas causes a reduction in the suspension density and thus an increase in buoyancy. Together with the introduced kinetic energy causes the promotion.

When flow results in the containers a Circulation flow.

It There is thus a transfer on the solid / gas suspension of the fluidized bed. This principle will in the present case to the gas / solid suspension of the fluidized bed transferred to the steam converter.

All These systems need a transport system to give up the biogenic Feedstocks in the carburetor. The following invention describes a system that processes the task of biogenic feeds in a carburettor, in particular in a pulse carburetor.

The Starting materials cover a wide range. So are extrudates, round pellets, as they arise in pelleting machines or biogenic input materials from agriculture (cereals).

Characteristic for this Biomasses are C contents of the starting material in the range of 40 to 50% by weight, with hydrogen contents in the range up to 6% by weight and oxygen content in the range of 40 to 50 mass%. typically, the calorific values of the feedstocks are in the range of up to 20 MJ / kg. The bulk density vary in the range between 200 and 700 kg / h. In addition to a certain share Fine material has extrusions of a diameter between 5 and 10 mm at a length from 10 to 20 mm, and lumpy Starting materials dimensions in the range of 20 × 30 mm and a thickness up 10 mm.

Overview of the Invention:

task The invention is a transport system that biomass efficient considering of particular properties of the reactor in these gives up.

Is solved this by a transport system with the characteristics of one or more Claims that further below were disclosed

Of the The process flow includes the following sub-steps, with the appropriate Devices performed become.

a. Intermediate buffer:

A Intermediate buffering in a silo (layer bunker) serves as a template for entry and dosage. In this cache, the starting materials be promoted by different camps.

b. Dosing and dispensing to the entry points in the carburetor:

outgoing from the net gas production acting as the target value (results from the control scheme for the Steam carburetor), the feedstock is dosed so and on, two or more entry points distributed that the required gas production established. The system also warrants the function of functioning as a pressure seal of the reactor system Stuffing screw. The system has the flexibility to use these tasks to meet the stated range of starting materials.

c. Sealing the reaction system against The atmosphere:

A Pressure seal of the reactor by the plug screw formed in the Material stopper and a multi - stage system of rotary valve and Gate valve before and after the plug screw, as well as an admission of the delivery tube with N2 (nitrogen) or CO2 (carbon dioxide) can be used in dependence be necessary for the reactor type.

This Material stopper is used in the entry organ in the carburetor Plug screw over an adjustment of the corresponding quantities continuously generated. The feed screws are controlled so that the mass flow and ensures the permanent formation of the sealing plug are.

This System is over characterized in that the stuffing screw (s) in their front Area with a nozzle system equipped is / are similar a jet pulse System, as it is known from the filter technology works.

The Stopfschecke features furthermore on cooling equipment the shaft and the coat. (Optionally, it is possible to the wave wings to cool this stuffing screw).

d. Avoiding return of the fluidized bed material in the entry and dosing system at standstill and when not in operation the entry and metering device:

The material is introduced during operation of the carburetor in a dense, fluidized fluidized bed. Measures have been taken to prevent the return flow of bed material into the screw when the entry screw / s is at a standstill, in particular during the start-up and shut-down processes. For this purpose, the system is equipped with a slide that works through the conveyed through and Ab made in a suitable manner. This device allows an emptying the emptying of this plug screw (s) as a precaution against burnback, as they can not be excluded in the case of short-term shutdowns in otherwise hot gasifier.

By these different approaches the system is suitable for all of these for the gasification process Question to promote upcoming feedstocks in the reactor. On Due to the specific properties, the system also allows the Entry at internal pressures up to 5 bar.

• – einen Zwischenspeicher mit geregelter Austragseinheit;
• – einer Dosierschnecke(n), die die Menge, die aus dem Zwischenspeicher geholt wird dosiert;
• – einer Transportschnecke, die die Menge zur Stopfschnecke transportiert;
• – einer Zellradschleuse, Absperrschieber vor und nach einer Stopfschnecke und einer Stopfschnecke.

It follows that, in a preferred embodiment, the entry and metering system consists of the following elements:

• - A buffer with regulated discharge unit;
• - a dosing screw (s), which doses the amount that is taken from the buffer;
• - A transport screw that transports the amount to the screw conveyor;
• - A rotary valve, gate valve before and after a plug screw and a plug screw.

The Amount of gas produced depends directly (proportional) on the amount of feedstock. These physical dependence is used as the control of the entry quantity. The measurement of the product gas quantity, or the comparison between the default value (setpoint specification) and measured product gas quantity, serves as a guide control of the amount of feedstock. As can be seen from the figures, these sizes work directly on the metering screws (simple, parallel or multiple design). These auger (s) are taken from the clearing and dosing screw of the Intermediate bunker regulated applied, these actuators are together with a level monitoring the feed chute the dosing screw (s) involved in the scheme.

The subsequent in a possible embodiment Uncontrolled transport screws lead the feed to the actual Entry system too.

The Overall control concept thus includes the entry of biogenic input materials in a gasifier for alotine gasification with generation of the heat of reaction Gasification reaction in special pulse burners.

Description of the figures:

1 shows an overall schematic view of the invention;

2 shows the schematic structure of the metering screw and the screw plug;

3 shows the stuffing screw in detail.

Preferred embodiments:

The Control concept includes the specifications by the product gas quantity for the dosage the feedstock by controlled discharge from a buffer and variable speed dosing screw with level monitoring the feed chute, the distribution on the entry organs and the formation of the stopper in the speed-controlled feed screw, wherein the speed over the Main controller (master controller) and level monitoring in the feeder to the entry system he follows. This entry system (for solids) under the Fluidized bed gasification is a significant advance.

The discharge system 1 ( 1 ) consists of one through the master controller 2 variable speed screw 3 centrally in the cache 4 is appropriate. The entire screw is also controlled by speed controlled rotary drive 5 moved over the silo bottom. The speed control is adjusted so that the degree of filling of this screw by screwing it into the material stored in the silo always ensures the same degree of filling. Thus, the delivery volume is directly proportional to the speed of the screw, so this discharge system is suitable as a dosage. As a reference variable for the speed control is the power consumption of the rotatably mounted screw, which is directly proportional to the torque of this screw.

Via a dosing screw 6 the amount is determined by the master controller depending on the target size of the product gas 7 certainly. Accordingly, the amount fetched from the buffer is metered.

One or more transport screws 8th , transport the amount to the stuffing screws 9 ,

The entry system consists of a cellular wheel 10 , Slider 11 in front of the screw for further transport and at the same time shut-off during start-up or shut-down and presentation of the screw conveyor 9 , The system is with a system 12 (please refer 3 ) for the admission of air as a barrier medium and / or inert gas such as N2 or CO2 or steam (the latter medium also as extinguishing and blocking medium) equipped.

How out 2 becomes clear, the system consists of the actual plug screw, in which the material plug is created for pressure shut-off. The snail is designed so that this Material plug in the entire speed range, so that remains stable even with different amounts of input material. This feedstock is fed through the open in the operation gate valve through a smooth, heat-resistant tube directly into the hot fluidized bed.

Furthermore, the snail has cooling facilities 13 . 14 for cooling the worm shaft 14 and alternatively the screw flights and the jacket 13 the snail. This is a wave cooling and a jacket cooling.

Part of the system is the gate valve 15 directly between entry screw and carburetor 16 which closes when the screw is stopped and prevents the inert bed material from flowing back into the screw.

This Slide is made of heat-resistant material, because he is at the intersection of hot in the carburetor and the cooled screw lies. By this measure will the reflux also prevented in the operating phases, in which not the registered Feedstock plug itself produces the barrier.

The feeding of the feedstock to the entry screw via chute 17 , Rotary valve 10 and gate valve 11 , The level monitoring 18 in this feed train ensures the necessary permanent formation of the material plug for the feed throughput set via the main control. The arrangement of rotary valve and gate valve in front of the screw also allows in operation the task of a barrier gas (air or inert gases such as CO2, nitrogen or steam in exceptional cases).

The slider 11 allows an additional gas-tight barrier.

Consequently are pressure range of the reaction system up to 5 bar ü., as a rule 1.5 bar ü controllable.

Claims (22)

Transport system for introducing biomass into a gasifier comprising: - a plug screw ( 9 ), which presses the biomass into the gasifier, wherein the plug screw is designed so that the biomass is compressed, on the one hand to promote pressure in the carburetor and on the other hand to leave gas and bed material in the carburetor, - with a gate valve ( 16 . 11 ), which adjoins the plug screw, and which feeds when stopping the plug screw, so that heat, steam and gas can not escape. The transport system according to the preceding claim, wherein a cooling ( 14 . 13 ) cools the plug screw from the inside and / or outside. The transport system according to one or more of the preceding claims, wherein a gate valve ( 11 ) and a gate valve ( 15 ) is arranged after the screw conveyor. The transport system according to one or more of the preceding claims, wherein a rotary valve ( 10 ) is arranged in front of the screw conveyor, to which a Zuführschurre borders. The transport system according to one or more of previous claims, the stuffing screw in its front area with a nozzle system equipped is similar a jet-pulse system works. The transport system according to one or more of previous claims, being in the case the sealing screw a sealing gas is introduced, in particular is a delivery tube with N2 (nitrogen) or CO2 (carbon dioxide) applied. The transport system according to one or more of the preceding claims, wherein a buffer which ( 4 ) with a controlled discharge unit ( 3 ), the stuffing screw is connected upstream. The transport system of the preceding claim, wherein the dispensing system is one of a controller 2 ) speed-controlled screw ( 3 ) stored centrally in the cache ( 4 ) is attached. The transport system according to the preceding claim, wherein the entire screw also by means of speed-controlled rotary drive ( 5 ) is movable over the silo bottom. The transport system according to one or more of previous claims, one or more dosing screw, the biomass coming out of the Buffer is fetched, dosed, and if necessary. A transport screw transports the biomass to the screw conveyor. The transport system according to one or more of the preceding claims, wherein a control unit ( 2 ), which calculates the amount of gas produced in proportion to the amount of feedstock to use this physical dependence as the control of the feed rate, so that the measurement of the product gas quantity, or the comparison between the default value and gemes sener product gas quantity, as a lead control of the amount of feed used. Method for introducing biomass into a gasifier comprising: - introducing the biomass via a plug screw, wherein the plug screw is controlled so that biomass is compressed, on the one hand to promote a pressure in the gasifier and on the other hand to leave gas and bed material in the gasifier, Closing a gate valve ( 16 . 11 ), which is adjacent to the screw conveyor, in case of stoppage of the screw conveyor, so that heat, steam and gas can not escape. The method according to the preceding method claim, wherein a cooling ( 14 . 13 ) cools the plug screw from the inside and / or outside. The method according to one or more of the preceding method claims, wherein a gate valve ( 11 ) and a gate valve ( 15 ) is arranged after the plug screw, and these are closed depending on the supply or the removal of the biomass. The method according to one or more of the preceding method claims, wherein a rotary valve ( 10 ) is arranged in front of the screw conveyor, to which a Zuführschurre borders, wherein the lock ( 10 ) is controlled so that the plug screw is continuously supplied with biomass. The method according to one or more of the preceding Method claims, the stuffing screw in its front area with a nozzle system equipped is that similar a jet-pulse system works to detract the biomass. The method according to one or more of the preceding Method claims, being in the case the sealing screw a sealing gas is introduced, in particular is a delivery tube with N2 (nitrogen) or CO2 (carbon dioxide) to prevent a pressure drop from occurring. The method according to one or more of the preceding method claims, wherein from a cache ( 4 ) by a regulated discharge unit ( 3 ) the stuffing screw is supplied. The method according to the preceding method claim, wherein the discharge system consists of a variable speed screw ( 3 ) stored centrally in the cache ( 4 ), and by a controller ( 2 ) is controlled. The method according to the preceding method claim, wherein the entire screw also by means of speed-controlled rotary drive ( 5 ) is moved over the silo bottom. The method according to one or more of the preceding Method claims, one or more dosing screw containing the amount coming out of the Buffer is fetched, dosed, and if necessary. A transport screw Transported biomass to the stuffing screw. The method according to one or more of the preceding method claims, wherein a control unit ( 2 ) which calculates the amount of gas produced in proportion to the amount of feedstock to use this physical dependency as the control of the feed rate, so that the measurement of the product gas amount, or the comparison between the preset value and the measured product gas amount, serves as a feedstock feed control.