WO2008022895A2

WO2008022895A2 - Input system

Info

Publication number: WO2008022895A2
Application number: PCT/EP2007/058034
Authority: WO
Inventors: Oliver Neumann
Original assignee: Spot Spirit Of Technology Ag
Priority date: 2006-08-24
Filing date: 2007-08-02
Publication date: 2008-02-28
Also published as: DE102006039622A1; EP2066764A2; US20090173005A1; WO2008022895A3

Abstract

Transporting system for introducing biomass into a gasifier, comprising: a stuffing screw (9), which forces the biomass into the gasifier, wherein the stuffing screw is formed in such a way that the biomass is compressed, in order on the one hand to provide a feed against a pressure in the gasifier and on the other hand to leave gas and bedding material in the gasifier, with a shut-off slide (16, 11), which is adjacent to the stuffing screw and during downtimes shuts off the stuffing screw such that heat, vapour and gas cannot escape.

Description

entry system

The invention relates to a system for the application of biogenic starting materials in a carburetor in particular in a pulse carburetor according to the applications DE 10 2006 022 265.2, DE 10 2006 017 355.4, DE 10 2006 017 353.8.

Field of the invention:

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

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

Of the many different technical approaches in the field of fixed-bed gasification, the Carbo-V process is shown here as an example.

Literature for fluidized bed gasification, which is part of this application, can be found in the following literature: Wolfgang Adlhoch, Rheinbraun AG, Hisaaki Sumitomo Heavy Industries, Ltd., Joachim Wolff, Karsten Radtke (Speaker ), Krupp ühde GmbH, Gasification Technology Conference, San Francisco, California, USA; October 8-11, 2000; Conference Proceedings. Literature for circulating fluidized bed in the composite system, can be taken from the following sources: "Decentralized electricity 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 - Ruedersdorfer 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 Rudioff; Lecture Paris, October 2005

Literature for combination for the fixed bed gasification (slag degassing gasifier) can be taken from the following sources: Operation Results of the BGL Gasifier at Schwarze Pumpe,

Dr. Hans-Joachim Sander SVZ, dr. Georg Daradimos, Hansjobst Hirschfelder, Envirotherm; Gasification Technologies 2003; San Francisco California, October 12-15 2003; Conference Proceedings

In the Carbo-V process, gasification takes place in two stages. First, the biomass is split at 500 ° C into its volatile and solid components. The result is a tar-containing gas and additionally "charcoal". The gas is burned at temperatures of more than 1200 ⁰ C, with the tars decay into CO2 and H2. The hot flue gas and the charcoal are then used to produce a CO and H2-containing product gas. Due to the high technical and economic costs, due to the high pressure level (up to 40 bar), these carburettor types are completely unsuitable for the gasification of biomass (which is regionally produced and has a significant impact on the costs of logistics and processing).

The fluidized bed gasifiers can be subdivided into two processes, which differ in the heating of the fluidized bed, the circulating fluidized bed gasifier and the stationary fluidized bed gasifier. Literature for desulfurization in a fluidized bed gasification may be taken from the following sources: Gasification of Lignite and Wood in the Lurgi Circulating Fluidized Be Gasifier; Research Project 2656-3; Final Report, August 1988, P. Mehrung, H.Vierrath; LURGI GmbH; for Electric Power Research Institute, Palo Alto, California: ZWS pressure gasification in the combi-block,

Final Report BMFT FB 03 E 6384-A; P. Mehrung, LURGI GmbH; Bewag

In Güssing (Austria), an allothermal, circulating fluidized bed gasification plant was put into operation in early 2002. The biomass is gasified in a fluidized bed with steam as the oxidant. To provide heat for the gasification process, part of the charcoal produced in the fluidized bed is burned in a second fluidized bed. The gasification under steam produces a product gas. Disadvantageous are the high initial 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 conveyor organ in which

Solid / water mixtures by means of compressed air (propellant gas), e.g. Injection of this air by means of nozzles in pipes or a stirred tank, is promoted. 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.

As flow results in the containers a circulation flow.

There is thus a transfer to the solid / gas suspension of the fluidized bed. In the present case, this principle is transferred to the gas / solid suspension of the fluidized bed of the steam reformer. All of these systems need a transport system to release the biogenic feedstocks into the gasifier. The following invention describes a system comprising the processes of giving up the biogenic feedstocks in a gasifier, in particular in a pulse carburetor. The starting materials cover a wide range. So are

Extrusions, round pellets, as they are approximately in

Pelleting machines are produced or biogenic feedstocks from agriculture (cereals).

Characteristic of these biomasses are C contents of the starting substance in the range from 40 to 50% by weight, with hydrogen contents in the range up to 6% by weight and oxygen content in the range from 40 to 50% by weight. Typically, the calorific values of the feedstock range up to 20 MJ / kg. The bulk density varies between 200 and 700 kg / h. In addition to a certain amount of fine material extruded have a diameter between 5 and 10mm with a length of 10 to 20 mm, and particulate feedstock dimensions in the range of 20 x

30 mm and a thickness up to 10 mm.

Summary of the Invention: The object of the invention is a transport system that gives up the biomass efficiently taking into account special properties of the reactor in these.

This is achieved by a transport system with the features of one or more claims, the others have been disclosed below

The process flow includes the following substeps that are performed with the appropriate devices.

a. Intermediate buffer: An intermediate buffer in a silo (layer bunker) serves as a template for the entry and dosage. In this cache the feedstocks can be funded by different camps.

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

Starting from the nominal net gas production (resulting from the regulation scheme for the steam carburetors), the feedstock is dosed and distributed to one, two or more entry points so that the required gas production occurs. The system also ensures the function of the gland as pressure seal of the reactor system. The system has the flexibility to accomplish these tasks using the mentioned range of feedstocks. c. Sealing of the reaction system against atmosphere:

A pressure seal of the reactor through the material plug formed in the stuffing screw and a multi-stage system of rotary valve and gate valve before and after the StopfSchnecke, as well as an admission of the introduction tube with N 2 (nitrogen) or CO 2 (carbon dioxide) may be necessary, depending on the reactor type.

This material plug is continuously generated in the stuffing screw serving as an entry organ in the carburettor via an adjustment of the corresponding quantities. The feed screws are controlled so that the mass flow and the permanent formation of the sealing plug are ensured.

This system is further characterized in that the stuffing worm (s) are / are equipped in their front area with a nozzle system which operates in a manner similar to a jet pulse system, as known from filter technology.

The Stopfschecke also has cooling means of the shaft and the shell. (Optionally it is possible to cool the wave wings of this stuffing screw).

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

The material is introduced during operation of the carburetor in a dense, fluidized fluidized bed. Measures are taken to avoid the return flow of bedding material into the stuffing screw when the entry screw / s is at a standstill, in particular during the startup and shutdown operations. For this purpose, the system is equipped with a slide that works through the conveyed and produces the conclusion in a suitable manner. This facility allows over an emptying device and the emptying of this

StopfSchnecke (s) as a precaution against burn-back, such as. in the case of short-term shutdowns in otherwise hot carburetor can not be excluded.

These different approaches make the system suitable, all of which are suitable for the gasification process

Feed materials to the reactor. Due to the specific properties, the system also allows entry at internal pressures of up to 5 bar.

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 quantity to the stuffing screw;

- A rotary valve, gate valves before and after a stuffing screw and a stuffing screw.

The amount of gas produced depends directly (is proportional) on the amount of feedstock. This physical dependency is used to control the entry amount. The measurement of the product gas quantity, or the comparison between the standard value (setpoint specification) and the measured product gas quantity, serves as a master control of the amount of starting material. As can be seen from the figures, these sizes act directly on the metering screws (single, parallel or multiple design). These screw (s) are acted upon by the clearing and dosing screw of the intermediate bunker, these actuators are together it a level monitoring the Zuführschurre the

Metering screw (s) involved in the scheme.

The subsequent transport screws, which are not regulated in one possible embodiment, feed the feedstock to the actual feeding system.

The overall control concept thus includes the entry of biogenic feedstocks into a gasifier for alotine gasification with generation of the heat of reaction of the gasification reaction in special pulse burners.

Description of the figures:

Fig. 1 shows an overall schematic view of the invention; Fig. 2 shows the schematic structure of the metering screw and the stuffing screw;

Fig. 3 shows the stuffing screw in detail.

Preferred embodiments:

The control concept includes the specifications by the product gas quantity for the dosage of feedstocks by controlled discharge from a buffer and speed controlled dosing with monitoring the level of the feed chutes, the distribution on the entry organs and the formation of the plug in the speed-controlled feed screw, with their speed on the main controller (Master controller) and the level monitoring in the feeder to the entry system takes place. This feed system (for solids) in the context of fluidized bed gasification is a significant advance. The discharge system 1 (Fig. 1) consists of a through the

Master controller 2 speed-controlled screw 3, which is centrally mounted in the buffer 4. The entire screw is moved by means of likewise speed-controlled rotary drive 5 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.

About a metering screw 6, the amount by the master controller depending on the target size for

Product gas 7 determined. Accordingly, the amount fetched from the buffer is metered.

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

The entry system consists of cell wheel 10, slide 11 in front of the screw for further transport and at the same time shut off both in startup or shutdown mode and the presentation of StopfSchnecke 9. The system is equipped with a system 12 (see Fig. 3) for applying 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.

As is clear from Fig. 2, the system consists of the actual StopfSchnecke, in which the material stopper is created for pressure shut-off. The screw is designed so that this material plug in the entire speed range, so even with different amounts to be entered Feedstock remains stable. 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 worm has cooling devices 13, 14 for cooling the worm shaft 14 and alternatively the worm helices and the shell 13 of the worm. This is a wave cooling and a jacket cooling.

Part of the system is the gate valve 15 directly between feed screw and carburetor 16, which is closed when the screw is stopped and prevents the back of the inert bed material in the screw.

This slide is made of heat-resistant material because it is located at the interface of the hot in the carburetor and the cooled screw. By this measure, the reflux is prevented even in the operating phases in which not the registered feedstock itself produces the barrier.

The supply of feedstocks to the entry screw via Schurre 17, rotary valve 10 and gate valve 11. The level monitoring 18 in this feed line ensures the necessary permanent formation of the material plug for the set on the main control feed throughput. 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 slide 11 allows an additional gas-tight barrier. Thus, the pressure range of the reaction system up to 5 bar ü., Normally 1.5 bar ü controllable.

Claims

claims

1. Transport system for introducing biomass into one

Carburetor comprising: - a stuffing screw (9), which injects the biomass into the

Presses carburetor, wherein the StopfSchnecke is formed so that the biomass is compressed to promote on the one hand against a pressure in the carburetor and on the other hand to leave gas and bed material in the carburetor, - with a gate valve (16, 11) to the

StopfSchnecke adjoins, and which feeds the StopfSchnecke at standstill, so that heat, steam and gas can not escape.

2. The transport system according to the preceding claim, wherein a cooling (14, 13) cools the Stopfschnecke from the inside and / or outside.

3. The transport system according to one or more of the preceding claims, wherein a gate valve (11) before and a gate valve (15) is arranged after the stuffing screw.

4. The transport system according to one or more of the preceding claims, wherein a rotary valve (10) is arranged in front of the stuffing worm, to which a Zuführschurre borders.

5. The transport system according to one or more of the preceding claims, wherein the stuffing worm is equipped in its front region with a nozzle system which operates similar to a jet-pulse system.

6. The transport system according to one or more of the preceding claims, wherein in the housing of the stuffing screw a sealing gas can be introduced, in particular an introduction tube with N 2 (nitrogen) or CO 2 (carbon dioxide) is applied.

7. The transport system according to one or more of the preceding claims, wherein a cache, the

(4) operates with a regulated discharge unit (3), which is upstream of the stuffing screw.

8. The transport system according to the preceding claim, wherein the discharge system from a by a controller

(2) speed-controlled screw (3), which is centrally mounted in the buffer (4).

9. The transport system according to the preceding claim, wherein the entire screw is also movable by means of speed-controlled rotary drive (5) over the silo bottom.

10. The transport system according to one or more of the preceding claims, wherein one or more metering screw, the biomass, which is fetched from the buffer, metered, and if necessary. A transport screw transports the biomass to Stopfschnecke.

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 dependency as control of the feed rate, so that the measurement of the amount of product gas, or the comparison between the default value and the measured value Product gas quantity, as lead control of

Amount of feed used.

12. A method of introducing biomass into a gasifier comprising:

Introducing the biomass via a stuffing screw, wherein the stuffing screw is controlled so that biomass is compressed, on the one hand to promote against 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) adjacent to the stuffing screw, in case of stoppage of the stuffing screw, so that heat, steam and gas can not escape.

13. The method according to the preceding method claim, wherein a cooling (14, 13) cools the Stopfschnecke from the inside and / or outside.

14. The method according to one or more of the preceding method claims, wherein a gate valve (11) before and a gate valve (15) is arranged after the StopfSchnecke, and these are closed depending on the supply or the removal of the biomass.

15. The method according to one or more of the preceding method claims, wherein a rotary valve (10) is arranged in front of the stuffing worm, to which a Zuführschurre borders, wherein the lock (10) is controlled so that the StopfSchnecke is continuously supplied with biomass.

16. The method according to one or more of the preceding

Method claims, wherein the stuffing screw is equipped in its front region with a nozzle system, this works similar to a jet - pulse system to the

Inject biomass.

17. The method according to one or more of the preceding method claims, wherein in the housing of the

StopfSchnecke a barrier gas is introduced, in particular, a feed tube with N2 (nitrogen) or C02 (carbon dioxide) is applied to avoid that a pressure drop occurs.

18. The method according to one or more of the preceding method claims, wherein from a temporary storage (4) by a controlled discharge unit (3) the stuffing screw is supplied.

19. The method according to the preceding method claim, wherein the discharge system consists of a variable speed screw (3) which is mounted centrally in the buffer (4), and which is controlled by a controller (2).

20. The method according to the preceding method claim, wherein the entire screw is also moved by means of speed-controlled rotary drive (5) over the silo bottom.

21. The method according to one or more of the preceding method claims, wherein one or more dosing screw, which doses the amount that is taken from the buffer, and if necessary. A transport screw biomass transported to the stuffing screw.

22. The method according to one or more of the preceding method claims, wherein a control unit (2), the calculates the amount of produced gas 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.