EP2007854A1

EP2007854A1 - Process and device for process-integrated hot gas purification from dust and gaseous constituents of a synthesis gas

Info

Publication number: EP2007854A1
Application number: EP07726772A
Authority: EP
Inventors: Oliver Neumann
Original assignee: Spot Spirit Of Technology AG
Current assignee: Spirit Of Technology AG
Priority date: 2006-04-11
Filing date: 2007-03-09
Publication date: 2008-12-31
Also published as: US20090056537A1; DE102006017353A1; WO2007118736A1

Abstract

The procedure for process-integrated gas purification of a synthesis gas encompasses the following steps: gasification of the substances used in a reactor with the use of an impulse burner; the addition of additives into the reactor or in the gas passage that follows the reactor for the purpose of removing sulfur-containing gas components to achieve in situ removal; elimination of dust particles in the synthesis gas in the gas passage that follows; return of the removed dust particles to the reactor.

Description

Method and apparatus for process integrated hot

Gas cleaning of dust and gaseous ingredients of a

synthesis gas

Field of the invention:

The development of thermal gasification processes has essentially produced three different gasifier types, 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 forms 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), "High-Temperature Winkler Gasification of Municipal Solid Waste", Krupp Uhde GmbH, Gasification Technology Conference, San Francisco, California, USA; October 8-11, 2000; Conference Proceedings Literature for circulating fluidized bed in the composite system which is part of this application can be taken from the following literature: "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 - Rüdersdorfer Zement 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) which is part of this application can be taken from the following literature: 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 (chlackeabstichvergaser) which is part of this application can be taken from the following literature: 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 ⁰ C in their volatile and solid components. The result is a tar-containing gas and additionally "charcoal". The gas is burned at temperatures in excess of 1200 ° C, with tars decomposing into CO2 and H2. With the hot flue gas and the Charcoal is then produced 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 which forms part of this application can be found in the following literature: 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 PaIo Alto Californic: ZWS Pressure Gasification in Combination 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.

One of the main problems with all approaches is the cleaning of the exhaust gases. Overview of the invention:

The object of the invention is a method and apparatus for process-integrated hot gas cleaning of dust and gaseous ingredients of a synthesis gas, which in the

Gasification occur, especially in the gasification of biomass.

This object is achieved by an invention having the features of the independent claims. No other known process is capable of producing a high quality syngas at unrivaled low prices - as a result of relatively low investment - subject to C02 reduction or energetic use, and at the same time, after appropriate cooling and purification, as fuel to process.

In the present invention, the biomass is also gasified in a fluidized bed with steam as the oxidation and fluidizing medium. However, this is a stationary fluidized bed with two specially developed pulse burners, which allow an indirect heat input into the fluidized bed located in the reactor.

The advantage compared to the fixed-bed gasifier and the circulating fluidized bed is the lack of pronounced temperature and reaction zones. The fluidized bed consists of an inert bed material. This ensures a simultaneous sequence of the individual partial reactions and a homogeneous temperature (about 800 ^° C.). The process is virtually depressurised (up to a maximum of 0.5 bar) and is therefore technically easy to implement. It is characterized by a high economic efficiency. The acquisition costs are among the aforementioned carburetor types. The starting point for further use as fuel is the medium-calorific gas from the bio-synthesis gas plant (based on renewable raw materials), which after dedusting and scrubbing of condensable hydrocarbons (oil quench) via a turbo compressor to about 20 bar compressed and by the the following process steps can be refined:

Gas purification and CO2 removal via a Rectisol system - optimization of the ratio of H2 to CO via the shift method

Fischer-Tropsch synthesis

- Delivery to a favored hydro-cracker / production diesel with highest cetane. As a result, it should be noted that the process of the present invention, based on the synthesis gas, is capable of producing 100 tons of biomass 23 tons of high-grade fuel.

The inventive method and the corresponding devices require a purification of the generated

Synthesis gas to this in the specially developed

Pulse burners (including pilot burner) energetically implement. The system is based on the "in situ removal" of the gaseous pollutants in the reaction space of the steam converter or directly in the corresponding one

Gas line.

The pollutant components (sulfur) to be removed from the product gas are released directly during the gasification process. An essential component of the presently described process is the direct chemical bonding of these with the components released from the starting materials by the addition of the adsorbent into the gasification reactor. This immediate adsorption immediately after release of the Pollutant components are referred to as "in situ" gas purification (im

Case of removal of sulfur-containing components as desulfurization). The sulfur component in question is thus directly at the place of formation, i. adsorbed in the reaction zone of the gasification by means of the additive (practically during the formation), the sulfur (or the homologues selenium and telur) react to the sulfides, selenides and telurides. This procedure is known from applications in combustion processes and similar gasification processes (Ref .: 6, 7). Similar processes have been described for other burns and gasification in the literature.

In a first step, the goal is the sulfur-containing gas components. (mainly H2S) with the help of aggregates such as limestone, dolomite or similar processed or naturally occurring aggregates.

In addition to the removal of sulfur-containing components, this method can also be used for the sulfur accompanying substances of the same main group of the periodic table Se (selenium) and Te (Telur).

Investigations of these processes show that the thermodynamic stability of the pollutants prevailing in the vapor splitter directly separates the pollutants sulfur, telur selenium with high efficiency, while the adsorption of chlorine requires more reactive adsorbents and an adaptation to the reaction temperatures. The gaseous pollutant components forming in the reaction of the starting materials are transported to the solid particles of the adsorbents in the form of a two-phase reaction (gas-solid) by convection and diffusion of the pollutant to the adsorbent particle and react thermodynamically there stable salt. These particles are discharged with the grayling or partially separated into the gas purification stages downstream of the gas path, in particular in the multi-cyclone and the sintered metal fine filters, where they are selectively discharged.

In the second step, the goal is the absorption or removal of chlorine, which is present as a chlorine radical and derived from organic chlorine compounds. Other chlorine compounds (for example the chlorine salts chlorides) are less relevant in the context of the process according to the invention.

The method can be extended to the group of halogens (Cl, J, Br, F) according to the thermodynamic properties of the individual components. The absorbents or reactants are introduced in terms of process technology at the most suitable site for the respective task. In addition to a direct task either as a supplement to the feedstock or the direct metering in the steam converter, the injection into the external cyclone is expedient, especially to find suitable reaction conditions for the case of chlorine absorption.

In general, the control of the metering of additives takes place either via a ratio control with variable ratio between feedstock and additive or via a trim-back control, the reference variable reflecting the pollutant concentration measured in the synthesis gas.

The deposition of dust as a further step in the synthesis gas makes special demands on the deposition of extremely fine, high-carbon dust. In the context of the method according to the invention is carried out after intermediate cooling to temperatures between 150 and 700 ⁰ C (above the dew point of the synthesis gas) the dedusting in one Multicyclone and a downstream battery of

Sintered metal filters.

This gas purification stage (dedusting) consists of a multicyclone as pre-treatment stage and downstream of a filter unit. The multi-cyclone consists of a battery of small cyclones, which are mounted in a housing on a support plate. The incoming product gas (containing dust and adsorbent), distributed according to the flow resistance almost equally to the individual elements of the multi-cyclone. In these elements, the separation of a partial flow of the dust takes place (together with the adsorbent). The gas leaves the apparatus, the dust collects together with the likewise deposited adsorbent in the funnel of the apparatus, from where the separated substances are discharged.

The second stage of this hot gas cleaning and dedusting consists of fine filters with sintered metal candles. At these forms of the candles of the non-separated in the multicyclone stage dust and laden Adsorbensanteilen a filter cake, which causes in addition to the dust separation in particular in the case of the deposition of chlorine-containing pollutants without significant increase in Schadstoffadsorption. In addition, it is possible to selectively meter adsorbent in this area again. Layer thickness and the low flow rate of the cake are essential parameters.

Figures Description:

The figure is intended to describe the operation of the method and to better understand the following detailed description of the preferred embodiment. Fig. 1 shows the purification steps in a carburetor, with

Pulse burners is operated.

Preferred embodiment: Fig. 1 shows a carburetor 11 with impulse burners 12 which are arranged in the central region of the carburetor 11, in order to form in this region a fluidized bed or a fluidized bed, which are preferably formed stationary. The number of pulse burners can be determined variably. There are both one and two or more conceivable.

Steam is introduced into the gasifier as the oxidation and fluidization medium 13. Other Fluidisiermedium, such as syngas or CO2 are also conceivable. Furthermore, starting materials 14 are introduced in the region of the pulse burner 12. These feedstocks can be biomass and other substances like. Lignite or secondary raw materials (such as municipal waste, Klarschlämme, waste etc from the food industry .. The biomass is gasified in a fluidized bed, consisting of inert bed material in the range of about 800 ⁰ C. The pulse burner Q operated with Q (pkt) ( In addition to the synthesis gas (product gas) produced in the reformer, the most varied fuel gas streams (from propane to natural gas and similar gases) can be used as the fuel gas, so that in particular in one Plant combination of these pulse burners for the combustion of so-called off-gases, which can be used as by-products in syntheses such as methanol synthesis, can be used and thus contributes to increasing the efficiency of an entire system.

This fuel gas comes in normal operation as a branch of the own production, that is the refining of the biomass to a new product: heating gas (mittelkalorisch). For a first cleaning step to remove sulfur-containing gas components, preferably H ₂ S, the starting materials 14 additives are added, these may be calcium carbonate, limestone, dolomite or the like. These are inserted immediately in the area 1 of the impulse burner or in the fluidized bed or mixed with the feed before they are introduced into the fluidized bed. Alternatively, they may also be introduced directly into the reactor in the form of calcium carbonate, limestone, calcium hydroxide or the like. Here, the additive is preferably incorporated directly in the upper region of the reactor.

In a further step, an absorption or removal of chlorine, which is present as a chlorine radical and is usually derived from organic chlorine compounds by other additives. These other additives are preferably hydrated lime or the like. These additives 3, 4 are preferably injected into the dust separator 17 or the multi-cyclone. Of course, it is also conceivable to inject them directly into the reactor 11 or to add them to the starting materials 14.

The control or regulation of the addition of the additives is carried out either via a ratio control with variable ratio between feedstock and additive or via a trim-back control, which are measured by sensors reference variables in the synthesis gas, then a conclusion can be made to the pollutants.

In a further step, the dust components are separated. Here, different filters and separators are connected in series. Their residues are returned to the reactor. The return can be done at different locations. Below the pulse burner, above the pulse burner or directly into the Bed of burners. Preferably, cyclones 17 and multi-cyclones 18 are used, as well as filters, in particular fine filters 19, which may be formed as a downstream battery of sintered metal filters. In a first step, a cyclone 17 is connected downstream, wherein via a dust separation 21, a return can be done below or above the pulse burner.

Thereafter, an intermediate cooling takes place in a cooler 22 to temperatures between 150 and 700 ⁰ C (above the dew point of the synthesis gas), and then cooled to be purified in a multicyclone.

The additive hydrated lime or the like can both in the cyclone

17 as well as in the multi-cyclone 18 are supplied.

Thereafter, the synthesis gas is supplied in parallel or in series to a series of fine filters 19.

The residues of the fine filter and the multi-cyclone are collected in a dust separator 21 and fed back to the reactor at different points, as already described above. Thus, the separated dust above or below the pulse burner can be supplied.

LIST OF REFERENCE NUMBERS

I Additive task together with feedstock 2 Additive task directly into the reactor

3 Additive task in H "hot" cyclone

4 Additive task in multicyclone

A additive calcium carbonate, limestone, dolomite or similar B additive calcium carbonate, limestone, calcium hydroxide or similar

C, C * additive hydrated lime or similar

II reactor, carburetor 12 impulse burner 13 fluidizing medium

14 starting materials

15 Additive 16Q (pkt) 17 Cyclone 18 Multi-cyclone

19 fine filters

20 dust collectors

21 dust collector

22 cooler / heat exchanger

Claims

claims

A process for process-integrated gas purification of a synthesis gas, comprising the following steps:

- gasifying the feedstocks in a reactor through the use of pulse burners;

Adding additives to the reactor or the gas line following the reactor to remove sulfur-containing gas components to provide an in-situ

Distance to reach;

- Separation of dust in the synthesis gas in the downstream gas line;

- Return of the deposited dust particles in the reactor.

2. The method according to the preceding claim, comprising a further step, wherein the addition of additives into the reactor or the gas subsequent to the reactor to remove chlorine takes place.

3. The method according to the preceding claim, wherein the additives for removing chlorine in one or more downstream cyclones are added.

4. The process according to the preceding claim, wherein the additives are introduced both in a cyclone in which the synthesis gas has not yet substantially cooled, and also introduced into a second cyclone, after which the synthesis gas has been cooled.

5. The method according to the preceding claim, wherein an intermediate cooling in a cooler to temperatures between 150 and 700 ⁰ C, in particular above the

Dew point of the synthesis gas, takes place.

6. The method according to one or more of the preceding claims, wherein the chlorine by

Injecting lime hydrate or similar substances is removed as an additive.

7. The method according to one or more of the preceding claims, wherein the sulfur-containing

Gas components with additives comprising one or more of the following: calcium carbonate, limestone, dolomite, calcium hydroxide-like substances are removed.

8. The method according to one or more of the preceding claims, wherein the additives for removing the sulfur-containing gas components are added at one or more of the following points: The feedstock, directly in the range of

Burner burner, above the pulse burner.

9. The method according to one or more of the preceding claims, wherein in the central region of the reactor, at least one pulse burner is arranged to form in this area a fluidized bed, which is preferably formed stationary.

10. The method according to one or more of the preceding claims, wherein the deposition of the

Dust fractions are carried out by cyclones or multi-cyclones and fine filters connected in series, whose residues are preferably returned to the reactor via a dust separation.

11. The method according to the preceding claim, wherein there is a cooling of the synthesis gas between the cleaning in the cyclones.

12. The method according to one or more of the preceding claims, wherein the return of the deposited dust particles at one or more points in the reactor is carried out comprising: Below the pulse burner, above the pulse burner or directly into the bed of the pulse burner.

13. An apparatus for process-integrated gas purification of a synthesis gas, comprising the following components: - Reactor with at least one pulse burner, by

Feedstocks are gasified;

Feed means for additives into the reactor or the gas train following the reactor to remove sulfur-containing gas components to achieve in-situ removal;

- Separator in the subsequent gas line for the separation of dust in the synthesis gas;

- recirculating agent for returning the separated dust particles into the reactor.

14. The device according to the preceding claim, comprising supply means for the addition of additives in the reactor or the reactor following the gas to remove chlorine.

15. The apparatus of the preceding claim, wherein the delivery means are arranged to add the chlorine removal additives in one or more downstream cyclones.

16. The device according to the preceding claim, wherein a cooling device is arranged between two cyclones, so that the additives are introduced both in a cyclone in which the synthesis gas is not yet substantially cooled, and as are introduced into a second cyclone, after the synthesis gas was cooled.

17. The device according to the preceding claim, wherein the cooling device to an intermediate cooling

Temperatures between 150 and 700 ⁰ C, in particular above the dew point of the synthesis gas, performs.

18. The device according to one or more of the preceding claims, wherein the supply means

Hydrated lime or similar substances injected as an additive to remove chlorine.

19. The device according to one or more of the preceding claims, wherein the supply means

Additive for removing the sulfur-containing gas components comprising one or more of the following: calcium carbonate, limestone, dolomite, calcium hydroxide-like substances.

20. The device according to one or more of the preceding claims, wherein the supply means additives for removing the sulfur-containing gas components is arranged at one or more of the following locations: In the field of introduction of the

Starting material, directly in the area of the pulse burner, above the pulse burner.

21. The device according to one or more of the preceding claims, wherein in the central region of the reactor at least one, preferably several

Pulse burners are arranged to form in this area a fluidized bed, which is preferably formed stationary.

22. The device according to one or more of the preceding claims, wherein the deposition of the dust components by successively connected cyclones or multi-cyclones and fine filter is carried out, the residues are preferably recycled via a dust separation in the reactor.

23. The device according to one or more of the preceding claims, wherein the means are provided for a return of the deposited

Dust at one or more points in the reactor to be carried out comprising: Below the pulse burner, above the pulse burner or directly into the bed of the pulse burner.