摘要:
A combustion system comprising a burner and a combustion chamber, is connected by way of a line to a membrane unit having a high-temperature membrane for extracting the combustion oxygen from the air, the membrane unit having a feed line for a flushing gas on the permeate side. The combustion system further comprises a circulation element for recirculated flue gas, a heat exchanger being disposed upstream of the membrane unit inside the flue gas line. Disclosed is a method for operating this combustion system, in which carbon-containing fuel is burned in an oxygen-flue gas atmosphere, and in which the oxygen for combustion is produced from air by means of a membrane unit comprising a high-temperature membrane, and in which the flue gas is in part recirculated. Disclosed are the steps of first cooling the recirculated flue gas, optionally for a flue gas scrubbing process, subsequently reheating the cooled flue gas to ensure the necessary operating temperature of the membrane, the heating energy being extracted by way of a heat exchange with the flue gas having the corresponding temperature level of the combustion process, and feeding the flue gas heated in this manner to the membrane unit as a flushing gas.
摘要:
A method for generating heat energy in a power plant by burning a carbonaceous fuel in a combustion chamber of the power plant and a system for carrying out the method is described. A combustion chamber is fluidly connected to a membrane chamber that includes a membrane operating at a temperature between 600 and 1000° C. The combustion chamber receives a cleaned flue-gas oxygen mixture for combustion from the membrane chamber. Oxygen from heated air passes through the membrane in the membrane chamber to the permeate side of the membrane, where it is mixed with cleaned heated flue gas and the resulting gas mixture is fed to the combustion chamber. Flue gas removed from the combustion chamber are cooled, cleaned and heated as described herein and recirculated to the membrane chamber.
摘要:
A method for separating carbon dioxide from a flue gas using a membrane (membrane module) is characterized in that the flue gas is at temperatures above the condensation point of the water vapor before entering the membrane separation stage. In this way, condensation of any potentially entrained water vapor out of the flue gas is avoided, so as to consistently prevent clogging of the membrane pores. The high temperatures can be achieved in different ways. The temperature of the flue gas can easily be increased to the necessary temperatures by way of an upstream heat exchanger or a burner. A compressor, which is connected upstream of the membrane module and also advantageously increases the CO2 partial pressure, brings about the necessary temperature increase at the same time. As a further alternative for the invention, the CO2 separation is performed even before desulfurizing the flue gas. This notably has the advantage of the flue gas in this process stage still being at temperatures above the condensation point of the water vapor, and thus not having to be heated separately, in addition to which, it generally carries little water vapor at this stage of the scrubbing operation.
摘要:
Provided is a power plant for generating electrical energy comprising a combustion chamber for producing steam, at least one downstream flue gas purification stage, a separation stage for CO2, a recycling circuit for the flue gas, and a high-temperature O2 membrane, which is connected upstream of the combustion chamber. The high-temperature O2 membrane has an inlet and an outlet on the feed side which are thermally coupled by way of a heat exchanger. On the permeate side, the high-temperature O2 membrane has only an outlet which is connected to the combustion chamber and/or the flue gas recycling circuit and a means for cooling and/or compression which is disposed in this outlet. The power plant, in which coal is burned using substantially pure oxygen, and in which the combustion waste gas is purified and partially recirculated to the combustion process, is operated in such a way that the oxygen that is used is obtained by separation from air using a high-temperature O2 membrane, wherein the membrane is operated with atmospheric air at a pressure of up to 2 bar on the feed side and a negative pressure of between 0.02 and 0.5 bar is applied on the permeate side.
摘要:
Provided is a power plant for generating electrical energy comprising a combustion chamber for producing steam, at least one downstream flue gas purification stage, a separation stage for CO2, a recycling circuit for the flue gas, and a high-temperature O2 membrane, which is connected upstream of the combustion chamber. The high-temperature O2 membrane has an inlet and an outlet on the feed side which are thermally coupled by way of a heat exchanger. On the permeate side, the high-temperature O2 membrane has only an outlet which is connected to the combustion chamber and/or the flue gas recycling circuit and a means for cooling and/or compression which is disposed in this outlet. The power plant, in which coal is burned using substantially pure oxygen, and in which the combustion waste gas is purified and partially recirculated to the combustion process, is operated in such a way that the oxygen that is used is obtained by separation from air using a high-temperature O2 membrane, wherein the membrane is operated with atmospheric air at a pressure of up to 2 bar on the feed side and a negative pressure of between 0.02 and 0.5 bar is applied on the permeate side.
摘要:
A composite membrane for selective gas separation, comprises a layer system having a continuously porous, mechanically stable carrier layer, which has an average pore size in the μm range, further having at least one continuously porous intermediate layer, which is disposed on the carrier layer and has an average pore size in the range of 2 to 200 nm, and further having a gastight functional layer, which is disposed on the intermediate layer and is made of a mixed-conductive material having a maximum layer thickness of 1 μm. The carrier layer comprises a structural ceramic, a metal, or a cermet and has a layer thickness of no more than 1 mm. The intermediate layer is present with a total layer thickness of no more than 100 μm and has an average pore size in the range of 10 to 100 nm. The functional layer comprises a perovskite, a fluorite, or a material having a K2NiF4 structure, such as La1-xSrxCo1-yFeyO3-8 (LSCF). The layer thickness of the functional layer is no more than 50 nm, and particularly between 25 and 400 nm. In order to produce this composite membrane, at least one porous intermediate layer is applied onto a continuously porous, mechanically stable carrier layer, which has an average pore size in the μm range, wherein the intermediate layer has an average pore size in the range of 2 to 200 nm. A further gastight, functional layer made of a mixed-conductive material and having a maximum layer thickness of 1 μm is applied onto the intermediate layer.
摘要:
The invention relates to a composite membrane for selective gas separation, comprising a layer system having a through-and-through porous, mechanically stable carrier layer, which has an average pore size in the μm range, further having at least one through-and-through porous intermediate layer, which is disposed on the carrier layer and has an average pore size in the range between 2 and 200 nm, and further having a gas-tight functional layer, which is disposed on the intermediate layer and is made of mixed-conductive material having a maximum layer thickness of 1 μm. The carrier layer comprises structural ceramics, a metal or a cermet and has a layer thickness of no more than 1 mm. The intermediate layer is present in a total layer thickness of no more than 100 μm and has an average pore size in the range of 10 and 100 nm. The functional layer comprises a perovskite, a fluorite, or a material having a K2NiF4structure, such as La1-xSrxCo1-yFeyO3-δ(LSCF). The layer thickness of the functional layer is no more than 50 nm, particularly between 25 and 400 nm. In order to produce said composite membrane, at least one porous intermediate layer is applied onto a through-and-through porous, mechanically stable carrier layer, which has an average pore size in the μm range, said intermediate layer having an average pore size in the range between 2 and 200 nm. A further gas-tight, functional layer made of a mixed-conductive material and having a maximum layer thickness of 1 μm is applied onto said intermediate layer.
摘要:
The invention relates to a device for electrically contacting electrodes in high-temperature fuel cells. The inventive device is characterized by an interconnector plate with openings and contact elements, which are located therein and which are provided for electrically contacting electrodes. The contact elements protrude from both sides of the interconnector plate at a predetermined height, and the openings are sealed in a gas-tight manner.
摘要:
The invention relates to a method for the hydrothermal production of a microporous membrane. According to said method, a colloidal solution comprising zeolite frameworks with 4-ring, 6-ring, and/or 8-ring pores which are provided as crystallites whose size ranges from 2 to 25 nm is applied to a porous substrate with the aid of a wet application technique. The applied layer is contacted with a hydrothermal liquid, and a nanocrystalline, microporous zeolite layer having an average pore diameter of 0.2 to 0.45 nm is synthesized at temperatures ranging between 50 and 250° C. and at an autogenous pressure. Such a microporous membrane comprising a porous substrate and at least one nanocrystalline zeolite layer that is disposed thereupon and has an average pore diameter of 0.2 to 0.45 nm is advantageously suitable for use as a separating device for gas phase separation, making it possible to separate particularly N2O2, N2/CO2, H2/CO2, or CO2/CH4 gas mixtures. Said separating device is especially temperature-resistant and can therefore be integrated directly into thermal processes.
摘要:
The material according to the invention is based on a material having the composition Ln6WO12 with a defect fluorite structure in which the cations, at least partially, have been substituted in a defined manner in the A and/or B position. It has the following composition: Ln1-xAx)6(W1-yBy)zO12-δ where Ln=an element from the group (La, Pr, Nd, Sm), A=at least one element from the group (La, Ce, Pr, Nd, Eu, Gd, Tb, Er, Yb, Ca, Mg, Sr, Ba, Th, In, Pb), B=at least one element from the group (Mo, Re, U, Cr, Nb), 0≦x≦0.7 and 0≦y≦0.5, wherein, however, either x or y>0, 1.00≦z≦1.25 and 0≦δ≦0.3. The mixed proton-electron conducting material exhibits an improved mixed conductivity, good chemical stability as well as good sintering properties, and can be used in particular as a material for a hydrogen-separating membrane or as a electrolyte at higher temperatures.
摘要翻译:根据本发明的材料基于具有缺陷萤石结构的组成为Ln6WO12的材料,其中阳离子至少部分地以限定的方式在A和/或B位置被取代。 它具有以下组成:Ln1-xAx)6(W1-yBy)zO12-delta其中Ln =来自基团的元素(La,Pr,Nd,Sm),A =至少一种元素(La,Ce ,Pr,Nd,Eu,Gd,Tb,Er,Yb,Ca,Mg,Sr,Ba,Th,In,Pb),B =至少一种元素(Mo,Re,U,Cr,Nb) ,0 @ x @ 0.7和0 @ y @ 0.5,其中,然而,x或y> 0,1.00 @ z @ 1.25和0 @ 混合的质子 - 电子导电材料具有改进的混合导电性,良好的化学稳定性以及良好的烧结性能,并且特别可用作氢分离膜或更高温度下的电解质的材料。