摘要:
A process for the in situ attrition and break up of an agglomerating, or agglomerated catalyst to maintain and control the fluidization characteristics of a bed wherein low molecular weight hydrocarbons, oxygen and steam are contacted with the bed to produce hydrogen and carbon monoxide via both partial oxidation and steam reforming reactions. The feeds are injected into the reaction zone with mechanical energy input sufficient to balance the intrinsic rate of agglomeration by fracturing and breaking apart in situ the agglomerated catalyst to maintain the fluidization characteristics of the bed throughout the cycle of operation.
摘要:
A process for the production of syn gas (hydrogen and carbon monoxide) by reaction at high temperature between low molecular weight hydrocarbons, steam and oxygen in an impurities-containing refractory lined reaction zone. The lined reaction zone is pretreated with steam, or with steam and a reducing gas, e.g. a mixture of steam and hydrogen to leach out, react with, and transport the impurities, i.e., the reaction products of silica, or silica plus phosphorus or sulfur, or silica plus phosphorus and sulfur, from the reaction zone. Steam alone may be used to leach out, convert the silica to gaseous silicic acid, and remove same from the reaction zone; and then the hydrocarbons, steam and oxygen feeds are introduced into the reaction zone to produce syn gas.
摘要:
A particulate, precalcined low silica content zirconia, especially one stabilizer with yttria, is useful as a catalyst support or as a heat transfer solids component for conducting chemical reactions at high temperature, in oxidizing, reducing or hydrothermal conditions, especially in syn gas operations. An admixture of precalcined particulate low silica content zirconia, particularly a low silica content yttria-stabilized zirconia, is employed in a preferred embodiment as a heat transfer solid, in concentrations ranging generally from about 10 wt. % to about 99.9 wt. % with a particulate catalyst notably a nickel-on-alumina catalyst, in concentration ranging generally from about 0. 1 wt. % to about 90 wt. %. Such an admixture provides a particularly useful catalytic contact mass in high temperature oxidizing, reducing and hydrothermal environments, notably in conducting synthesis gas generation operations. This type of bed promotes continuous, highly efficient heat and mass transfer within the reacting gas phase. The presence of the heat transfer solid as a bed component maintains excellent bed fluidization characteristics, suppressing the normal tendency of the catalyst to sinter or agglomerate; tendencies which promote defluidization of the bed. Moreover, the heat transfer particles of the bed are highly attrition resistant, and are chemically compatible with the catalyst particles of the admixture.
摘要:
A process utilizing a particulate catalyst, or particulate catalyst admixed with particulate heat transfer solids for conducting high temperature fluidized bed syn gas operations. Hydrogen and carbon monoxide are produced from a low molecular weight hydrocarbon by contact thereof, at high temperature in the presence of oxygen, or steam and oxygen, with a fluidized bed comprising said particulate solids. In one of its forms, barium hexaluminate is employed as a heat transfer solid, in concentrations ranging generally from about 10 wt. % to about 99.9 wt. %, in admixture with a particulate catalyst containing a metal, or metals, component catalytic for the production of hydrogen and carbon monoxide from low molecular weight hydrocarbons contacted with a fluidized bed of the catalyst at high temperature hydrothermal conditions. The catalyst, suitably one having a barium hexaluminate carrier component, is employed in concentration ranging generally from about 0.1 wt. % to about 90 wt. %. Such an admixture provides a particularly useful catalytic contact mass for conducting fluidized bed synthesis gas generation operations. This type of bed promotes continuous, highly efficient heat and mass transfer within the reacting gas phase. The presence of the catalyst having a barium hexaluminate carrier component, or barium hexaluminate heat transfer solid as a bed component maintains excellent bed fluidization characteristics, suppressing the normal tendency of the catalyst to sinter or agglomerate; tendencies which promote defluidization of the bed. Moreover, the heat transfer particles of the bed are highly attrition resistant, and are chemically compatible with the catalyst particles of the admixture.
摘要:
High surface purity heat transfer solids are formed, suitably by washing and treating particulate refractory inorganic solids, notably alumina, which contains as impurities up to about 0.5 wt. % silicon and/or up to about 500 wppm boron, with an acid, or dilute acid solution sufficient to reduce the concentration of silicon and boron in the outer peripheral surface layer of the particles, e.g., as measured inwardly toward the center of a particle to a depth of about 50 .ANG. using X-ray photoelectron spectroscopy, to no greater than about 5 atom percent silicon and boron, preferably about 2 atom percent silicon and boron, based on the total number of cations within said outer peripheral surface layer, thereby reducing the tendency of said particles to sinter and agglomerate in the conversion of said hydrocarbon to hydrogen and carbon monoxide in a fluidized bed synthesis gas operation vis-a-vis particles otherwise similar except that the particles are not treated with the acid. The tendency of the particles to sinter and agglomerate is further reduced by the additional removal of sodium, iron, calcium, and titanium impurities from the outer peripheral surface layer of the particles. Preferably the latter named impurities, or impurities other than silicon and boron, are reduced to a concentration below about 20 atom %, more preferably to a concentration below about 15 atom %, in the outer surface layer of the particles.
摘要:
A structurally modified alumina useful as a catalyst support, or heat transfer solid for fluidized bed synthesis gas processing. A Group IIA metal, or metals, particularly magnesium and barium, is composited with a particulate alumina to provide a catalyst support, or alumina heat transfer solid, having increased resistance to sintering and agglomeration; properties which promote defluidization of the bed in conducting fluidized bed reactions at high temperatures. The particles of preference are represented by formulas (1) and (2), a composite particle being represented by formula (1), as follows:M.sub.x Al.sub.2 O.sub.3+x (1)with the core of the particle being represented by formula (2), as follows:M.sub.y Al.sub.2 O.sub.3+y (2)where in formulas (1) and (2) M is a Group IIA metal, x is a number ranging from about 0.01 to about 0.4 and is representative of the number of moles of the metal M per mole of Al.sub.2 O.sub.3 y is a number equal to or greater than zero, and x is greater than y.
摘要翻译:用作催化剂载体的结构改性氧化铝,或用于流化床合成气处理的传热固体。 IIA族金属或金属,特别是镁和钡与颗粒氧化铝复合以提供具有增加的耐烧结和附聚性能的催化剂载体或氧化铝传热固体; 促进床在高温下进行流化床反应的流化的性质。 优选的颗粒由式(1)和(2)表示,复合颗粒由式(1)表示,如下:颗粒的核心由式(2)表示的M x Al 2 O 3 + x(1) 如下:MyAl2O3 + y(2)其中式(1)和(2)中的M是IIA族金属,x是约0.01至约0.4的数,代表每个金属M的摩尔数 摩尔的Al 2 O 3 y是等于或大于零的数,x大于y。
摘要:
High surface purity heat transfer solids are formed, suitably by washing and treating particulate refractory inorganic solids, notably alumina, which contains as impurities up to about 0.5 wt. % silicon and/or up to about 500 wppm boron, with an acid, or dilute acid solution sufficient to reduce the concentration of silicon and boron in the outer peripheral surface layer of the particles, e.g., as measured inwardly toward the center of a particle to a depth of about 50 .ANG. using X-ray photoelectron spectroscopy, to no greater than about 5 atom percent silicon and boron, preferably about 2 atom percent silicon and boron, based on the total number of cations within said outer peripheral surface layer, thereby reducing the tendency of said particles to sinter and agglomerate in the conversion of said hydrocarbon to hydrogen and carbon monoxide in a fluidized bed synthesis gas operation vis-a-vis particles otherwise similar except that the particles are not treated with the acid. The tendency of the particles to sinter and agglomerate is further reduced by the additional removal of sodium, iron, calcium, and titanium impurities from the outer peripheral surface layer of the particles. Preferably the latter named impurities, or impurities other than silicon and boron, are reduced to a concentration below about 20 atom %, more preferably to a concentration below about 15 atom %, in the outer surface layer of the particles.
摘要:
A particulate, precalcined low silica content zirconia, especially one stabilized with yttria, is useful as a catalyst support or as a heat transfer solids component for conducting chemical reactions at high temperature, in oxidizing, reducing or hydrothermal conditions, especially in syn gas operations. An admixture of precalcined particulate low silica content zirconia, particularly a low silica content yttria-stabilized zirconia, is employed in a preferred embodiment as a heat transfer solid, in concentrations ranging generally from about 10 wt. % to about 99.9 wt. %, with a particulate catalyst, notably a nickel-on-alumina catalyst, in concentration ranging generally from about 0.1 wt. % to about 90 wt. %. Such an admixture provides a particularly useful catalytic contact mass in high temperature oxidizing, reducing and hydrothermal environments, notably in conducting synthesis gas generation operations. This type of bed promotes continuous, highly efficient heat and mass transfer within the reacting gas phase. The presence of the heat transfer solid as a bed component maintains excellent bed fluidization characteristics, suppressing the normal tendency of the catalyst to sinter or agglomerate; tendencies which promote defluidization of the bed. Moreover, the heat transfer particles of the bed are highly attrition resistant, and are chemically compatible with the catalyst particles of the admixture.
摘要:
Alumina heat transfer solids are admixed with a catalyst, or catalysts, and used in conducting high temperature fluidized bed reactions, particularly in a process for the production of hydrogen and carbon monoxide from a low molecular weight hydrocarbon by contact with a fluidized bed of catalyst and said heat transfer solids at high temperature in the presence of oxygen, or steam, or both oxygen and steam. The particulate heat transfer solids are characterized as having a performance index, PI, greater than 20, preferably greater than 40, as characterized by the formula PI=[(i).times.(ii).times.(iii).times.(iv)].sup.-1 where (i) the peripheral outer surface of the particle contains
摘要:
In a coal gasification operation or similar conversion process carried out in the presence of an alkali metal-containing catalyst wherein solid particles containing alkali metal residues are produced, alkali metal constituents are recovered from the particles by treating them with a calcium or magnesium-containing compound in the presence of water. The treating process is carried out under conditions such that the calcium or magnesium-containing compound reacts with water insoluble constituents of the alkali metal residues such as alkali metal aluminosilicates to produce an aqueous solution containing water soluble alkali metal constituents. The aqueous solution is recycled to the gasification process where the alkali metal constituents serve as at least a portion of the alkali metal constituents which comprise the alkali metal-containing catalyst. The process permits increased recovery of alkali metal constituents, thereby decreasing the overall cost of the gasification process by reducing the amount of makeup alkali metal compounds necessary.