1351 results about "Space velocity" patented technology

The invention relates to a process for preparing arene selectivity by enhancing methanol aromatizatian. The process uses methanol as raw material, compositely modifies HZSM-5 molecular sieve catalyst by active ions like Ga, Zn, Cu, Cr and Ag for catalyzing methanol aromatizatian, employs the fixed bed continuous process or the floating bed continuous process, wherein the reaction pressure is 0.1-3.5MPa; the reaction temperature is 380-500 DEG C; the space velocity of raw material liquid is 0.1-10.0 h; and N2 space velocity is 120-800 h. The advantages of the invention lie in collocation combination of mixing ion modification, and arene selectivity reaches to 70%.

A particulate pre-reduction cobalt supported Fischer-Tropsch synthesis catalyst precursor which comprises a catalyst support impregnated with cobalt, is treated with a pure hydrogen reducing gas, at a first specific feed gas space velocity, SV1, and at a first heating rate, HR1, to obtain a partially reduced precursor. The support contains reducible cobalt oxide in a calcined state and having a formula-unit in which each mole of cobalt atoms is associated with more than 4 / 3 moles of oxygen atoms and displaying a reducible cobalt oxide specific surface area at least equal to that of Co3O4 spinel. The partially reduced precursor is then treated with a pure hydrogen reducing gas, at a second specific feed gas space velocity, SV2, and at a second heating rate, HR2, to obtain an activated supported Fischer-Tropsch catalyst, with SV2≦SV1 and / or HR2≧HR1; however, when SV2=SV1, HR2≠HR1 and when HR2=HR1, SV2≠SV1.

The invention discloses a dehydrogenation catalyst for feed gas containing carbon monoxide, a preparation method and an application method thereof. The catalyst takes alumina as a carrier, palladium and / or platinum as an active component and 2 to 4 MOxes as an additive, M is sodium, potassium, magnesium, titanium, zirconium, vanadium, manganese, iron, nickel, cobalt, copper, molybdenum, tungsten or cerium, and components of the catalyst (calculated by carrier mass) are: 0.01 to 2 percent of the palladium and / or 0.01 to 1 percent of the platinum, and 1 to 2 percent of MOxes. The preparation method for the catalyst comprises the following steps that: firstly, an additive metal salt solution is used to impregnate the carrier; a palladium and / or platinum salt solution is used to impregnate the carrier after the carrier is dried and roasted; and the impregnated carrier is roasted at a temperature of between 450 and 850 DEG C to obtain the catalyst. Before the use, H2-N2 mixed gas containing more than 10 percent of hydrogen or pure hydrogen is activated by the catalyst at a temperature of between 450 and 650 DEG C. The catalyst can perform deep removal on less than 5 percent of hydrogen in the feed gas with the CO content of between 10 and 99 percent, the using temperature is between 100 and 300 DEG C, the space velocity is between 500 and 9,000h<-1>, the dehydrogenation rate is more than 99 percent, the content of outlet hydrogen is less than 100 ppm, and the loss of the carbon monoxide is less than 0.5 percent.

A process and apparatus for catalytic production of single walled carbon nanotubes. Catalytic particles are exposed to different process conditions at successive stages wherein the catalytic particles do not come in contact with reactive (catalytic) gases until preferred process conditions have been attained, thereby controlling the quantity and form of carbon nanotubes produced. The reaction gas is preferably provided at a high space velocity to minimize CO2 build-up. The process also contemplates processes and apparatus which recycle and reuse the gases and catalytic particulate materials, thereby maximizing cost efficiency, reducing wastes, reducing the need for additional raw materials, and producing the carbon nanotubes, especially SWNTs, in greater quantities and for lower costs.

The invention discloses a supported noble metal catalyst for low-temperature catalytically oxidizing benzene series (benzene, methylbenzene and dimethylbenzene) gas to CO2 and H2O. Active components of the noble metal catalyst are: at least one of Pd, Pt, Ag, Au and Rh; carrier is at least one of active carbon, red mud, molecular sieve, aluminum sesquioxide, titanium dioxide, manganese dioxide, zirconium dioxide, silicon dioxide, cerium dioxide, lanthanum sesquioxide, cobalt oxide, magnesium oxide, zinc oxide, calcium oxide and cupric oxide. Under general pressure, in atmosphere ambient, in fixed bed reactor, with a space velocity range from 10,000 to 100,000h<-1> and at a temperature range from 110 to 210 DEG C, the catalyst can be used for directly oxidizing 100 to 800ppm benzene series gas to CO2 and H2O without byproduct, which shows good low-temperature catalytic activity. The catalyst of the invention has the advantages of simple preparation, lower complete oxidation temperature, immunity to H2O, good stability and high practical value.

The invention relates to a method for preparing 1, 2-cyclohexanedicarboxylic acid ester of binary, comprising a reaction system composed by binary phthalate ester, hydrogen and a catalyst; the reaction temperature ranges from 100 to 250 DEG C; the reaction pressure ranges from 3.0 to 12.0 Mpa; the molar ratio of H2 and X ranges from 50 to 450; the liquid space velocity of binary phthalate ester ranges from 0.1 to 2.5 h<-1>; the catalyst uses Al2O3, ZrO2, TiO2 or SiO2-Al2O3 as vehicle, and load active component can be Ru, Pt, Pd, Rh, Fe, Co, Ni and Cu; the binary phthalate ester is diisonynol phthalate, diisooctyl phthalate or dibutyl phthalate; the product 1, 2-cyclohexanedicarboxylic acid ester of binary is 1, 2-cyclohexane diisononyl dimethyl ester, 1, 2-cyclohexane diisooctyl dimethyl ester or 1, 2-cyclohexane dibutyl dimethyl ester.

Provided is a method for preparing methyl acetate by dimethyl ether carbonylation, comprising passing a feed gas including dimethyl ether, carbon monoxide and optional hydrogen through a reactor filled with a mordenite and / or ferrierite molecular sieve based catalyst and reacting at a reaction temperature of 190-320°C, a reaction pressure of 0.5-20.0 MPa and a gas space velocity of 500-5000 h-1 so as to prepare methyl acetate, wherein the molar ratio of dimethyl ether to carbon monoxide is DME / CO=1 / 1-1 / 15, the molar ratio of hydrogen to carbon monoxide is H2 / CO=0-10 / 1, and the feed gas is distributed into each catalyst bed layer in a segmental feeding manner. A feed gas including dimethyl ether and carbon monoxide is uniformly distributed into each catalyst bed layer via a gas distributor, in a segmental feeding manner, which can remarkably improve the conversion rate of dimethyl ether, effectively control or adjust the temperature distribution of a catalyst bed layer, avoid the appearance of a hot spot, and prolong the service life of a catalyst.

The ammonia decomposition catalyst of the present invention is a catalyst for decomposing ammonia into nitrogen and hydrogen, including a catalytically active component containing at least one kind of transition metal selected from the group consisting of molybdenum, tungsten, vanadium, chromium, manganese, iron, cobalt, and nickel, preferably including: (I) a catalytically active component containing: at least one kind selected from the group consisting of molybdenum, tungsten, and vanadium; (II) a catalytically active component containing a nitride of at least one kind of transition metal selected from the group consisting of molybdenum, tungsten, vanadium, chromium, manganese, iron, cobalt, and nickel; or (III) a catalytically active component containing at least one kind of iron group metal selected from the group consisting of iron, cobalt, and nickel, and at least one metal oxide, thereby making it possible to effectively decompose ammonia into nitrogen and hydrogen at relatively low temperatures and at high space velocities to obtain high-pure hydrogen.