English:
[0016] Another method of interstage heating is the oxidative reheat method that involves the admixture of a controlled amount of oxygen into the reactants and the selective oxidation of hydrogen generated in the aromatization process. The oxidation is accomplished in the presence of a catalyst that selectively promotes the oxidation of hydrogen as compared to the destructive combustion or oxidation of the more valuable feed and product hydrocarbons. However, the reaction generates steam that can be detrimental to the aromatization catalyst and can react with methane to form hydrogen and carbon monoxide.
[0026] Preferably, the process further includes transferring a second portion of the catalyst to a regeneration zone separate from said heating zone and contacting said second catalyst portion with a regeneration gas in said regeneration zone to remove at least part of the coke generated by said contacting
[0028] In a further aspect, the invention resides in a process for converting methane to higher hydrocarbons including aromatic hydrocarbons, the process comprising: and
[0029] Conveniently, said transferring (b) and (e) and said returning (d) and (g) are effected continuously.
[0031] As used herein, the term "dehydrocyclization catalyst" is intended to include not only the active component(s) of the catalyst but also any inert solids which may be present in addition to the active component(s) to enhance the physical properties of the catalyst and/or to aid heat transfer.
[0032] Figure 1 is a diagram of a dehydrocyclization reactor and catalyst reheater according to a first embodiment of the invention.
[0033] Figure 2 is a diagram of a dehydrocyclization reactor with a catalyst reheater and a catalyst regenerator according to a second embodiment of the invention.
[0034] Figure 3 is a diagram of a multiple fluid bed dehydrocyclization reactor according to a third embodiment of the invention.
[0035] Figure 4 is a diagram of a catalyst lift apparatus for use with the risers employed in the first, second and third embodiments of the invention.
[0036] Figure 5 compares the temperature profile of the flue gas with the temperature profiles at different radial positions within a catalyst particle having a diameter of 3650 [mu]m when heated in a riser with all the heat being supplied by burning fuel at the bottom of the riser.
[0037] Figure 6 compares the temperature profile of the flue gas with the temperature profiles at different radial positions within a catalyst particle having a diameter of 3650 [mu]m when heated in a riser with the heat being supplied by burning fuel at spaced positions along the length of the riser.
[0056] Suitable metal components for the catalyst include calcium, magnesium, barium, yttrium, lanthanum, scandium, cerium, titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, rhenium, iron, ruthenium, cobalt, rhodium, iridium, nickel, palladium, copper, silver, gold, zinc, aluminum, gallium, silicon, germanium, indium, tin, lead, bismuth and transuranium metals. Such metal components may be present in elemental form or as metal compounds, such as oxides, carbides, nitrides and/or phosphides, and may be employed alone or in combination.
[0066] In one practical embodiment, the heating zone is elongated and the first catalyst portion is passed through the heating zone from an inlet at or adjacent one end of the heating zone to an outlet at or adjacent the other end of the heating zone, with heat being applied to first catalyst portion at a plurality of locations spaced along the length of the heating zone, hi this way, the heat input to the first catalyst portion can be distributed along the length of the heating zone thereby minimizing catalyst surface temperatures and internal gradients.
[0067] Where the first catalyst portion is heated by direct contact with the burning source of fuel in the heating zone, gradual heating of the catalyst can be achieved by supplying substantially all of the supplemental fuel to the inlet end of the heating zone and then supplying the oxygen-containing gas incrementally to said heating zone at said plurality of spaced locations along the length of heating zone.
[0068] Where the first catalyst portion is heated by direct contact with hot combustion gases generated in a separate combustion zone, gradual heating of the catalyst can be achieved by supplying the hot combustion gases to said plurality of spaced locations along the length of heating zone.
[0072] In addition, since the reheating step may tend to oxidize catalytically active metal species, particularly metal carbides, contained by the first catalyst portion, the reheated catalyst is preferably subjected to a carburizing step prior to being reintroduced into the reaction zone.
[0079] In an alternative embodiment, the dehydrocyclization step is conducted in a plurality of fiuidized bed reactors connected in series, with the feedstock entering the first reactor in the series and the heated first catalyst portion and the regenerated second catalyst portion being returned to the final reactor in the series. Conveniently, said first and second catalyst portions are removed from the first reactor.
[0098] The resultant methanol and/or other oxygenates can be sold as a separate product, can be used to alkylate the aromatics generated in the dehydrocyclization step to higher value products, such as xylenes, or can be used as a feedstock for the production of lower olefins, particularly ethylene and propylene. The conversion of methanol to olefins is a well-known process and is, for example, described in U.S.
[00111] In addition, methane and CO2 and/or steam may be fed to a reverse shift reactor to generate syngas which can then be mixed with a portion of the dehydrocyclization effluent to adjust the H2/CO/CO2 ratios as required for the alkylation step.
[00112] Typically, the reverse shift reactor contains a catalyst comprising a transition metal on a support, such as Fe, Ni, Cr, Zn on alumina, silica or titania, and is operated under conditions including a temperature of about 500C to about 1200C, such as about 600C to about 1000C, for example about 700C to about 950C and a pressure of about 1 IcPa to about 10,000 kPa, such as about 2,000 kPa to about 10,000 kPa, for example about 3000 kPa to about 5,000 kPa. Gas hourly space velocities may vary depending upon the type of process used, but generally the gas hourly space velocity of flow of gas through the catalyst bed is in the range of about 50 hr to about 50,000 hr, such as about 250 hr to about 25,000 hr, more preferably about 500 hr to about 10,000 hr.
[00113] The effluent from the reverse shift reactor can then be fed to an alkylation reactor operating under conditions to cause reactions such as the following to occur:

中文:
[0016]另一种级间加热的方法是氧化再加热方法,该方法包括将受控量的氧混入反应物并将芳构化过程中生成的氢选择性氧化。与将更有价值的进料和产物烃破坏性地燃烧或者氧化相比,该氧化在催化剂的存在下实现,该催化剂选择性地促进了氢的氧化。然而,该反应产生了会对芳构化催化剂有害并且能够与甲烷反应以形成氢和一氧化碳的蒸汽。此外,由于使用第二种选择性氧化催化剂,这种方法具有额外的复杂性和成本。
[0026]优选地,该方法还包括:将该催化剂的第二部分转移至与所述加热区分离的再生区,并使所述第二催化剂部分在所述再生区中与再生气体接触以除去至少一部分由所述接触(a)产生的焦炭。
[0028]在另一方面,本发明涉及用于将甲烷转化为包括芳族烃的更高级烃的方法,该方法包括:
[0029]适宜地,连续地进行所述转移(b)和(e)以及所述送回(d)和(g)。
[0031]本文所使用的术语′′脱氢环化催化剂′′意在不仅包括催化剂的活性组分(一种或多种),还包括除该活性组分(一种或多种)之外可能存在的用来提高该催化剂的物理性能和/或帮助传热的任何惰性固体。
[0032]图1是根据本发明的第一个实施方案的脱氢环化反应器和催化剂再加热器的示意图。
[0033]图2是根据本发明的第二个实施方案的脱氢环化反应器与催化剂再加热器和催化剂再生器的示意图。
[0034]图3是根据本发明的第三个实施方案的多重流化床脱氢环化反应器的示意图。
[0035]图4是与用于本发明的第一、第二和第三个实施方案的提升管一起使用的催化剂提升装置的示意图。
[0036]图5对当在提升管中加热并且所有热都是通过在该提升管底部燃烧燃料来提供时,将烟道气的温度分布与在直径为3650μm的催化剂颗粒内的不同径向位置处的温度分布进行了比较。
[0037]图6对当在提升管中加热并且通过在沿着该提升管长度的分隔位置处燃烧燃料提供热时,将烟道气的温度分布与在直径为3650μm的催化剂颗粒内的不同径向位置处的温度分布进行了比较。
[0056]适合于催化剂的金属组分包括钙、镁、钡、钇、镧、钪、铈、钛、锆、铪、钒、铌、钽、铬、钼、钨、锰、铼、铁、钌、钴、铑、铱、镍、钯、铜、银、金、锌、铝、镓、硅、锗、铟、锡、铅、铋和铀后金属。所述金属组分可以元素形式或作为金属化合物存在,如氧化物、碳化物、氮化物和/或磷化物,以及可以单独或组合使用。也可以将铂和锇用作金属组分之一,然而一般不是优选的。
[0066]在一个实际的实施方案中,延长该加热区并使该第一催化剂部分从位于该加热区的一端或其附近的入口到位于该加热区的另一端或其附近的出口通过该加热区,其中在沿着该加热区的长度上分隔的多个位置上向第一催化剂部分施加热。以这种方式,输入给该第一催化剂部分的热可以沿该加热区的长度分布,从而使催化剂表面温度和内部梯度最小化。
[0067]当通过与燃烧的燃料源在加热区中直接接触来加热该第一催化剂部分时,可以如下实现该催化剂的逐渐加热:将基本上所有的补充燃料提供给该加热区的入口端然后在沿着加热区的长度的所述多个分隔的位置处将该含氧气体逐渐增加地提供给所述加热区。或者,可以将燃烧所述补充燃料所要求的基本上所有的含氧气体提供给该加热区的入口端,并且在所述多个分隔的位置处将该补充燃料逐渐增加地提供给该加热区。
[0068]当通过与单独的燃烧区中产生的热燃烧气体直接接触来加热该第一催化剂部分时,可以通过将该热燃烧气体提供给沿着加热区长度的所述多个分隔的位置来实现该催化剂的逐渐加热。
[0072]此外,由于该再加热步骤可能往往使将该第一催化剂部分包含的活性金属物质,尤其是金属碳化物催化氧化,所以该再加热的催化剂优选在再引入该反应区之前经历渗碳步骤。适宜地,该渗碳步骤通过使该第一催化剂部分与H2,和CO、CO2,和/或烃如甲烷、乙烷或丙烷接触来进行,并且可以与该水/氧汽提步骤同时或分别进行。
[0079]在备选实施方案中,该脱氢环化步骤在多个串联连接的流化床反应器中进行,其中原料进入该串联中的第一个反应器,将加热的第一催化剂部分和再生的第二催化剂部分送回至该串联中的最后一个反应器。适宜地,将所述第一和第二催化剂部分从该第一个反应器中取出。
[0098]所得甲醇和/或其它含氧化合物可以作为单独的产物销售,可以用于将脱氢环化步骤中生成的芳族化合物烷基化成更高价值的产物如二甲苯,或者可以用作生产低级烯烃,特别是乙烯和丙烯的原料。甲醇至烯烃的转化是公知的工艺,例如在美国专利No.4,499,327中得到描述,其通过引用并入本文。
[00111]此外,可以将甲烷和CO2和/或蒸汽进料至逆向变换反应器以产生合成气,然后可以将该合成气与脱氢环化流出物的一部分混合以根据烷基化步骤的需要调节H2/CO/CO2比例。
[00112]通常,逆向变换反应器包含在载体上含有过渡金属的催化剂,如在氧化铝、二氧化硅或二氧化钛上的Fe、Ni、Cr、Zn,以及在下列条件下运行:包括大约500°C-大约1200°C、如大约600°C-大约1000°C、例如大约700°C-大约950°C的温度,大约1kPa-大约10,000kPa、如大约2,000kPa-大约10,000kPa、例如大约3000kPa-大约5,000kPa的压力。气时空速可以取决于所用方法的类型改变,然而一般地通过催化剂床的气体流动的气时空速为大约50hr-1-大约50,000hr-1、如大约250hr-1-大约25,000hr-1、更优选大约500hr-1-大约10,000hr-1。
[00113]然后可以使来自逆向变换反应器的流出物进料至烷基化反应器中,该反应器在使得诸如下列等的反应发生的条件下运行: