In Situ Catalytic Upgrading of Heavy Crude with CAPRI: Influence of Hydrogen on Catalyst Pore Plugging and Deactivation due to Coke
In Situ Catalytic Upgrading of Heavy Crude with CAPRI: Influence of Hydrogen on Catalyst Pore Plugging and Deactivation due to Coke
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DOI：
10.3390/en11030636
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发表时间：
2018-03-01
期刊：
影响因子：
3.2
通讯作者：
Wood, Joseph
中科院分区：
文献类型：
--
作者：
Hart, Abarasi;Wood, Joseph
已知重质原油与轻质油相比具有低的氢碳比。这是由于富含碳的物质如树脂和沥青质的显著含量;因此它们的升级通常通过碳排斥。然而，碳排斥促进催化剂的快速结垢和孔堵塞，产生低改质油，并且因此在蒸馏时产生低燃料馏出物馏分。在预先建立的条件（425 ℃，LHSV 11.8 h（-1）和20-40 bar）下，使用模拟的固定床反应器研究了氢气添加对原位催化改质的作用，所述模拟的固定床反应器模拟围绕趾部到跟部空气注入（THAI）工艺的水平生产井的催化剂的环形鞘（卡普里）。发现在加入H的情况下，改质油美国石油学会（API）比重增加到约5度，相比之下，用高于13度的N-2（THAI进料油）获得3度。燃料馏出物馏分相对于40.6%（THAI进料油）增加到62%（N-2，20巴）、65%（H-2，20巴）和71.8%（H-2，30巴）;而实验后催化剂的焦炭含量为35.3重量%（N-2）和27.2重量%（H-2）。还发现，由于焦炭导致的催化剂孔堵塞和失活在氢气下比在氮气下显著更低;因此，当在氢气下进行升级反应时，催化剂对焦炭结垢不太敏感。焦炭结垢随着氢气压力的增加而进一步减少，而从20巴到40巴的压力每增加10巴，改质油的API比重略微增加0.3度。
Heavy crude oil is known to have low hydrogen-to-carbon ratios compared to light oil. This is due to the significant content of carbon-rich species such as resins and asphaltenes; hence their upgrading is commonly through carbon-rejection. However, carbon-rejection promotes rapid fouling of catalyst and pore plugging, yielding low upgraded oil and consequently low fuel distillate fractions when distilled. The roles of hydrogen-addition on in situ catalytic upgrading were investigated at pre-established conditions (425 degrees C, LHSV 11.8 h(-1), and 20-40 bars) using a simulated fixed-bed reactor that mimics the annular sheath of catalyst (CAPRI) surrounding the horizontal producer well of the Toe-to-Heel Air Injection (THAI) process. It was found that with H-addition, the upgraded oil American Petroleum Institute (API) gravity increased to about 5 degrees compared to 3 degrees obtained with N-2 above 13 degrees (THAI feed oil). The fuel distillate fractions increased to 62% (N-2, 20 bar), 65% (H-2, 20 bar), and 71.8% (H-2, 30 bar) relative to 40.6% (THAI feed oil); while the coke contents of the catalyst after experiments were 35.3 wt % (N-2), and 27.2 wt % (H-2). It was also found that catalyst pore plugging and deactivation due to coke was significantly lower under hydrogen than with nitrogen; hence the catalyst is less susceptible to coke fouling when the upgrading reaction is carried out under hydrogen. The coke fouling further decreases with increasing hydrogen pressure while the API gravity of the upgraded oil marginally increases by 0.3 degrees for every 10 bar increase in pressure from 20 to 40 bar.