By hydrotreatment

Carbazole is a non-basic nitrogen compound, whose removal via hydrotreating is limited by its low reactivity. The removal of nitrogen by hydrotreatment involves a number of steps that take place on the catalyst surface. The weak interaction of neutral nitrogen compounds with catalysts precludes carbazole and its derivatives from being denitro-genated and makes them the most recalcitrant components in HDN of gas oils [308], In fact, it has been found that the nitrogen content of hydrotreated gas oil from Athabasca bitumen was composed primarily of alkyl carbazoles [309],... 

HDN as applied to coal liquefaction can be performed either during the liquefaction process itself or by hydrotreatment of the released oil. In H-Coal and Synthoil processes4 19,68d the coal is directly in contact with CoMo or NiMo catalysts in the H-Coal process, a slurry of H2, coal, ex-coal oil, and... 

Table VI. Relative Response of Synthoil and SRC to Upgrading by Hydrotreatment...

All around the world there exists an installed capacity to process residue utilizing solvent deasphalting as a carbon rejection technology followed by hydrotreatment of the deasphalted oil (DAO) or the residual. Severity of the hydrotreating stage depends on the downstream use of the hydrotreated DAO or the residual, which can be used as feedstocks to catalytic cracking/ hydrocracking or as components of low sulfur fuel. 

Facile preparation of nanostructured manganese oxides by hydrotreatment of commercial particles... 

Sheu, Y-H.E. Kinetic Studies of Upgrading Pine Pyrolytic Oil by Hydrotreatment, Ph.D. Dissertation, Texas A M University, 1985. 

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