Hiroshi Nagaishi

Chemical structure changes in Cold Lake oil-sand bitumen and catalytic activities during catalytic hydrotreatment

Abstract Chemical structure changes in Cold Lake oil-sand bitumen and catalytic activities of red-mud/sulfur and Niue5f8Mo catalysts during catalytic hydrotreatment are discussed. Particular attention is given to hydrogenation and hydrogenolysis of structural units, and to the removal of heteroatoms. Niue5f8Mo catalyst at 450°C reaction temperature gives high conversion of oil-sand bitumen to lower boiling fractions improving H C ratio and extensive removal of heteroatoms. According to the deposition of metals on the spent catalysts, red-mud/sulfur catalyst is effective for bitumen demetallization, removing V and Ni metals.

Colombian coal liquefaction and its coprocessing with Venezuelan crude oil

Titiribi coal from Colombia shows an excellent reactivity to liquefaction and coprocessing. Anthracene oil was excellent as a vehicle oil to facilitate the liquefaction reaction during the initial stage at 400°C. In the case of coprocessing with Morichal crude oil and red-mud/sulfur catalyst, the maximum conversion of Titiribi coal was ca. 79 wt% daf at 400°C and ca. 93 wt% daf at 450°C. The hydrogen consumption in the presence of Morichal crude oil is lower than that in the presence of anthracene oil. It is considered to be the effect of hydrogen sulfide and the hydrogen donor ability of Morichal crude oil.

Hydropyrolysis of Alberta coal and petroleum residue using calcium oxide catalyst and toluene additive

Abstract Hydropyrolysis of a mixture of Alberta coal and Athabasca bitumen was carried out in a batch reactor using calcium oxide as an alternate catalyst and the results were compared with those of widely used iron oxide and well-known NiMo/Al2O3 catalysts. Most of the reactions were done at temperatures of 500–540°C, residence time of 1xa0min and hydrogen pressure of 3.4xa0MPa. Maximum distillable oil (below 523°C) yield of 55xa0wt% and pitch conversion of 62xa0wt% were obtained in the presence of CaO or Fe2O3 and these values were higher than those without catalyst, although NiMo/Al2O3 catalyst gave much higher oil yield and pitch conversion. Catalyst concentration (above 2xa0wt%) has no consequence upon the distribution of various product fractions. In another study, addition of 15% toluene to the feed in the absence of catalyst led to higher distillable oil yield (68xa0wt%) and pitch conversion (72xa0wt%) in the hydroconversion of coal and bitumen mixture. Increase in toluene concentration from 15 to 50xa0wt% had no positive effect on the product yields.

Behavior of solid particles in a bubble column with simultaneous gas-liquid injector.

気液同時吹き込みノズルを備えた気泡塔を気液固系に応用し, 固体粒子の軸ならびに半径方向濃度分布を測定した.吹き込み部近傍では, 噴流の粒子層内吹き抜けのため, 塔壁部に中心部に比べて高濃度の粒子層が形成された.塔中心部の固体粒子の軸方向濃度分布は, 既存の沈降拡散モデルで説明でき, これに基づいて粒子の軸方向混合拡散係数の実験式を得ることができた.また, 粒子径の異なる2種類の粒子が共存する場合も両粒子の軸方向混合拡散係数は一致し, 粒子間の相互作用は認められなかった.

Catalytic effect of selenium and selenium dioxide on the devolatilization of Yallourn coal.

Devolatilization of Yallourn coal with selenium and selenium dioxide were examined under nitrogen atmosphere in the temperature range of 653 to 873 K using thermogravimetric method. The H2, CH4 and CO released from coal were analyzed in the temperature range. It has been shown that selenium and selenium dioxide catalysts accel-erate the volatilization reaction above 723 K. Particularly, the CO evolution was promoted at 773 K and the amount of CO released from coal with the catalysts was about 8 or 12 times as much as without the catalysts. Furthermore, the CO/CH4 volumetric ratio over the both catalysts was larger than that in the absence of the catalysts, namely the catalysts accelerated CO evolution selectively.