煤焦油固定床加氢原料切割点确定及工艺研究

Determination of feed cutting point of coal tar fixed-bed hydrogenation unit and study of hydrogenation process conditions

以煤焦油各窄馏分占原料油的百分比及沥青质含量为依据,确定了煤焦油固定床加氢原料的切割点,并以切割后的煤焦油轻组分为原料,在3 ×400 mL固定床加氢中试装置上进行加氢改质,考察了催化剂床层温度和进料空速对加氢效果的影响.实验表明：460℃为该煤焦油合适的固定床进料切割点,煤焦油初馏点～460℃馏分固定床加氢最佳的工艺条件为：保护剂床层温度260℃、精制催化剂床层温度380℃、芳烃饱和催化剂床层温度380℃,空速为0.8h-1.在此工艺条件下,加氢改质后油品密度、残炭、杂原子含量显著降低,H/C提高.产品石脑油、柴油、蜡油收率依次为25.9％,63.2％,10.9％,石脑油芳烃含量高,可作为重整原料,柴油十六烷值高,硫、氮含量低,可作为优质的柴油调合油,蜡油精制后作为润滑油基础油.

The cutting point of feedstock of fixed-bed hydrogenation process was determined based upon the percentage of different narrow fractions of coal tar oil and asphaltene contents.The cut light fraction of coal tar oil was used as feedstock and upgraded in a 3 × 400 mL fixed-bed hydrogenation pilot plant,and the impact of catalyst bed temperature and feed flow velocity on the hydrogenation performance was studied.The demonstration tests show that the appropriate feed cutting point of cal tar fixed-bed hydrogenation unit is 460 ℃.The optimum process conditions of fixed-bed hydrogenation for IBP ～460 ℃ fraction are：260 ℃ guard catalyst bed temperature,380 ℃ refining catalyst bed temperature,380 ℃ aromatics saturation catalyst bed temperature and 0.8 h-1 space velocity.Under these process conditions,the density,carbon residue,heteroatom content of upgraded oil is significantly decreasd and H/C is increased.In additional,the product oil with 25.9％ naphtha,63.2％ diesel and 10.9％ heavy gas oil and high aromatic in naphtha is a good feedstock for continuous catalytic reformer.The diesel oil,which is high in cetane number and low in sulfur and nitrogen,is a good blending component for high-quality diesel oil production.The heavy gas oil can be used as the base oil for lube oil production after hydrotreatment.