高温煤焦油馏分油加氢改质生产清洁燃料研究

PRODUCING CLEAN FUEL BY HYDRO-UPGRADING ON HIGH-TEMPERATURE COAL TAR

采用加氢预精制催化剂、加氢精制催化剂、加氢裂化催化剂以及加氢饱和催化剂适宜的级配方式对高温煤焦油馏分油进行二段加氢改质,结果表明,高温煤焦油馏分油的性质经加氢改质后得到大幅度改善,密度由1 169.7kg/m3降低到900.9kg/m3以下,氢碳原子比由0.79提高到1.63以上,残炭降低到0.02%(质量分数);其石脑油馏分的硫、氮含量分别小于5μg/g和1μg/g,芳烃潜含量大于68%(质量分数),是催化重整的优质原料;其柴油馏分的硫含量很低,凝点和冷滤点均小于-30℃,十六烷值大于39,是国Ⅳ低凝柴油的优质调和组分;而加氢尾油基本由芳烃组成,不宜作为催化裂化的原料.

ABSTRACT The process of two-stage hydro-upgrading of high-temperature coal tar has been proved to be feasible with adapted proportion of catalysts for hydro-pretreating, hydro-fin- ishing, hydro-cracking and hydro-saturation. The results of lab experiments show that the quali- ties of the high-temperature coal tar can be significantly upgraded by hydro-upgrading, such as density reduced from 1 169.7 kg/ma to 900.9 kg/ma and less, H/C ratio increased from 0.79 to 1.63, the carbon residue content reduced to 0.02~; while the potential aromatics content in the hydro-upgraded naphtha fraction is more than 68~ , sulfur and nitrogen contents are less than 5 /ag/g and 1/~g/g respectively, so the naphtha is a high quality feedstock for catalytic reforming process. With an ultra low sulfur content, freezing point and cold filter plug point less than --30 ~C, and a ce- tane number higher than 39, the hydro-upgraded diesel fraction is also an excellent blending com- ponent for low freezing point diesel. Meanwhile, the hydro-upgraded tail oil is not suitable to be directly used as feedstock for FCC process due to its highly aromatic composition. KEY WORDS coal tar, hydrogenation, catalyst, fixed bed, pilot-scale experiment, naph- tha, diesel