Effect of Dephenolization on Low-Temperature Coal Tar Hydrogenation To Produce Fuel Oil

Abstract

The experiment of fuel oil production through hydrogenation has been conducted on a hydrorefining− hydrocracking two-stage serial fixed-bed reactor with coal tar distillate [CTD; initial boiling point (IBP)−360 °C] and phenol extraction coal tar distillate (PE-CTD) as the feedstocks. By comparison of the changes in chemical composition and carbon number distribution as well as product distribution and properties before and after hydrogenation in the two feedstocks, the influences of phenol extraction treatment on fuel oil production with coal tar hydrogenation were studied. The experimental conditions of this study include the reaction pressure of 13 MPa, liquid hourly space velocity of 0.5 h −1 , hydrorefining reaction temperature at 360 °C, hydrocracking reaction temperature at 380 °C, and filling proportion of hydrorefining catalyst/ hydrocracking catalyst of 1:1. The experimental result shows that phenol extraction reduces the naphtha yield by 8.69 wt % but produces 13.58% of mixed phenols. Furthermore, the phenol extraction treatment is favorable for converting a heavy distillate of coal tar to a light fraction.

Designing Ionic Liquids with Dual Lewis Basic Sites to Efficiently Separate Phenolic Compounds from Low-Temperature Coal Tar

“…Phenolic compounds, as a typical example, are among the most versatile and important industrial organic chemicals, and exhibit a wide range of applications, such as for the production of bisphenol A, phenolic resin, engineering plastics, and synthetic fiber . However, phenolic compounds can increase hydrogen consumption in the hydrogenation of coal tar during the production of fuel oils, and the water produced by the reaction can adversely affect the activity and life of the catalyst. , Therefore, separating phenolic compounds from coal tar is highly crucial for the coal chemical industry …”

“…5 However, phenolic compounds can increase hydrogen consumption in the hydrogenation of coal tar during the production of fuel oils, and the water produced by the reaction can adversely affect the activity and life of the catalyst. 6,7 Therefore, separating phenolic compounds from coal tar is highly crucial for the coal chemical industry. 8 The traditional method for separating phenolic compounds from coal tar, namely, the caustic washing method, has brought tremendous environmental pollution and has thus seriously restricted the development of clean, high value-added chemicals from coal tar.…”

Combined Process of Hydrocracking and Hydrofining of Coal Tar

“…In the experiment, the self-made Ni-Mo/γ-Al 2 O 3 catalyst was selected as the hydrofining catalyst. The hydrocracking catalyst used in this study is a kind of catalyst which can be obtained from commercial channels, and its code name is FC36 . The basic properties of the two catalysts are shown in Table .…”

“…In fact, it is very common to complete the hydrogenation experiment of coal tar by two or more catalysts through gradation loading. − However, most of the previous studies have completed all the experiments under a certain grading ratio, but no detailed study has been carried out on the grading method. Because the hydrocracking process of coal tar produces a large amount of water, which will harm the hydrocracking catalyst, some studies will design an oil–water separation device before the entrance of the hydrocracking reactor …”

Selective hydrodeoxygenation of p-cresol as a model for coal tar distillate on Ni–M/SiO2 (M = Ce, Co, Sn, Fe) bimetallic catalysts

“…6 In the process of hydrotreating, these compounds oen lead to the formation of large amounts of naphthenes and water; thus, it is not only difficult to obtain high-octane fuel, but the catalyst life is adversely affected. 7 Moreover, if the intent is to use the hydrogenation product downstream to produce BTX, a dehydrogenation reforming process is also necessary. 8 Therefore, the selective hydrodeoxygenation of monocyclic phenolic compounds enriched in coal tar can improve the quality of fuel oil and can also benet the production of BTX products.…”