Hydroprocessing of soybean oil on nickel-phosphide supported catalysts

摘要

Ni_2P/silica and Ni_2P/HY were prepared and for the first time tested in hydroprocessing of soybean oil. The content of Ni_2P in each catalyst was about 25 wt%. The experiments conducted in a trickle-bed reactor operated at conditions normally used in such processes, yielded high hydrodeoxygenation (HDO) activity of both catalysts. No apparent hydrocracking activity was recorded with Ni_2P/silica while Ni_2P/HY displayed high hydrocracking and isomerization activity that diminished with time on stream. Characterization of the fresh and spent Ni_2P/HY indicated that exposing the catalyst to water vapors generated by hydrodeoxygenation reduced the acidity of the catalyst thus reducing its hydrocracking activity. After removal of ＞99.5% oxygen by HDO of soybean oil and separation of water vapors, the Ni_2P/HY material displayed stable operation during >250 h on stream yielding up to 50 vol% of light fraction boiling out at ＜250℃.