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Hydrofinishing of re-refined used lubricating oil

Technical Report ·
OSTI ID:5599657

This study was conducted to establish hydrotreating as an environmentally attractive and economically feasible waste oil re-refining final process step. The major emphasis of this study was on determining the feasibility of using heterogenous catalysts for polishing distilled used lube oil. Considerable attention also was focused on reactor corrosion and plugging problems. Armak-840, a commercial Ni-Mo-Al/sub 2/O/sub 3/ catalyst, was determined to have the highest activity for product liquid color improvement and nitrogen removal among the catalysts we tested. Operating the hydrofinishing reactor at a temperature of 350/sup 0/C, a pressure of 800 psig, and a space velocity of 1.0 hr/sup -1/ produced liquids of acceptable chemical and physical properties. Guard-bed reactors containing high surface area alumina and operated in a temperature range of 285 to 295/sup 0/C effectively removed all the metals and phosphorus present in the feed liquid. During the extended catalyst life-test study of the Armak-840 Ni-Mo-Al/sub 2/O/sub 3/ catalyst, severe loss in hydrodenitrogenation activity was observed after 300 hours of oil-catalyst contact. No such decay was observed for the product liquid color. It is argued that the catalysts had not reached their equilibrium activity during the 564 hours of operation. Ammonium chloride, a white crystalline material, formed in the hydrofinishing reactor by the reaction of ammonia and hydrochloric acid, deposited in the reactor exit lines causing severe reactor plugging. Accelerated lowering of the reactor effluent temperature causes the plug to disappear. This problem only occurred in the hydrofinishing reactor. Dark residues were formed in the guard-bed reactor at temperatures higher than 310/sup 0/C. Operating the guard-bed reactor in a temperature range of 285 to 29/sup 0/C suppressed the residue formation. 18 refs., 27 figs., 18 tabs.

Research Organization:
National Inst. for Petroleum and Energy Research, Bartlesville, OK (USA)
DOE Contract Number:
AC22-84BC10826
OSTI ID:
5599657
Report Number(s):
DOE/BC/10826-1; ON: DE86010849
Country of Publication:
United States
Language:
English