摘要 |
High melting, deoiled and mildly deasphalted tank bottoms wax is catalytically refined in two stages using a catalyst comprising nickel molybdate on alumina. The first stage is maintained at a temperature at least about 50 DEG F. higher than the second stage and the temperature in the second stage is allowed to go no higher than about 575 DEG F. Hydrofined wax product from the second stage is recycled back into same and the temperature in the first stage is periodically increased in order to counteract deactivation of the catalyst. By using a judicious combination of process conditions, unrefined high melting tank bottoms microwax stocks can be made into high quality, high melting point microwax having excellent color and meeting FDA purity requirements.
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