Fixed bed catalytic reactor system with improved liquid distribution

A continuous process for treating a wax-containing lubricant range petroleum oil in a multi-phase fixed bed catalytic reactor system having at least two catalyst hydrodewaxing beds, comprising the steps of

• feeding the oil and hydrogen-containing gas at feed flow rates above a first horizontal porous bed of acid hydrodewaxing catalyst particles at elevated temperature under hydrodewaxing conditions for concurrent downward flow therethrough;
• collecting and withdrawing the treated oil from the first bed and redistributing at least a portion of the treated oil to at least one succeeding horizontal porous catalyst bed of acid hydrodewaxing catalyst particles while permitting withdrawn gaseous phase produced in said first bed to flow directly to a succeeding catalyst bed;
• recycling a quantity of treated oil collected below a catalyst bed to a preceding redistribution zone above the bed from which treated oil is collected;
• measuring the rate of oil feed, comparing the oil feed rate with a total design flow rate;
• and
• adjusting recycle of treated oil in at least one bed, whereby the total of oil feed rate and recycled treated oil flow rate in at least one bed, is maintained at a liquid flux rate sufficient to provide catalyst wetting.