Two-stage catalytic hydroconversion of hydrocarbon feedstocks using resid recycle

Claim 2

A process for catalytic hydroconversion of hydrocarbon feedstocks to lower boiling hydrocarbon liquids and gas, comprising: (a) feeding a hydrocarbon feedstock containing fine particulate solids with hydrogen into a reactor containing an ebullated bed of particulate catalyst, said reactor being maintained at 780°-850° F. temperature, 800-3000 psig hydrogen partial pressure, and 0.3-2.5 V f /hr/V f space velocity for hydroconverting said feedstock to a mixture of hydrocarbon gas and lower boiling hydrocarbon liquid fractions; (b) phase separating said gas from said liquid fractions and withdrawing from said liquid fractions a light hydrocarbon liquid product having a normal boiling range of 180°-400° F.; (c) combining said gas with the remaining liquid fractions from said separation and passing the combined material to a second stage reactor containing an ebullated bed of particulate catalyst and further hydroconverting the material to hydrocarbon gas and other lower boiling liquid fractions; (d) separating said hydrocarbon gas from said other liquid fractions and withdrawing said other liquid fractions; (e) distilling said other liquid fractions to produce a medium boiling hydrocarbon liquid product having normal boiling range of 400°-975° F. and also a 975° F. + vacuum bottoms material; and (f) recycling a portion of said vacuum bottoms material to said second stage ebullated bed reactor to produce increased yields of said medium boiling hydrocarbon liquid product.

Claim 3

The process of claim 1, wherein the combined feed material to said second stage reactor is reheated to a temperature not exceeding about 750° F.

Claim 4

The process of claim 1, wherein the second stage reaction conditions are 760°-840° F. temperature, 800-3000 psig hydrogen partial pressure, and 0.2-2.5 V f /hr/V r space velocity.

Claim 5

The process of claim 1, wherein said first stage reactor contains catalyst particles having 0.025-0.035 inch effective diameter and said second stage reactor contains catalyst particles having 0.050-0.070 inch effective diameter.

Claim 6

The process of claim 1, wherein the catalyst replacement rate for said first stage reactor is 0.1-0.3 pounds/barrel feed.

Claim 7

The process of claim 1, wherein the catalyst replacement rate for second stage reactor is 0.1-0.5 times that for said first stage reactor.

Claim 8

The process of claim 1, wherein said first stage reaction conditions are 790°-840° F. temperature, 1000-2800 psig hydrogen partial pressure and 0.5-1.5 V f /hr/V r space velocity.

Claim 9

The process of claim 1, wherein the recycled vacuum bottoms material is 0.2-1.5 times the feedstock.

Claim 10

The process of claim 1, wherein the feedstock is bitumen from tar sands.

Claim 11

The process of claim 1, wherein the feedstock is coal-derived liquid normally boiling above about 650° F.

Claim 12

A process for catalytic hydroconversion of hydrocarbon feedstocks containing fine particulate solids, comprising: (a) feeding a hydrocarbon feedstock with hydrogen into a reactor containing an ebullated bed of catalyst particles having 0.025-0.035 inch effective diameter, said reaction conditions being maintained at 780°-850° F. temperature, 800-3000 psig hydrogen partial pressure, and 0.3-2.5 V f /hr/V r space velocity for hydroconverting said feedstock to a mixture of hydrocarbon gas and lower boiling liquid fractions; (b) separating said gas from said liquid fractions and withdrawing a light hydrocarbon liquid product having a normal boiling range of 180°-400° F.; (c) combining said gas with said heavy liquid fraction from said separation and feeding the combined material to a second stage reactor containing an ebullated bed of catalyst particulates having 0.050-0.070 inch effective diameter and further hydroconverting the material to produce hydrocarbon gas and other lower boiling liquid fractions; (d) separating said hydrocarbon gas from said other liquid fractions and then withdrawing said other liquid fractions; (e) distilling said other liquid fractions to produce a medium boiling hydrocarbon liquid product having normal boiling range of 400°-975° F. and also a 975° F. + vacuum bottoms stream; and (f) recycling a portion of said vacuum bottoms material to said second stage ebullated bed reactor to produce increased yields of said medium boiling hydrocarbon liquid product.

Claim 13

A process for catalytic hydroconversion of hydrocarbon feedstocks containing fine particulate solids, comprising: (a) feeding a hydrocarbon feedstock with hydrogen into a reactor containing an ebullated bed of catalyst particles having 0.025-0.035 inch effective diameter, said reaction conditions being maintained at 780°-850° F. temperature, 800-3000 psig hydrogen partial pressure, and 0.3-2.5 V f /hr/V r space velocity for hydroconverting said feedstock to a mixture of hydrocarbon gas and lower boiling liquid fractions; (b) separating said gas from said liquid fractions and withdrawing a light hydrocarbon liquid product having a normal boiling range of 180°-400° F.; (c) combining said gas with said heavy liquid fraction from said separation and feeding the combined material to a second stage reactor containing an ebullated bed of catalyst particulates having 0.050-0.070 inch effective diameter and further hydroconverting the material to produce hydrocarbon gas and other lower boiling liquid fractions; (d) separating said hydrocarbon gas from said other liquid fractions and then withdrawing said other liquid fractions; (e) distilling said other liquid fractions to produce a medium boiling hydrocarbon liquid product having normal boiling range of 400°-975° F. and also a 975° F. + vacuum bottoms stream; and (f) recycling a portion of said vacuum bottoms material to said second stage ebullated bed reactor to produce increased yields of said medium boiling hydrocarbon liquid product.