Process and catalyst for the hydrotreatment of a heavy hydrocarbon feedstock

A method of making a catalyst composition useful in the hydrotreatment of a heavy hydrocarbon feedstock, said method comprising the steps of:

• forming a shaped support particle comprising high purity pseudo-boehmite powder;
• heat treating said shaped support particle at a temperature between 676° C. and 788° C. to achieve a heat treated support particle having a median pore diameter in the range of from 100 Å to 120 Å, a surface area in the range of from 280 m2/g to 240 m2/g, greater than 70% of the total pore diameter distribution between 90 Å and 130 Å, less than 5 percent of the total pore size distribution is greater than 350 Å, and a total mercury pore volume less than 0.85 cc/g;
• and
• contacting said heat treated support particle with a catalytic solution, said solution comprising a Group 6 metal component and a Group 10 metal component to thereby provide an impregnated alumina support having a median pore diameter in the range of from 120 Å to 150 Å and a total mercury pore volume of less than 0.85 cc/g;
• and
• heat treating said impregnated alumina support to provide said catalyst composition having a median pore diameter in the range of from 120 Å to 150 Å, and wherein said catalyst composition has a total mercury pore volume between 0.3 and 0.6 cc/g.

A catalyst composition useful in the hydrotreatment of a heavy hydrocarbon feedstock, wherein said catalyst composition comprises:

• an alumina support particle comprising gamma-alumina, wherein said alumina support particle has a median pore diameter in the range of from 100 Å to 120 Å, a surface area in the range of from 280 m2/g to 240 m2/g, greater than 70% of the total pore diameter distribution between 90 Å and 130 Å, less than 5 percent of the total pore size distribution is greater than 350 Å, and a total mercury pore volume less than 0.85 cc/g;
• and
• wherein said alumina support particle is impregnated with a Group 6 metal component and a Group 10 metal component to provide an impregnated alumina support particle having a median pore diameter in the range of from 120 Å to 150 Å;
• and wherein said catalyst composition exhibits an increase in relative volumetric activity of at least 10% with respect to the kinetic rate constant for a reduction in nitrogen content to 10 ppm as compared to a catalyst comprising an alumina support particle having a surface area of at least 300 m2/g , and wherein said catalyst composition has a total mercury pore volume between 0.3 and 0.6 cc/g.