System for producing a crude product, comprising: an upstream contacting zone; one or more catalysts in the upstream contacting zone, the one or more catalysts comprising a first catalyst, the first catalyst having, per gram of first catalyst, 0.0001 grams to 0.06 grams of: one or more metals from Column 6 of the Periodic Table, one or more compounds of one or more metals from Column 6 of the Periodic Table, calculated as weight of metal, or mixtures thereof; a downstream contacting zone positioned downstream of the upstream contacting zone; and one or more catalysts in the downstream contacting zone, the one or more catalysts comprising a second catalyst, the second catalyst having, per gram of second catalyst, at least 0.02 grams of: one or more metals from Column 6 of the Periodic Table, one or more compounds of one or more metals from Column 6 of the Periodic Table, calculated as weight of metal, or mixtures thereof, wherein the total content of Column 6 metal(s), per gram of second catalyst, is greater than the total content of Column 6 metal(s) in the first catalyst.