TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: The process further involves isomerizing at least a portion of the paraffin in the second effluent by contacting the second effluent with an isomerization catalyst at isomerization conditions to isomerize at least a portion of the paraffin to branched-paraffin; passing at least a portion of the second effluent and a third portion of renewable feedstock to a third reaction zone and treating the third portion of renewable feedstock in the third reaction zone by hydrogenating and deoxygenating the third portion of the feedstock at reaction conditions to provide a third effluent comprising paraffin, where the recycle stream comprises a portion of the third effluent; isomerizing at least a portion of the paraffin in the third effluent by contacting the third effluent with an isomerization catalyst at isomerization conditions to isomerize at least a portion of the paraffin to branched-paraffin; passing at least a portion of the third effluent and a fourth portion of renewable feedstock to a fourth reaction zone and treating the fourth portion of renewable feedstock in the fourth reaction zone by hydrogenating and deoxygenating the fourth portion of the feedstock at reaction conditions to provide a fourth effluent comprising paraffin, where the recycle stream comprises a portion of the fourth effluent; isomerizing at least a portion of the paraffin in the fourth effluent by contacting the fourth effluent with an isomerization catalyst at isomerization conditions to isomerize at least a portion of the paraffin to branched-paraffin; and pre-treating at least one portion of the renewable feedstock in a pretreatment zone at pretreatment conditions to remove at least a portion of contaminants. The pretreatment step involves contacting with an acidic ion exchange resin or with an acid solution. The process further involves treating a petroleum hydrocarbon feedstock in the first reaction zone or the second reaction zone. Preferred Components: The first portion and the second portion of renewable feedstock are generated by separating a feedstock into two portions. The first portion and the second portion of renewable feedstock have different compositions. The first reaction zone and the second reaction zone are housed in separate vessels. The first reaction zone and the second reaction zone are housed in a single vessel. The recycle stream comprises both a portion of the first effluent and a portion the second effluent. The first reaction zone comprises a hydrogenation and deoxygenation catalyst at 200-300 degrees C and a pressure of 1379 kPa absolute (200 psia) to 4826 kPa absolute (700 psia). The deoxygenation comprises at least one of decarboxylation, decarbonylation, and hydrodeoxygenation. EXAMPLE - No suitable example given.