The SELOP technology offers a high selectivity to normal butenes and normal pentenes with minimum normal butane and normal pentane formation. No skeletal isomerization occurs so no isobutene or isopentene are formed. Depending on the desired product, a low or high linear isomerization catalyst can be used permitting the desired product to be maximized. This selectivity maximizes the value of the product stream and capacity of the downstream users thereby producing the best return on investment. There is no oligomer or polymer formation, leading to very long run times between regenerations and eliminating the need for a spare reactor on all but the first stage reactor, thereby minimizing investment. Superior hydrogen distribution by proprietary reactor internals minimizes reactor size and catalyst volume, further minimizing investment. The high selectivity for mixed C5 hydrogenation is unique to the SELOP process making it the system of choice for selective C5 hydrogenation. The superior catalyst offers long life and long cycle times while maintaining high selectivity.