Oligomerization of ethylene to liquid transportation fuels with post synthesis treated zsm-5 catalyst

Oligomerizing ethylene to transportation fuel products in a reactor with a fixed bed of ZSM-5 catalyst that is essentially free of catalyst metals other than silica and alumina wherein the ZSM-5 catalyst has been provided with post synthesis base-acid treatment to resist coke formation in the zeolite crystallites and extend catalyst life wherein the oligomerizing is conducted at a pressure between 0 psig and 800 psig, a temperature of between 260° C. and 420° C., and a gas hourly space velocity of between 1000 and 5000 inverse hours wherein at least 85% of the ethylene is converted, wherein the post synthesis treatment of the catalyst comprises a first base treatment with sodium hydroxide at between about 0.0075 and about 0.15 Molar concentration, at a temperature above 35° C. for at least about 45 minutes, a second washing step using distilled water, a third acid treatment of hydrogen chloride step at between about 1 and 10 Molar concentration at a temperature above 60° C. for at least about 45 minutes, an additional washing step using distilled water followed by a drying step for at least 4 hours at a temperature above about 105° C. which is then followed by a calcining step for the catalyst at a temperature above 400° C. for at least about 3 hours, all of the treatment of the catalyst being performed prior to oligomerizing the ethylene.