The invention is concerned with the production of 1-hexene and octenes from ethene. 1-Butene is optionally also to be produced. The problem addressed by the present invention is that of developing a process for producing 1-hexene from ethene by MTHxE etherification to achieve better chemical utilization of the employed carbon atoms. This problem is solved by catalytic retrocleavage of MTHxE into the C.sub.6 olefins and the alcohol, reuse of the alcohol in the etherification and reaction of the obtained C.sub.6 olefins with ethene to afford C.sub.8 olefins. In this way the alcohol is not lost from the process but rather is internally recirculated as a derivatizing agent. The less attractive C.sub.6 olefins from the cleavage product are upgraded to octene with further ethene in order to provide a further commercial product.

The invention is concerned with the production of 1-hexene and octenes from ethene. 1-Butene is optionally also to be produced. The problem addressed by the present invention is that of developing a process for producing 1-hexene from ethene by MTHxE etherification to achieve better chemical utilization of the employed carbon atoms. This problem is solved by catalytic retrocleavage of MTHxE into the C.sub.6 olefins and the alcohol, reuse of the alcohol in the etherification and reaction of the obtained C.sub.6 olefins with ethene to afford C.sub.8 olefins. In this way the alcohol is not lost from the process but rather is internally recirculated as a derivatizing agent. The less attractive C.sub.6 olefins from the cleavage product are upgraded to octene with further ethene in order to provide a further commercial product.

Provided are a chromium catalyst precursor, an ethylene oligomerization catalyst including the same, and a method of preparing an ethylene oligomer using the same. More particularly, a chromium catalyst precursor which may oligomerize ethylene with high activity and high selectivity in spite of not using methylaluminoxane (MAO) or modified-methylaluminoxane (MMAO), an oligomerization catalyst including the same, and a method of preparing an ethylene oligomer using the same are provided.

Provided are a chromium catalyst precursor, an ethylene oligomerization catalyst including the same, and a method of preparing an ethylene oligomer using the same. More particularly, a chromium catalyst precursor which may oligomerize ethylene with high activity and high selectivity in spite of not using methylaluminoxane (MAO) or modified-methylaluminoxane (MMAO), an oligomerization catalyst including the same, and a method of preparing an ethylene oligomer using the same are provided.

Provided is a method of producing an oligomer, the method including: supplying a monomer stream and a solvent stream to a reactor to perform an oligomerization reaction to produce a reaction product; supplying a discharge stream of the reactor to a separation device, and supplying an upper discharge stream of the separation device including an unreacted monomer to the reactor and supplying a lower discharge stream of the separation device to a settling tank; settling a polymer in the settling tank and removing the polymer, and supplying the lower discharge stream of the separation device from which the polymer is removed to a high-boiling point separation column; removing a high-boiling point material from a lower discharge stream of the high-boiling point separation column and supplying an upper discharge stream of the high-boiling point separation column including an oligomer to a solvent separation column; and separating a solvent and the oligomer in the solvent separation column.

Provided is a method of producing an oligomer, the method including: supplying a monomer stream and a solvent stream to a reactor to perform an oligomerization reaction to produce a reaction product; supplying a discharge stream of the reactor to a separation device, and supplying an upper discharge stream of the separation device including an unreacted monomer to the reactor and supplying a lower discharge stream of the separation device to a settling tank; settling a polymer in the settling tank and removing the polymer, and supplying the lower discharge stream of the separation device from which the polymer is removed to a high-boiling point separation column; removing a high-boiling point material from a lower discharge stream of the high-boiling point separation column and supplying an upper discharge stream of the high-boiling point separation column including an oligomer to a solvent separation column; and separating a solvent and the oligomer in the solvent separation column.

Disclosed herein is a method of preparing 1-octene at high activity and high selectivity while stably maintaining reaction activity by tetramerizing ethylene using a chromium-based catalyst system comprising a transition metal or a transition metal precursor, a cocatalyst, and a P—C—C—P backbone structure ligand represented by (R.sup.1)(R.sup.2)P—(R.sup.5)CHCH(R.sup.6)—P(R.sup.3)(R.sup.4).

Disclosed herein is a method of preparing 1-octene at high activity and high selectivity while stably maintaining reaction activity by tetramerizing ethylene using a chromium-based catalyst system comprising a transition metal or a transition metal precursor, a cocatalyst, and a P—C—C—P backbone structure ligand represented by (R.sup.1)(R.sup.2)P—(R.sup.5)CHCH(R.sup.6)—P(R.sup.3)(R.sup.4).

Disclosed herein is a method of preparing 1-octene at high activity and high selectivity while stably maintaining reaction activity by tetramerizing ethylene using a chromium-based catalyst system comprising a transition metal or a transition metal precursor, a cocatalyst, and a P—C—C—P backbone structure ligand represented by (R.sup.1)(R.sup.2)P—(R.sup.5)CHCH(R.sup.6)—P(R.sup.3)(R.sup.4).

The invention relates to a process for oligomerization of ethylene, preferably for selective trimerization of ethylene to hex-1-ene, comprising simultaneously bringing ethylene into contact with the components of a catalytic composition based on chromium.