A method for producing diene comprises a step 1 of obtaining a straight chain internal olefin by removing a branched olefin from a raw material including at least the branched olefin and a straight chain olefin; and a step 2 of producing diene from the internal olefin by oxidative dehydrogenation using a first catalyst and a second catalyst, and the first catalyst has a complex oxide including bismuth, molybdenum and oxygen, and the second catalyst includes at least one selected from the group consisting of silica and alumina.

Provided herein is a gaseous isoprene composition comprising isoprene, carbon dioxide and water, wherein the isoprene is in an amount between about 0.1% and about 15% by volume; wherein the carbon dioxide is in an amount between about 0.04% and about 35% by volume; wherein the water is in an amount greater than about 70% of its saturation amount. Also provided herein is a liquid isoprene composition comprising isoprene in an amount of at least 65% by weight and carbon dioxide in an amount between about 0.01% and about 1% by weight.

Provided herein is a gaseous isoprene composition comprising isoprene, carbon dioxide and water, wherein the isoprene is in an amount between about 0.1% and about 15% by volume; wherein the carbon dioxide is in an amount between about 0.04% and about 35% by volume; wherein the water is in an amount greater than about 70% of its saturation amount. Also provided herein is a liquid isoprene composition comprising isoprene in an amount of at least 65% by weight and carbon dioxide in an amount between about 0.01% and about 1% by weight.

A method of preparing a catalyst, comprising: (1) mixing a ZSM-5 molecular sieve, a phosphorus source, a matrix material, a bonding agent and water to formulate an aqueous slurry, wherein the total content of the components except for water is 20-50 wt % based on the total weight of the aqueous slurry; (2) spray drying the slurry obtained in step (1) to obtain a granular intermediate product; and (3) calcining the granular intermediate product obtained in step (2) to obtain the catalyst used for preparing olefin from methanol in a fluid bed. The invention also provides a catalyst prepared according to said method, and a process of preparing olefin from methanol using said catalyst. In the methanol-to-olefin process, the conversion of methanol is >99%; the propylene selectivity is high; and the C4 selectivity is up to 32%.

A method of preparing a catalyst, comprising: (1) mixing a ZSM-5 molecular sieve, a phosphorus source, a matrix material, a bonding agent and water to formulate an aqueous slurry, wherein the total content of the components except for water is 20-50 wt % based on the total weight of the aqueous slurry; (2) spray drying the slurry obtained in step (1) to obtain a granular intermediate product; and (3) calcining the granular intermediate product obtained in step (2) to obtain the catalyst used for preparing olefin from methanol in a fluid bed. The invention also provides a catalyst prepared according to said method, and a process of preparing olefin from methanol using said catalyst. In the methanol-to-olefin process, the conversion of methanol is >99%; the propylene selectivity is high; and the C4 selectivity is up to 32%.

A process for operating a chemical process includes deriving coefficients for a process performance model from historical feed data and historical production data; formulating the process performance model using the coefficients; determining a predicted change in production of a product of the chemical process using the process performance model; and changing a processing parameter of the chemical process based on economic data and the predicted change in production of the product of the chemical process.

A process for operating a chemical process includes deriving coefficients for a process performance model from historical feed data and historical production data; formulating the process performance model using the coefficients; determining a predicted change in production of a product of the chemical process using the process performance model; and changing a processing parameter of the chemical process based on economic data and the predicted change in production of the product of the chemical process.

Co-extraction techniques for separating and purifying butadiene and isoprene from a C.sub.4 hydrocarbon mixture including butadiene and a C.sub.5 hydrocarbon mixture including isoprene are provided. In an exemplary embodiment, a system includes a dimerization heat exchanger, a C.sub.5 purification column; an extraction zone including a mainwasher column, a rectifier column and an afterwasher column; a distillation zone; a degassing zone; and an isoprene finishing column. The system can further include a C.sub.5 washer column, an absorption column, and a distillation column.

Disclosed are a catalyst composition for oxidative dehydrogenation and a method of preparing the same. More particularly, disclosed is a catalyst composition comprising a multi-ingredient-based metal oxide catalyst and a mixed metal hydroxide. The catalyst composition and the method of preparing the same according to the present disclosure may prevent loss occurring in a filling process due to superior mechanical durability and wear according to long-term use, may inhibit polymer formation and carbon deposition during reaction, and may provide a superior conversion rate and superior selectivity.