Methods for determining ethylene concentration in an ethylene oligomerization reactor using an ultrasonic flow meter are described, and these methods are integrated into ethylene oligomerization processes and related oligomerization reactor systems.

Methods for determining ethylene concentration in an ethylene oligomerization reactor using an ultrasonic flow meter are described, and these methods are integrated into ethylene oligomerization processes and related oligomerization reactor systems.

The invention relates to a method for regulating the gas velocity of the empty bed in a fluidized bed, wherein solid catalysts are used as fluidized particles or as a part of fluidized particles, characterized in that the gas velocity of the empty bed μ of the reaction zone of the fluidized bed is measured, compared with the bed average catalyst density ρ of the solid catalysts in the reaction zone of the fluidized bed, the gas velocity of the empty bed μ being adjusted as required such that the gas velocity of the empty bed μ and the bed average catalyst density ρ satisfy the formula (I) below: ρ=0.356μ.sup.3−4.319μ.sup.2−35.57μ+M; wherein M=250−; where μ is provided in m/s and ρ is provided in kg/m.sup.3. The method can be used for the industrial production of lower olefin.

The catalyst productivity of a polyolefin catalyst in the methods disclosed herein may be increased by increasing the concentration of an induced condensing agent (ICA) in the reactor system. The effect the increased ICA concentration may have on a melt index may be counteracted, if necessary, in various ways.

According to one or more embodiments disclosed herein, methods for operating dehydrogenation processes during non-normal operating conditions, such as at start-up, shut-down, system recycle, or unit trip, are described. The methods may include contacting a feed stream with a catalyst in a reactor portion of a reactor system to form a reactor effluent stream, separating at least a portion of the reactor effluent stream from the catalyst, passing the catalyst to a catalyst processing portion and processing the catalyst, wherein processing the catalyst comprises contacting the catalyst with oxygen, passing the catalyst from the processing portion to the reactor portion, wherein the catalyst exiting the processing portion comprises at least 0.001 wt. % oxygen, and contacting the catalyst with supplemental hydrogen, the contacting removing at least a portion of the oxygen from the catalyst by a combustion reaction.

According to one or more embodiments disclosed herein, methods for operating dehydrogenation processes during non-normal operating conditions, such as at start-up, shut-down, system recycle, or unit trip, are described. The methods may include contacting a feed stream with a catalyst in a reactor portion of a reactor system to form a reactor effluent stream, separating at least a portion of the reactor effluent stream from the catalyst, passing the catalyst to a catalyst processing portion and processing the catalyst, wherein processing the catalyst comprises contacting the catalyst with oxygen, passing the catalyst from the processing portion to the reactor portion, wherein the catalyst exiting the processing portion comprises at least 0.001 wt. % oxygen, and contacting the catalyst with supplemental hydrogen, the contacting removing at least a portion of the oxygen from the catalyst by a combustion reaction.

The present specification relates to a method comprising: (A) mixing a ferrite-based catalyst molded article with diluent material particles; and (B) adding the mixture to a catalyst reactor, and a method for preparing butadiene using the same.

The present specification relates to a method comprising: (A) mixing a ferrite-based catalyst molded article with diluent material particles; and (B) adding the mixture to a catalyst reactor, and a method for preparing butadiene using the same.

Methods for determining ethylene concentration in an ethylene oligomerization reactor using an ultrasonic flow meter are described, and these methods are integrated into ethylene oligomerization processes and related oligomerization reactor systems.

Silicon granulate is produced in a fluidized bed reactor having a fluidized bed region fluidized by a gas flow and heated by a heating apparatus. Seed particles and a feed gas including hydrogen and silane and/or halosilane is continuously supplied, and elemental silicon is deposited on the seed particles to form the silicon granulate, which is discharged as a continuous product stream from the reactor. The fluidized bed temperature affects the quality and formation of the product stream, which may be determined as the temperature of an offgas stream from the fluidized bend region. The temperature, as a responding variable may be determined and controlled by means of the mass and energy balance of a defined scheme.