A method for processing a mixture of recycled polyester material and a polyester prepolymer from a polyester manufacturing process, wherein a recycled polyester material is mixed with a polyester prepolymer, from a polyester manufacturing process, and treated in a bulk thermal treatment reactor (7) with a process gas which flows in a counter-current or a cross-current flow direction to the flow direction of the mixture. In this process, the process gas, before entering a catalyst vessel (14), is passed through a protective bed (11) containing a solid adsorbent material that removes high-boiling organic substances or organic substances, with a high combustion temperature, from the process gas stream.

Aspects provide for volatilizing a biomass-based fuel stream, removing undesirable components from the resulting volatiles stream, and combusting the resulting stream (e.g., in a kiln). Removal of particles, ash, and/or H2O from the volatiles stream improves its economic value and enhances the substitution of legacy (e.g., fossil) fuels with biomass-based fuels. Aspects may be particularly advantageous for upgrading otherwise low-quality biomass to a fuel specification sufficient for industrial implementation. A volatilization reactor may include a fluidized bed reactor, which may comprise multiple stages and/or a splashgenerator. A splashgenerator may impart directed momentum to a portion of the bed to increase bed transport via directed flow.

A system for producing a hydrocarbon by high-temperature Fischer-Tropsch synthesis is described. The system includes a Fischer-Tropsch synthesis unit, a reaction water separation unit, and a catalyst reduction unit. The catalyst reduction unit uses a gas containing the tail gas of the synthesis unit as a reducing gas and a small amount of synthesis gas for adjusting the hydrogen to carbon ratio, to react with the Fischer-Tropsch synthesis catalyst. After the reduction reaction, the reacted gas is cooled to room temperature, and enters a gas-liquid separator to obtain a gas phase and a liquid phase. The gas phase flows to a cryogenic separation unit to recover gaseous hydrocarbons. The liquid phase is separated into reaction water and Fischer-Tropsch oil products. The reduced catalyst is sent to the Fischer-Tropsch synthesis unit. The catalyst reduction unit achieves high energy efficiency, product diversity, and risk resistance.

Methods of reducing heat exchanger fouling rate or of producing polyolefins may include providing a first gas stream comprising a gas and entrained fine polyolefin particles to a gas outlet line; removing a portion of the entrained fine polyolefin particles from the gas outlet line to form a bypass stream; and providing the bypass stream to a bypass line comprising a bypass line inlet and a bypass line outlet. The bypass line inlet and outlet are located upstream and downstream of a first heat exchanger. The methods may further include providing at least a portion of the first gas stream to the first heat exchanger; and combining the bypass stream and a second gas stream at the bypass line outlet to form a combined gas stream comprising one or more olefins or paraffins. A temperature of the combined gas stream is below the dew point of the combined gas stream.

A method of controlling particle additions to a fluidized bed reactor includes measuring pressure fluctuations inside the fluidized bed reactor over a selected time period, determining a pressure parameter indicative of amplitudes of the pressure fluctuations, comparing the pressure parameter to a specified threshold, and controlling particle additions to the fluidized bed reactor when the pressure parameter deviates from the specified threshold.

An advanced regulatory controller for a converter of a catalytic olefins unit is disclosed. A Fluid Catalytic Cracking (FCC) type converter (i.e., reactor-regenerator) is combined with an ethylene style cold-end for product recovery. The regulatory controller operates using an Advanced Regulatory Control (ARC) application using variables, such as a controlled variable, four disturbance variables, associated variable, and a manipulated variable. The ARC application manipulates fuel oil or tail gas flow to a regenerator in response to an expected future steady state value of a regenerator bed temperature resulting from changes in the values of a selected set of the variables.

Processes and apparatuses for alkylating aromatic hydrocarbons with an alkylating reagent to produce an alkylated aromatic product are described. The processes and apparatuses use a riser reactor operated at a superficial velocity of 10 m/s to 25 m/s to produce the alkylated aromatic product. In some embodiments, a combination of steam and aromatic hydrocarbon is used to lift the catalyst.

A method for fluid catalytic cracking (FCC) of petroleum oil feedstock includes reacting the petroleum oil feedstock with a catalyst mixture in a reaction zone of an FCC unit to obtain a product stream including desulfurized hydrocarbon product, unreacted petroleum oil feedstock, and spent catalyst. During the reacting a process control system develops a process model based on data collected during the reacting, the process model characterizing a relationship among the feed rate of the base cracking catalyst, the feed rate of the FCC additive, the operating conditions, the composition of the product stream, and emissions from the reaction; and one or more of (i) a target feed rate of the base cracking catalyst, (ii) a target feed rate of the FCC additive, and (iii) one or more target operating conditions of the reaction in the reaction zone to reduce the emissions from the FCC unit and to increase a yield of the desulfurized hydrocarbon product in the product stream are determined.

Methods for determining the catalytic activity of an activated chemically-treated solid oxide using a color measurement technique are described, and these methods are integrated into transition metal-based catalyst preparation processes and systems, as well as into olefin polymerization processes and related polymerization reactor systems.

Systems and methods of reducing heat exchanger fouling rate and of producing polyolefins are provide herein. In some aspects, the methods include providing a first gas stream comprising a gas and entrained fine polyolefin particles to a gas outlet line; preferentially removing a portion of the entrained fine polyolefin particles from the gas outlet line to form a bypass stream comprising a higher concentration of the entrained fine polyolefin particles than is present in the first gas stream; providing the bypass stream to a bypass line comprising a bypass line inlet and a bypass line outlet, wherein the bypass line inlet is located upstream of a first heat exchanger, and wherein the bypass line outlet is located downstream of the first heat exchanger; providing at least a portion of the first gas stream to the first heat exchanger, which produces a first cooled gas stream; and combining the bypass stream and a second gas stream at the bypass line outlet to form a combined gas stream comprising one or more olefins or paraffins, wherein a temperature of the combined gas stream is below the dew point of the combined gas stream.