Abstract:
In a distillation control system, a nuclear magnetic resonance (NMR) sensor identifies the composition of petroleum distillates from a distillation tower, and preferably also identifies the composition of the input feed method. This information is processed to obtain estimates of values of selected properties of the distillates and the feed. These values are provided to a multivariate controller, together with a setpoint of desired quality factors selected on the basis of competitive market forces, environmental regulations and economic factors including feed and product prices and operating cost. On the basis of the NMR measured values of selected quality properties, the multivariate controller generates values of manipulated operating variables that, when applied to the distillation system, adjust the distillation operation to reduce differences between the controlled variables and their respective setpoints. The ultimate values of the operating variables are determined, preferably in conjunction with an optimizer so that product qualities are maintained and the tower is operated in an economically optimum manner subject to specific characteristics of the refinery.
Abstract:
A method for controlling the output of a distillation tower fed by a fluid catalytic cracker uses one or more NMR sensors to obtain on-line measurements of values of selected properties of feedstock and/or of distillation tower outputs. The measured values are provided to a multivariate controller. On the basis of the measured values and setpoint information provided by an optimizer, the multivariate controller determines values of manipulated variables for controlling the catalytic cracker to produce products of desired qualities and maximize unit economic return.
Abstract:
In an exemplary embodiment, the apparatus includes a reaction vessel (2) having an interior portion adapted to receive a reaction mixture. An agitator (10) is disposed relative to the reaction vessel (2) such that the agitator (10) is capable of agitating the reaction mixture. A conduit (11) is placed in fluid communication with the interior portion of the reaction vessel (2). A temperature probe (13) is placed in thermal communication with the reaction vessel (2), and an optical analyzer (20) adapted to perform real-time in situ analysis of the reaction mixture is placed proximate or within the reaction vessel (2). In operation, the reaction is monitored and reaction conditions are adjusted, if necessary, to maintain the reaction within pre-determined parameters. The reactor can be used for parallel screening of potential reactants and process conditions.
Abstract:
A novel reaction vessel apparatus (110) is provided. The reaction vessel (110) includes internally placed temperature controlling thermal probes (400) in which liquid is boiled. The energy of vaporization is supplied by the reaction vessel contents. The vapor produced by the boiling may be directed to channel coils (100) which surround the outside of the reaction vessel wall (120). The channel coils (100) contact the outside wall (120) of the reaction vessel (110) perpendicularly, and provide mechanical support for the reaction vessel. The mechanical support from the channel coils (100) allows for a decrease in the thickness of the reaction vessel wall (120) and corresponding increased heat transfer efficiency between the channel coil contents and the reaction vessel contents. The entire above described apparatus is enclosed within an evacuated shell (300) which provides additional insulation.
Abstract:
This invention relates to methods of recycling catalyst in oxidations of hydrocarbons, such as cyclohexane for example, to respective intermediate oxidation products, such as adipic acid for example, by a direct process. The catalyst remains in solution despite removal of water from the composition, since the water removal is controlled at such temperatures and such remaining water levels that prevent catalyst from precipitating. The water removal is preferably conducted before removal of the intermediate oxidation product. Also, preferably, some, and more preferably all steps of the process are conducted in a single liquid phase region.
Abstract:
A method and system for quantifying the amount of byproduct buildup in the reaction chamber and support systems used to fabricate semiconductor device layers is disclosed. One embodiment of the present invention places a film thickness measuring device in an exhaust pipe (150) of a reactor (100). The film thickness measuring device is positioned such that the operating parameters, for example temperature, of that particular device are optimized. The thickness of the exhaust byproduct buildup is then measured using the film thickness measuring device. Once the amount of byproduct buildup is quantified at the location of the film thickness measuring device then the byproduct buildup at other locations in the system be determined.
Abstract:
A system (10) for generating a desired output gas (S) from an input fuel (F) for use in a downstream process (12) is disclosed. The system includes a plurality of fuel processing units (14) to generate the desired output gas (5), wherein each of the plurality of fuel processing units (14) includes a reformer which uses waste gas output (G) from the downstream process (12) to facilitate the processing of the fuel. Each of the fuel processing units is operational over a range up to full capacity, wherein the plurality of fuel processing units are interconnected in a collective operating scheme to process the fuel. A control system (16) is provided for controlling the plurality of fuel processing units (14) in response to requirements of a dynamic load demand (LS) from the downstream operation (12). The control system (16) is operative to adjust the operational level of each of the plurality of fuel processing units (14) to produce individual responses from each of the fuel processing units. The individual responses are combined to produce a collective response for meeting the requirements of the dynamic load demand. A method for generating a desired output gas from an input fuel for use in a downstream process is also provided.
Abstract:
A tube heat exchanger intended to be used for the production of carbon black, comprises a cylindrical chamber (16) which is enclosed by a cylindrically shaped outer shell wall (14') and two end walls (17, 18), and a plurality of tubes (13') which extend through the entire cylindrically shaped chamber (16), from one end wall to the other. To the heat exchanger are provided an inlet (1') and an outlet (25) for gas intended to flow on the outside of the tubes (13'). Moreover, the heat exchanger comprises a further shell wall (23), which is cylindrical and placed inside and concentrically with the outer shell wall (14'), so that a cylindrically shaped gap space (29), which is open at both ends, is formed between the two shell walls. The gas entering through the inlet (1') passes this gap space (29) before it comes into contact with the tubes (13'). The advantage of this is that the outer shell wall is cooled and that the amount of carbon precipitations within the tubes diminishes.
Abstract:
An apparatus and process are disclosed for optimizing the repetitive steps in a solid-phase oligonucleotide synthesis by continuous optical scanning of the effluent stream from the reaction module and by computerized processing and implementation of the scanning data.
Abstract:
A method for controlling a process for synthesising at least one chemical in a plant including at least one reactor (R) that may be considered as a perfectly mixed reactor, wherein control variables (GC) enable the process to be controlled so that a number of variables known as controlled variables (GR) and related to the properties of the product and/or the operation of the process match corresponding set values (CGR). Said method comprises the steps of (a) inputting set values for the controlled variables (CGR); (b) using a prediction unit (OP) to calculate predictions of the controlled variables (PGR) on the basis of measurements of the process control variables (MGC); (c) using a control unit (OC) to calculate set values for the process control variables (CGC) on the basis of the set values (CGR) and predictions (PGR) of the controlled variables; and (d) transmitting set values for the process control variables (CGC) to process control actuators. The prediction unit (OP) is based on a mathematical process model known as a direct model (M), and designed in such a way that the mass MXR of at least one component (X) in the reactor (R) is predicted by means of the equation MXR = LAG (FXRin . tau X, tau X), wherein FXRin is the mass flow rate of component X at the inlet of the reactor R, tau X is the dwell time of x in the reactor, and the function y = LAG (u, tau ) is the solution of the differential equation tau . dy/dt + y, calculated with the instantaneous value of u and tau as well as with the last calculated value of y.