Processes and systems that control operation of a commercial refinery distillation column and/or splitter operable to separate hydrocarbons. An automated process controller (APC) receives signal from at least one analyzer that provides information about the concentration of at least a first chemical in a first fraction and a second chemical in a second fraction obtained from the distillation column. The APC comprises programming in the form of an algorithm that calculates real-time monetary values for the first chemical and the second chemical and alters the operation of the distillation column to change either the percentage of the first chemical in the second fraction or the percentage of the second chemical in the first fraction, thereby maximizing overall operational profit for the distillation column.

The present invention relates to the field of distillation of isotopes obtained by distillation columns. An object of the present invention is to describe an innovative distillation column which provides significant improvements to the prior art. In particular, the distillation column will be a modular innovatively conceived column having any needed height.

A method to continuously monitor for tube leakage in a shell and tube thermosiphon reboiler for heating feedstock in a fractionating column includes: determining the column is in service by continuously monitoring an input flow of the feedstock into the column; determining the reboiler is inactive by continuously monitoring an output valve of tube-side heating fluid from the reboiler; determining the reboiler is losing the heating fluid by continuously monitoring an output flow of the heating fluid from the reboiler; determining the reboiler is heat exchanging by continuously monitoring a temperature difference between input and output flows of shell-side bottoms fluid with the column; and determining the tube leakage in the reboiler is taking place when the column is determined to be in service, the reboiler is determined to be inactive, the reboiler is determined to be losing the heating fluid, and the reboiler is determined to be heat exchanging.

A mass transfer column comprising: a shell (12); an open internal region (14) defined by said shell; and a mass transfer assembly (16) positioned in the open internal region (14), the mass transfer assembly (16) comprising: a dividing wall (18) forming first and second sub-regions; one or more zones of mass transfer structures positioned in the first and second sub-regions (22 and 24); and a liquid flow divider (48) positioned above the dividing wall (18) for delivering a volumetric split of liquid to the first and second sub-regions. The liquid flow divider (48) may comprise a moveable weir (68) or a valve (180) in order the change the ratio of liquid flow between the two sub-regions.

In some implementations, a control system may obtain historical data associated with usage of a distillation column during a historical time period. The control system may configure a prediction model to monitor the distillation column for a hazardous condition. The prediction model may be trained based on training data that is associated with occurrences of the hazardous condition. The control system may monitor, using the prediction model, the distillation column to determine a probability that the distillation column experiences the hazardous condition within a threshold time period. The prediction model may be configured to determine the probability based on measurements from a set of sensors of the distillation column. The control system may perform, based on the probability satisfying a probability threshold, an action associated with the distillation column to reduce a likelihood that the distillation column experiences the hazardous condition within the threshold time period.

Disclosed are a diaryl carbonate containing a compound of the following formula (I) in an amount of less than 1,000 ppm by mass, and a method for producing the same: ##STR00001## wherein R.sup.l represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryl group, or an aryloxy group. Disclosed methods include reacting urea with an alkyl alcohol to provide a dialkyl carbonate; reacting the dialkyl carbonate with an aryl alcohol to provide an alkylaryl carbonate; subjecting the alkylaryl carbonate to disproportionation to yield a mixture comprising a diaryl carbonate; and purifying the mixture.

Flowing a first buffer fluid and a second buffer fluid through a heat exchanger network thermally coupled to heat sources of a Natural Gas Liquid (NGL) fractionation plant, and transferring heat from the heat sources to the first buffer fluid and the second buffer fluid. Generating power via a first sub-system thermally coupled to the heat exchanger network and generating potable water from brackish water via a second sub-system thermally coupled to the heat exchanger network.

Provided is a method of separating and purifying a mixture of components having small difference in boiling point, and the method may maximize an energy collecting amount and collect a product to be desired in high purity and high yield.

Process for isolating pure 1,3-butadiene from a crude C.sub.4 fraction by extractive distillation using a selective solvent, wherein (a) the crude C.sub.4 fraction is introduced into a predistillation column, a first low boiler fraction comprising C.sub.3-hydrocarbons is taken off as overhead stream, a gaseous C.sub.4 fraction is taken off as side stream and a first high boiler fraction is taken off as bottom stream, (b) the gaseous C.sub.4 fraction is brought into contact with a selective solvent in at least one extraction column, giving an overhead fraction comprising butanes and butenes and a bottom fraction comprising 1,3-butadiene and selective solvent, (c) crude 1,3-butadiene is desorbed from the bottom fraction in at least one stripping column, with a stripped selective solvent being obtained and the stripped selective solvent being recirculated to the extraction column, and (d) at least part of the crude 1-3-butadiene is fed to a pure distillation column and a second high boiler fraction is separated off and a gaseous purge stream is taken off. Gaseous purge streams from the columns which are necessary in order to keep the concentration of molecular oxygen below a predetermined concentration limit are consolidated with output streams which are in any case provided for discharging other components in the process. The recirculation of the second high boiler fraction to a lower section of the predistillation column creates a further degree of freedom in operation of the pure distillation column.

Disclosed is a vapor splitter including: a chimney tray dividing an internal space of a housing into an upper space and a lower space; a chimney provided on the chimney tray to enable the upper space and the lower space to communicate with each other; a cap covering the chimney with a gap therebetween such that a gas discharge hole is formed so that gas, coming out through the chimney, can be transferred to the upper space through the gas discharge hole; a liquid feeding unit for feeding liquid to the upper space; and a liquid discharging unit for discharging the liquid out of the upper space. The size of the gas discharge hole is adjusted by controlling the height of the liquid collected on the chimney. Further disclosed is a method of adjusting a vapor split ratio using the vapor splitter.