A plant or refinery may include equipment such as reactors, heaters, heat exchangers, regenerators, separators, or the like. Types of heat exchangers include shell and tube, plate, plate and shell, plate fin, air cooled, wetted-surface air cooled, or the like. Operating methods may impact deterioration in equipment condition, prolong equipment life, extend production operating time, or provide other benefits. Mechanical or digital sensors may be used for monitoring equipment, and sensor data may be programmatically analyzed to identify developing problems. For example, sensors may be used in conjunction with one or more system components to detect and correct maldistribution, cross-leakage, strain, pre-leakage, thermal stresses, fouling, vibration, problems in liquid lifting, conditions that can affect air-cooled exchangers, conditions that can affect a wetted-surface air-cooled heat exchanger, or the like. An operating condition or mode may be adjusted to prolong equipment life or avoid equipment failure.

A plant or refinery may include equipment such as reactors, heaters, heat exchangers, regenerators, separators, or the like. Types of heat exchangers include shell and tube, plate, plate and shell, plate fin, air cooled, wetted-surface air cooled, or the like. Operating methods may impact deterioration in equipment condition, prolong equipment life, extend production operating time, or provide other benefits. Mechanical or digital sensors may be used for monitoring equipment, and sensor data may be programmatically analyzed to identify developing problems. For example, sensors may be used in conjunction with one or more system components to detect and correct maldistribution, cross-leakage, strain, pre-leakage, thermal stresses, fouling, vibration, problems in liquid lifting, conditions that can affect air-cooled exchangers, conditions that can affect a wetted-surface air-cooled heat exchanger, or the like. An operating condition or mode may be adjusted to prolong equipment life or avoid equipment failure.

The present invention relates to a process for the continuous production of nitrobenzene by the nitration of benzene with nitric acid and sulphuric acid under adiabatic conditions, not the entire production plant being shut down during a production stop, but the production plant being entirely or at least partly operated in recirculation mode. The invention further relates to a plant for producing nitrobenzene and to a method for operating a plant for producing nitrobenzene.

Apparatuses and methods are disclosed for detecting catalyst transfer pipe plugging in a chemical plant or petrochemical plant or refinery. The catalyst transfer pipe may extend from a reactor to a catalyst collector and enable the flow of catalyst from the reactor to the catalyst collector. Specifically, one or more sensors affixed to a catalyst transfer pipe may collect sensor data for analysis. Based on one or more detected changes in the sensor data outside a range, a data collection platform may send one or more alerts and/or send one or more signals to a control platform to adjust a flow rate, a pressure differential, or perform another action to clear a developing catalyst buildup and thereby attempt to avoid a catalyst transfer pipe from becoming plugged.

A chemical production assembly for producing an isocyanate. comprising n serially arranged units U (i), i=1 . . . n, n2. wherein a unit U(i) is for preparing a chemical product cp(i) at a preparation rate PR(i) by using, as starting material. a chemical product cp(i+1) preprared in the unit U(i+1) arranged upstream of said unit U(i), wherein said unit U(i) comprises an inlet means for receiving said chemical product cp(i+1) at an input rate IR(i). said unit U(i) being characterized by a nominal preparation rate PRN(i) and a nominal input rate IRN(i); and a unit U(i+1), i=1 . . . n-1, is for preparing the chemical product cp(i+1) and for supplying said chemical product cp(i+1) to the inlet means of the unit U(i) arranged downstream of said unit U(i+1) at a supply rate SR(i+1) with SR(i+1)=IR(i).

The present invention relates to a process for the continuous production of nitrobenzene by the nitration of benzene with nitric acid and sulphuric acid under adiabatic conditions, not the entire production plant being shut down during a production stop, but the production plant being entirely or at least partly operated in recirculation mode. The invention further relates to a plant for producing nitrobenzene and to a method for operating a plant for producing nitrobenzene.

A reactor for carrying out a chemical reaction has a reactor vessel, one or more reaction tubes and means for the electrical heating of the one or more reaction tubes. The reactor vessel has one or more discharge orifices which are permanently open or are set up to open above a preset pressure level, and gas feed means are provided, which are set up to feed an inerting gas into an interior of the reactor vessel.

The method can include receiving a baseline signal curve, operating a thermal reactor, measuring a signal, optionally determining a state (e.g., state of health) of the thermal reactor, and controlling the thermal reactor based on the signal. The method can include receiving (e.g., determining, measuring, etc.) a resistance-temperature and/or resistance-time curve; operating a thermal reactor comprising resistively heating a porous catalytic element; measuring an electrical signal (e.g., resistance, current, voltage, etc.) of the thermal reactor; optionally inferring a temperature of the thermal reactor based on the electrical signal and the resistance-temperature; and controlling the thermal reactor based on the electrical signal. The system can include one or more of a reaction module (e.g., an electrical coupler or electrode and catalytic element, etc.), inlet and outlet valves, power source, electrical feedthroughs (e.g., leads, supports, etc.), sensors, and computing system (e.g. controller).