A method and apparatus for producing a biocide from a hypochlorite oxidant and an ammonium salt are provided. The method includes monitoring a control parameter to optimize the ratio between the hypochlorite oxidant and the ammonium salt. The control parameter may be oxidation-reduction potential, conductivity, induction or oxygen saturation.

A process for converting an anhydrous off-gas stream from melamine synthesis plants to urea and the relative plant for the direct conversion of an anhydrous off-gas stream from melamine synthesis plants into urea, are described.

The present invention concerns a process for increasing the productivity of equilibrium-restricted reactions and for increasing the productivity of a target compound. This process comprises the steps of (a) providing a reaction mixture comprising reactants; (b) subjecting the reaction mixture to the equilibrium reaction in a reactor or sequence of reactors, to obtain a reactor outlet mixture comprising the target compound and at least one of the reactants; (c) regenerating the loaded sorbent obtained in step (e), by flushing the loaded sorbent with the reactor outlet mixture originating from step (b), to obtain regenerated sorbent and an effluent comprising desorbed product; (d) separating the effluent originating from step (c) into a product stream and a reactant stream; and (e) a sorption step, wherein (i) the reactant stream originating from step (d); and/or (ii) an intermediate reaction mixture, which is obtained at the outlet of a reactor not being the last reactor of the reactor sequence, prior to being subjected to the subsequent reactor of the reactor sequence, is contacted with a sorbent selective for one or more of the products of the equilibrium reaction, to obtain a loaded sorbent and a depleted mixture.

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 method of determining multimodal polyethylene quality comprising the steps of (a) providing a multimodal polyethylene resin sample; (b) determining, in any sequence, the following: that the multimodal polyethylene resin sample has a melt index within 30% of a target melt index; that the multimodal polyethylene resin sample has a density within 2.5% of a target density; that the multimodal polyethylene resin sample has a dynamic viscosity deviation (% MVD) from a target dynamic viscosity of less than about 100%; that the multimodal polyethylene resin sample has a weight average molecular weight (M.sub.w) deviation (% M.sub.wD) from a target M.sub.w of less than about 20%; and that the multimodal polyethylene resin sample has a gel permeation chromatography (GPC) curve profile deviation (% GPCD) from a target GPC curve profile of less than about 15%; and (c) responsive to step (b), designating the multimodal polyethylene resin sample as a high quality resin.

Provided is a reactor capable of generating a proposed target solution in a short time by reacting the raw material solutions with each other while allowing a mixed raw material solution containing a plurality of kinds of raw material solutions mixed with each other to flow, and restraining the temperature of the mixed raw material solution from excessively rising. The reactor includes a reaction channel allowing the mixed raw material solution to flow and a solvent channel allowing a solvent dissolvable in the mixed raw material solution to flow. The solvent channel is connected to the reaction channel between the upstream end and the downstream end of the reaction channel so that the solvent flowing in the solvent channel is mixed with the mixed raw material solution flowing in the reaction channel from the middle of the reaction channel.

Fuel tank inerting systems for aircraft are provided. The systems include a fuel tank, a catalytic reactor arranged to receive a first reactant from a first reactant source and a second reactant from a second reactant source to generate an inert gas that is supplied to the fuel tank to fill an ullage space of the fuel tank, a heat exchanger arranged between the catalytic reactor and the fuel tank and configured to at least one of cool and condense an output from the catalytic reactor to separate out the inert gas, and a controller configured to perform a light-off operation of the catalytic reactor by controlling at least one light-off parameter and, after light-off occurs, adjusting the at least one light-off parameter to an operating level, wherein the at least one light-off parameter comprises a space velocity through the catalytic reactor.

Processes for producing high biogenic concentration Fischer-Tropsch liquids derived from the organic fraction of municipal solid wastes (MSW) feedstock that contains a relatively high concentration of biogenic carbon (derived from plants) and a relatively low concentration of non-biogenic carbon (derived from fossil sources) wherein the biogenic content of the Fischer-Tropsch liquids is the same as the biogenic content of the feedstock.

Processes for producing high biogenic concentration Fischer-Tropsch liquids derived from the organic fraction of municipal solid wastes (MSW) feedstock that contains a relatively high concentration of biogenic carbon (derived from plants) and a relatively low concentration of non-biogenic carbon (derived from fossil sources) wherein the biogenic content of the Fischer-Tropsch liquids is the same as the biogenic content of the feedstock.

Systems and methods are provided for controlling chemical production and/or petroleum processing reaction systems to allow for improved control of control variables relative to desired set points. The improved control can be achieved by use of a modified proportional-integral-derivative (PID) controller or a similar type of controller that includes dynamic tuning logic. The modified PID controller can be operated using different coefficients based on the relative values of a control variable and a reasonable progress curve determined based on the values of the control variable.