The invention relates to a virtual sensing method and system for controlling at least one composition variable in a urea production process, based on a plurality of online measured process variables and a model, wherein the model is used to estimate, during the urea production process, the at least one composition variable indicative of a urea content on the basis of the plurality of online measured process variables, and modifying at least one of the plurality of online measured process variables for ensuring that a value of the at least one composition variable is within a predetermined range. The invention also relates to determining the model.

The method for setting polymerization conditions includes a physical property acquiring step, in which, when a composition which includes a polymerizable reactive compound including an episulfide compound, and a polymerization catalyst is heated and maintained at a predetermined temperature, a physical property value a derived from a functional group of the polymerizable reactive compound before heating and a physical property value b derived from a remaining functional group after maintaining heat for a predetermined time, are acquired; a remaining functional group ratio calculating step of calculating a remaining functional group ratio; a reaction rate coefficient calculating step for calculating a reaction rate coefficient; and a polymerization temperature calculating step of back-calculating each polymerization temperature every predetermined time in a polymerization time.

The invention relates to a method for operating a production plant for producing a chemical product (1) by reacting a H-functional reactant (2) with phosgene (3) during an interruption in production when taking at least one plant part of the production plant out of operation, wherein low-oxygen and oxygen-rich phosgene-containing exhaust gas flows are directed separately from one another in different phosgene decomposition directions and separately from one another—at spatially different points—into a combustion device, wherein plant parts that have not been taken out of operation are operated in a closed-circuit operating mode. The invention also relates to a production plant for producing a chemical product by reacting H-functional reactants with phosgene, which is suitable for being operated with the method according to the invention.

According to one aspect of the present invention, a hydrogen production apparatus includes a hydrogen production mechanism configured to produce a hydrogen gas from a raw material by using a catalyst; and an operation control circuit configured to input a parameter value as an index indicating a state of the catalyst, and configured to control an operation maximum load of the hydrogen production mechanism to be variable in correspondence with the parameter value.

A method of producing a soft sensor for a reference morphology of multiphase latex polymer particles synthesized in a production process is provided. The method is used in monitoring and/or controlling the production process. The method may also be used for optimizing production capacities of the production process.

A device for generating hydrogen gas having two or more storages, each storage storing a reactant or mix of reactants, and each storage coupled to a means of injecting the stored reactant or mix of reactants into a reaction chamber in a controlled manner and at an optimum rate, so that a chemical reaction occurs in the reaction chamber that produces hydrogen gas efficiently.

A chemical reaction apparatus includes a horizontal flow-type reactor in which a content horizontally flows with an unfilled space being provided thereabove, a microwave generator that generates microwaves, and at least one waveguide that transmits the microwaves generated by the microwave generator to the unfilled space in the reactor.

A calcium reaction control method and device, which can adjust the input amount of carbon dioxide gas inputted into the calcium reactor according to the measurement of the concentration of carbonate ions in the solution to be tested, and input the calcium reaction water from the calcium reactor into the water tank to provide the required carbonate ion concentration in the water tank. By means of the present invention, the amount of carbon dioxide input and the amount of calcium reaction water can be controlled, which can improve the control accuracy and ease of use.

A synthesis machine for preparation of a targeted inorganic material for recommended synthesis by a computer program that determines optimal solid-state methods for synthesis of an inorganic material. The computational method involves inputting a target inorganic material, querying structural data and thermodynamic data for the target inorganic material, enumerating possible synthetic reactions to construct a synthetic reaction database with a viable subset of the possible synthetic methods. The routine generates a nucleation metric and competition metric that are combined to provide recommended synthetic methods. The output for each of the recommended syntheses are input into a robotic synthesis machine where the delivery of reactants, reaction conditions, and analysis of extent of reaction, and product quality is controlled by a processor.

The present invention is concerned with a process for providing a homogeneous particle-containing slurry comprising the steps of: (a) providing a vessel comprising at least one impeller rotating around a vertical axis of the vessel, wherein a rotational speed n.sub.1 of the at least one impeller is higher than n.sub.min according to equation (1), the vessel further comprising an inlet and an outlet; (b) introducing a particle-containing slurry into the vessel or introducing components forming the particle-containing slurry into the vessel; (c) rotating the at least one impeller at least around the vertical axis for homogenizing and/or maintaining a homogeneous particle distribution within the slurry; (d) withdrawing the homogeneous particle-containing slurry via the outlet; (e) reducing the rotational speed n.sub.1 of the at least one impeller to a reduced rotational speed n.sub.red, whereas n.sub.red is lower than n.sub.1 and higher or equal gas inlet than n.sub.min according to equation (1):

[00001]$\begin{array}{cc}{n}_{\min }=\frac{S{v}^{0.1}{D_p^{0.2}\left(g\frac{\Delta \rho }{{\rho }_f}\right)}^{0.45}{B}^{0.13}}{D_a^{0.85}}& \left(1\right)\end{array}$