The present invention relates to a method to control a liquid feed stream carried out by measuring at least one spectrum of the liquid feed stream comprising an initiator or catalyst, determining its activity using a predictive model on the basis of said spectrum and adjusting the feed streams and/or the preparation conditions of the feed stream comprising the initiators or catalysts in order to attain or maintain a desired level of total activity. In a further aspect the invention relates to a controlled process for the preparation of polymers in a polymerization reactor by contacting liquid feed streams comprising monomers and initiators or catalysts, whereby the control of the feed streams entering the polymerization reactor and/or the initiator or catalyst preparation is carried out by measuring at least one spectrum of the liquid feed stream comprising an initiator or catalyst, determining its activity using a predictive model on the basis of said spectrum and adjusting the feed streams and/or the preparation conditions of the feed stream comprising the initiators or catalysts in order to attain or maintain a desired level of total activity within the polymerization reactor. More particularly, the invention relates to a method for controlling the activity of aluminum containing initiators in a process for the co-polymerization of isolefins and multiolefins, in particular isobutylene and isoprene. The present invention further to device and a chemical plant suitable to operate said process.

Systems and methods conducive to the formation of one or more alkene hydrocarbons using a methane source and an oxidant in an oxidative coupling of methane (OCM) reaction are provided. One or more vessels each containing one or more catalyst beds containing one or more catalysts each having similar or differing chemical composition or physical form may be used. The one or more catalyst beds may be operated under a variety of conditions. At least a portion of the catalyst beds may be operated under substantially adiabatic conditions. At least a portion of the catalyst beds may be operated under substantially isothermal conditions.

A method of monitoring a solid component of a reactor feed stream in a polymer production system, comprising (a) measuring a turbidity of the reactor feed stream, wherein the reactor feed stream comprises a solid component of a polymerization catalyst system, and (b) translating the turbidity of the reactor feed stream into a concentration of the solid component in the reactor feed stream. A method of monitoring a solid component of a reactor feed stream in a polymer production system, comprising (a) measuring a turbidity of a precontactor feed stream, wherein the precontactor feed stream comprises a solid component of a polymerization catalyst system, and (b) translating the turbidity of the precontactor feed stream into a concentration of the solid component in a precontactor effluent stream, wherein the precontactor effluent stream comprises the reactor feed stream.

In a process for producing methanol, a synthesis gas that has been recovered from biomass is fed to a methanol synthesis apparatus. In a main operating mode in which sufficient electrical power is available for electrolytic hydrogen recovery, correspondingly electrolytically recovered hydrogen is fed to the methanol synthesis apparatus. In a secondary operating mode in which insufficient electrical power is available for electrolytic production of hydrogen, a tail gas that arises from a biogas recovered from a biomass on removal of the synthesis gas is fed to a generator in order to provide electrical power for apparatuses involved in the process.

A feeding system for feeding an inlet material to a process system, comprising a pressure force unit, upstream of a flow force unit, configured to increase a pressure of an inlet material flow; and an upstream control valve configured to subject the inlet material flow to a pressure-drop; a control unit configured to control a start-up of the feeding system by: circulating the inlet material flow in a circulation loop, while a valve system is arranged in the first position; increase the pressure of the inlet material flow; subject the inlet material flow to a first pressure-drop: when the inlet material flow is circulating, arrange the valve system in the second position; subject the inlet material flow to a second pressure-drop, wherein the first pres-sure-drop is greater than the second pressure-drop.

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 process for the production of syngas comprising the steps of providing a feed gas comprising a hydrocarbon, carbon dioxide and optionally steam, contacting a flow of said feed gas with a metal oxide to form syngas, wherein the mole fraction of carbon dioxide or in the case the feed gas comprises steam, the sum of the mole fractions of carbon dioxide and steam, in the feed gas is between 0.3 and 0.7; and/or wherein the mole fraction of the hydrocarbon in the feed gas is between 0.3 to 0.5, wherein the feed gas is contacted with the metal oxide at a temperature of between 1050K and 1600K.