Micro device and modeling method for studying gas-solid intrinsic chemical reaction kinetics

Abstract

The invention discloses a micro device for studying gas-solid intrinsic chemical reaction kinetics. The micro device comprises a weighing component, a reactor component, a bracket and a three-directional switching valve, wherein the weighing component comprises a computer, a data acquirer, a strain gage, a glass protecting cover and a metal wire hook; the reactor component comprises a hollow quartz glass reactor, a metal hoisting basket, a heating furnace, a hollow quartz connecting part, a gas collection bag, a thermocouple and a temperature control box. The invention further provides a modeling method using the micro device. The modeling method comprises the following steps: on the premise that the influence caused by flowing such as internal and external diffusion is eliminated, firstly, confirming the conversion rate of a gas reactant and the yield of a multi-component gas product, and finally with the combination of change of the mass of solid test samples in different time periods, acquiring a gas-solid intrinsic chemical reaction kinetics model. By adopting the micro device disclosed by the invention, the problems that a conventional thermogravimetry device is small in test sample amount, a product cannot be quantified, the influence caused by internal and external diffusion is hard to eliminate, and the like are overcome, and a novel method for studying the gas-solid intrinsic chemical reaction kinetics is developed.

Description

technical field [0001] The invention belongs to the field of studying gas-solid intrinsic chemical reaction kinetics, and in particular relates to a micro-device and a modeling method for studying gas-solid intrinsic chemical reaction kinetics. Background technique [0002] The gas-curing chemical reaction is a very complicated process of physical diffusion and chemical reaction. When the gas-phase reactant contacts with the solid, a chemical reaction will occur to change the quality of the solid, and at the same time, gas-phase products will be released. [0003] In the existing research methods of chemical reaction kinetics, fixed bed / fluidized bed is generally used to study the gas-phase product release characteristics of gas-solid two-phase reaction and the change of solid properties, but real-time monitoring of the change of solid mass is difficult to achieve. Thermogravimetric analyzer (TGA) is a typical instrument that uses thermogravimetric method to detect the temp...

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Problems solved by technology

[0003] In the existing research methods of chemical reaction kinetics, fixed bed / fluidized bed is generally used to study the release characteristics of gas-phase products and the properties of solids in gas-solid two-phase reactions changes, and real-time monitoring of solid quality changes is difficult to achieve

Thermogravimetric Analyzer (TGA) is a typical instrument that uses thermogravimetric method to detect the temperature-mass relationship of substances, but it has some shortcomings in the study of gas-solidification chemical reaction kinetics: (1) The internal and external diffusion of gas has not been effectively controlled. Elimination, flow and reaction are not decoupled, so the reaction kinetics obtained from TGA is a macroscopic kinetics including flow and reaction factors, and the error is large in practical applications; (2) The mass of the solid sample is too small (generally less than 20 mg), the amount of gas products is too small to perform qualitative analysis such as GC / MS

The above thermogravimetric analysis devices have their own advantages, but there are also disadvantages such as insufficient accuracy and complex structure.

More importantly, they obtain macroscopic dynamics including flow factors, and the model extension is poor

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