Development and Application of Formaldehyde Dynamic Standard Gas Generator Based on Trioxane Diffusion and Cracking

Abstract

Aiming at the engineering application problems of traditional static cylinder formaldehyde standard gas, such as large adsorption loss, rapid concentration attenuation, difficulty in preparing low-concentration gas and poor traceability of measured values, an integrated formaldehyde dynamic standard gas generator integrating constant-temperature trioxane diffusion cracking system and high-precision dynamic gas distribution system is developed in this paper. Taking solid trioxane as the gas source matrix, the equipment realizes stable vapor release through a precision constant-temperature diffusion unit, generates high-purity formaldehyde monomers via a high-temperature tubular cracking device for ring-opening cracking, and then completes accurate proportional dilution relying on dual-channel mass flow controllers, so as to realize on-line real-time preparation of formaldehyde standard gas with wide range and high stability.Featuring simple structure, high degree of automation and low operation and maintenance cost, this equipment can be widely applied in instrument calibration for environmental monitoring, indoor air detection, formaldehyde emission detection of industrial building materials, laboratory scientific research calibration and other scenarios, and has good engineering promotion value and industrial practical value.