An Improvement Research Of Semiautomatic Zero-length Column System Base On CO₂ Adsorption

With the development of the industrialized society,the consumption of fossil fuels has increased a lot.CO₂,one of the most serious pollution components,has draw many people's attention because the emission of CO₂ has exceeded the earth's tolerance.Considering the severe situation,CO₂ capture and storage technology will play an important role in coping with the global warming crisis.The solid absorption method has attracted the attention of many scholars due to the advantages of low energy consumption,simple equipment and corrosion resistance.The family of solid adsorbents can be complex and they can be modified by different methods,which greatly increase the variety and quantity of solid absorbents.Currently,we have been using gravimetric or volumetric methods to measure adsorption equilibrium accurately,but there are still some disadvantages about aforementioned methods,such as time-consuming and require a large amount of absorbents.So it is important to find a device that can detect the adsorption equilibrium of CO₂ quickly and accurately.In this paper,we have improved a new semi-automatic zero length column?ZLC?system to screen the materials of CO₂ absorption quickly.This mass of adsorbent sample that the system needs is about 3-20mg,the systems equips with detector system?TCD and MS?and a new gas dosing system,and the new system can use water vapour directly without a chilled bath and bubbler devices,thus preventing the possibility of gas leakage.At the same time,the intake flow rate of the new gas dosing system can be controlled in a lower range,thereby reducing consumption of gases,and the system can be operated under equilibrium control,the stability and reliability of the system are verified by debugging the new ZLC system.In addition,using the ZLC theoretical mathematical model,an algorithm which can deal with experimental data quickly is proposed,and the blank volume of the ZLC system is calculated to be 0.30cc on the Matlab simulation platform.Furthermore,the new ZLC system was used to sort the CO₂ adsorption capacity of two typical zeolites molecular sieves.Using less than 20mg of adsorbent material,a sample can be detected within 1h,and the adsorption capacity of the adsorbent can be sorted by c/c0-Ft/M.The desorption curves for 5A and 13X molecular sieves present a clear nonlinear equilibrium,and the adsorption isotherm of the 13X molecular sieves at four different temperatures?311K,333K,353K,373K?are obtained,under the point of interest for flue gas application?311K,0.1barpartial pressure?,the maximum adsorption capacity is 2.62mmol/g,which is obviously better than 2.20mmol/g of 5A,and the adsorption heat determined according to different temperatures was37k J/mol.The ZLC column oven has enough space,therefore the system can be easily modified to mount a lager column?grams of adsorbent?and run breakthrough experiments.Based on the breakthrough experimental studies of two kinds of molecular sieves,the adsorption properties of CO₂ under three different flow rates and two different volume fractions were measured,and the differences of capture rate,the unused-bed height and bed utilization rate were calculated and compared.In this paper,a new semi-automatic ZLC system and the data processing algorithm are proposed to achieve requirements of rapid screening of CO₂ adsorbents materials and rapid data processing.