Investigating the Relation between Absorption and Gas Concentration in Gas Detection Using a Diffuse Integrating Cavity

The relationship between absorption and gas concentration was studied using a diffuse integrating cavity as a gas cell. The light transmission process in an arbitrary diffuse cavity was theoretically derived based on a beam reflection analysis. It was found that a weak absorption condition must be satisfied to ensure a linear relationship between absorbance and gas concentration. When the weak absorption condition is not satisfied, a non-linear relation will be observed. A 35 × 35 × 35 cm diffuse integrating cavity was used in the experiment. Different oxygen concentrations were measured by detecting the P9 absorption line at 763.8 nm, based on tunable diode laser absorption spectroscopy. The relationship between the absorption signals and oxygen concentration was linear at low oxygen concentrations and became non-linear when oxygen concentrations were higher than 21%. The absorbance value of this transition point was 0.17, which was considered as the weak absorption condition for this system. This work studied the theoretical reason for the non-linear phenomenon and provided an experimental method to determine the transition point when using a diffuse integrating cavity as a gas cell.

CO2 Capturing by MDEA-PZ-TETA in a Rotating Packed Bed

The absorption performance of CO2 using MDEA-PZ-TETA ternary absorbent in a rotating packed bed was investigated. The effects of the concentration of the ternary absorbent, the absorbing liquid temperature, the rotating speed, the liquid flow rate and gas flow rate on the absorption performance of CO2 were discussed in detail. The experimental results showed that the optimum absorption condition was the absorbent concentration of 0.05 mol/L, the absorption temperature of 290 K, the rotating speed of 454 rpm and the ratio of gas to liquid of 1.2, which could provide a molar absorption saturated capacity of 1.3688 molCO2/molAm and a satisfying CO2 absorptivity of 93.18%.

Performance of MDEA-PZ-TETA for Absorption and Desorption of CO2

The absorption performance of CO2 from the simulated flue gas using fresh MDEA-PZ-TETA absorbent and the desorption behavior of CO2 from the CO2-saturated absorbent were investigated. In the process of CO2 absorption, the absorption temperature and the inlet flow rate of CO2 played important effects on the absorption performance. The experimental results showed that the suitable absorption condition of CO2 using fresh absorbent was the absorption temperature of 20 oC for 18 min and the inlet flow rate of CO2 of 50 mL/min. In the process of CO2 desorption from the used absorbent, the desorption temperature played an important role and the regeneration time had little effect on the desorption behavior. The suitable desorption condition was the desorption temperature of 105 oC for 1.0 h and the regeneration time of 1.

Study on the Adsorption Effect of Active Carbon of Various Compozitions in Polytetrahydrofuran Waste Water

This paper prensents the chromatography analysis condition study on the main poluted compozotion(furaldehyde and furfuran) in polytetrahydrofuran waste water with HPLC-DAD. Given the chromatography condition is that ODS is the stationary phase, the mix liquid in which methenyl:water = 75:25 is the mobile phase, the flow is 1.00 mL•min-1, using diode array detector(detect wavelength when furaldehyde is 274 nm and furfuran in 208nm), the injection volume is 2.0µL, the column temperature is 25.0°C. This paper presents the study of treatment of polytetrahydrofuran waste water by active carbon adsorption, investigates the three conditions of the amount of active carbon, stirring time and absorption temprature, and confirms that the best absorption condition is that the amount of active carbon is 3.0g, stirring for 30min and room temprature 20°C.