Preparation of Nanoporous Carbonaceous Promoters for Enhanced CO2 Absorption in Tertiary Amines

Aqueous solutions of tertiary amines are promising absorbents for CO2 capture,as they are typically characterized by a high absorption capacity,low heat of reaction,and low corrosivity.However,tertiary amines also exhibit very low kinetics of CO2 absorption,which has made them unattractive options for large-scale utilization.Here,a series of novel nanoporous carbonaceous promoters(NCPs)with different properties were synthesized,characterized,and used as rate promoters for CO2 absorption in aqueous N,N-diethylethanolamine(DEEA)solutions.To prepare a DEEA–NCP nanofluid,NCPs were dispersed into aqueous 3 mol∙L1 DEEA solution using ultrasonication.The results revealed that among microporous(GC)and mesoporous(GS)carbonaceous structures functionalized with ethylenediamine(EDA)and polyethyleneimine(PEI)molecules,the GC–EDA promoter exhibited the best performance.A comparison between DEEA–GC–EDA nanofluid and typical aqueous DEEA solutions highlighted that the GC-EDA promoter enhances the rate of CO2 absorption at 40C by 38.6%(36.8–50.7 kPamin1)and improves the equilibrium CO2 absorption capacity(15 kPa;40C)by 13.2%(0.69–0.78 mol of CO2 per mole of DEEA).Moreover,the recyclability of DEEA–GC–EDA nanofluid was determined and a promotion mechanism is suggested.The outcomes demonstrate that NCP–GC–EDA in tertiary amines is a promising strategy to enhance the rate of CO2 absorption and facilitate their large-scale deployment.

An Algorithm for Detecting Ice Cloud at Different Altitudes by Combining Dual CrIS Full Spectrum Resolution CO2 Channels

Using infrared sensors to detect ice clouds in different atmospheric layers is still a challenge.The different scattering and absorption properties of longwave and shortwave infrared channels can be utilized to fulfill this purpose.In this study,the release of Suomi-NPP Cross-track Infrared Sounder(Cr IS)full spectrum resolution is used to select and pair channels from longwave(~15μm)and shortwave(~4.3μm)CO2 absorption bands under stricter conditions,so as to better detect ice clouds.Besides,the differences of the weighting function peaks and cloud insensitive level altitudes of the paired channels are both within 50 h Pa so that the variances due to atmospheric conditions can be minimized.The training data of clear sky are determined by Visible Infrared Imaging Radiometer Suite(VIIRS)cloud mask product and used to find the linear relationship between the paired longwave and shortwave CO2 absorption channels.From the linear relationship,the so-called cloud emission and scattering index(CESI)is derived to detect ice clouds.CESI clearly captures the center and the ice cloud features of the Super Typhoon Hato located above 415 h Pa.Moreover,the CESI distributions agree with cloud top pressure from the VIIRS in both daytime and nighttime in different atmospheric layers.

Impacts of CaO Solid Particles in Carbon Dioxide Absorption Process from Ship Emission with NaOH Solution

CO_2 emitted from ship exhaust is one of the major sources of atmospheric pollution. In order to reduce ship CO_2 emissions, this paper comes up with the idea of recovering CO_2 from ship exhaust by Na OH solution and improves the absorption rate by adding Ca O solid particles. The effect mechanism of Ca O solid particles on CO_2 absorption efficiency is analyzed in detail, and the mathematical model is deduced and the Ca O enhancement factor is calculated through experiments. Experiment result demonstrates that the effect of CaO solid particles on the absorption of CO_2 in alkali solution is significant. The absorption rate of pure CO_2 gas,the simulated ship exhaust gas and 6135 AZG marine diesel engine emission can be increased by 10%, 15.85% and10.30%, respectively. So it can be seen that CaO solid particles play an important role in improving the absorption efficiency of ship CO_2 emission.

Activated carbon produced from paulownia sawdust for high-performance CO_2 sorbents

In this paper, activated carbons （ACs） with high specific surface areas were successfully synthesized by simple one-step carbonization-activation from paulownia sawdust biomass, and the effects of the synthetic conditions on their CO2 capture capacity were investigated as well. The results show that, when the mass ratio between activator and biomass is 4, the activation temperature is 700℃ and the activation time is 1 h, as-made AC provides the most micropores for CO2 adsorption. As a consequence, the maximum CO2 uptake of 8.0 mmol/g is obtained at 0 ℃ and 1 bar.

Single-frequency and free-running operation of a single-pass pulsed Ho:YLF amplifier

A single-frequency pulsed holmium-doped yttrium lithium fluoride(Ho:YLF)amplifier pumped by a Tm-doped fiber laser was demonstrated.The seed was an injection-seeded Q-switched Ho:YLF laser.The output energy from the singlefrequency pulsed amplifier was 24.2 mJ,with a pulse width of 250 ns at a pulse repetition frequency(PRF)of 100 Hz.The energy stability during 30 min was improved to 1%after the single-frequency pulsed Ho:YLF laser was amplified.The line width of the single-frequency pulsed spectrum of the Ho:YLF amplifier was 2.81 MHz.The single-frequency pulsed Ho:YLF amplifier can be applied to differential absorption lidar(DIAL),since its output spectrum is around the P12 CO2 absorption line.