Performance Of CO2 Capture Research Articles

Rate-Based Modeling of CO2 Absorption in Aqueous NH3 in a Packed Column

A rigorous rate-based model for the aqueous ammonia (NH3) based CO2 absorption in a packed column has been used to simulate the recently available results from pilot plant trialing of aqueous NH3 based post combustion process (PCC) at the Munmorah power station, New South Wales, Australia. The model is based on RateSep module, a rate- based absorption & stripping unit operation model in Aspen Plus®, and uses an improved thermodynamic model for NH3-CO2-H2O system to predict the performance of CO2 capture. The evaluation of the thermodynamic model via validation of vapor liquid equilibrium and heat of absorption of the NH3-CO2-H2O system shows that the model can satisfactorily predict experimental results from the published literatures. The predicted results from the rate-based model also agree reasonably well with pilot plant results including CO2 absorption rate and NH3 loss rate. The rate- based model is then utilized for the extended study of the effect of operation pressure, aqueous NH3 concentration and liquid inlet temperature on the CO2 absorption and NH3 loss. Two different absorber configurations split flow and inter-cooling have been investigated as possible options for control of the NH3 loss.

Techno-economic prospects for CO2 capture from distributed energy systems

CO2 emissions from distributed energy systems are expected to become increasingly significant, accounting for about 20% for current global energy-related CO2 emissions in 2030. This article reviews, assesses and compares the techno-economic performance of CO2 capture from distributed energy systems taking into account differences in timeframe, fuel type and energy plant type. The analysis includes the energy plant, CO2 capture and compression, and distributed transport between the capture site and a trunk pipeline. Key parameters, e.g., capacity factor, energy prices and interest rate, were normalized for the performance comparison.The findings of this study indicate that in the short-mid term (around 2020–2025), the energy penalty for CO2 capture ranges between 23% and 30% for coal-fired plants and 10–28% for natural gas-fired plants. Costs are between 30 and 140€/tCO2 avoided for plant scales larger than 100MWLHV (fuel input) and 50–150€/tCO2 avoided for 10–100MWLHV. In the long-term (2030 and beyond), the energy penalty for CO2 capture might reduce to between 4% and 9% and the costs to around 10–90€/tCO2 avoided for plant scales larger than 100MWLHV, 25–100€/tCO2 avoided for 10–100MWLHV and 35–150€/tCO2 avoided for 10MWLHV or smaller.CO2 compression and distributed transport costs are significant. For a distance of 30km, 10€/tCO2 transported was calculated for scales below 500tCO2/day and more than 50€/tCO2 transported for scales below 5tCO2/day (equivalent to 1MWLHV natural gas). CO2 compression is responsible for the largest share of these costs.CO2 capture from distributed energy systems is not prohibitively expensive and has a significant cost reduction potential in the long term. Distributed CO2 emission sources should also be considered for CCS, adding to the economies of scale of CO2 transport and storage, and optimizing the deployment of CCS.

Experimental Studies on CO<sub>2</sub> Absorption in Immersed Hollow Fiber Membrane Contactor

Carbon dioxide (CO2) absorption performance from flue gas was investigated using monoethanolamine (MEA) solution in porous hydrophobic polyvinylidene fluoride (PVDF) hollow fiber membranes contactor. The influence of operating parameters on CO2 removal efficiency and flux were studied in the immersion operating mode. The experimental results indicated that the CO2 removal efficiency and flux decreased with the increase of flue gas load and carbonization degrees, but the increase of the absorbent concentration and temperature promoted membrane performance of CO2 capture. An increase of 84 m3•m-2•h-1 in the flue gas load resulted in a 68% decrease in the removal efficiency. Absorbent carbonation degree increased to 0.45 mol CO2•mol-1MEA led to the decrease of active ingredient amounts in the absorption solution, and the corresponding removal efficiency and membrane flux dropped by 50% of the initial amounts, respectively. The increase of concentration and temperature of absorbent also benefited membrane absorption performance of CO2 absorption, so that the concentration and temperature of the solvent increased lead to the CO2 removal efficiency and flux increased.

Amino functionalized mesostructured SBA-15 silica for CO2 capture: Exploring the relation between the adsorption capacity and the distribution of amino groups by TEM

The distribution of amino groups on amino-functionalized SBA-15 materials for CO2 adsorption was studied by transmission electron microscopy (TEM) in combination with a staining technique using RuO4 in order to analyze the influence of the aminated organic chains location on the CO2 adsorption properties. Mesostructured amino-functionalized SBA-15 materials were obtained by co-condensation, grafting and impregnation using aminopropyl, AP(N), ethylene-diaminepropyl, ED(NN), diethylene-triaminepropyl, DT(NNN) and polyethyleneimine, PEI, as functionalizing agents. CO2 adsorption isotherms of functionalized samples at 45°C showed that both the adsorption capacity (mgCO2/g ads) and the efficiency of amino groups (mol CO2/mol N) depend on the functionalization technique and the amount of organic compound used. While samples synthesized by co-condensation showed negligible CO2 uptake and efficiency, adsorbents prepared by grafting and impregnation presented significant CO2 adsorption capacities but a dissimilar efficiency. Key differences in the location of aminated chains explained the performance of CO2 capture for every adsorbent, being grafted samples the adsorbents where amino groups were better distributed, favouring CO2 diffusion trough the whole structure.

Optimization of Pressure Swing Adsorption and Fractionated Vacuum Pressure Swing Adsorption Processes for CO2 Capture

This work focuses on the optimization of cyclic adsorption processes to improve the performance of CO2 capture from flue gas, consisting of nitrogen and carbon dioxide. The adopted processes are the PSA (pressure swing adsorption) process and the FVPSA (fractionated vacuum pressure swing adsorption) process, modified from the FVSA (fractionated vacuum swing adsorption) process developed by Air Products and Chemicals, Inc. The system models are currently bench scale and adopt zeolite13X as an adsorbent. The high-temperature PSA is better for high purity of product (CO2), and the high-temperature FVPSA is much better than the normal-temperature PSA processes. The main goal of this study is to improve the purity and recovery of carbon dioxide. The Langmuir isotherm parameters were calculated from experimental data taken at National Energy Technology Laboratory (Siriwardane, R.; NETL, DOE, 2004). Moreover, efficient optimization strategies are essential to compare these processes. To perform optimization work...