Optimization the Process of Chemically Modified Carbon Nanofiber Coated Monolith via Response Surface Methodology for CO2 Capture

Abstract

In the present study, a sequence of experiments was performed to assess the influence of the key process parameters on the formation of a carbon nanofiber-coated monolith (CNFCM), using a four-level factorial design in response surface methodology (RSM). The effect of reaction temperature, hydrocarbon flow rate, catalyst and catalyst promoter were examined using RSM to enhance the formation yield of CNFs on a monolith substrate. To calculate carbon yield, a quadratic polynomial model was modified through multiple regression analysis and the best possible reaction conditions were found as follows: a reaction temperature of 800 °C, furfuryl alcohol flow of 0.08525 mL/min, ferrocene catalyst concentration of 2.21 g. According to the characterization study, the synthesized CNFs showed a high graphitization which were uniformly distributed on a monolith substrate. Besides this, the feasibility of carbon dioxide (CO2) adsorption from the gaseous mixture (N2/CO2) under a range of experimental conditions was investigated at monolithic column. To get the most out of the CO2 capture, an as-prepared sample was post-modified using ammonia. Furthermore, a deactivation model (DM) was introduced for the purpose of studying the breakthrough curves. The CO2 adsorption onto CNFCM was experimentally examined under following operating conditions: a temperature of 30–50 °C, pressure of 1–2 bar, flow rate of 50–90 mL/min, and CO2 feed amount of 10–40 vol.%. A lower adsorption capacity and shorter breakthrough time were detected by escalating the temperature. On the other hand, the capacity for CO2 adsorption increased by raising the CO2 feed amount, feed flow rate, and operating pressure. The comparative evaluation of CO2 uptake over unmodified and modified CNFCM adsorbents confirmed that the introduced modification procedure caused a substantial improvement in CO2 adsorption.

K2CO3 on porous supports for moisture‐swing CO2 capture from ambient air

“…7 Research has been extensively carried out on a number of porous materials 8 with CO 2 adsorption properties such as carbon nanotubes, molecular sieves, and metal-organic frameworks (MOFs). [9][10][11] Although some materials have been shown to exhibit good CO 2 adsorption properties in environments with high CO 2 concentrations, the CO 2 adsorption performance of these materials is usually significantly reduced when used as DAC adsorbents because of the extremely low partial pressure of CO 2 in the air as compared to the point sources such as flue gas. [12][13][14] Moisture-swing adsorbents were first proposed by Lackner et al 15 for capturing CO 2 from ambient air.…”

“…CO 2 capture from ambient air is commonly referred to as direct air capture (DAC) technology, whose positive headlines include compensating for mobile and small distributed CO 2 emissions, skipping CO 2 transportation costs for CO 2 utilization/storage, and offering a practical method for negative emissions 7 . Research has been extensively carried out on a number of porous materials 8 with CO 2 adsorption properties such as carbon nanotubes, molecular sieves, and metal–organic frameworks (MOFs) 9–11 . Although some materials have been shown to exhibit good CO 2 adsorption properties in environments with high CO 2 concentrations, the CO 2 adsorption performance of these materials is usually significantly reduced when used as DAC adsorbents because of the extremely low partial pressure of CO 2 in the air as compared to the point sources such as flue gas 12–14 …”

K2CO3-Impregnated Al/Si Aerogel Prepared by Ambient Pressure Drying for CO2 Capture: Synthesis, Characterization and Adsorption Characteristics

“…In contrast, the solid adsorbent can effectively avoid these problems [ 7 ]. In recent years, studies on the adsorption characteristics of CO 2 by porous materials such as activated carbon, molecular sieves, carbon nanotubes, and metal organic frameworks (MOFs) have been widely carried out [ 8 , 9 , 10 , 11 ]. Although some materials have exhibited a good CO 2 adsorption performance under high pressure, the CO 2 adsorption properties of these materials are not satisfactory under normal pressure condition especially in the presence of water vapor: poor selectivity, low adsorption capacity and slow adsorption kinetics.…”