a b s t r a c tThe cordierite monolith was successfully modified to carbonaceous material termed as carbon coated monolith (CCM). Surface studies showed about 65% of the total pore volume falls in mesopore range with acidic functionality dominating over the surface. Batch adsorption experiments were carried out to study the applicability of CCM for the removal of methyl orange (MO) from aqueous solution. Different parameters such as effect of MO concentration, contact time, initial pH, regeneration and desorption potential of CCM were studied. Optimum adsorption of MO on CCM was observed at pH 6 (27.2 mg/g). The increase in initial MO concentration from 50 to 500 mg/L leads to increase in adsorption capacity from 15.99 to 88.5 mg/g. The observed equilibration time ranged in between 5000 and 5800 min. Linear and non-linear isotherm studies showed better applicability of Freundlich model. Kinetics studies showed better fitting for pseudo-second-order model. The Weber and Morris model showed multi-linearity indicating two or more steps were involved to describe the adsorption process. Desorption studies showed maximum recovery of MO when alkaline NaOH solution was used as an eluent. The regeneration studies showed decrease in adsorption capacity from 47.93 to 23.76 mg/g after three cycles.

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During the past few years the scientific and medical community has been confronted with a continual interest in vitamin E with the interest prompted by new discoveries. Tocopherols and tocotrienols, commonly known as vitamin E, are extremely invaluable compounds and have various nutritional functionalities and benefits to human health. Great deals of research projects have been launched in order to develop effective methods for the extraction of vitamin E. By and large, three distinct extractive methods are usually employed: supercritical fluid extraction (SFE), molecular distillation, and adsorption methods. These methods are sensitive to different experimental conditions, such as pressure, temperature, and flow rate with noticeable effects on the efficiency of the extraction and enrichment of vitamin E. This review has covered the most commonly adapted extraction methods and has probed into the extraction yields under variable operational parameters.

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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.

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