No abstract

The separation of CO2/CH4 using porous carbon can be increased by the presence of a functional group of nitrogen on the carbon surface. This study explores the potential of porous carbon derived from the palm kernel shell (C-PKS) impregnated with a deep eutectic solvent (DES), which is one of the chemicals containing a nitrogen element. The DES was composed of a quaternary ammonium salt of choline chloride (ChCl) and a hydrogen bond donor of alcohol. Three alcohols of 1-butanol (-ol), ethylene glycol (-diol), and glycerol (-triol) were employed to study the effects of a number of hydroxyl groups in the separation performance. The research steps included (i) the preparation of DES-impregnated porous carbon synthesized from the palm kernel shell (DES/C-PKS), (ii) characterization of the material, and (ii) a separation test of CO2/CH4 with a breakthrough system. Materials were characterized using scanning electron microscopy (SEM) combined with energy-dispersive X-ray spectroscopy (EDX), N2-sorption analysis, and Fourier transform infrared (FTIR) spectroscopy. SEM images showed a significant morphological difference of pristine carbon and DES/C-PKS. There was a significant decrease in the range of 67–73% of a specific surface area with respect to pristine carbon, having initially 800 m2/g. However, the N element on the carbon surface increased after impregnation treatment, which was shown from the intensity of the FTIR graphs and EDX analysis. Adsorption isotherm revealed that DES/C-PKS could enhance up to 1.6 times the adsorption capacity of CO2 at 1 atm and 30 °C while increasing the selectivity of CO2/CH4 up to 125%. The breakthrough experiment showed that all DES/C-PKS materials displayed a better performance for the separation of CO2/CH4, indicated by a longer breakthrough time and enhancement of CO2 uptake. The best separation performance was achieved by DES/C-PKS using glycerol as a hydrogen bond donor with 15.4 mg/g of CO2 uptake or equivalent to 95% enhancement of the uptake capacity compared to pristine porous carbon. Also, the cycling test revealed that DES/C-PKS can be used repetitively, which further highlights the efficiency of the material for the separation of CO2/CH4.

The purpose of this study is to develop natural zeolite impregnated with potassium nitrate (KNO3) as a heterogenous catalyst for the transesterification of rice bran oil (RBO) in order to produce Fatty Acid Methyl Ester (FAME). We conducted the Nitrogen adsorption-desorption method, Fourier Transform Infra-Red (FT-IR) spectrometer, and X-Ray Diffraction (XRD) analysis in order to characterize the physicochemical properties of the modified natural zeolite catalysts. We investigated the influences of RBO to methanol mole ratio in the range of 1:6 to 1:12. The variation of natural zeolite catalyst amount performed, also, at 1, 2.5, 5 and 10 wt. % of RBO. Moreover, the reaction temperatures were varied at room temperature (32C), 60C and 67.5C. The highest biodiesel yield was 83.2% which was obtained at a ratio of 1:12 RBO to methanol mole, an amount of modified natural zeolite catalyst of 10 wt.% of RBO and a reaction temperature of 67.5C. In order to study the reusability of modified natural zeolite catalyst, three successive transesterification reactions were carried out using the same reaction conditions.

Ethylene is naturally generated by climacteric fruits and can promote the ripening process faster. For effective long-distance transport and subsequent storage, removing ethylene from the storage environment has been of interest to suppress its undesirable effect. In this study, ethylene removal by an adsorptive method using cobalt-loaded nanoporous carbon is studied. Cobalt oxide-loaded carbon was prepared by incipient wetness method followed by calcination process at 200 °C under inert flow. Ethylene adsorption test was performed at 20, 30, and 40 °C using a static volumetric test. The results showed that cobalt oxide/carbon system has significant ethylene adsorption capacity up to 3.5 times higher compared to blank carbon. A higher temperature adsorption is more favorable for this chemisorption process. Ethylene uptake increases from 100 to 150 mL g-1adsorbent STP by increasing cobalt oxide loading on carbon from 10 to 30 wt.% Co. The highest uptake capacity of 6 mmol ethylene per gram adsorbent was obtained using 30 wt.% cobalt oxide. Therefore, ethylene adsorption by cobalt-loaded nanoporous carbon may represent a potential method in ethylene removal and it could serve as a basis for development of ethylene scavenging material.

The separation of CO2/CH4 can be enhanced by impregnating porous carbon with iron oxide.