Tatang Hernas Soerawidjaja

H2S–CO2 Separation Using Room Temperature Ionic Liquid [BMIM][Br]

Solubility and selective absorption of hydrogen sulfide (H2S) over carbon dioxide (CO2) in a room temperature ionic liquid, 1-butyl-3-methylimidazolium bromide ([BMIM][Br]) has been evaluated under ambient temperature and pressure. [BMIM][Br] demonstrated its potential as a solvent for selective removal of H2S from CO2/H2S mixture. Our investigation indicated that H2S solubility in [BMIM][Br] is comparable to or better than that in commercially available MDEA-based solvents. Meanwhile, CO2 solubility in [BMIM][Br] is lower than that in the same amine resulting in H2S/CO2 absorption selectivity of within 3.5 to 3.75. The solubility behavior is relatively maintained after 4 times absorption-desorption cycles. A computational molecular study suggested that intramolecular hydrogen bonding interaction between anion Br and hydrogen atom of H2S could stabilize the complex and resulted lower complexation energy than CO2 interaction with [BMIM][Br]. Based on the experiment results, a separation process employing [BMIM][Br] is proposed to control the CO2/H2S ratio existing in a natural gas feed.

Decolorization of crude terpineol by adsorption

ABSTRACT Industrial terpineol is commonly manufactured from more readily available turpentine or α-pinene rather than extracting from natural plants or woods. The product of the synthesis results in a dark-color liquid that could reduce the price and limit the use of the product itself. Finding a suitable solid adsorbent that is able to adsorb the impurities could be a better way to solve the problem rather than using energy-demanding process, such as stage-wise distillation. In this study, four different solid adsorbents were tried to decolorize the dark color of synthesized terpineol from α-pinen. Bentonite shows a very promising result as it could alter the color of the liquid into light yellow. Compared to other adsorbents, bentonite performed better at the same particle size and solid loading. The decolorization performance was also influenced significantly by the size of the solid adsorbent.

An innovative method to produce drop-in fuel by alkaline earth-transition metals basic soap decarboxylation

Decarboxylation of metal soap is an emerging method to produce drop-in fuels as an alternative to the expensive hydrotreatment process. In this study, the Mg-Fe basic soap produced from palm kernel fatty acid had been successfully decarboxylated into jet-fuel type biohydrocarbons. The Mg-Fe basic soap with ratio of 8:2 mol was decarboxylated for 5 hours at atmospheric pressure and temperature varied up to 370°C; it produced a liquid product whose yield was around 60 %-weight. The resulting hydrocarbon product was a complex mixture consisted of normal paraffins in the range of carbon chain length C 8 – C 17 , iso-and cyclo-paraffins, and various olefin products.

The sooting tendency of aviation biofuels and jet range paraffins: effects of adding aromatics, carbon chain length of normal paraffins, and fraction of branched paraffins

ABSTRACT The smoke point of several fuel mixtures was measured using a smoke meter defined by American Society for Testing Material D1322. The threshold soot index (TSI) was calculated to compare the sooting tendency of fuels. Two aviation biofuels produced by hydroprocessing of coconut oil, four jet range normal paraffins (n-paraffins), iso-octane, and propylbenzene were used to investigate the effects of chain length of n-paraffins, iso-paraffins, and aromatics on the sooting tendency. The results show that the effect of propylbenzene on the smoke point of the mixtures is dominant compared to that of the chain length of n-paraffins and the fraction of iso-paraffins. The differences in the sooting tendency among these n-paraffins are insignificant. In addition, blending aviation biofuels with Jet A1 leads to a decrease in the sooting tendency. Aromatics in Jet A1 play an important role on the sooting tendency of the mixtures of aviation biofuels and Jet A1.

An innovative technique to suppress alkene-bond in green diesel by Mg–Fe basic soap thermal decarboxylation

ABSTRACT The catalytic effect of magnesium and magnesium–zinc or copper(II), iron(III), aluminium(III), chromium(III) metal combination on ratio of the alkane to 1-alkenes and carbon number distribution in the green diesel product from metal basic soaps’ decarboxylation has been studied. Palm stearin was chosen as a model compound to produce metal basic soaps. Batch decarboxylation of metal basic soap was conducted at 350°C and atmospheric pressure for 3 h. Ratio of alkane to 1-alkene at the green diesel product was found following this order: Mg–Fe (14.6%) > Mg–Al (11.8%) > Mg–Cu (10.1%) > Mg–Zn (4.7%) > Mg–Cr (3.1%) > Mg (2.9%). Mg–Fe metal combination was preferable because it has high selectivity to alkane and capable of suppressing the 1-alkane formation during the metal basic soap decarboxylation process.