Fundamental studies on theoretical approaches are also investigated to understand thermophysical properties and generate new interaction parameters using the thermodynamics model. Examples of research of the Thermodynamics and Sustainable Energy Laboratory:

Biological buffer effect on liquid-liquid equilibria of systems containing hydrophilic compounds

The study of liquid-liquid equilibrium (LLE) and the impact of salting out on LLE in different ternary systems has garnered significant interest. The utilization of LLE (liquid-liquid extraction) and the salt effect is prevalent in chemical engineering and wastewater treatment, primarily owing to their extensive industrial and economic applications. The salting-out phenomenon finds significant utility in the separation of highly hydrophilic compounds, including bio-based alcohols, diols, and organic acids, from aqueous fermentation broths. This separation is achieved through the implementation of aqueous two-phase systems or the application of an organic extraction solvent, commonly referred to as salt extraction. Another notable application of the salting-out phenomenon is the separation of 5-hydroxymethylfurfural. However, the salting-out procedure has been found to result in equipment deterioration, especially when high salt concentrations are involved. The substitution of salt with a green auxiliary agent may necessitate the use of a novel phase separation technology.

Relevant SCI Journal papers have been published as follows, and early research results have also been published in domestic and international conferences:

[1] Altway, S.*, Tiwikrama, A. H.*, Rahayu, S. D., Zuchrillah, D. R., Soeprijanto, S., Ramli, N. B., Maulidia, M. I., Suprihatin, S., Liquid-liquid equilibria of butyric acid, water, and methyl isobutyl ketone with the aid of biological buffer as a green auxiliary agent. Journal of Chemical Engineering Data 2023, 68, 1706-1715. https://doi.org/10.1021/acs.jced.3c00132

[2] Tiwikrama, A. H.*, Altway, S., Effect of EPPS buffer on the liquid-liquid equilibria of carboxylic acids (acetic acid or propionic acid)-water-methyl isobutyl ketone at elevated temperatures.  Journal of Chemical Engineering Data 2022, 67, 1228-1236. https://doi.org/10.1021/acs.jced.2c00084

Phase Behavior of Binary/Ternary Systems Containing CO2 in Near Critical Region

In recent years, the industries has paid a great deal of attention to the application of supercritical fluid extraction (SFE), specifically the use of liquid and supercritical carbon dioxide. This separation method generates extraction yields comparable to those of conventional extraction methods employing organic solvents. Moreover, in contrast to organic solvents, carbon dioxide is non-toxic, non-flammable, non-corrosive, inexpensive, and readily available in large quantities with high purity. The reliable phase equilibrium data of CO2 + solute are needed to develop the separation processes. Obviously, vapor-liquid equilibrium (VLE) behavior is of the utmost relevance for separation technology. However, the VLE data of CO2 + solute are limited in literature, especially in near critical region. Therefore, in this study, the phase equilibrium analyzer (PEA) was employed to observed several phase behavior of CO2 + solute systems. 

Relevant SCI Journal papers have been published as follows, and early research results have also been published in domestic and international conferences:

[3] Tiwikrama, A. H.*, Khudaida, S. H., Long, C. Y., Vapor-liquid equilibrium phase behavior of binary systems of carbon dioxide with eugenol or guaiacol. Journal of Chemical Engineering Data 2023 (proceeding conference on Properties and Phase Equilibria for Product and Process Design) accepted.

[4] Kristanto, T., Tiwikrama, A. H.*, Lee, M. J.*, Vapor-liquid equilibrium phase behavior of binary systems of carbon dioxide with dimethyl adipate or monomethyl adipate. Journal of Supercritical Fluids 2023, 194, 105856-105864. https://doi.org/10.1016/j.supflu.2023.105856

[5] Kristanto, T., Tsai, P. S., Tiwikrama, A. H.*, Lee, M. J.*, Vapor-liquid equilibrium phase behavior of binary systems of carbon dioxide with dimethyl succinate or dimethyl glutarate. Journal of the Taiwan Institute of Chemical Engineers 2022, 136, 104402-104410.https://doi.org/10.1016/j.jtice.2022.104402

Pressure-Volume-Temperature (PVT) Properties for Binary Oligomeric Solutions

Thermodynamic properties are fundamentally important for providing experimental evidence on the intermolecular interactions and also forming a data basis to develop thermodynamic models and engineering applications. For polymeric systems, density (or P−V−T) is one of the thermodynamic properties, which is more plentiful in the literature and also relatively simpler to determine from the experiment. The PVT data of oligomeric systems are insufficient when compared to conventional organic mixtures and mixtures containing high-molecular-weight polymers, especially over a wide pressure range. The results of such studies are definitely helpful in getting insight into the intermolecular interactions between polymeric glycol ethers and high polarity solvents, such as ethers and alcohols. 

Relevant SCI Journal papers have been published as follows, and early research results have also been published in domestic and international conferences:

[6] Chung, Y. F., Ku, T. J., Tiwikrama, A. H.*, Lee, M.J.*, PVT properties of binary systems of poly(ethylene glycol mono-4-octylphenyl ether) with anisole or benzyl alcohol at pressures up to 50 MPa. Journal of Chemical Engineering Data 2023, 68, 1584-1598. https://doi.org/10.1021/acs.jced.3c00119

[7] Lee, M. J., Tiwikrama, A. H.*, Lee, M. J.*, Pressure-volume-temperature properties for binary oligomeric solutions of anisole with polyethylene glycol mono-laurate or polyethylene glycol mono-4-nonylphenyl ether at pressures up to 50 MPa. Fluid Phase Equilibria 2023, 565, 113661-113677. https://doi.org/10.1016/j.fluid.2022.113661

 [8] Tiwikrama, A. H., Yen, P. K., Lee, M. J.*, PVT properties of binary systems of diisopropylethylammonium octanoate ionic liquid with oligomeric polyethylene glycol or polypropylene glycol at elevated pressures. Journal of Molecular Liquids 2021, 331, 115646-115657. https://doi.org/10.1016/j.molliq.2021.115646