Deep desulfurization of diesel fuel has attracted the attention of a growing number of scientists and engineers due to the stringent regulations imposed on the presence of sulfur in fuel (10 ppm). To bring down the concentration of sulfur compounds to less than 10 ppm is very challenging and demands newer technologies. Novel processes are being proposed for this purpose. It is observed that ionic liquids as class of green solvents can play a major role in the deep desulfurization of diesel fuel. For this reason, this review focuses on the current status in application of ionic liquids for achieving ultra-low-sulfur diesel (ULSD). To get a comprehensive perspective about the topic, other techniques of desulfurization are also discussed in brief in the introduction. Here we propose that the appropriate removal method should be selected according to different systems. To achieve deep desulfurization using ionic liquids, a better understanding regarding the regeneration of ionic liquids is vitally important.

A review focussed on the preparation methods and applications of polyethylene glycol (PEG) based solid–solid phase change materials (PCMs).

Toxicological evaluation of a new group of ionic liquids was performed on human colon cancerous cells—CaCo-2. They belong to different classes of cations: imidazolium (IM), dimethyl-guanidinium (dmg) and tetramethyl-guanidinium (tmg), methyl-pyrrolidinium (MPyr), 2-methyl-1-ethyl-pyridinium (2-MEPy), quaternary ammonium (benzyltriethyl-ammonium–BzTEA; phenyltrimethyl-ammonium–PhTMA; tri-n-octyl-methylammonium-Aliquat) and tri-n-hexyl-tetra-n-decylphosphonium (P6,6,6,14). The new results were compared with data obtained in previous reported studies performed in our lab, and we clearly saw that toxicity can vary significantly with the type of anion. Dicyanoamide-[DCA] and bis(trifluoromethanesulfonyl)amide-[NTf₂] were seen to visibly change the impact of some cations. Some were considerably less harmful for CaCo-2 monolayer when the anion was [DCA] or [NTf₂ ], while others induced an abnormal increase of cellular metabolism when [NTf₂ ] was present and therefore, they were considered toxic. However, some cations induced similar responses in the presence of a broad number of anions as (1-butyl-3-methylimidazolium)-[C₄MIM] (with the exception of [FeCl₄ ]), (1-(2-hydroxyethyl)-3-methylimidazolium)-[C₂OHMIM] and [C₄MPyr] and did not cause toxicity. Consequently, they are considered promising cations for building human friendlier solvents. But, a reasonable number of other combinations involving different classes of cations were also seen to not significantly affect viability of the CaCo-2 monolayer.