The present invention relates to a composition comprising a carrier liquid and lignin or lignin derivatives solubilized in said carrier liquid; wherein at least one of the hydroxyl groups of the lignin or lignin derivatives have been substituted with ester groups forming esterified lignin or lignin derivatives. The composition may be used for preparing fuels or lubricants.

A lubricant formulation. The lubricant formulation includes a polyol-based base lubricant, an ionic liquid, and an organic nanoparticle. The ionic liquid is selected from the group consisting of trihexyltetradecylphosphonium bis(2-ethylhexyl) phosphate, trihexyl(tetradecyl)phosphonium bis-2,4,4-(trimethylpentyl)phosphinate, and trihexyl(tetradecyl)phosphonium bis(trifluoromethylsulfonyl)imide, or a combination thereof. The organic nanoparticle has a median particle size less than about 200 nm. The organic nanoparticle forms about 0.01 to about 5% by weight of the lubricant formulation. The ionic liquid forms about 0.5 to about 10% by weight of the lubricant formulation.

A lubricant formulation. The lubricant formulation includes a polyol-based base lubricant, an ionic liquid, and an organic nanoparticle. The ionic liquid is selected from the group consisting of trihexyltetradecylphosphonium bis(2-ethylhexyl) phosphate, trihexyl(tetradecyl)phosphonium bis-2,4,4-(trimethylpentyl)phosphinate, and trihexyl(tetradecyl)phosphonium bis(trifluoromethylsulfonyl)imide, or a combination thereof. The organic nanoparticle has a median particle size less than about 200 nm. The organic nanoparticle forms about 0.01 to about 5% by weight of the lubricant formulation. The ionic liquid forms about 0.5 to about 10% by weight of the lubricant formulation.

Provided is a grease composition containing a base oil (A) and a urea-based thickener (B), the base oil (A) containing a poly--olefin (PAO), the urea-based thickener (B) being one or more selected from diurea compounds represented by the general formula (b1): R.sup.1NHCONHR.sup.3NHCONHR.sup.2 (b1), when a content of the chain hydrocarbon group in R.sup.1 and R.sup.2 in the general formula (b1) is X molar equivalents and a content of the alicyclic hydrocarbon group in R.sup.1 and R.sup.2 in the general formula (b1) is Y molar equivalents, the grease composition satisfying the following Requirement (1) and having an increased cone penetration at a low temperature (40 C.): Requirement (1): having a X/Y ratio of 2/1 to 10/1.