Abstract: Crude glycerol obtained from raw materials, such as the glycerol obtained during the production of biodiesel or glycerol obtained during the conversion of fats or oils, is purified by forming a dioxolane therefrom by reacting the crude glycerol with a ketone or aldehyde, separating the dioxolane thus formed, converting the dioxolane into purified glycerol and ketone/aldehyde, and recovering the glycerol thus purified.

Abstract: A catalytic composition with a corrosion-inhibiting effect on metal surfaces is described. Also described, is a corrosion-inhibiting process and use of a corrosion inhibitor. Further, the catalytic composition can have a corrosion-inhibiting effect on metal surfaces in contact with an esterification medium comprising a carboxylic acid and an alcohol, wherein the composition comprises as a catalyst, a strong protonic acid and, as corrosion inhibitor, an iron(III) carboxylate.

Abstract: Multi-purpose cleaning compositions, in particular multi-purpose aqueous alkaline compositions for cleaning surfaces, and base preparations for this purpose. Such base preparations comprise one or more solvents that are at least partially water-miscible, one or more alkali metal salts of carboxylic acids, and water. Such multi-purpose cleaning compositions comprise at least such base preparation, a surfactant, a basifying agent, and water.

Abstract: Multi-purpose cleaning compositions, in particular multi-purpose aqueous alkaline compositions for cleaning surfaces, and base preparations for this purpose. Such base preparations comprise one or more solvents that are at least partially water-miscible, one or more alkali metal salts of carboxylic acids, and water. Such multi-purpose cleaning compositions comprise at least such base preparation, a surfactant, a basifying agent, and water.

Abstract: A catalytic composition with a corrosion-inhibiting effect on metal surfaces is described. Also described, is a corrosion-inhibiting process and use of a corrosion inhibitor. Further, the catalytic composition can have a corrosion-inhibiting effect on metal surfaces in contact with an esterification medium comprising a carboxylic acid and an alcohol, wherein the composition comprises as a catalyst, a strong protonic acid and, as corrosion inhibitor, an iron(III) carboxylate.

Abstract: The present invention generally concerns a treatment process for crude alkaline glycerol obtained as a by-product of transesterification reaction of natural oils and fats with lower alcohols. The present invention particularly concerns the treatment of crude alkaline glycerol obtained as a by-product of the biodiesel production from vegetable oils and animal fats using organic alkyl carboxylic acids or their aqueous solution, comprising the steps of: (a) acidification of the crude alkaline glycerol stock to pH in the range of about 4 to about 6, particularly 4 to 5, with organic alkyl carboxylic acids, in the presence of water in the range from about 5% to about 50%, particularly 15 to 30%, in weight with respect to the weight of the crude alkaline glycerol stock; (b) separating the formed free fatty acids, for instance by flotation; (c) removing the alcohol present in the acidified crude glycerol stock, for instance by distillation; (d) separating the acidic glycerol.

Abstract: Crude glycerol obtained from raw materials, such as the glycerol obtained during the production of biodiesel or glycerol obtained during the conversion of fats or oils, is purified by forming a dioxolane therefrom by reacting the crude glycerol with a ketone or aldehyde, separating the dioxolane thus formed, converting the dioxolane into purified glycerol and ketone/aldehyde, and recovering the glycerol thus purified.

Abstract: The present invention relates to a process of tanning where the step of contacting the hides with chromium salts is preceded by acidification with organic acids sufficient to reach a pH of from about 3.5 to 5 at the surface of the hide and pH of from about 4.0 to 6.5 at the internal part of a cross section of the hide.