Abstract: A process for isolating lignin from an alkaline process stream of thickened black liquor which is introduced continuously into a lower region of at least one circulation reactor having two reactor zones in concentric arrangement, liquid level of the alkaline process stream in the interior of the reactor is at a level with an upper end of an inner tubular reactor zone, a CO2-containing gas is blown continuously from the bottom into the inner tubular reactor zone of the reactor, wherein the CO2-containing gas is absorbed by the alkaline process stream in the inner circulation reactor zone and offgas is drawn off with residual amounts of the CO2 at the top of the reactor, the process is run at 1 atm, and thickened black liquor with a reduced lignin content together with precipitated lignin present are drawn off optionally after settling at the base of the reactor.

Abstract: A process for isolating lignin from an alkaline process stream of thickened black liquor which is introduced continuously into a lower region of at least one circulation reactor having two reactor zones in concentric arrangement, liquid level of the alkaline process stream in the interior of the reactor is at a level with an upper end of an inner tubular reactor zone, a CO2-containing gas is blown continuously from the bottom into the inner tubular reactor zone of the reactor, wherein the CO2-containing gas is absorbed by the alkaline process stream in the inner circulation reactor zone and offgas is drawn off with residual amounts of the CO2 at the top of the reactor, the process is run at 1 atm, and thickened black liquor with a reduced lignin content together with precipitated lignin present are drawn off optionally after settling at the base of the reactor.

Abstract: The invention relates to a process for the production of carboxylic acid esters by esterification of carboxylic acids and/or transesterification of carboxylic acid esters with alcohols in the presence of a liquid metal catalyst, characterized in that the liquid metal catalyst is the alkaline earth metal salt of a carboxylic acid.

Abstract: A thin-film evaporator with a vertical drum (1), a supply line (4) that is arranged in the upper region of the drum (1) and is used to supply a medium to be evaporated, a heating jacket (3) arranged on the periphery of the drum and forming vapors, a discharge line (20) for discharging the residue left in the lower end of the drum, and a condenser (11) supplied with a coolant, for increasing the separating capacity and optionally for performing chemical reactions, is characterized in that an inner device (24) influencing the action of the thin-film evaporator is provided in the path of the vapors from the heating jacket (3) to the condenser (11).

Abstract: The invention relates to a process for the production of carboxylic acid esters by esterification of carboxylic acids and/or transesterification of carboxylic acid esters with alcohols in the presence of a liquid metal catalyst, characterized in that the liquid metal catalyst is the alkaline earth metal salt of a carboxylic acid.

Abstract: The invention relates to a method for processing residues containing at least one non-ferrous metal, preferably chosen from the group comprising zinc, lead, nickel, copper and cadmium and/or compounds thereof. According to this method, the non-ferrous metal is extracted from the residues by an extracting agent containing a carboxylic acid and/or a substituted carboxylic acid and/or its alkali salts and/or ammonium salts and/or mixtures thereof.