NOVELTY - Continuously producing bio-diesel by a transesterification of animal-derived triglycerides involves reacting a first stream containing the triglycerides with a second stream containing ethanol and/or methanol in the presence of fluid carbon dioxide (CO2) within a pressurized conduit to produce bio-diesel and glycerol at a pressure of at least 1000 psia and a temperature of at least 80degreesF.    USE - Used for producing bio-diesel and glycerol (claimed).    ADVANTAGE - The process separates the residual fluid CO2 from the bio-diesel and provides pure, contaminant free bio-diesel. The apparatus enhances the miscibility of the triglycerides with lower alcohols. The process provides improved and efficient production of renewable fuels, e.g. normally liquid, fluid, renewable fuels and bio-diesel, from animal and plant fats or triglycerides by trans-esterification. The apparatus reduces the floor space needed to install the complete production system, when compared with the typical bio-diesel processing plant used previously and/or to create conditions under which triglycerides and lower alcohols mix efficiently. The liquid or fluid, dense phase CO2 reduces significant reaction time and facilitates a more complete reaction of triglycerides with a lower alcohol such as methanol or ethanol; improves separation of firstly, clean bio-diesel and secondly, glycerol from the remaining fluid comprising excess methanol and/or ethanol, catalyst, L-CO2 and impurities.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for an apparatus (A1) for combining fluids comprising:    (a) a first drive shaft capable of rotating, defining a first central conduit in communication with at least one aperture running perpendicular to the central conduit;    (b) a first disc fixed around one end of the first drive shaft, having a planar surface and radial ridges extending along the planar surface;    (c) a second drive shaft capable of rotating, defining a second central conduit in communication with at least one apertures running perpendicular to the central conduit;    (d) a second disc fixed around one end of the second drive shaft and mounted in parallel, contacting proximity with the first disc such that an annular space is formed between the first and second discs, where the apertures of the first drive shaft and the apertures of the second drive shaft open into the annular space between the first and second discs and further where the radial ridges of the first disc define radial slots between the planar surface of the first disc and the contacting surface of the second disc; and    (e) an enclosing cover enclosing the space around the first and second discs and defining a conduit for transferring fluids out of the enclosed space.