Abstract: A method of esterifying free fatty acid in natural oil comprises heating the natural oil (2) to a first temperature above a reaction temperature, feeding the heated natural oil into an acid-resistant pipe reactor (5), providing a mixture of acid catalyst (6) and short chain alcohol (8) at a second temperature below the reaction temperature, and feeding the mixture of acid catalyst and short chain alcohol into the natural oil in the pipe reactor (5). The short chain alcohol and free fatty acid react at the reaction temperature to form an ester.

Abstract: A method of esterifying free fatty acid in natural oil comprises heating the natural oil (2) to a first temperature above a reaction temperature, feeding the heated natural oil into an acid-resistant pipe reactor (5), providing a mixture of acid catalyst (6) and short chain alcohol (8) at a second temperature below the reaction temperature, and feeding the mixture of acid catalyst and short chain alcohol into the natural oil in the pipe reactor (5). The short chain alcohol and free fatty acid react at the reaction temperature to form an ester.

Abstract: The present invention provides a method and apparatus for reacting a natural oil with a short chain alcohol in the presence of alkaline catalyst, in which a mixture of natural oil, short chain alcohol and alkaline catalyst is fed in one direction along a pipe reactor under transitional or turbulent conditions, so that the reactants are mixed in a direction normal to the flow direction to a greater degree than in a direction parallel to the flow direction or so that the reactants are mixed in a direction normal to the flow direction, such that the time taken for 90% of the elements of fluid to pass through the reactor is within 20% of the mean residence time of reactant in the reactor. There is also provided a ship, comprising means for storing a raw material used in the synthesis of biodiesel, a plant for the synthesis of biodiesel and means for storing the biodiesel synthesized.

Abstract: The present invention provides a method and apparatus for reacting a natural oil with a short chain alcohol in the presence of alkaline catalyst, in which a mixture of natural oil, short chain alcohol and alkaline catalyst is fed in one direction along a pipe reactor under transitional or turbulent conditions, so that the reactants are mixed in a direction normal to the flow direction to a greater degree than in a direction parallel to the flow direction or so that the reactants are mixed in a direction normal to the flow direction, such that the time taken for 90% of the elements of fluid to pass through the reactor is within 20% of the mean residence time of reactant in the reactor. There is also provided a ship, comprising means for storing a raw material used in the synthesis of biodiesel, a plant for the synthesis of biodiesel and means for storing the biodiesel synthesised.

Abstract: The present invention provides a reverse flow cyclone separator including a container closed at one end, a component for introducing a fluid mixture swirling about an-axis at a region of the container remote from said end, a barrier between said region and said end, the barrier having a surface facing the introducing component and extending towards the outer wall of the container leaving a gap therebetween, and an outlet for lighter phases of the mixture, the outlet opening from the region, the barrier having an outer perimeter which extends in the axial direction a distance not less than the radial extent of the gap. Since the outlet opens from the region, the flow of fluid from the fluid introducing component to the outlet is not obstructed by the barrier and does not pass through the gap.

Abstract: A cyclone separator has an inlet chamber 52 and an outlet chamber 53, means 51 for introducing a fluid mixture into the inlet chamber so that it swirls around the chamber and passes to the outlet chamber in which it swirls about an outlet chamber axis, the outlet chamber being provided with means 62 for conducting heavier phase fluids from the outlet chamber at a relatively large distance from the outlet chamber axis and an outlet 63 for lighter phase fluids at a relatively small distance from the outlet chamber axis 55. The flow through the separator and the efficiency of separation are improved by forming at least one of the chambers 52, 53 as involute shaped, the corresponding one 51, 62 of said means being defined by the curved wall of the involute of maximum radius.