Abstract: Waste water emissions from a biodiesel production facility are substantially reduced by recovering water from a spent water stream used in a water washing step in the refining of crude biodiesel which water washing removes glycerin. The water is recovered from the spent water stream is concentrated to provide an aqueous fraction which can be recycled for the water washing. The concentration also provides a glycerin-containing fraction containing that can be blended with crude glycerin by-product generated by transesterification of glycerides to make the biodiesel.

Abstract: A rotary gas seal in which a first member, e.g., a tip, cooperates with a second member to inhibit gas flow therebetween, the improvement wherein, the tip is provided with a ceramic or metallic coating bonded thereto, the surface of the coating having a plurality of laser-formed depressions and providing a wear-resistant, cutting surface capable of cutting into the second member. Also, a turbine or compressor blade having a tip surface adapted to cooperate with a sealing surface to form a seal between the blade and the sealing surface and a ceramic or metallic carbide coating bonded to said tip surface, the coating having a plurality of laser-formed depressions and providing a wear-resistant, cutting surface capable of cutting into the sealing surface.