Abstract: There is provided a method for producing fatty acid alcohol ester useful as a substitute fuel for light oil in which an ester interchange reaction between fats or oils and alcohol is carried out in a reactor 1 by applying ultrasonic irradiation at a frequency of 15 to 100 kHz and irradiation intensity of 0.5 to 20 W/cm2 in the presence of a catalyst, followed by an application of ultrasonic irradiation at a frequency of 200 to 3,000 kHz and irradiation intensity of 0.5 to 20 W/cm2 to the reaction product in a separation tank 4 to separate fatty acid alcohol ester and glycerol. Such ultrasonic irradiation in the separation tank 4 may be applied to an interface between fatty acid alcohol ester and glycerol.

Abstract: A method of treating a gaseous hydrocarbon contained in waste gas by using adsorbent layers of single-tower or multi-tower configuration is characterized in that (1) double-cylinder type or multi-cylinder type adsorption apparatus, in which each adsorbent layer is indirectly cooled by cooling water, are employed as adsorption apparatus; (2) each adsorbent layer is a packed layer of one or more kinds of materials selected from activated carbon, synthetic zeolites and hydrophobic silica gel; (3) swing time required for switching between adsorption and desorption processes is set to 1 to 15 minutes; (4) each adsorbent layer is evacuated under vacuum while being purged by using part of clean gas evacuated from each adsorbent layer and/or air in the desorption process; and (5) the gaseous hydrocarbon is recovered from outflow purge gas. This method makes it possible to prevent abnormal temperature increase within each adsorbent layer and enhance the safety of the apparatus.