alkylene carbonate per 250 ml of carbon per hour and in another embodiment is about 5 ml of alkylene carbonate per 250 ml carbon per hour pressures are preferably sufficient to maintain liquid conditions in continuous operation the apparatus is usually equipped in a conventional manner so that effluent is free of carbon particles in any mode by which the process of this carbon treatment is conducted temperature is typically greater than or equal to about 0 degree centigrade and more frequently greater than or equal to about 10 degrees centigrade preferably temperature is typically less than or equal to about 200 degrees centigrade more typically less than or equal to about 100 degrees centigrade more typically less than or equal to about 50 degrees centigrade in one embodiment the temperature is in the range from about 10 to about 50 degrees centigrade in another embodiment the temperature is in the range from about 20 to about 30 degrees centigrade this is advantageous because the treatment can occur under ambient temperatures in the case of ethylene carbonate depending on pressure the temperature should typically be 40 degrees centigrade or higher to ensure that the ethylene carbonate does not solidify in any mode by which the process of this carbon treatment is conducted the process is conducted under conditions effective such that the uv absorbance of the resulting alkylene carbonate is typically less than about 0 350 at 220 nanometers nm with less than about 0 310 nm being preferred and typically less than about 0 930 at 215 nm with less than about 0 910 being.