Abstract: A process is disclosed for the catalytic conversion of an olefin-containing C.sub.3 and/or C.sub.4 feed (1) into aromatic hydrocarbons (22) and C.sub.3 and/or C.sub.4 paraffins (25,26). The process may result in a net consumption of hydrogen and operates at relatively mild temperature conditions, with preferred temperatures in the reaction zone (4) being less than 425 degrees Celsius. The severity of the operating conditions and the length of time the catalyst is used are controlled to hold down total carbon deposition and to increase aromatics selectivity. A catalyst comprising gallium supported on a zeolite containing base is preferred. The feed stream contains a mixture of paraffins and olefins, with aromatics production being directly related to feed olefin content.

Abstract: Method and apparatus for removing ash formed within, and accumulated at the lower portion of, a fluidized bed coal gasification reactor vessel. A supplemental fluidizing gas, at a temperature substantially less than the average fluidized bed combustion operating temperature, is injected into the vessel and upwardly through the ash so as to form a discrete thermal interface region between the fluidized bed and the ash. The elevation of the interface region, which rises with ash accumulation, is monitored by a thermocouple and interrelated with a motor controlled outlet valve. When the interface rises above the temperature indicator, the valve opens to allow removal of some of the ash, and the valve is closed, or positioned at a minimum setting, when the interface drops to an elevation below that of the thermocouple.