An ash filter and reboiler (ash filter/reboiler) includes an inlet tube heat exchanger including an outer column (column) having a vapor inlet tube through an inlet of the column coupled therein to receive fuel vapors including entrained ash particles and to direct the fuel vapors including the entrained ash particles out from a bottom of the vapor inlet tube toward a bottom portion of the column. A cooler over the bottom portion of the column for condensing the fuel vapors including the entrained ash particles to liquid fuel. A pump coupled to an outlet in a bottom of the column is for pumping out an ash particle laden portion of the liquid fuel. A heater is above the cooler for vaporizing the liquid fuel into reboiled vapor, and a vapor outlet is at a top of the column for releasing the reboiled vapors out from the column.