Patent FR-3001210-A1 (FR)
Title: Preparing a fuel gas from fuel, comprises heating a mixture including liquid fuel and water to obtain mixture of vaporized fuel and steam and the balance of water and liquid fuel, and overheating and diluting the mixture of fuel and steam
Inventor: MOLIERE MICHEL
IPC: C01B3/34
Filed: 2013-01-18
Abstract: The method comprises heating a mixture including a liquid fuel and water so as to obtain a mixture of vaporized fuel and steam and the balance of water and liquid fuel, and overheating and diluting the mixture of fuel and steam. The overheating step comprises adding dry steam with sufficient quantity to the saturated mixture so that the temperature of fuel gas obtained reaches or exceeds a predetermined value so as to avoid the water and liquid fuel formation the obtained fuel gas. The first step is carried out in a container (R). The method comprises heating a mixture including a liquid fuel and water so as to obtain a mixture of vaporized fuel and steam and the balance of water and liquid fuel, and overheating and diluting the mixture of fuel and steam. The overheating step comprises adding dry steam with sufficient quantity to the saturated mixture so that the temperature of fuel gas obtained reaches or exceeds a predetermined value so as to avoid the water and liquid fuel formation the obtained fuel gas. The first step is carried out in a container (R) whose temperature is maintained at a selected value so that the pressure of the saturated mixture in the container allows a transfer of fuel gas downstream from the container. The obtained fuel gas at the conclusion of the overheating step has a predetermined content of steam or a temperature exceeding a predetermined variation compared to its temperature of hydrocarbon dew point and/or a predetermined variation compared to its temperature of aqueous dew point. The method is carried out in a continuous mode. The container is powered in continuous or intermittent mode so as to ensure the permanent and simultaneous presence of the water and liquid fuel. One of the water and the liquid fuel is continuously transferred through a first valve (V1) in a line (L) that includes a mixer at the entry of which the dry steam is added. The opening of the first valve is controlled to keep a constant pressure downstream from the mixer. The flow rate of added steam is controlled by controlling the opening of a third injection valve for the opening of the first valve so as to maintain constant ratio of flow rate of steam and hydrated gas fuel. The obtained secondary hydrated gas fuel is output through a second valve (V2), which ensures the relaxation of the specified pressure. The method further comprises mixing the obtained fuel gas with a fuel gas or an inert gas. The method is carried out in a device including: the container that is supplied with liquid fuel and water and includes a temperature control unit; the first valve whose opening is controlled to keep constant pressure in the line; and the line that includes the mixer, a pressure transmitter, the second valve whose opening is controlled by the hydrated gas fuel at the exit of the method, and the third valve that delivers the overheated steam to an upstream of the mixer of the line, comprises an opening controlled to that of the first valve and delivers secondary hydrated gas fuel output from of the overheating at its exit. A heat source of the container includes overheated water, steam, or a coil traversed electrically or crossed by a hot fluid. A lower part of the container includes two compartments separated by a vertical partition (W) whose upper edge is horizontal. The first compartment contains the water and liquid fuel. The second compartment is permanently filled with water upto the upper edge of the partition. A driving unit permanently extracts the water from the first compartment and the transfers to the second compartment so as to cause a permanent overflow of water of the second compartment over the upper edge of the partition. The vapor introduced into the container is used to aspire the water of the container through a vapor ejector, which injects the vapor mixed with water aspired within the atmosphere of the container. The water introduced into the container is injected by spraying under the pressure in the atmosphere of the container using a tube. The water or vapor injections are carried out in a specific container chamber that communicates with an exit chamber of the container through a set of vertical baffles intended to ensure an inertial effect by stopping liquid vesicles.