35 results about "Downdraft gasifier" patented technology

Method and apparatus for generating a low tar, renewable fuel gas from biomass and using it in other energy conversion devices, many of which were designed for use with gaseous and liquid fossil fuels. An automated, downdraft gasifier incorporates extensive air injection into the char bed to maintain the conditions that promote the destruction of residual tars. The resulting fuel gas and entrained char and ash are cooled in a special heat exchanger, and then continuously cleaned in a filter prior to usage in standalone as well as networked power systems.

A method for using a downdraft gasifier comprising a housing and a refractory stack contained within the housing. The refractory stack may comprise various sections. Apertures in the sections may be aligned to form multiple columnar cavities. Each columnar cavity may comprise an individual oxidation zone. The method of use may include the steps of placing a feedstock into an upper portion of the refractory stack, measuring the temperature of each columnar cavity, and adjusting the flow of oxygen to a particular columnar cavity to maintain the temperature of the particular columnar cavity within a particular range.

A downdraft gasifier is disclosed. The gasifier has a biomass feeding unit, a combustion chamber, and a separator unit. The biomass feeding unit accepts raw biomass materials and selectively feeds the materials into the combustion chamber. The combustion chamber provides means to induce pyrolysis, tar cracking, and char gasification of the raw biomass materials to produce gases and ash. The separator unit accepts the gases and ash from the combustion chamber and separates the gases from the ash.

An entrained flow gasifier designed as a component for an Integrated Gasification Combined Cycle plant of optimized efficiency is provided. The raw gas initially flows through a waste heat unit designed as a radiation cooler and subsequently flows through a full water quench. This results in a higher ratio of steam in the raw gas, which decreases the medium-pressure steam supply before the water-gas shift and thus improves efficiency in IGCC plants with CO₂ separation.

A method and apparatus is provided for use in a fixed-bed gasification system for the disengagement of gas and the removal of ash and charcoal. In one example, the invention includes an auger system, a water seal system, and a gas disengagement system. The gas disengagement mechanism prevents plugging and blinding of the gas offtake system and simultaneously limits particulate entrainment in the gas produced by the gasifier.

The invention discloses a large-scale biomass briquette fuel fixed-bed gasification power generation system, which includes a feeding device, a downdraft gasifier, a purification system and a gas generator set. The downdraft gasifier includes a furnace, and the furnace includes A cylindrical water interlayer, the top of the water interlayer is provided with a top cover, and the bottom of the water interlayer is connected with an ash bin. The upper part is provided with a fire grate; the top cover is provided with a material level power device, and the material level power device is connected with a fixed plate, and the fixed plate is fixedly connected with a distribution motor. The output shaft of the distribution motor extends downward into the top cover and its bottom A rake is provided; the feeding device is a feeding hoist, and the discharge pipe of the feeding hoist passes through the top cover and extends into the interior of the furnace. The invention is suitable for using biomass briquette fuel as a raw material, and the structure of the gasification furnace makes the diameter break through the limit of 2 meters in the past, which can ensure the continuous operation of the large gasifier, and the power generation power breaks through the limit of 1MW.

Embodiments of the invention are directed toward a coaxial gasifier for enhanced hydrogen production, comprising: downdraft gasifier comprising a hot zone for converting biomass to synthesis gas; and a coaxial gas converter disposed within the downdraft gasifier, the coaxial gas converter comprising a biochar inlet valve, a coaxial char tube, and a biochar and ash outlet valve.

A downdraft gasifier and method of gasification that utilizes a plurality of vertically positioned tubes to create a pyrolysis zone, an oxidation zone beneath the pyrolysis zone and a reduction zone beneath the oxidation zone. The shape of the tubes eliminates the need for a restriction (hearth), which limits the maximum achievable throughput. A rotating and vertically adjustable grate is located beneath, but not attached to, the reduction zone of the gasifier.

A method for using a downdraft gasifier comprising a housing and a refractory stack contained within the housing. The refractory stack may comprise various sections. Apertures in the sections may be aligned to form multiple columnar cavities. Each columnar cavity may comprise an individual oxidation zone. The method of use may include the steps of placing a feedstock into an upper portion of the refractory stack, measuring the temperature of each columnar cavity, and adjusting the flow of oxygen to a particular columnar cavity to maintain the temperature of the particular columnar cavity within a particular range.

In a reactor for gasification of entrained solid and liquid fuels at temperatures between 1,200 and 1,900° C. and at pressures between ambient pressure and 10 MPa using an oxidizing agent containing free oxygen, the cooling screen is connected to the pressure shell in a gastight manner via a sliding seal in order to allow length changes. Continuous gas purging of the annular gap between pressure shell and cooling screen is unnecessary and gasification gas is prevented from flowing behind.

The invention belongs to a biomass downdraft fixed bed gasifier heat supply system which comprises a primary stock bin (1), a secondary stock bin (3), and a gas storage device (9), and is characterized in that a downdraft gasifier body (4) is mounted below the secondary stock bin (3) and is communicated with a waste heat recovery device (6); an upper exhaust pipe of the waste heat recovery device (6) is communicated with a gas storage cylinder (27); a gas outlet pipe of the gas storage cylinder (27) is communicated with a spiral dedusting washing device (7); the upper end of the spiral dedusting washing device (7) is connected with a secondary oxygen supply port (22) and is communicated with a Roots frequency conversion fan (8); the upper end of the waste heat recovery device (6) is communicated with the gas storage cylinder (27) through a pipeline; the gas storage cylinder (27) is communicated with the spiral dedusting washing device (7) through a pipeline; the lower end of the waste heat recovery device (6) is communicated with a water vapor reduction hydrogen adding device (13) through a pipeline. The system of the invention is high in temperature in the gasifier, high in thermal efficiency, low in tar content, beneficial for environmental protection, low in equipment investment, high in heat production amount, and sufficient in fuel source.

The invention includes a downdraft gasifier having a rotatable auger/grate extending through its reduction zone. The auger at times moves biofuel through the gasifier and at times supports it in the gasifier. A frusto-conical biomass grate funnels biomass onto the auger and is perforate for permitting the passage of gases while retaining the biomass. A guide tube surrounds the auger below the frusto-conical biomass grate. The invention also includes mixing gas or solid particulate fuel in a conduit segment that houses a mixing chamber. Fuel is fed through a fuel inlet port into the mixing chamber. High velocity combustion air from a blower is forced into the mixing chamber through a restricted orifice that generates a suction pressure for drawing gas or solid particulate fuel into the mixing chamber. A combustion chamber supply conduit delivers fuel from the mixing chamber into a burner.

The invention relates to the technical field of biomass gasification furnaces, and discloses a downdraft gasification furnace which comprises a furnace body, an oxidation zone is arranged in the furnace body, a reduction zone is arranged below the oxidation zone, a lower neatening plate is fixedly mounted in the reduction zone, an upper neatening plate is fixedly mounted in the oxidation zone, and gas inlet pipes are arranged on the two sides of the oxidation zone. According to the invention, the upper and lower neatening plates are arranged in the oxidation zone and the reduction zone, materials from a cracking zone are uniformly distributed in a neatening cavity, then the cavity for airflow flowing is arranged on the outer side of the neatening cavity, and air holes in the cavity are utilized to uniformly distribute air from multiple angles from the top and the peripheral side of a carbon block, and thus the internal oxidation-reduction reaction of the neatening plates is ensured to be carried out uniformly and thoroughly, the incomplete reaction caused by non-uniform air supply is avoided, the temperature of discharged gas is uniform, the condition of non-uniform drying of a drying area caused by non-uniform temperature is avoided, meanwhile, the components of the discharged gas are stabilized, and the gas quality is improved.

The invention discloses a biomass gasifier control method and relates to the field of automatic control. The device of the application mainly comprises: a downdraft biomass gasification furnace, a gasification agent inlet valve, a plurality of temperature sensors arranged around the hearth, a roots blower, a temperature sensor at ever-burning fire and a data acquisition camera. The main emphasis is on that: the camera and the temperature sensors are combined to be applied to detection of calorific value information of gas-producing combustible gas, a calorific value coefficient concept is introduced, and during temperature loop control, a fuzzy-PID composite controller with Smith estimation is adopted to enable the temperature in the downdraft gasifier to be in the optimal gasification state.

The invention discloses a method and a system for preparing a red mud-biochar composite catalyst and purifying tar, a red mud raw material and a biomass raw material are mixed and dried and then are fed into a rotary furnace for carbon thermal reduction reaction to obtain the red mud-biochar composite catalyst, and the red mud-biochar composite catalyst has a special structure and catalytic activity; volatile components generated in the preparation process of the catalyst enter a downdraft gasifier and are used as a gasifying agent in the gasifier to be subjected to a pyrolysis gasification reaction with biomass raw materials, and an obtained gas product enters a fixed bed reformer to be subjected to a catalytic reforming reaction under the obtained red mud-biological coke composite catalyst after passing through a cyclone dust collector, the content of biomass gasification tar is greatly reduced, and a gas product of the catalytic reforming reaction is driven to a gas turbine through an induced draft fan and drives a power generator to generate power. Combustion tail gas serves as a heat source of the rotary furnace and the drum-type dryer. The whole system is high in energy efficiency and low in operation cost, and a catalyst preparation process and a biomass gasification tar deep purification process are effectively coupled.