Gasifier and method of using the same for gasification of biomass and solid waste

A gasifier, comprising:

• a vertically disposed furnace body, the furnace body comprising an upper nozzle for spraying vapor, a lower nozzle for spraying CO2/vapor, and a syngas outlet disposed at the top of the furnace body, the lower nozzle comprising a nozzle opening;
• bed materials;
• a feeder, the feeder being disposed in the middle part of the furnace body and communicating with the furnace body;
• one or two layers of microwave plasma generators;
• an external heater configured to supply external thermal energy for the gasifier;
• a circulating material outlet;
• a circulating material inlet;
• and
• a monitoring unit;
• wherein
• the upper nozzle is disposed in a clearance zone of the furnace body;
• the lower nozzle and the bed materials are disposed at the bottom of the furnace body;
• the nozzle opening is disposed toward the bed materials;
• the monitoring unit is disposed in a close proximity to the syngas outlet;
• the one or two layers of microwave plasma generators are disposed above the upper nozzle in the clearance zone of the gasifier, each layer of the microwave plasma generators comprises three or four working gas inlets, the microwave plasma generators are adapted to spray plasma into the clearance zone of the gasifier horizontally/tangentially;
• the external heater is separated from the furnace body;
• the circulating material outlet is disposed at the bottom of the furnace body and the circulating material inlet is disposed at the top of the furnace body, or the circulating material outlet and the circulating material inlet are both disposed at a sidewall of the furnace body;
• the external heater is disposed between the circulating material outlet and the circulating material inlet;
• when in use, circulating materials are transferred through the circulating material outlet to the external heater and then back to the furnace body via the circulating material inlet;
• and
• the external heater comprises a slag outlet for discharging slags.