Process and system for coupling pressurized pyrolysis of biomasses

Provided is a process for the coupling pressurized pyrolysis of biomasses, which pyrolyses the biomasses using microwaves coupled with plasmas, and treats the carbon residues after the pyrolysis using plasmas. The method has a high efficiency, and a high carbon conversion. The synthetic gas has a good quality and the volume of the effective gas reaches above 90%. Also provided is a pyrolyzing furnace for the above-mentioned pyrolysis process, which includes a pyrolysis furnace (2), a feeding system, a cyclone separator (4). The lower part of the pyrolyzing furnace is provided with multiple microwave inlets (12) and a plasma torch (13) interface, and the bottom thereof is provided with a slag storage pool. Both the microwave inlets (12) and the plasma torch (13) interface of the pyrolyzing furnace are distributed in multiple layers with each layer being placed at a uniform distance. The plasma torch (13) interface is placed below the microwave inlets (12) and above the level of the liquid in the slag storage pool and the jet direction of the plasma at the plasma torch (13) interface is in the range of a microwave field at the microwave inlets. The thus resultant synthetic gas is free of tar, and the subsequent purification process is simple, without environmental pollution.