Methods for producing syngas from biomass-co2 coupled converter smelting processes

Abstract

A method for producing syngas from a biomass-CO 2 coupled converter smelting process is provided, including: initiating smelting in a converter by injecting a primary injection gas while simultaneously injecting biomass and a carrier gas; 5-90 seconds after the smelting begins, increasing an injection flow rate of the primary injection gas from 60% to 100% of a designed flow rate, and keeping injecting the carrier gas at the designed flow rate; when an oxygen concentration in the syngas drops to ≤1%, injecting the biomass at the designed flow rate; in a mid-decarburization period: reducing the injection flow rate of the primary injection gas, and increasing the injection flow rate of the biomass to a maximum value; after a peak decarburization phase: increasing the injection flow rate of the primary injection gas, and decreasing the injection flow rates of the biomass and the carrier gas.

What is claimed is: 
     
         1 . A method for producing syngas from a biomass-CO 2  coupled converter smelting process, comprising:
 initiating smelting in a converter by injecting a primary injection gas while simultaneously injecting a biomass and a carrier gas, wherein the primary injection gas is oxygen (O 2 ) or a mixture of O 2  and CO 2 , injected at 60% of a designed flow rate; and the carrier gas is injected at the designed flow rate and includes CO 2 ;   5-90 seconds after the smelting begins, increasing an injection flow rate of the primary injection gas from 60% to 100% of the designed flow rate, and keeping injecting the carrier gas at the designed flow rate: when an oxygen concentration in the syngas drops to ≤1%, injecting the biomass at the designed flow rate, while maintaining a powder-to-gas ratio of 0.5-1.5 between an injection flow rate of the biomass and an injection flow rate of the carrier gas throughout the smelting;   in a mid-decarburization period: reducing the injection flow rate of the primary injection gas: increasing the injection flow rate of the biomass to a maximum value; and modulating in real-time the injection flow rate of the carrier gas and the injection flow rate of the biomass;   after a peak decarburization phase: increasing the injection flow rate of the primary injection gas: decreasing the injection flow rate of the biomass and the injection flow rate of the carrier gas; and   in a final smelting stage: further increasing the injection flow rate of the primary injection gas: further decreasing the injection flow rate of the biomass and the injection flow rate of the carrier gas; and terminating biomass injection after exceeding 90% of a total smelting duration to obtain the syngas.   
     
     
         2 . The method according to  claim 1 , wherein the biomass is a biomass feedstock or a carbonized biomass, and the biomass has a particle size of 50 mesh-800 mesh, a moisture content ≤30 wt %, and a calorific value of 500-6000 kcal/kg. 
     
     
         3 . The method according to  claim 1 , wherein during the mid-decarburization period, the powder-to-gas ratio is controlled to be in a range of 1.2-1.7: after the peak decarburization phase, the powder-to-gas ratio is controlled to be in a range of 1.1-1.4; and in the final smelting stage, the powder-to-gas ratio is controlled to be in a range of 0.8-1.2. 
     
     
         4 . The method according to  claim 1 , wherein the method adopts an apparatus including: a syngas injection lance extending into an interior of the converter, wherein the syngas injection lance includes a primary injection gas channel for injecting the primary injection gas and a biomass conveying duct for co-injecting the biomass and the carrier gas, with the biomass conveying duct being connected to a biomass injection nozzle and the primary injection gas channel being connected to a main injection nozzle. 
     
     
         5 . The method according to  claim 4 , wherein a vertical distance between an outlet of the biomass injection nozzle and an outlet of the main injection nozzle is in a range of 0-3 m. 
     
     
         6 . The method according to  claim 4 , wherein the apparatus further includes a biomass carrier gas system and a biomass injection system connected to the biomass carrier gas system via the biomass conveying duct, wherein the biomass injection system is connected to the syngas injection lance. 
     
     
         7 . The method according to  claim 6 , wherein the apparatus further includes an injection smelting system configured to set injection parameters for both the biomass carrier gas system and the biomass injection system. 
     
     
         8 . The method according to  claim 4 , wherein the syngas injection lance is connected to an oxygen system through an oxygen channel. 
     
     
         9 . The method according to  claim 4 , wherein the apparatus further includes a syngas composition analyzer configured to control both a lance height setting and injection parameters of the syngas injection lance.