生物质能在炼铁领域应用的研究现状及展望

 在国家碳达峰和碳中和目标下,炼铁行业在改进生产技术的同时,开发可替代的新型能源以减少一次化石燃料的消耗,是实现其低碳发展的必由之路。生物质能作为一种清洁可再生能源,具有来源广泛、环境友好和碳中性等特点。天然生物质能挥发分含量高、易燃烧,而热解后的生物炭的理化性能与煤粉接近,将生物质能作为燃料和还原剂应用于炼铁生产,可以有效发挥其节能减排作用。在分析生物质能理化性能的基础上,系统阐述了生物质能在制备焦炭、高炉喷吹、烧结、球团工序中应用的研究现状。首先指出,生物质和煤粉的共热解技术是利用生物质混煤炼焦的关键。为了推进生物质焦炭在高炉冶炼中的应用,需要加强生物质焦炭对高炉软熔带透气透液性的影响研究。其次,生物质的热值、燃烧特征温度和燃烧率是影响生物质混煤喷吹效果的主要因素。提出开发生物质协同煤粉造气新技术可以拓宽高炉喷吹用生物质能的选择范围,并可生产优质富氢还原煤气用于高炉喷吹。第三,指出用适量的生物质能替代焦粉或煤粉进行铁矿粉烧结,可以保证烧结矿的质量,并产生显著的减排效果。在制备生物质含碳球团时,需要严格控制生物质的添加量,以获得高金属化率和适宜黏结性指数的球团。在今后的研究中应重点进行生物质的种类和添加量对烧结矿和球团矿质量的影响研究。最后,指出目前生物质能炼焦、高炉喷煤、烧结和球团中的应用还多处于基础研究阶段,建议今后应加快生物质能在炼铁各工序生产中的应用实践,以进一步评估生物质能在炼铁领域的使用效果和应用潜力。

Application status and prospect of biomass energy in ironmaking process

Under the national carbon emission peak and neutrality targes,the ironmaking industry should develop alternative energy to reduce the consumption of primary fossil fuels along with the improvement of production technology,which is one of the key ways to achieve low-carbon development. As a clean and renewable energy,biomass energy has the characteristics of wide sources,environment-friendly and carbon neutral. Natural biomass energy has high volatile content and is easy to burn,while the physical and chemical properties of biochar after pyrolysis are close to those of coal. The application of biomass energy as fuel and reducing agent in ironmaking can effectively play its role in energy conservation and emission reduction. Based on the analysis of the physical and chemical properties of biomass energy,the research status of the application of biomass energy in coke preparation,blast furnace injection,sintering and pelletizing are mainly introduced. It is pointed out that the co-pyrolysis technology of biomass and pulverized coal is the key to coking with biomass blended coal. In order to promote the application of biomass coke in blast furnace smelting,it is necessary to explore the influence of biomass coke on the permeability of blast furnace soft melt zone. Then,it is pointed out that the main factors effecting pulverized coal injection with biomass energy include calorific value,combustion characteristic temperature and combustion rate of biomass. A new technology of coal gasification with biomass and breeze is put forward,which can broaden the selection range of biomass energy for blast furnace injection,and produce high-quality hydrogen rich reduction gas for blast furnace injection. Furthermore,the quality of sinter can be guaranteed and significant emission reduction effect can be achieved by adjusting the proportion of biomass and sintering process parameters. Pellets with high metallization rate and suitable bond index can be obtained through strictly controlling the kind of biomass and its content. At the same time,the effect of biomass addition content on the quality of sinter and pellets should be researched further. Finally, most of the above studies are in the basic research stages. Therefore,it is suggested that the production practice of biomass energy in blast furnace ironmaking,sintering,pelletizing should be accelerated in order to deeply evaluate the application potential of biomass energy in low-carbon ironmaking fields.