利用熔铁浴高温粗煤气冶炼DRI的能耗估算  

Estimation on energy consumption for smelting DRI with high temperature crude gas in molten iron bath

作　　者：苏亚杰 牛强[2] 杜英虎 陈寿林[4] Su Yajie;Niu Qiang;Du Yinghu;Chen Shoulin(Shanxi Coking Coal Group Co.,Ltd.,Taiyuan 030024,Shanxi;Green Hydrogen Energy Research Institute,Zhejiang Institute,Chinese Academy of Sciences,Jiaxing 314002,Zhejiang;Taiyuan Iron&Steel(Group)Co.,Ltd.,Taiyuan 030034,Shanxi;China Research Institute of Daily Chemical Industry,Taiyuan 030001,Shanxi)

机构地区：[1]山西焦煤集团有限责任公司,山西太原030024 [2]中国科学院浙江研究院绿色氢能研究所,浙江嘉兴314002 [3]太原钢铁(集团)有限公司,山西太原030034 [4]中国日用化学工业研究院,山西太原030001

出　　处：《烧结球团》2020年第6期23-28,共6页Sintering and Pelletizing

摘　　要：为降低炼铁能耗,本文提出熔铁浴煤制气加热循环还原气生产直接还原铁(DRI)的新工艺,并对过程能耗进行了估算。新工艺流程:DRI炉顶气经除尘、CO变换H2、洗涤降温至25℃后脱S和CO2后,被转化成H2体积分数>90%的循环还原气;利用熔铁浴产生的1300~1700℃的高温粗煤气加热25℃循环还原气至850℃,使V(H)/V(C)(体积比)>1.3,并将还原气送入竖炉冶炼DRI。能耗估算结果表明:新工艺的能耗为329.4 kg标煤/tDRI;若利用转炉富余热量全流程加入30%DRI用于炼钢,与2018年的全国炼钢平均技术指标相比,其能耗降低225.84 kg标煤/t,能源成本降低459元/t;此外,30%DRI加入转炉炼钢比DRI直接加入电炉的能耗降低135.46 kg标煤/t,能源成本降低162元/t。由于利用了高温粗煤气的显热、压力,新工艺的能耗、排放和成本大幅降低。此外,该工艺可低成本回收纯净CO2,利用绿色H2(核能或可再生电力生产的H2)将CO2合成尿素或甲醇后,可以实现CO2零排放。In order to reduce the energy consumption of ironmaking,a new process for producing direct reduced iron(DRI)by heating and circulating the reduction gas from the molten Fe-slag bath gasification is proposed,and the process of the energy consumption is estimated.New process flow:the off-gas of DRI shaft is heated from 25℃to 850℃by syngas with 1300~1700℃from Fe-slag bath gasifier,undergoing a series of dust removal,conversion of CO into H2,washing and quenching,desulphurization and CO2 removal,as reducing gas ofφ(H2)>90%.The mixed gas recycles to enter the DRI shaft with the ratio of V(H)/V(C)>1.3.The results show that,the energy consumption of the new process is 329.4 kg standard coal/t DRI;if the surplus heat of the converter is used to add 30%DRI to steelmaking in the whole process,compared with the national steelmaking average technical indicators in 2018,the energy consumption will be reduced by 225.84 kg standard coal/t,and the energy cost will be reduced by 459 yuan/t;in addition,the energy consumption of 30%DRI added to the converter steelmaking is reduced by 135.46 kg standard coal/t and the energy cost is reduced by 162 yuan/t compared with DRI directly added to the electric furnace.The energy consumption,emission level and cost of the noval process decreases sharply due to the sensible heat and pressure of hot syngas.What is more,it is easy to capture CO2 with low cost to synthetise urea or methanol with green H2,produced by renewable energy or nuclear power,and so the ZERO CO2 emission is practical.

关 键 词：熔铁浴煤制气 粗煤气显热 直接还原铁 余热炼铁 氢还原铁 

分 类 号：TF5[冶金工程—钢铁冶金] TQ546.5[化学工程—煤化学工程]