The Shanghai Meishan Iron and Steel Co., Ltd. has a large supply of coke oven gas (COG) and has the potential to develop and apply the spraying of COG on the surface of a sinter bed. The effects of the amount of COG, ...The Shanghai Meishan Iron and Steel Co., Ltd. has a large supply of coke oven gas (COG) and has the potential to develop and apply the spraying of COG on the surface of a sinter bed. The effects of the amount of COG, the spraying time, and the spraying distribution with the process on the quantity and quality indexes of sinter were investigated in the laboratory experi-ments. The results showed that the COG spraying can improve the sinter indexes to a large extent if appropriate parameters were used. It was found that an appropriate amount of COG, a relatively long spraying time, and a decreasing distribution of the COG amount with the spraying process all help to obtain a better performance for sinter quantity and quality indexes. When the COG spraying was applied to the No. 3 sintering machine, the sinter tumbler index increased by 0.45%, the overall finished product rate increased by 0.72%, the solid fuel consumption decreased by 4.06kg/t, the reducibility increased by 3.89%, and the cost of iron decreased by 5.29 CNY/t, and the CO2, SO2 and Nox emissions also decreased, thus proving the feasibility of this technology. Therefore, COG spraying provides a new way to improve sinter and also decrease the energy consumption and pollution.展开更多
This study focused on the manufacture of microcrystalline cellulose(MCC)from wheat straw using environmentally-friendly solvents.Raw cellulose was separated from wheat straw after thermal decomposition of lignin follo...This study focused on the manufacture of microcrystalline cellulose(MCC)from wheat straw using environmentally-friendly solvents.Raw cellulose was separated from wheat straw after thermal decomposition of lignin followed by dissolution of lignin using a recyclable ethanol/acetic acid/water solvent system.Then,pure cellulose was produced using a four-step refining process,including chelating,O_(3),H_(2)O_(2),and xylanase treatments.Finally,MCC was obtained through hydrolysis,drying,and mechanical treatments.The effects of acetic acid,O_(3),H_(2)O_(2),NaOH,pretreatment time,and temperature on the properties of wheat straw cellulose(including Kappa number,yield,α-cellulose content,crystallinity,KMnO4 value,degree of polymerization(DP),and brightness)were investigated.The results showed that the addition of acetic acid enhanced lignin removal and hemicellulose degradation,improving the purity of the raw cellulose.The optimized acetic acid dosage in the wheat straw thermal decomposition step was 2%(w/w).The optimized O_(3)dosage was 1.2%(w/w).The optimized conditions for H_(2)O_(2)treatment were found to be 3%(w/w)H_(2)O_(2)and 1.8%(w/w)NaOH at 70°C for 120 min.The KMnO4 value was 2.0,brightness was 84.1%ISO,the viscosity was 934 mL/g,and the DP was 626 for refined cellulose.Xylanase effectively improved theα-cellulose content of wheat straw cellulose.With an optimized xylanase dosage of 1.5 IU/g,theα-cellulose content was 94.7%,the brightness was 85.6%ISO,and the DP was 615 for wheat straw cellulose.展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant Number 51804027)Fundamental Research Funds for the Central Universities(FRF-IC-18-010).
文摘The Shanghai Meishan Iron and Steel Co., Ltd. has a large supply of coke oven gas (COG) and has the potential to develop and apply the spraying of COG on the surface of a sinter bed. The effects of the amount of COG, the spraying time, and the spraying distribution with the process on the quantity and quality indexes of sinter were investigated in the laboratory experi-ments. The results showed that the COG spraying can improve the sinter indexes to a large extent if appropriate parameters were used. It was found that an appropriate amount of COG, a relatively long spraying time, and a decreasing distribution of the COG amount with the spraying process all help to obtain a better performance for sinter quantity and quality indexes. When the COG spraying was applied to the No. 3 sintering machine, the sinter tumbler index increased by 0.45%, the overall finished product rate increased by 0.72%, the solid fuel consumption decreased by 4.06kg/t, the reducibility increased by 3.89%, and the cost of iron decreased by 5.29 CNY/t, and the CO2, SO2 and Nox emissions also decreased, thus proving the feasibility of this technology. Therefore, COG spraying provides a new way to improve sinter and also decrease the energy consumption and pollution.
基金the Doctoral Program of Higher Education Projects(for the priority development areas)by Ministry of Education of China(Grant No.20126125130001)State Key Laboratory of Pulp and Paper Engineering open foundation(Grant No.201505)the Doctoral Scientific Research Foundation(Grant No.BJ13-02)by Shaanxi University of Science and Technology.
文摘This study focused on the manufacture of microcrystalline cellulose(MCC)from wheat straw using environmentally-friendly solvents.Raw cellulose was separated from wheat straw after thermal decomposition of lignin followed by dissolution of lignin using a recyclable ethanol/acetic acid/water solvent system.Then,pure cellulose was produced using a four-step refining process,including chelating,O_(3),H_(2)O_(2),and xylanase treatments.Finally,MCC was obtained through hydrolysis,drying,and mechanical treatments.The effects of acetic acid,O_(3),H_(2)O_(2),NaOH,pretreatment time,and temperature on the properties of wheat straw cellulose(including Kappa number,yield,α-cellulose content,crystallinity,KMnO4 value,degree of polymerization(DP),and brightness)were investigated.The results showed that the addition of acetic acid enhanced lignin removal and hemicellulose degradation,improving the purity of the raw cellulose.The optimized acetic acid dosage in the wheat straw thermal decomposition step was 2%(w/w).The optimized O_(3)dosage was 1.2%(w/w).The optimized conditions for H_(2)O_(2)treatment were found to be 3%(w/w)H_(2)O_(2)and 1.8%(w/w)NaOH at 70°C for 120 min.The KMnO4 value was 2.0,brightness was 84.1%ISO,the viscosity was 934 mL/g,and the DP was 626 for refined cellulose.Xylanase effectively improved theα-cellulose content of wheat straw cellulose.With an optimized xylanase dosage of 1.5 IU/g,theα-cellulose content was 94.7%,the brightness was 85.6%ISO,and the DP was 615 for wheat straw cellulose.