几种改性同时脱硫脱硝吸收剂的比较研究

利用模拟烟气,在固定床上对几种改性同时脱硫脱硝吸收剂的性能进行了比较实验研究。结果表明:EDTA合铁、H2O2、尿素、半胱氨酸合铁、锰系物M以及复合剂F(N/NaClO2)等添加剂改性后其脱硫效率提升并不明显,但脱硝效果差异较大,其中复合添加剂F改性后脱除效率最高,用量最少,成本最低。利用正交试验,确定了复合添加剂F改性后同时脱硫脱硝剂的最佳实验条件为添加剂含量为0.2%,反应温度为60℃,Ca/(S+N)为1.2。     

使用固硫添加剂减少煤燃烧SO_2排放的研究

通过实验对影响钙基固硫率的各种因素进行了初步分析.结果表明,随着Ca/S比的增大,煤的固硫率逐渐升高,Ca/S比为2.5时,煤的固硫率最高;投放不同的添加剂时,当Ca/S比为2,NaCl、Na2CO3、Fe2O3的投放量分别为固硫剂的6%、3%、6%时,煤的固硫率最高;当炉温为1 000℃、粒度为0.1 mm时,煤的固硫率最高.此外,添加剂在煤燃烧过程中投放时的固硫率高于在燃烧前和燃烧后投放时的固硫率.本研究对促进固硫工艺的发展,并为分散式民用燃煤提供了理论和研究方法上的依据.     

Application of the random pore model to the carbonation cyclic reaction

Calcium oxide has been proved to be a suitable sorbent for high temperature CO₂ capture processes based on the cyclic carbonation‐calcination reaction. It is important to have reaction rate models that are able to describe the behavior of CaO particles with respect to the carbonation reaction. Fresh calcined lime is known to be a reactive solid toward carbonation, but the average sorbent particle in a CaO‐based CO₂ capture system experiences many carbonation‐calcination cycles and the reactivity changes with the number of cycles. This study applies the random pore model (RPM) to estimate the intrinsic rate parameters for the carbonation reaction and develops a simple model to calculate particle conversion with time as a function of the number of cycles, partial pressure of CO₂, and temperature. This version of the RPM model integrates knowledge obtained in earlier works on intrinsic carbonation rates, critical product layer thickness, and pore structure evolution in highly cycled particles. © 2009 American Institute of Chemical Engineers AIChE J, 2009     

THERMAL DEHYDRATION OF THE SODIUM CARBONATE HYDRATES

A thermal gravimetric method was employed to explore the course of dehydration of Na₂CO₃ · 10 H₂O, and Na₃CO₃ · H₂O particles. Experimental data were amassed both in the temperature-increasing and constant temperature mode. Very small sample masses were used in an effort to eliminate an effect of heat and mass transfer processes on the rate of reaction. Kinetic equations of Arrhenius type were proposed for two stages of the dehydration and tested against the results collected by experiment.     

Synthetic Ca‐based solid sorbents suitable for capturing CO2 in a fluidized bed

Coprecipitation and hydrolysis of CaO have been employed to produce Ca‐based synthetic sorbents suitable for capturing CO₂ in a fluidized bed. Their composition, CO₂ uptake, volume in small pores (2–200 nm) and resistance to attrition were measured and compared to those of limestone and dolomite. Sorbents produced by hydrolysis showed the highest uptake and resistance to attrition. After 20 cycles of carbonation and calcination, two sorbents exceeded the uptake of both limestone and dolomite, when subjected to the same regimes of reaction. A sorbent's uptake of CO₂ was shown to be determined by the volume in pores narrower than ～200 nm.     

Studies on defluoridation of water by coal‐based sorbents

Drinking water containing fluoride above a level of 1 mg dm^?3 is considered to be unsafe for human consumption. Higher intake of fluoride can cause potential health hazards. The conventional processes of fluoride removal from water are ion exchange, reverse osmosis and electro‐dialysis. However, the utility of these processes has been limited due to their expensive operation and subsequent disposal problem of the waste brine generated. Defluoridation of water samples by coal‐based sorbents was studied at different adsorbent dosages. First‐order adsorption rate constants using the Lagergren equation, the Freundlich adsorption isotherm, the Langmuir adsorption isotherm, film diffusion and pore diffusion coefficients have been evaluated for each system. The effect of pH on fluoride removal and the mechanism has also been discussed. Copyright © 2001 Society of Chemical Industry     

三元复合钙基材料CaO-Ca3Al2O6-MgO的合成及其CO2吸附性能

采用Al₂O₃和MgO同时掺杂改性的方法制备了CaO-Ca₃Al₂O₆-MgO复合钙基高温吸附CO₂材料。复合钙基材料孔隙发达,活性物相为CaO,惰性骨架物相为Ca₃Al₂O₆和MgO。Ca₃Al₂O₆/MgO质量比偏小的材料,表面微粒粒径较小。在10%（体积分数,下同）CO₂和90% N₂的混合气气氛下,采用热重分析仪测量了复合钙基材料吸附CO₂容量、碳化反应速率以及循环碳化（670℃）/煅烧（900℃）过程的稳定性。结果发现,复合钙基材料CaO-Ca₃Al₂O₆-MgO具有较好的吸附CO₂性能,提高Ca₃Al₂O₆/MgO质量比,合成材料的循环稳定性较好;降低Ca₃Al₂O₆/MgO质量比,合成材料的碳化反应速率加快,CaO转化率提高。最后,通过对不同循环次数下复合钙材料的比表面积、孔径分布、微观形貌、表面元素分布,晶相、晶粒大小进行研究分析,对合成材料的失活以及掺杂物质对烧结的抑制机理进行了讨论。     

国内铅蓄电池板栅材料的研究进展

阐述了铅锑基合金、铅钙基合金、基材镀铅等板栅材料的特性,这几种板栅系列在电解液中的耐腐蚀性能、电性能、物理性能等各有优劣;简要介绍这几种板栅材料在蓄电池中的适用范围;综述了国内板栅材料的研究历史和现状;最后对板栅材料的研究发展趋向做了展望。     

CuO/Al203烟气脱硫吸附剂再生技术的研究

对已经硫化的CuO/Al2O3脱硫吸附剂的可再生性进行了实验研究.实验证明,负载型金属氧化铜脱硫吸附剂在硫化后用还原性气体再生是实际可行的;CuO/Al2O3脱硫吸附剂最佳的再生温度为485℃、最佳反应气体流量为2.4L/min、最佳CH4浓度为1.1%.