Two-step harmless treatment of secondary aluminum dross (SAD) by vacuum distillation and alkaline roasting

Journal of Material Cycles and Waste Management - Secondary aluminum dross (SAD) is classified as hazardous waste by many countries in the world because it contains a large number of toxic and...     

Study on the denitrification performance of FexLayOz/activated coke for NH3-SCR and the effect of CO escaped from activated coke at mid-high temperature on catalytic activity

Currently, activated coke is widely used in the removal of multiple pollutants from industrial flue gas. In this paper, a series of novel Fe_xLa_yO_z/AC catalysts was prepared by the incipient wetness impregnation for NH₃-SCR denitrification reaction. The introduction of Fe-La bimetal oxides significantly improved the denitrification performance of activated coke at mid-high temperature, and 4% Fe_0.3La_0.7O_1.5/AC exhibited a superior NO_x conversion efficiency of 90.1% at 400 °C. The catalysts were further characterized by BET, SEM, XRD, Raman, EPR, XPS, FTIR, NH₃-TPD, H₂-TPR, et al., whose results showed that the perovskite-type oxide of LaFeO₃ and oxygen vacancies were produced on the catalysts’ surfaces during roasting. Fe-La doping enhanced the amount of acid sites (mainly Lewis and other stronger acid sites) and the content of multifarious oxygen species, which were beneficial for NO_x removal at mid-high temperature. Moreover, it was investigated that the effect of released CO from activated coke at mid-high temperature on the NO_x removal through the lifetime test, in which it was found that a large amount of CO produced by pyrolysis of activated coke could promote the NO_x removal, and long-term escaping of CO on the activated coke carrier did not have a significant negative impact on catalytic performance. The results of the TG-IR test showed that volatile matter is released from the activated coke while TG results showed that the weight loss rate of 4% Fe_0.3La_0.7O_1.5/AC only was 0.0015~0.007%/min at 300–400 °C. Hence, 4% Fe_0.3La_0.7O_1.5/AC had excellent thermal stability and denitrification performance to be continuously used at mid-high temperature. Finally, the mechanisms were proposed on the basis of experiments and characterization results.

     

聚α-烯烃合成油的清洁生产工艺

针对聚α-烯烃合成油（PAO）生产旧工艺存在的问题,介绍了以固载化AlCl3为催化剂的PAO生产新工艺,考察了各种因素对PAO收率的影响。实验结果表明,在反应温度为100℃、反应时间为8h、A1C1,与α-烯烃质量比为10：75的条件下,PAO收率为48．8％。采用新工艺后,PAO产品质量有了明显提高,黏度指数为132,碱和白土的消耗为零,且没有废渣产生,可实现清洁化生产。     

Study on Biodegradable Starch/OMMT Nanocomposites for Packaging Applications

The thermoplastic starch (TPS) and nanocomposite(TPS/OMMT) was prepared with 15% carbamide, 15% ethanolamine and different contents of organic activated montmorillonite (OMMT) by twin-screw extruder with a 130 °C barrel temperature. Fourier transforms infrared spectroscopy and wide angle X-ray diffraction shown that the alkylamine in dodecyl benzyl dimethyl ammonium bromide could react with MMT via cation exchange reaction. After treated, the d(001)space distance of MMT increased from 1.5 to 1.7 nm. Scanning electron microscope revealed that the lower contents of OMMT could disperse well in the matrixes of TPS. The carbamide, ethanolamine and the OMMT could destroy the crystallization behavior of starch, but only the OMMT restrained this behavior for long-term storing. Mechanical properties investigation indicated that the tensile strength and modulus of TPS/OMMT nanocomposites were better than those of TPS, while the elongation at break was descended with the increasing of OMMT contents. When the content of OMMT was 4%, the tensile strength and modulus of TPS was improved from 4.2 and 42 MPa to 6.0 and 76 MPa, respectively.     

环境友好型材料的研究

材料产业是资源(能源)消耗和污染排放的主要责任者之一,并由此产生严重的生态环境问题.通过分析传统材料产业发展带来的能源和环境危机,阐述了环境友好型生态材料的内涵与研发内容,说明只有从系统的观点出发,了解与掌握发展环境友好型材料的技术途径,大力推广其研究与应用,才能最终实现人类与自然的协调发展.     

发展循环经济 开辟航空业新纪元

随着人们环保意识的逐渐增强,航空业所造成的环境和噪声污染已经越来越成为令人关注的重大问题.从5个方面介绍了发达国家航空业发展循环经济的经验,指出我国作为发展中国家,要正视与发达国家的差距,借鉴国外先进经验,转变观念、大胆创新,大力发展循环经济,开辟我国航空业的新纪元.     

北京蟹岛集团发展循环经济调查

通过对民营企业北京蟹岛集团的实地调查,对其以“低消耗、低排放、低污染、高效益”为经营方针,以“生态、环保、可持续”为经营理念,成功实现“资源－消费－再利用”的循环经济增长模式进行详细介绍。并通过蟹岛集团自身的发展证明：循环经济不仅可以改变传统“资源－效益—废弃物”的线性增长模式,还可以促进企业的发展,为企业带来可观的经济效益。     

单切口坝对稀性泥石流的拦砂性能——试验研究与比较分析

通过室内水槽试验,探讨了单切口坝对稀性泥石流的拦砂性能,并与梳子坝的试验结果进行了比较分析。初步得到：（1）单切口坝有全闭塞、部分闭塞和不闭塞3种闭塞类型。当切口宽度b与稀性泥石流中最大颗粒粒径dmax之比b／dmax≤0．394时,切口全闭塞;b／dmax≥1．478时,切口不闭塞;0．394〈b／dmax〈1．478时,切口为部分闭塞。（2）单切口坝在降低过坝泥石流密度变化量上,与梳子坝有相似规律。对单切口坝而言,b／dmax在0．394～0．739之间,过坝泥石流密度变化量随b／dmax增大而增大,在b／dmax=0．739时,过坝泥石流密度变化量达到最大,其后随着b／dmax的进一步增大,过坝泥石流密度变化量逐渐减小;在0．493≤b／dmax≤0．986之间,单切口坝降低过坝泥石流密度变化量较显著。（3）在相同的试验条件下,以过坝泥石流平均密度及其降低率为防治泥石流的效益指标,显示梳子坝与单切口坝的坝后平均密度的比值大多小于1,表明在相同的试验条件下梳子坝对稀性泥石流的防治效果较好。     

餐厨垃圾高温厌氧消化产沼气的试验研究

探究了温度、含固率、pH及接种率对餐厨垃圾厌氧消化产沼量的影响,并设计L9(34)正交试验进行厌氧发酵工艺优化研究。结果表明,在温度为55℃、含固率为8%(质量分数)、pH为7.00、接种率为90%(质量分数)时,厌氧发酵累积产沼量为809.0mL/g(以挥发性固体计);各影响因素对产沼量的影响大小为温度pH接种率含固率。