Platinum on nitrogen doped graphene and tungsten carbide supports for ammonia electro-oxidation reaction

Ammonia electrooxidation reaction involving multistep electron-proton transfer is a significant reaction for fuel cells, hydrogen production and understanding nitrogen cycle. Platinum has been established as the best electrocatalyst for ammonia oxidation in aqueous alkaline media. In this study, Pt/nitrogen-doped graphene (NDG) and Pt/tungsten monocarbide (WC)/NDG are synthesized by a wet chemistry method and their ammonia oxidation activities are compared to commercial Pt/C. Pt/NDG exhibits a specific activity of 0.472 mA∙cm^–2, which is 44% higher than commercial Pt/C, thus establishing NDG as a more effective support than carbon black. Moreover, it is demonstrated that WC as a support also impacts the activity with further 30% increase in comparison to NDG. Surface modification with Ir resulted in the best electrocatalytic activity with Pt-Ir/WC/NDG having almost thrice the current density of commercial Pt/C. This work adds insights regarding the role of NDG and WC as efficient supports along with significant impact of Ir surface modification.     

Ammoniaksynthese als Beispiel einer stofflichen Nutzung von intermittierend erzeugtem Wasserstoff

Producing hydrogen‐rich chemicals, such as methane, ammonia or methanol, from renewable energy may foster the integration of renewables into the current energy system. Here, a flexible ammonia synthesis concept is introduced, which is then compared to the widely discussed power‐to‐gas concepts on a technical and economic level. The current ammonia prices result in comparably high hydrogen‐specific revenues, which imply the ability to operate the system more profitable under fluctuating electricity prices and thereby increase the plant capacity factor.     

破乳剂在太钢焦化厂的应用

太钢焦化厂应用煤调湿技术后,焦油、氨水分离及氨水的后续处理出现了循环氨水喷嘴堵塞、横管初冷器阻力高、焦油质量下降等现象。投加破乳剂后,解决了焦油、氨水分离问题,稳定了生产。     

管式炉蒸氨新工艺在攀钢的应用

介绍了管式炉蒸氨新工艺的改造内容和技术特点,改造后,实现了系统连续稳定运行,废水处理量120t/h,蒸氨废水氨氮含量为95.7mg/L,下降幅度达37.2%。     

新型薄管板转化废热锅炉的应用

分析了新疆泽普石化厂二段炉后转化废热锅炉频繁出现故障的原因,并对替换的新型薄管板的结构性能和应用情况作了介绍,该废锅至今已平稳运行了3年。     

负荷及温度对人工湿地去除氨氮的影响

本研究在借鉴他人研究成果的基础上,利用海泡石这一江西特有的矿物质为基质,辅以香根草等适应环境能力强,去污效果好的植物,构成海泡石人工湿地系统。通过试验发现,该人工湿地对生活污水中氨氮具有良好的去除效果。     

Improving physicochemical characteristics and anaerobic digestion performance of rice straw via ammonia pretreatment at varying concentrations and moisture levels

Rice straw physicochemical characteristics and anaerobic digestion(AD) performance via ammonia pretreatment at varying ammonia concentrations(2%, 4%, and 6%) and moisture contents(30%, 50%, 70%, and 90%)under a mild condition were investigated. The results showed that the ammonia pretreatment effectively damaged the rice straw structure, increased the soluble organic concentration, and improved rice straw hydrolysis and AD performance. After pretreatment, the ester bond and ether bond were ruptured in lignocellulose and the volatile fatty acids(VFAs) were within the range of 1457.81–1823.67 mg·L~(-1). In addition, ammonia pretreatment had high selectivity on lignin removal, resulting in a maximum lignin removal rate of 50.80%. The highest methane yield of rice straw was 250.34 ml·(g VS)~(-1) at a 4% ammonia concentration coupled with a 70% moisture content, which was 28.55% higher than that of the control. The result showed that ammonia pretreatment of rice straw is technically suitable to enhance AD performance for further application.     

大型合成氨装置联产甲醇初探——以煤为原料合成氨联产甲醇

针对三种以煤为原料的大型合成氨流程。分别提出联产甲醇的建议。冷法净化合成氨装置,可采用并联联醇;非冷法净比与油改煤合成氨装置,可采用串联联醇,均具有相当的经济效益。     

74-1型氨合成催化剂在高压流程中的应用 (Ⅱ)应用部分

介绍了７４－１型氨合成催化剂的特性。分析了其在高压流程中不同合成塔内的应用方法和应用效果,表明７４－１是一种性能优良的催化剂,适用于我国中小型氮肥厂的高压流程,并可收到节能效果。     

Generation of spatio-temporal concentration profiles for cell culture systems: A case study in ammonia

Cellular behavior is influenced by micro-concentration gradients existing in their immediate spatio-environment. A practical real-time measurement system, composed of miniaturized long-lasting sensors placed within a two-dimensional bioreactor and a 32-channel data acquisition system for ammonia, is presented in this paper aiming to generate the spatio-temporal ammonia concentration profiles for the whole culture process. Our results demonstrate the feasibility of the system and its applicability in elucidating the cell growth micro-environment within a bioreactor, which can potentially facilitate the intelligent control of ammonia levels in cell culture systems. The presented system is flexible enough to interface other sensors for generating their spatio-temporal profiles of the sensed cell culture parameters.