丁烯氧化脱氢铁系催化剂绿色制备关键因素的考察

丁烯氧化脱氢是工业生产丁二烯常用的工艺,其中,铁系催化剂是丁烯氧化脱氢工业使用的主流催化剂,为满足清洁生产的需要,了解催化剂制备过程中产生的NOx及废水等排放物的组成尤为重要。对铁系催化剂生产过程中前驱体制备步骤的气体生成及组成进行研究,同时对沉淀洗涤步骤产生的废液成分进行检测。通过XRD、TG-DSC、ICP和TPC等技术对催化剂性质及制备排放物进行分析,考察制备条件对催化剂结构和性能的影响及废物排放的变化规律。结果表明,在前驱体制备溶铁过程中,空气气氛下提高硝酸浓度可有效抑制氢气的产生;不同焙烧温度阶段,生成NOx种类有较大差别;排放废水中含有较多的Zn离子。焙烧条件试验表明,最佳焙烧温度为(650~700)℃,焙烧时间低于9 h。

Key factors investigation of green preparation of Fe-based catalyst for oxidative dehydrogenation of butene

Oxidative dehydrogenation of butene is commonly used in industrial process of butadiene production.Fe-based catalyst is one of the main commercial catalysts for oxidative dehydrogenation of butene.In order to meet the need of clean production,it is particularly important to understand the composition of the generated NOx,wastewater and other emissions during the catalyst preparation process.In this paper, the production and composition of gas during the process of Fe-based catalyst preparation were studied,and the composition of the waste liquid during the precipitation and washing processes was analyzed.The catalyst properties and emissions were characterized by XRD,TG-DSC,ICP and TPC,etc.The influence of preparation conditions on the structure and properties of the catalyst and the change law of waste emission were investigated.The results showed that improvement of the concentration of nitric acid could effectively inhibit the generation of hydrogen under air atmosphere during the process of dissolving iron for the precursor preparation.There were more different NOx species under different calcination temperatures.The discharge wastewater contained more zinc ions.The experimental results of calcination condition indicated that the optimal calcination temperature was （650-700） ℃ and calcination time was less than 9 h.