Back-End Modifications of Portland Cement Plants to Reduce Emissions of Hazardous Air Pollutant

波特兰水泥厂后端改造以减少有害空气污染物的排放

• 批准号: 9613422
• 负责人: Sukhjinder Sidhu
• 金额: $ 33万
• 依托单位: University of Dayton
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-10-01 至 2000-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9613422&HistoricalAwards=false
• 关键词: Back; End; Modifications; Portland; Cement

Abstract 9613422 Sidhu This proposal focuses on the reduction of hazardous air pollutants (HAP) such as hydrocarbons, hydrochloric acid, and polychlorinated dibenzo-p-dioxins and polychlorinated furans (PCDD/F), produced in the production of Portland cement. Volatilization of organics from the feed stock during preheating and drying and conditions in the Air Pollution Control (APC) device and in the transfer ducting zones appear to be primarily responsible for the formation of these HAPs. Several process modifications such as the thermal pretreatment of feed stock, elimination of hydrocarbon recycle, temperature reduction in the preheat off-gas transfer duct, increased oxidation, and modification of preheater conditions may help reduce and/or prevent this HAP formation. An experimental program is proposed in order to determine which of these strategies is most effective and what precise process modifications are necessary to implement them. A high temperature flow reactor, operating in the range of 200 to 700 C will be used to study the speciation, partitioning, and reaction of raw meal hydrocarbons and chlorine in an environment containing cement kiln feed stock and NOx, O2, and water. This data should enable the design of specific process modifications to prevent the formation and emission of HAPs from Portland cement kilns without the addition of control devices.

摘要9613422 本提案侧重于减少波特兰水泥生产过程中产生的碳氢化合物、盐酸、多氯二苯并对二恶英和多氯呋喃等有害空气污染物。 在预热和干燥过程中原料中的有机物的挥发以及空气污染控制（APC）装置和输送管道区域中的条件似乎是形成这些HAP的主要原因。 几种工艺改进，例如原料的热预处理、消除烃再循环、预热废气输送管道中的温度降低、增加氧化和预热器条件的改进可有助于减少和/或防止这种HAP形成。 提出了一个实验方案，以确定这些策略是最有效的，什么样的精确的过程修改是必要的，以实现它们。 一个高温流动反应器，在200至700摄氏度的范围内运行，将被用来研究的形态，分配，和生料烃和氯在含有水泥窑原料和氮氧化物，氧气和水的环境中的反应。 这些数据应有助于设计具体的工艺修改，以防止波特兰水泥窑在不增加控制装置的情况下形成和排放有害生物。