Nitric Acid (HNO₃)

Nitric acid is one of the most used chemicals. The 1994 U.S. production was approximately 17.65 billion pounds. It is a colorless to a yellow liquid, which is very corrosive. It is a strong oxidizing acid that can attack almost any metal. The most important use of nitric acid is to produce ammonium nitrate fertilizer.

Nitric acid is commercially produced by oxidizing ammonia with air over a platinum-rhodium wire gauze. The following sequence represents the reactions occurring over the heterogeneous catalyst:

The three reactions are exothermic, and the equilibrium constants for the first two reactions fall rapidly with increase of temperature. Increasing pressure favors the second reaction but adversely affects the first reaction.

For this reason, operation around atmospheric pressures is typical. Space velocity should be high to avoid the reaction of ammonia with oxygen on the reactor walls, which produces nitrogen and water, and results in lower conversions. The concentration of ammonia must be kept below the inflammability limit of the feed gas mixture to avoid explosion. Optimum nitric acid production was found to be obtained at approximately 900°C and atmospheric pressure.

مواضيع ذات صلة

سلوك المعادن الطينية في علاقتها مع الماء

تصنيف النفط الخام Classification of Crude Oils

التحليل المطلق Ultimate Analysis

المكونات الرئيسية للنفط الخام الموجود في منطقة القيارة

نفط خام القيار

النفط الخام ومكوناته

النفط والطاقة Oil and Energy

مزائج اسفلت – اسفلتين

أساليب تحوير المواصفات الريولوجية للاسفلت

صفات الاسفلت الريولوجية Properties of Asphalt Rheological

استخدامات الاسفلت Asphalt Uses of

التركيب الكيميائي للاسفلت Chemical Composition of Asphalt