年产23万合成氨变换工段工艺设计

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摘要：氨是重要的基础化工产品之一，在国民经济中占有重要地位。合成氨生产经过多年的发展，现已发展成为一种成熟的化工生产工艺[1]。

本设计是以天然气为原料年产二十三万吨合成氨转变工序的设计。近年来合成氨工业发展很快，大型化、低能耗、清洁生产均是合成氨设备发展的主流，技术改进主要方向是开发性能更好的催化剂、降低氨合成压力、开发新的原料气净化方法、降低燃料消耗、回收和合理利用低位热能等方面上。61925

设计采用的工艺流程简介：天然气经过脱硫压缩进入一段转化炉，把CH4和烃类转化成H2，再经过二段炉进一步转化后换热进入高变炉，在催化剂作用下大部分CO和水蒸气反应获H2和CO2，再经过低变炉使CO降到合格水平，去甲烷化工序。

本设计综述部分主要阐述了国内外合成氨工业的现状及发展趋势以及工艺流程、参数的确定和选择，论述了建厂的选址；介绍了氨变换工序的各种流程并确定本设计高-低变串联的流程。工艺计算部分主要包括转化段和变换段的物料衡算、热量衡算、平衡温距及空速计算。设备计算部分主要是高变炉催化剂用量的具体计算，并根据设计任务做了转化和变换工序带控制点的工艺流程图。

本设计的优点在于选择较为良好的厂址和原料路线，确定良好的工艺条件、合理的催化剂和能源综合利用。另外，就是尽量减少设备投资费用[6]。

毕业论文关键字：合成氨；天然气；转化；变换；

Ammonia (230 thousand tons annually) carbon monoxide transform process design section

Abstract: Ammonia is the most important one of basic chemical products, plays an important role in the national economy. Ammonia production after years of development, now has developed into a mature chemical production processes[20].

The design is based on annual output of 230,000 tons of natural gas as raw material, the design of synthetic ammonia transformation process. In recent years, the large-scale industrial development soon ammonia, low energy consumption, the clean production of synthetic ammonia equipment development are the main direction of technical improvement, is to develop better performance of catalyst, reducing ammonia synthesis pressure, the development of new materials gas purification methods, reduce fuel consumption, low heat recovery and reasonable utilization, etc.

The design process used in brief are: compressed natural gas after desulfurization and conversion into a furnace, the methane and hydrocarbons into hydrogen, through the Secondary reformer further transformed into the highly variable furnace heat exchanger, the great catalyst part of the reaction of carbon monoxide and hydrogen and carbon dioxide vapor, then through the low-temperature shift to reduce to an acceptable level of carbon monoxide to methanation process[21].

The design review described some of the major domestic and international situation and the development of synthetic ammonia industry trends and technological process, parameter identification and selection, discusses the plant's location; introduced the transformation process of the various processes and determine the design of high temperature shift and low temperature Transformation series of the process. Calculation of some of the major transformation process, including segment and transform section material balance, heat balance, equilibrium temperature and airspeed calculation. Calculation of some of the major equipment is a high temperature shift catalyst of specific terms[23], and according to the design task to do the conversion and transformation process flow chart with control points.

Advantage of this design is to choose a better site and raw materials line to determine the good conditions, reasonable catalyst and energy utilization. In addition, investment in equipment designed to minimize costs.