Building a high-integrity ammonia storage tank—1988

In late 1984, initial work began on preparing a project to install atmospheric ammonia storage at DuPont's Victoria, Texas plant. This storage was to supplement the existing ammonia spheres. In the aftermath of Bhopal and, in light of DuPont's response to that incident, the project focus was changed to one of replacing all pressurized ammonia storage and rail car unloading at the site and installing atmospheric ammonia storage of the highest possible integrity. This paper discusses the various phases of the project and the high-integrity design of the storage facilities.     

利用氨吸收电厂烟道气中的CO2及对大气减排CO2的分析

对以氨吸收电厂烟道气中CO2生产碳酸氢铵的技术可行性进行了分析,并从氨的来源、各种合成氨工艺的能源消耗、附带CO2排放情况和碳酸氢铵在土壤中被植物吸收情况等方面进行了综合分析。结果表明,由于以天然气为原料合成氨生产过程中附带CO2排放相对较少,用于吸收电厂烟道气中CO2生产碳酸氢铵肥料,在碳酸氢铵能够有效被植物吸收的前提下能够达到减排CO2的综合效果。     

An accident at a lithuanian fertilizer plant

On March 20, 1989 a tank started to leak spilling large quantities of ammonia which evaporated and caught fire. A layer of warm, unstable ammonia that had accumulated at the bottom of the tank exploded because of the hydrostatic pressure.     

The effect of oxygen and water on stress corrosion cracking of mild steel in liquid and vaporous ammonia

The influence of water and oxygen concentration on stress corrosion cracking of steels in liquid ammonia. Vapor phase cracking in water-inhibited ammonia storage spheres is also discussed.     

改造水塔侧汽提 提高脱氨效率

针对含酚废水处理中水塔自投产后处理水量和脱氨效率一直达不到设计指标的实际运行状况,通过对多年运行情况进行分析,得出造成这一状况的主要原因是水塔侧汽提氨冷器冷却面积不足和通量不够,并针对性地采取了改进措施,提高了处理水量和脱氨效率。     

一株反硝化细菌在尾水中的脱氮性能研究

为了提高城市尾水中氮的去除率,优化筛选出一株好氧同步硝化-反硝化细菌,通过调整尾水的氨氮浓度,研究其在不同氨氮浓度的尾水中的反硝化能力。结果表明:好氧同步硝化-反硝化细菌FX7h的硝化和反硝化能力较强,在24,48h硝态氮降解率分别达到83.1%和91.1%;在氨氮质量浓度为10mg/L的城市尾水中,总氮、氨氮、硝态氮去除效果最明显,去除率分别为56.9%,70.2%,91.1%;亚硝态氮出现累积,累积率为20%;氨氮质量浓度为15,25mg/L条件下,总氮与氨氮去除效果明显降低;在25mg/L条件下,亚硝态去除率增加,硝态氮去除率不明显。因此,好氧同步硝化-反硝化细菌FX7h在氨氮质量浓度为10mg/L的城市尾水中进行异养硝化和好氧反硝化作用的效果最好,其在实验过程中以去除氨态氮为主。所采用的细菌脱氮方法与传统的生物脱氮相比具有节约运行成本、耐氧性好、平衡pH值等优势,有着广阔的应用前景。     

酞菁蓝颜料生产废水中铜和氨氮回收工艺的试验研究

酞菁蓝颜料生产废水酸性强,铜和氨氮浓度高,处理难度大.采用铁粉置换法回收铜,用化学沉淀剂(镁盐和磷酸盐)可去除废水中的氨氮,并得到有用的磷酸铵镁复合肥料,从而实现了环境效益和经济效益的统一.     

MBBR悬浮填料低温处理生活污水对比实验研究

悬浮填料是MBBR工艺处理污水的核心技术,也是填料性能工艺效果和工程成本的关键因素。采用自主研发的高亲水、低成本高分子合金材料,制备成蜂窝状悬浮填料,并与国内具有代表性的3种悬浮填料进行了性能对比实验研究。实验结果表明,MBBR工艺条件下,使用自制悬浮填料其亲水性、挂膜启动时间以及低温COD、氨氮降解效果具有优势;30%(体积分数)填充率的条件下,低温氨氮去除率达99%(质量分数),出水氨氮小于1 mg/L(质量浓度)。     

厌氧氨氧化反应器的启动与运行研究

将具有厌氧氨氧化活性的污泥与厌氧颗粒污泥按2∶1比例混合,作为接种污泥,成功启动了厌氧氨氧化反应器,并讨论了容积负荷、溶解氧对反应器运行的影响。试验表明厌氧氨氧化反应器具有良好的耐容积负荷冲击性。当氨氮容积负荷、总氮容积负荷从分别平均为32.78 mg/(L.d),78.62 mg/(L.d)提高到分别平均为78.55 mg/(L.d),180.16 mg/(L.d)时,氨氮、总氮去除率从分别平均为71.20%,66.65%经小幅下降后回升到分别平均为62.11%和56.59%;试验进水存在溶解氧时,NH4+-N去除量与NO2--N去除量的实际比值(1∶1.27)高于理论比值1∶1.32),厌氧氨氧化反应器内同时发生好氧氨氧化反应和厌氧氨氧化反应,厌氧氨氧化反应为主导反应。     

Positive pressure testing system (PPTS)

A positive pressure testing system for primary reformers, auxiliary boilers and start-up heaters in ammonia plants to provide a reliable, positive method of testing.     

Causes of ammonia plant shutdowns survey V

The onstream factor for large tonnage ammonia plants has plummeted to 80.8 percent as inventory control and feedstock curtailment cause almost fifty percent of total downtime.     

Ammonia vessel integrity program: A modern approach

The probability of fracture of an ammonia storage vessel due to stress cracking can be calculated based on the vessel's likelihood of failure.     

Foam system design for ammonia storage tank areas

Foam application is a successful method of reducing the release of vapors from anhydrous ammonia spills. It is a simple process also proving to be the most economical.     

Damage to and replacement of an ammonia storage tank foundation

An ammonia tank foundation suffered structural damage and was replaced. While foundation damage, soil freezing and tank movement were apparent, the failure-triggering event remains inconclusive though theorized to have been of seismic origin.     

Metallurgical examination of existing piping in an ammonia plant

Based on their previous problems and recent experiences at other ammonia plants, Columbia Nitrogen decided to inspect all high alloy piping containing hydrogen to determine if proper metallurgy had been used in piping and welds.     

Introduction to expert systems and potential ammonia plant applications

A conceptual approach for applying expert systems to ammonia plants, on an off-line basis, is discussed. These systems can be used for plant problem diagnostics, operator training, safety studies, and risk analysis.     

HAZOP-proof ammonia plant: A new way of defining a safe and reliable design

This new technique, which meets interacting design criteria of a 1,800-MTPD ammonia project, offers special safety features and withstands a detailed HAZOP study.     

An ammonia storage tank study

An in-depth hazards review and subsequent field work on a 20-year-old ammonia tank are discussed, as well as a new method used to change tank valves. Included are a risk assessment of critical piping and a fracture mechanic study of the tank.     

The behavior of denser than air ammonia in the presence of obstacles—wind tunnel experiments

In case of the release of pressurized liquid ammonia, a heavier than air gas cloud can be formed. It was found that the dispersion is very strongly influenced by the presence of obstacles.     

Problems with leakages at large flanges in the BASF new ammonia plant

Leakage from large diameter flanges had occurred several times in a new 1360 t/d ammonia plant. One such incident resulted in a large fire. The causes of this incident are examined.