Acid tank project

The intentions to improve the environment were noble, but the simple vent system design possessed an unrecognized flaw that allowed a minor overfill situation to suddenly and completely destroy the vessel. The acid tank project was rather simple, so the proposal was accepted and no one asked pointed questions like, What happens if the acid storage tank is overfilled by a tank truck (As we shall see, many unforeseen problems have occurred on equipment so simple that a detailed examination of the proposal may have been considered unnecessary in years past.)... 

Part II of the Design Project (Case Study) for the production of nitric acid concerns the design of two main plant units (the NOx absorption column and the steam superheatei), a pump to deliver red product acid from the absorption column to the product bleaching column, and finally a product storage tank. 

To maintain the required residence time, a new reaction tank of 80 m edacity was installed to replace a tank that has been used as a fourth purification step. Also, a pumping tank was refurbished as a reaction tank to replace another one used in this project in the fourth purification step. A calcine feeder was also installed to deliver calcine to the fifth tank, as previously, and to establish a better control over the acidity in this stage. 

On December 13, 1978, a railway tank car of concentrated sulfuric acid (93%) was spilled as a result of a train derailment about 10 km northwest of the town of Springhill, Nova Scotia. The spill caused visible damage to vegetation over a limited area. In the fall of 1985, seven growing seasons after the spill. Environment Canada contracted MacLaren Plansearch Limited, in association with P. Lane and Associates Limited, to undertake a study to document the effects of the spill and make recommendations on appropriate response measures for future spills of sulfuric acid (Environment Canada, 1986). Some Environment Canada scientists were also involved in the research project. This spill and the results of the study are discussed in Section 35.8.2. 

An unaccelerated, low viscosity, flame retardant (<25 ASTM E-84 with 3% antimony trioxide) and corrosion resistant (acidic and alkaline environments), styrenated vinyl ester offering high strength and excellent impact strength and toughness, suitable for hand-lay, spray/projection lamination in the manufacture of tanks, pipes, ducts, stacks, scrubbers and linings. 

More recent pilot plant data are available from the Coal Gasification/Gas Cleaning Test Facility at North Carolina State University (Ferrell et al., 1987). The acid gas removal system includes a gas absorption column, one or more flash tanks for intermediate pressure reduction, and a packed stripping column operated with a reboiler. Both of the columns are packed with 0.25-in. ceramic Intalox saddles. The project included the development of a system model and simulation program covering absorption, flashing, and stripping. 

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