Global Journal of Researches in Engineering, E: Civil & Structural, Volume 23 Issue 2

Table 4: Influence of tank color to reduce losses from VOC Emissions Product Roof type Color Relevance Gasoline Fixed White H External Floating A Internal Floating A Diesel Fixed White A External Floating White or Gray L Internal Floating White or Gray L Crude Oil Fixed White A External Floating A Internal Floating A H – High Relevance // A – Average Relevance // Low Relevance Source: Adapted from Castilho (2023) ii. Evaluation of the Solar Irradiation Area The solar irradiation area is obtained by evaluating the diameter/height ratio of the storage tank. With this analysis, it was concluded that, for the same volume, tanks with a smaller diameter/height ratio – smaller area of solar irradiation – provide reductions in VOC emissions. According to Castilho et al (2023) the reduction of emissions in gasoline storage tanks was around 40% for tanks with an external floating roof and above 50% in tanks with an internal floating roof. The option for the smallest irradiation area allows the designer to obtain tank dimensions close to those that occupy a smaller surface area. And, therefore, the amount of sheet necessary for the construction of the tank and maintenance of the external coating will be smaller, consequently the cost for the construction of the tank will be lower. According to Castilho et al (2023) the use of tanks with the smallest irradiation area and in the appropriate amount can lead to reductions of up to 80% of VOC emissions in the storage of gasoline and oil in a tank park, regardless of the type of ceiling adopted. III. C onclusions The universe of data and information necessary for the proper sizing of a storage tank is very wide and the current tendency of projects is to use the API-650 and API-653 standards, which are complete standards, but designed for sizing tanks. to be installed in an industry where operational risks are greater and, consequently, the rigor required in sizing is also greater. However, it is observed that, in general, designers do not observe the other existing normative frameworks, which are equally competent in their specialties. This mistaken decision leads to the dimensioning of greater thicknesses, which increases the cost of the storage tank, due to the greater amount of metal for construction, which becomes unnecessary both from an economic and environmental point of view. The sizing criteria, even being a preliminary analysis, will allow tank designers to avoid increasing the construction cost of the tank and minimize the environmental impact due to reduced emissions and energy loss. It is worth mentioning that for some situations of greater risk, such as flammable products, location of installation with unfavorable weather conditions and specificities of the industry, the analysis criteria must be complemented with specific information, however these do not invalidate the criteria proposed in this study. The environmental criteria identified in this study should not override other relevant criteria for the entrepreneur, such as logistics, maintenance, operational facilities and construction or installation. It is recommended that they be evaluated together with these, that is, that tank designs consider emission estimates when deciding on the best constructive alternative. The list of criteria established in this work can also be complemented with the evaluation of other parameters, such as types of sealing, roofs supported by columns, types and number of accessories, relief valves with different pressures and tanks with geodesic fixed roofs according to the designer's assessment deems relevant for specific cases of tank sizing. R eferences R éférences R eferencias 1. ABNT - BRAZILIAN ASSOCIATION OF TECHNICAL STANDARDS. NBR 7821: Welded Tanks for Storing Oil and Derivatives. Standard body, chapters 1 to 13 and annexes: D - Floating ceilings; H - Covered Floating Ceilings. Rio de Janeiro, 1983. 2. ABNT - BRAZILIAN ASSOCIATION OF TECHNICAL STANDARDS. NBR 17505: Storage of Flammable and Combustible Liquids. Rio de Janeiro, 2006. 3. API - American Petroleum Institute. API-2000: Venting Atmospheric and Low-pressure storage Tanks. Standard body, 6th Ed, November, 2009. 4. API - American Petroleum Institute. API-650 Welded Tanks for Oil Storage. Standard body, chapters 1 to 10 and annexes: C - External Floating Roofs; G – Structurally-Supported Aluminum Dome Roofs; H – Internal Folating Roofs. 11th Edition, May, 2010. Global Journal of Researches in Engineering © 2023 Global Journals ( ) E Volume XxXIII Issue II Version I 8 Year 2023 Atmospheric Storage Cylindrical Tanks: Project Optimization Considering Environmental Criteria