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

The establishment of environmental criteria, in addition to economic ones, are important for the development of hydrocarbon storage tank projects to minimize the environmental impact of tank parks due to the fugitive emission of VOCs. In this context, the objective of this study was to propose a preliminary analysis that considers financial costs, technical and structural safety, as well as the environmental impact of tank sizing. The analysis also included suggestions for accessories that improve the tank's performance and promote the reduction of energy losses and fugitive emissions from the tank throughout its useful life. In this way, the tank design parameters were organized to establish a methodology for the project that considered in its development, the normative framework, the product characteristics, the construction materials and boundary conditions (accessories for performance improvement), without forgetting the environmental impacts. This analysis will enable the dimensioning of equipment with adequate costs in its construction (financial criterion), guarantee of durability during its period of operation (technical criteria) of operation and better energy conditions (environmental criteria), bringing environmental and economic gains throughout its operation. In this sense, this study presents some important guidelines in relation to the framework in technical standards; product features; material selection, accessories for performance improvement; painting; adequate selection of the irradiation area to contemplate the environmental criteria in the design of hydrocarbon storage tanks. II. E stablishment of D esign C riteria for S torage T anks When checking the construction standards for tanks, the design criteria for the equipment are predominantly functional and economic, with no emphasis on issues related to air pollution caused by emissions related to this equipment. The evaluation of VOC emissions in different types of hydrocarbon storage tanks indicates that the application of some constructive criteria can represent considerable environmental advantages, with associated economic advantages. a) Criterion in Relation to Compliance with Technical Standards Atmospheric tanks have a wide range of applications, and their designs range from small low- volume tanks (from 1 to 100 m³) used in small industries for storing small amounts of oil, chemical products and even water to large volume tanks (above 60,000 m³) applied to the petrochemical, oil and gas industry. Therefore, it is essential to have a correct normative framework to establish a project optimized. Among the most widely used and well-known Brazilian standards for tank design, the NBR-7821 is cited (ABNT, 1983) and the complementary standard N-270 (PETROBRÁS, 2020), Petrobras' internal standard, which is most used as a reference. In addition to these, the standards of the American Petroleum Institute, USA, API-650 (API, 2010) and API-653 (API, 2009) are considered, the first being aimed at new projects and the second for tank renovations. These four standards deal specifically with tanks for the oil and gas industry. However, in addition to these four standards, we can also cite other standards, such as the American standard NFPA 22 (NFPA, 2013) for tanks of fire-fighting systems, the European standard EN-1993-4-2 (EN, 1999) and the American standard AWWA D-100-96 (AWWA, 1997) intended for water storage tanks. These standards apply only to welded tanks, there are also specific standards for bolted, riveted, helical mounting and “Australian” type tanks. In these standards, the methodology and calculation have the same technical basis. In general, the hydrostatic pressure of the product to be stored is related to the mechanical resistance of the thickness of the cylindrical body of the tank. What differentiates the standards is the safety factor adopted by the standard, which normally allows for the determination of minimum working thicknesses of the tank. With the exception of the EN-1993-4-2 (EN, 1999) standard, which, in addition to basic calculations, allows for a more refined dimensioning since it considers the calculation of resistance by finite elements that allows a more precise calculation when performed by experienced designers, as it does not apply simplifications common in standards to its design, which, as they always work with a safety margin, normally end up over-dimensioning the project. Therefore, observe it should be noted that, for each tank application, the standard that best fits its functionality must be correctly selected, in order not to oversize the tank thicknesses when applying a more rigorous standard, incurring in greater consumption of metal for the construction of the tank and unnecessary costs. In this way, the use of an adequate standard makes the project sustainable and of lower cost. The study of the cited norms provided the elaboration of Table 1, which allows a comprehensive vision and an initial reference for the analysis of the designer. In this analysis, it was considered that small tanks are those with a capacity of less than 200 m³. This type of tank can be purchased ready-made, that is, without the need for assembly at the installation site. Global Journal of Researches in Engineering © 2023 Global Journals ( ) E Volume XxXIII Issue II Version I 2 Year 2023 Atmospheric Storage Cylindrical Tanks: Project Optimization Considering Environmental Criteria