Implementing a PSM in a New Ethylene Production Project Pablo Ricardo Barrera Braskem – South Basic Petrochemical Unit (UNIB-RS) Porto Alegre, Rio Grande do Sul, Brazil [email protected] ABSTRACT The process safety management in a petrochemical company is a key factor for sustainability, since it is intended to prevent or minimize the consequences of a major accident due to a release of toxic, reactive, flammable or explosive substance from a process. This work aims to present an approach to implement a Process Safety Management (PSM) in the project of a new Ethylene plant that will be constructed at Braskem - Basic Petrochemical Unit in the South Petrochemical Complex, Brazil and was conceived to produce Ethylene in an Ethanol basis. The start-up is schedule for September/2010. All the 13 elements of the PSM proposed for this plant were based on OSHA 3132 (29 CFR 1910.119) and have being considered in each phase of the Enterprise: design, pre-startup and operating phase. The relation between these elements is also presented, the chronology of implementation and the expected results for each phase. The incorporation of current practices, considering the 27 and 10 year experience of two existing Ethylene units (naphtha basis), such as technical standards, operational and management practices, is also considered an important synergy factor. 1 INTRODUCTION The process safety management in a petrochemical company is a key factor for sustainability, since it is intended to prevent or minimize the consequences of a major accident due to a release of toxic, reactive, flammable or explosive substance from a process. Braskem, the leading petrochemical company in Latin America, is committed, since its foundation, to act in accordance with the principles of sustainable development. Thus, we decided to build a new ethylene plant from a renewable raw material, ethanol, instead of traditional plants that use naphtha and condensate. The startup is schedule to September 2010. The implementation of the process safety management in all phases of the project, starting with conceptual design, is a key factor to the success of the enterprise. 2 PROCESS SAFETY MANAGEMENT The following is a schematic representation where the elements of the PSM are presented in 4 dimensions: Documentation, Analysis, Plans and procedures, Qualification. The elements were divided between the pre-startup, startup and normal operation. The relationship between the elements is also presented. Figure 1- Pre-startup phase. Figure 2- Transition from pre-startup to operation phase Figure 3- Operation phase and the learning process 2.1 Process Safety Information The new ethylene plant used as a technological route the catalytic dehydration of ethanol, and the basis of design was obtained from a similar plant, which was built in the 60th on a site of Braskem in Maceió-Alagoas and now is deactivated. An extensive review of the project was undertaken in order to update it in accordance of current engineering standards. New process flow diagrams (PFD) including material and energy balances, piping and instrument diagrams (P&Id) and data sheet of equipments are examples of documentation that were prepared. In this step, an important factor was the incorporation of Best Practices considering the 27 and 10 year experience of two existing Ethylene units (naphtha basis), such as technical standards, operational and management practices. Examples of these improvements include: 1 Adoption of closed drainage systems (sumps) 2 SDCD (philosophy and standard) 3 Strategy for control and protection of compressors (ethylene and propylene refrigerant) 4 Standard for emergencies combat system (fixed protection) 2.2 Process Hazard Analysis The project went through an extensive and systematic risk analysis that began with a preliminary hazard analysis, which involved more than 500 risk scenarios. This step was performed after the completion of the conceptual engineering design. By the end of Basic Engineering, extensive HAZOP studies were conducted resulting in more than 1000 risk scenarios and 300 recommendations for risk mitigation. For those risk scenarios that presented safety instrumented system (SIS) as a safeguard, Safety Integrity Level (SIL) studies were performed. Figure 4- Risk Matrix for Outside Battery Limit (OSBL) PHA studies Another important study was a quantitative risk analysis to determine the best location of the new large (3000 m3) ethylene storage sphere. There were three possibilities, two behind the current cryogenic ethylene tanks and another one near the park spheres. After this analysis the location was chosen based on financial risks associated. Industrial area 3 Position 2 (Sphere) Position 3 (Sphere) Industrial area 4 Industrial area 2 Tank area 2 Pumps Industrial area 5 Industrial area 1 Tank area 1 Tank area 3 Pumps Position 1 (Sphere) Figure 5- Alternative positions for ethylene storage sphere 2.3 Operating Procedures Operating procedures are being developed, considering the result of these two previous steps: Process Hazard Analysis and Process safety information. These procedures will meet all requirements of OSHA 3132 (PSM) and covers: - Commissioning; - Initial startup; - Normal operations; - Emergency operations including shutdown; - Normal shutdown; and - Startup following a turnaround, or after an emergency shutdown. Figure 6- Schematic model of Emergency Operating Procedure (example) 2.4 Emergency Planning and Response The UNIB-RS has a complete and comprehensive system of planning and response to emergencies, consisting of: - Material resources: firewater system, fire fighting vehicles and other emergency devices; - Human resources: professionally trained fire response personnel shift divided in administrative and shift staff; - Procedures: pre planning and emergency procedures in ISO format. For the new plant, was necessary to expand the firefighting water system, and the development of new procedures for emergency response (pre-planning) specific to the new plant, especially to emergency response involving ethanol scenarios, which is a polar substance, different of most hydrocarbons, which are nonpolar. PRÉ PLANO DE EMERGÊNCIA PCEM EQUIPAMENTO DADOS DO EQUIPAMENTO • Diâmetro interno:4.40mt •Comprimento:13.20m • Volume total vaso: 223.2m³ • Volume fase líquida (60%): 130m³ • PSV: alívio para flare. 14V54 • Sentido predominante dos ventos: SUDESTE • Itinerário: RUAS N, 19, M, 18. • Ruas à isolar: 16/G-19/F-21A/G-N/16-N/21A DADOS FISICO-QUÍMICOS • Produto: PROPENO (GÁS) • P.F. (ºC): -108 ºC • Temp. de Ignição (ºC): 497 ºC • Densidade do Líquido (água=1): 0,514 (a 1 atm) • Densidade Vapor (ar=1): 1,46 • Temp. de Armazenamento (ºC): 38ºC (LIQUÍDO) • Pressão de Trabalho: 19Kgf/cm² • Solubilidade em água: APRECIÁVEL • Limites de explosividade: 2,4 % - 10,1% • Fórmula: C3H6 • Temp. crítica: 91,8ºC RECURSOS NECESSÁRIOS RECURSOS MATERIAIS • 01 válvula de abertura dos spray’s do • proteção respiratória ( + 06) 14V54/57 entre 13R02A e rua “19” . • 02 Bombas de AF com • 02 hidrantes canhões e 01 hidrante vazão de 925 m³/h – Pressão canhão de 04 bocais na rua 18. de 12.6kgf/cm². • 02 canhões willians. • 01 ambulância.(preventivo). • 02 margaridas no pipe rack área 14 • Viatura líder. • 02 mangueira de 2 ½”, 08 mangueiras de 1 • 01 VGE (preventivo) ½”, 04 chaves união storz, 02 derivantes e 04 esguichos de 1 ½” no total. TOXICIDADE • ONU: 1077 (Gás) • LT: asfixiante simples • Classe: 2,3 •Ação no organismo: (causa queimadura (fase liquída) nos olhos, pele, e trato respiratório. Em ambiente confinado, concentrações altas diminui o oxigênio e em concentrações menores causa dor de cabeça e tonturas. RECURSOS HUMANOS • 13 brigadistas da OE Turno. (01motorista da VGE, 01 brigadista para acionar spray´s, 01 líder intervenção e 01 líder resgate,02 coordenadores (líder executivo, coordenador geral) 06 brigadista para linha padrão e/ou canhões. • 01 motorista ambulância. CENÁRIOS ACIDENTAIS / AÇÃO VAZAMENTO EM QUALQUER UM DOS FLANGES JUNTO AO VASO: • Acionar sistema de sprays para, contenção e diluição do gás; • Tentar reaperto do flange se possível, caso contrário, parar 14C01 e 14C21; • Isolar vaso através da 14MOV04 • Despressurizar o vaso enviando produto (fase líquida) através da linha de fundo para 14V51/52/53 e fase gasosa para flare via PSV's e 14PV86; • Injeção de N2; • Aplicar neblina d'água para diluição do gás nas áreas adjacentes; • Avaliar o deslocamento da nuvem de gás, isolar a área e orientar evasão num raio aproximado de 500m; VAZAMENTO SEGUIDO DE FOGO: • Acionar sistema de sprays na rua 19, para refrigeração do vaso em emergência e do vaso vizinho; • Não apagar o fogo; • Tentar reduzir sua intensidade com aplicação de neblina d'água ou diminuindo a pressão interna do vaso enviando produto (fase líquida) através da linha de fundo para 14V51/52/53 e fase gasosa para flare via PSV's e 14PV86; • Parar 14C01 e 14C21; • Isolar vaso através da 14MOV04; • Posicionar o Posto de Comando na rua "M" com 18 e orientar os isolamentos de ruas e definição das Zonas de Ação; • Observar constantemente o resfriamento do vaso com fogo e o vaso vizinho; EXPLOSÃO DE NUVEM DE GÁS: • • • • Parada imediata da produção e abandono de área. Acionar alarme de emergência "Abandono de Área". Avisar as demais áreas. Reavaliar as consequências após explosão e controlar os incêndios secundários(efeito dominó). • • INCÊNDIO TIPO JATO DE FOGO(FLASH FIRE). Avaliar se há vazamento e eliminá-lo. Figure 7- Schematic model of Pre Planning (example) 2.5 Pre startup safety review For this project two Design Review are scheduled, which aims to verify if the safety aspects are properly addressed, such as recommendations coming from the HAZOP studies and if the Detailed engineering is being conducted in accordance with the specifications of Basic engineering. Two Pre startup safety review will also take place, the first one when project implementation is around 60% and another with 95%, in order to verify if implementation of the project, Construction and equipment are in accordance with design specifications allowing the plant for startup. 2.6 Training For the project, an extensive and comprehensive systematic of training will be conducted considered all the information compiled in the previous steps. 2.7 Other elements Again, it is possible to highlight the synergy achieved by the installation of new plant in a petrochemical complex that already has two ethylene production units. The new plant will be inserted in a context where PSM elements such as Mechanical Integrity, Work Permit, Management of Change, Incidents investigation and Compliance audits, have already established and in use practices. 3 CONCLUSION Consider the implementation of management tools such as the PSM since the beginning of a project becomes an imperative key factor for projects success. All the initial and structured planning in process safety, reduce project costs, and also ensures a reliable and safe operation.