石油炼制的环境、健康和安全指南（英文版）.pdf

ENVIRONMENTAL, HEALTH, AND SAFETY GUIDELINES PETROLEUM REFINING November 17, 2016 1 ENVIRONMENTAL, HEALTH, AND SAFETY GUIDELINES FOR PETROLEUM REFINING INTRODUCTION 1. The Environmental, Health, and Safety (EHS) Guidelines are technical reference documents with general and industry-specific examples of Good International Industry Practice (GIIP).1 When one or more members of the World Bank Group are involved in a project, these EHS Guidelines are applied as required by their respective policies and standards. These industry sector EHS Guidelines are designed to be used together with the General EHS Guidelines document, which provides guidance to users on common EHS issues potentially applicable to all industry sectors. For complex projects, use of multiple industry sector guidelines may be necessary. A complete list of industry sector guidelines can be found at: ifc/ehsguidelines. 2. The EHS Guidelines contain the performance levels and measures that are generally considered to be achievable in new facilities by existing technology at reasonable costs. Application of the EHS Guidelines to existing facilities may involve the establishment of site-specific targets, with an appropriate timetable for achieving them. 3. The applicability of the EHS Guidelines should be tailored to the hazards and risks established for each project on the basis of the results of an environmental assessment in which site-specific variablessuch as host country context, assimilative capacity of the environment, and other project factorsare taken into account. The applicability of specific technical recommendations should be based on the professional opinion of qualified and experienced persons. 4. When host country regulations differ from the levels and measures presented in the EHS Guidelines, projects are expected to achieve whichever is more stringent. If less stringent levels or measures than those provided in these EHS Guidelines are appropriate, in view of specific project circumstances, a full and detailed justification for any proposed alternatives is needed as part of the site-specific environmental assessment. This justification should demonstrate that the choice for any alternate performance levels is protective of human health and the environment. APPLICABILITY 5. The EHS Guidelines for Petroleum Refining cover processing operations from raw crude oil to finished products, for example refinery fuel gas, liquefied petroleum gas (LPG), motor gasoline (Mo-Gas), kerosene, diesel oil, heating oil, fuel oil, bitumen, asphalt, lubricant oils, waxes, sulfur, pet-coke, and intermediate products (e.g., propane/propylene mixtures, virgin naphtha, middle distillate and vacuum distillate, aromatics) for the petrochemical industry. Annex A contains a description of industry activities. 1 Defined as the exercise of professional skill, diligence, prudence and foresight that would be reasonably expected from skilled and experienced professionals engaged in the same type of undertaking under the same or similar circumstances globally. The circumstances that skilled and experienced professionals may find when evaluating the range of pollution prevention and control techniques available to a project may include, but are not limited to, varying levels of environmental degradation and environmental assimilative capacity, as well as varying levels of financial and technical feasibility. ENVIRONMENTAL, HEALTH, AND SAFETY GUIDELINES PETROLEUM REFINING November 17, 2016 2 Further information on EHS issues related to storage tank farms is provided in the EHS Guidelines for Crude Oil and Petroleum Product Terminals. This document is organized in the following manner: 1. Industry-Specific Impacts and Management . 2 1.1 Environment . 2 1.2 Occupational Health and Safety . 13 1.3 Community Health and Safety . 17 2. Performance Indicators Monitoring . 18 2.1 Environment . 18 2.2 Occupational Health and Safety . 21 3. References . 23 Annex A. General Description of Petroleum Industry Activities . 26 1. INDUSTRY-SPECIFIC IMPACTS AND MANAGEMENT 6. The following section provides a summary of the EHS issues that may arise during the operational phase of petroleum refining, along with recommendations for their management. Recommendations for the management of EHS issues common to most large industrial facilities during the construction and decommissioning phases are provided in the General EHS Guidelines. 1.1 Environment 7. Environmental issues associated with petroleum refining include the following: Emissions to atmosphere; Handling and disposal of process wastewater (storage, transportation, and treatment); Handling of hazardous materials and wastes; and Noise from operating machinery. Emissions to Atmosphere Flue Gases 8. Flue gas emissions to the atmosphere of carbon dioxide (CO2), nitrogen oxides (NOx), sulfur oxides (SOx), carbon monoxide (CO), and particulate matter (PM) in the petroleum refining sector result from the combustion of gas and oil in gas turbines, boilers, engines, and process heaters for power, steam, and heat generation. Flue gas can also be emitted from waste heat boilers associated with some process units during continuous catalyst regeneration (CCR) or fluid petroleum coke combustion. For example, flue gas is emitted from the stack to the atmosphere in the Bitumen Blowing Unit (BBU), from the catalyst regenerator in both the Fluid Catalytic Cracking Unit (FCCU) and the Residue Catalytic Cracking Unit (RCCU), and in the sulfur recovery unit (SRU), possibly also containing small amounts of SOx and hydrogen sulfide (H2S). ENVIRONMENTAL, HEALTH, AND SAFETY GUIDELINES PETROLEUM REFINING November 17, 2016 3 9. Guidance for the management of small combustion source emissions with a capacity of up to 50 megawatt thermal (MWth), including air emission standards for exhaust emissions, is provided in the General EHS Guidelines. For combustion source emissions such as boilers, engines, and turbines with a capacity greater than 50 MWth, refer to the EHS Guidelines for Thermal Power Plants. 10. For process heaters, the following primary pollution prevention and control measures should be considered: Installation of combustion air preheaters, to increase furnace efficiency; Optimization of furnace operations, and hence combustion efficiency, by continuous monitoring and advanced control of the operations variables (temperature and oxygen concentration of flue gas for combustion optimization air/fuel ratio for the fuel mix; optimizing excess air to minimize heat losses via unburned gases or unburned residues); High-thermal-efficiency heater designs with good control systems (e.g., oxygen trim); Prevention of the condensation of exhaust gas on surfaces; Minimization of power requirements by use of high-efficiency pumps, fans, and other equipment; Techniques to control CO emissions, such as good operation and control, constant delivery of liquid fuel in the secondary heating, good mixing of the exhaust gases, and catalytic afterburning; Regular cleaning of heating surface (soot blowing) for liquid fuel or mixed firing; and High-emissivity refractories for radiant heat transfer improvement, e.g., by application of ceramic coatings as reflecting surfaces. Venting and Flaring 11. Venting and flaring are important operational and safety measures used in petroleum refining facilities, particularly during non-routine operational periods such as malfunction or upset, as a means of safely disposing of vapors. Hydrocarbons are emitted from emergency process vents and safety valve discharges. These are collected in the blow-down network that is flared. 12. For planned start-up and shutdown, a flare gas recovery system should be used. During non-emergency releases, excess gas from process vents should be recovered or controlled and the volume of gas to be flared should be minimized. 13. Flaring modifies, by means of combustion, the chemical nature of the emitted substances (e.g., the combustion of H2S generates sulfur dioxide (SO2), while the combustion of hydrocarbon generates CO2 plus water vapor). Monitoring of gas emissions should encompass both the concentration of pollutants at ground level as well the total quantity of pollutants released annually. Before flaring is adopted, feasible alternatives for the use of the gas should be evaluated andwhere practical, reasonable, and safeintegrated into production design to the maximum extent possible. Flaring volumes for new facilities should be estimated during the initial commissioning period so that fixed-volume flaring targets can be developed. The volumes of gas flared for all flaring activities should be recorded. Flare management plans should be prepared and implemented.2 2 Such as; U.S. EPA, 40 CFR 60 Standard of Performance for New Stationary Sources- Subpart Ja (2015). ENVIRONMENTAL, HEALTH, AND SAFETY GUIDELINES PETROLEUM REFINING November 17, 2016 4 14. The following pollution prevention and control measures should be considered for gas flaring: Implementing source gas reduction measures to the maximum extent possible; Using efficient flare tips (i.e., optimal released gas sonic velocity, in order to avoid malfunctioning of the flare due to its flame off), and optimization of the size and number of burner nozzles (not less than three, which will ensureacting as pilot burners, positioned 120 from each otherthe continuity of flaring); Maximizing flare combustion efficiency by controlling and optimizing flare fuel/air/steam flow rates to ensure the correct ratio of assist stream to flare stream; Minimizing flaring from purges and pilots, without compromising safety, through measures including the installation of purge gas reduction devices, flare gas recovery units (mainly for continuous or predictable releases), an upstream knock-out drum (vaporliquid separator used to avoid entrainment of liquid to the flare stack), soft-seat valve technology (where appropriate), conservation pilots, the use of inert purge gas, and the diversion of flows into the refinery fuel gas distribution network; Minimizing the risk of pilot blow-out by ensuring sufficient exit tip velocity and providing wind guards; Using a reliable pilot auto-ignition system; Installing high-integrity instrument pressure protection systems, where appropriate, to reduce over-pressure events and avoid or reduce flaring situations; Minimizing liquid carry-over and entrainment in the gas flare stream with a suitable liquid separation system; Minimizing flame lift (flash off) and flame lick (flash back); Operating flares to control odor and visible smoke emissions using suitable optical instruments, such as flame detectors, which act on the steam injection in case of black smoke at tip; Locating flares at a safe distance from local communities and the workforce, including workers accommodation units; Implementing burner maintenance planning and replacement programs to ensure continuous maximum flare efficiency; Metering flare gas on a monthly basis in the interest of pollution evaluation, mainly in terms of CO2 and SO2, as well as of released heat (which is an indirect estimation of the greenhouse gas (GHG) emissions); Avoiding over-steaming, as too much steam in a flare will reduce flare performance; Avoiding a wake-dominated flame. A strong crosswind at high velocity can have a powerful effect on the flares flame dimensions and shape, causing the flame to be wake-dominated (i.e., the flame is bent over on the downwind side of a flare and imbedded in the wake of the flare tip), reducing flare performance and potentially damaging the flare tip; and Avoiding flame lift-off, a condition in which a flame separates from the tip of the flare and there is space between the flare tip and the bottom of the flame due to excessive air induction as a result of the flare gas and center steam exit velocities. This type of flame can reduce flare performance and can progress to a condition where the flame becomes completely extinguished. ENVIRONMENTAL, HEALTH, AND SAFETY GUIDELINES PETROLEUM REFINING November 17, 2016 5 15. To minimize flaring events as a result of equipment breakdowns and plant upsets, plant reliability should be high (95 percent). Provisions should be made for taking equipment offline for planned maintenance regimes and plant turnaround protocols, to the extent that the refinery does not exceed 8,000 operating hours/year (corresponding to one month/year of refinery-planned shut-down for general maintenance). This means achieving a Refinery Service Factor of 91 percent (or 8,000 operating hours/24 hours per day x 365 days= 0.91). Fugitive Emissions 16. Fugitive emissions in petroleum-refining facilities may occur from leaking tubing, valves, connections, flanges, gaskets, steam traps, packing, open-ended lines, floating roof storage tanks and pump seals, gas conveyance systems, compressor seals, pressure relief valves, breathing valves, tanks or open pits/containments, oil-water separators, and in the storage, loading, and unloading operations of hydrocarbons. Depending on the refinery process scheme, fugitive emissions may comprise: Hydrogen; Methane; Volatile organic compounds (VOCs), (e.g., ethane, ethylene, propane, propylene, butanes, butylenes, pentanes, pentenes, C6-C9 alkylate, benzene, toluene, xylenes, phenol, and C9 aromatics); Polycyclic aromatic hydrocarbons (PAHs) and other semi-VOCs; Inorganic gases, including ammonia (NH3), CO, CO2, SO2 and sulfur trioxide (SO3) from sulfuric acid regeneration in the sulfuric acid alkylation process, NOx, methyl tertiary butyl ether (MTBE), ethyl tertiary butyl ether (ETBE), t-amylmethyl ether (TAME), methanol, and ethanol; and If occurring, hydrofluoric acid (HF) from hydrogen fluoride alkylation and H2S. 17. There is significant potential for VOC emissions from cone-roof storage tanks during loading due to fugitive releases from the out-breathing valves; fugitive emissions of hydrocarbons through the roof seals