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BP Texas City Story
Crude oil is a complex mixture of thousands of different hydrocarbons and varying amounts of other compounds containing sulphur, nitrogen, and oxygen as well as salts, trace metals, and water. Crude oils can vary from a clear liquid, similar to gasoline, to a thick tar-like material needing to be heated to flow through a pipeline. A petroleum refinery's main job is to split crude oil into its many parts (or fractions) which are then reprocessed into useful products. The type, number, and size of process units required at a particular refinery depends on a variety of factors including the type of crude oil and the products required. The interconnected units making up a refinery are a maze of tanks, furnaces, distillation towers and fractionating columns), reactors, heat exchangers, pumps, pipes, fittings, and valves.
Products of crude oil refineries include• fuels such as gasoline, diesel fuel, heating oil, kerosene, jet fuel, bunker fuel oil, and liquefied petroleum gas• petroleum solvents including benzene, toluene, xylene, hexane, and heptanes, which are used in paint thinners, dry-cleaning solvents, degreasers, and pesticide solvents• lubricating oils produced for a variety of purposes, and insulating, hydraulic, and medicinal oils• petroleum wax• greases, which are primarily a mixture of various fillers• asphalt. These products can be hazardous not only in their final state but as they are being processed and refined. Health and Safety Hazards The plant and equipment of refineries are generally modern, and the processes are largely automatic and totally enclosed. Routine operations of the refining processes generally present a low risk of exposure when adequate maintenance is carried out and proper industry standards for design, construction, and operation have been followed. The potential for hazardous exposures always exists, however.
Because of the wide variety of hydrocarbon hazards and their complexity, it is impossible to identify all of the hazards here – and impossible for construction crews to now everything they may need for protection when performing maintenance, repair, or installation work in an oil refinery. As a worker you must depend on the knowledge available from the plant operating and maintenance staff, normally available through your employer. If there is reasonable doubt about a situation in which you find yourself, exercise your “right to know” and make use of whims to obtain the
information, equipment, and procedures necessary to protect yourself and your fellow workers. Hazardous Chemicals In a refinery, hazardous chemicals can come from many sources and in many forms. In crude oil, there are not only the components sought for processing, but impurities such as sulphur, vanadium, and arsenic compounds. The oil is split into many component streams that are further altered and refined to produce the final product range. Most, if not all, of these component stream chemicals are inherently hazardous to humans, as are the other chemicals added during processing. Hazards include fire, explosion, toxicity, corrosiveness, and asphyxiation.
Information on hazardous materials manufactured or stored in a refinery should be supplied by the client's representative when a work permit is issued. Fire and Explosion The principal hazards at refineries are fire and explosion. Refineries process a multitude of products with low flashpoints. Although systems and operating practices are designed to prevent such catastrophes, they can occur. Constant monitoring is therefore required. Safeguards include warning systems, emergency procedures, and permit systems for any kind of hot or other potentially dangerous work. These requirements must be followed by all workers. The use of matches, lighters, cigarettes, and other smoking material is generally banned in the plant excepting specially designated areas. Health and Hygiene Hazards Table 1 highlights major potential air contaminants which can escape from a typical refinery operation and their
major sources. It does not attempt to identify all such possible hazards. Table 2 reviews common hazardous chemicals and
chemical groups typically present and their most significant hazards to workers. Care should be exercised at all times to avoid inhaling
solvent vapors, toxic gases, and other respiratory contaminants. Because of the many hazards from burns and skin contact, most plants require that you wear long sleeved shirts or coveralls. Major Shutdown and Maintenance The principal exposures to hazardous substances occur during shutdown or maintenance work, since these are a deviation from routine operations. Plant turnarounds
require careful planning, scheduling, and step-by-step procedures to make sure that unanticipated exposures do not occur. Any plant shutdown requires a complete plan in writing to cover all activities, the impact on other I REFINERIES AND PETROCHEMICAL PLANTS
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operations, and emergency planning. Plans are normally formulated by plant personnel in conjunction with contractors. Construction personnel should always keep in mind the responsibilities of the various workplace parties under theOccupational Health and Safety Act, the regulations forconstruction projects, and WHMIS legislation. This shouldespecially be considered in the bidding and planning
stages of any contract to ensure that the refinery providesall of the required health and safety information.
Common Hazardous Materials
Table 2 lists common hazardous materials that may beencountered on a refinery site. Note, however, that thetable is not all-inclusive. See the chapters on WHMIS andBasic Occupational Health in this manual.WHMIS labelsand MSDSs provide detailed information for specificproducts.
Maintenance Hazards and Precautions
Tank CleaningHydrogen sulphide is a potential problem in the transportand storage of crude oil. The cleaning of storage tanks
presents a high hazard potential. Many of the otherclassic confined-space entry problems can occur here, including oxygen deficiency resulting from previousinerting procedures, rusting, and oxidation of organic coatings. Carbon monoxide can be present in the inerting
gas. In addition to H2S, depending on the characteristics of the product previously stored in the tanks, other chemicals that may be encountered include metalcarbonyls, arsenic, and tetraethyl lead.“Alky” (Alkylation) UnitThe lightest fraction from the crude unit is first processed in the gas plant. Some of the liquid hydrocarbons from thewet gas are run straight to the gasoline blending plant, but
others go through the alkylation process. These light parts are put together using hydrofluoric acid or sulphuric acidas catalysts.
The main hazards in this process come from possibleexposure to the catalysts, hydrofluoric acid or sulphuricacid, and their dusts, byproducts, and residues as well ashydrogen sulphide, carbon monoxide, heat, and noise.Other processes utilize acid catalysts and caustic“washes.” These can lead to hazardous situations,especially in shutdowns where a contractor's personnelmay be exposed to residues or other contaminants.Information is required from refinery personnel andspecialized training is required in the necessary
OIL REFINERIES AND PETROCHEMICAL PLANTS
Material Dominant Hazard
Additives – usually skin irritantsAmmonia – toxic on inhalationAsbestos – designated substance under constructionregulations. See chapter on asbestos in thismanual.Asphalt – dermatitis (can be photosensitizer)Benzene – designated substance under industrialregulationsCarbon monoxide – toxic on inhalationCaustic soda – corrosive to skin and eyesChlorine – corrosive to skin and tissue on contact orinhalationHBAHs (high boiling – potential carcinogensaromatic hydrocarbons)Hydrofluoric acid – corrosive to skin and tissue on contact orinhalationHydrogen sulphide – toxic on inhalationMEK (methyl – corrosive to skinethyl ketone)Nitrogen – asphyxiantPAHs (polynuclear – potential carcinogensaromatic hydrocarbons)Phenol-acid – corrosive to skin and tissueSilica – designated substance under industrialregulationsSulphuric acid – corrosive to skin and tissue on contact or
inhalationSulphur dioxide – toxic on inhalation
Table 2: Common Table 1 – Major potential air contaminents Hazardous Materials
Air Contaminants Major SourcesHydrocarbon • transfer and loading operationsvapours — • storage tankscompounds of • crude unit, atmospheric, and vacuum towerscarbon (C) and • cracking units (“cat”, hydrocracking, coking–hydrogen (H) polynuclear aromatic hydrocarbons [PAHs]and high-boiling aromatic hydrocarbons[HBAHs] are of concern because of theircarcinogenic potential)• rearranging and combining processes suchas reformers and alkylation units• treating operations• cracking unit regeneration• heat exchangers• boilers and heaters• pumps, valves• cooling towersSulphur dioxide • boilers(SO2) •cracking unit regeneration• treating operations• flaresCarbon monoxide • rearranging and combining processes such(CO) as reformers and alkylation units• catalyst regeneration• flares• boilers• furnacesNitrogen dioxide • flares(NO2) •boilersHydrogen sulphide • sour crudes(H2S) • liquid wastes• pumps• crude tower• cracking operations• rearranging and combining processes suchas reformers and alkylation units• hydrogeneration
Particulates • catalyst dusts – cracking units, catalystregeneration, and rearranging andcombining processes such as reformers andalkylation units
• petroleum coke dust – cracking unitsChlorine (CI or CI2) caustic unitAmmonia (NH3) compressors36 – 3procedures and personal protective equipment, includingits care and use.Confined SpacesOn most jobsites there are potential confined spacehazards. These hazards are multiplied, however, on arefinery site because of the complex collection of tanks,reactors, vessels, and ducts combined with a wide varietyof hazardous chemicals and emissions, often in enclosedareas. Many of these chemicals can produce oxygendeficient,
toxic, or explosive atmospheres. Knowledge ofgeneral confined space procedures and specific in-plantrequirements are both critical in refinery work. For moreinformation, refer to the chapter on Confined Spaces inthis manual.
SafeWork Practices and Procedures
Personnel• Hearing protection and safety glasses must be wornin all operating areas or as posted.• Respiratory protection or quipment must be fittested.Facial hair is unacceptable where the maskmust make an airtight seal against the face.• Shirts must be long-sleeved and worn with full-lengthpants or coveralls.• Clothing must not be of a flammable type such asnylon, Dacron, acrylic, or blends. Fire-resistant typesinclude cotton, Nomex, and Proban.• Other PPE required may include acid hood,impervious outerwear, rubber boots, face shields,rubber gloves, disposable coveralls, monogoggles,and fall-arrest equipment.• Smoking is allowed only in designated areas.Vehicles• Vehicle entry is by permit only and keys are to be leftin parked vehicles.• Vehicles must be shut down at the sound of anyemergency alarm.• Vehicles must be equipped with ground straps orcables.Permit Systems
No work takes place in a refinery without a safe work permit.A safe work permit is a document issued by an authorizedrepresentative of the client permitting specific work for aspecific time in a specific area.Work permits should indicatethe date and time of issue, the time of expiry, a descriptionof the work to be done, and the name of the companyperforming the work. Permits also specify any hazards andcontrolled products underWHMIS and any protectiveequipment needed for the job. The permit will advise you of
any steps required to make the area or equipment safe forwork, tell you the results of any gas tests, advise you of anyelectrical lockouts that have been done, and tell you of anywork practices required for the specific job.Safe work permits are valid only for a imited time andmust be renewed following expiry or normally after anyone-hour stoppage, after an emergency warning on the
site, or for other safety reasons. After such an event, anyrequired gas testing or other testing must be repeated toensure a safe return to the work.The types of safe work permits required typically includethe following. Specific categories may vary from site tosite.
• Hot work – covers any work that involves heat or anignition source, including welding, grinding, and theuse of any kind of motor. In high-risk areas, a sparkwatch may be required.• X-ray and radiation• Benzene – required when a benzene exposurehazard exists.
• Confined space entry hot work – involving potentialignition hazards.• Confined space entry cold work – involving workthat will not produce a spark.• Hoisting – permit.• Electrical – for other than routine work.• Camera – typically requires a hot work permit when
lighting is required.• Asbestos – required whenever an asbestos exposurehazard exists.• Vehicle movement• Hydrant – permits the use of plant fire hydrants. Special Authorization PermitsIn addition to safe work permits, special authorizationpermits are normally required for the following operations:• excavation• hoisting with major mobile equipment• hot tap and non-conventional repairs• opening live flare lines• temporary electrical facilities.EmergencyWarning System and ProceduresIn oil refineries there will be both plant alarms or whistlesand individual unit alarms. All workers must receivetraining in recognizing and responding to these alarms.Verbal messages usually accompany the alarms.There will be different alarms for a fire emergency andtoxic alarms.• When an alarm sounds, secure all equipment andshut down all vehicles.• Note the wind direction (wind socks) and proceed tothe appropriate assembly area (or safe haven).• Do a head count to make sure all personnel areaccounted for and report the result to a client contactperson.
• Know the local designated safety areas or safe havens and emergency phone number(s).If you are the one who is first aware of an emergency,then call the emergency number.• Report your name.• Describe the emergency.• Identify its location.• Indicate whether anyone is injured.• Proceed to the assembly area.Electrical Precautions• Electrical tagging and lockout procedures must beunderstood and followed by all workers.• All electric tools, cords, and equipment must begrounded or double-insulated.• Use explosion-proof fixtures where required. EINERIE AND PETROCHEMICAL PLANTS
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• Sewers must be covered when hot work is being donein the vicinity.• Sewer covers must be in good condition with noopenings for vapour flow.• Sewer covers are to be removed when hot work isdiscontinued at the end of the job or overnight toaccommodate drainage.Blinding or Blanking-off• Piping connected to a work area from vessels, pumps,and other sources is isolated or blinded with a solidplate prior to the start of work.• Blanking can sometimes be done with two valves anda bleeder valve between them. In this case the valvesshould be closed, chained, locked, and tagged.Petrochemical PlantsPetrochemicals refers to a group of chemicals that are
manufactured using crude petroleum and natural gasfeedstocks as raw materials.Petrochemicals are versatile starting points for the
production of thermoplastic and thermosetting materials.Thermoplastics are materials that can be softenedrepeatedly by the of heat. The most importantthermoplastics are high and low density polyethylene,polypropylene (polyolefins), polyvinyl chloride, and
polystyrene.Thermosetting materials are those that undergo achemical change when heated and shaped and thereforecannot be reshaped by another application of heat. Somethermosetting plastics are thermosetting resins (includingphenol and urea ormaldehydes), epoxy resins,unsaturated polyesters and polyurethanes, andengineered plastics such as polyacetyls, polyamides, and
polycarbonates.The hazards of the petrochemical industry are closelyrelated to those of oil refining, particularly in the rawmaterial stages.Atmospheric contamination hazards in the petrochemicalindustry can be complex, particularly when substances or
processes combine. These combined effects are oftenmuch more toxic and dangerous than individual effects.
As they do in oil refineries, construction crews inpetrochemical plants must comply with regulations as wellas in-plant procedures. Cooperation between contractorand client is essential for safe work, from the biddingstage until the contract is completed.OIL REFINERIES AND PETROCHEMICAL PLAN