Hydrocarbon fires Explosions

Oxidation Feedstocks generally hydrocarbons Hazard of fire/explosion arises from contact of flammable material with oxygen Reactions highly exothermic equilibrium favours complete reaction... 

Double and triple bonded hydrocarbons Fire and explosion... 

While RP14C provides guidance on the need for process safety devices, it is desirable to perform a complete hazards analysis of tlie facility to identify hazards that are not necessarily detected or contained by process sLifety devices and that could lead to loss of containment of hydrocarbons or otherwise lead to fire, explosion, pollution, or injury to personnel. The industry consensus standard, American Petroleum Institute Recommended Practice 14J, Design and Hazards Analysis for Offshore Facilities (RP14J), provides guidance as to the use of various hazards analysis techniques. 

Fire, explosions and environmental pollution are the most serious "unpredictable" life affecting and business losses having an impact on the hydrocarbon industries today. These issues have essentially existed since the inception of industrial scale petroleum and chemical operations during the middle of the last century. They continue to occur with ever increasing financial impacts. It almost appears that the management of industry is oblivious, or else must be careless, to the potential perils under their command. Although in some circles most accidents can be thought of as non-preventable, all accidents are in fact preventable. 

Hydrocarbon processing facilities pose severe risks with respect to fire, explosions and vessel ruptures. Among the prime methods to prevent and limit the loss potential from such incidents are the provisions of hydrocarbon inventory isolation and removal system. These systems are commonly referred to in the petroleum industry as ESD (emergency shutdown) and depressuring or blowdown. Although most standards and practices acknowledge the need for depressuring capabilities the exact determination of their requirement is not wholly defined. NFPA fire codes and standards rarely mention the subject. 

Explosions are the most destructive occurrence that can transpire at a hydrocarbon facility. Explosions may happen too quickly for conventional fire protection systems to be effective. Once an explosion occurs damage may result from several events ... 

The scope of this book is to provide a practical knowledge and guidance in the understanding of prevention and mitigation principals and methodologies from the effects of hydrocarbon fires and explosions. The Chemical Process Industry (CPI), presents several different concerns that this book does not intend to address. However the basic protection features of the Hydrocarbon Process Industry (HPI) are also applicable to the chemical process industry and other related process industries. 

Precaution Flamm. dangerously reactive dangerous fire/explosion risk may detonate under high temps, and pressures incompat. with acids, alkali metals, inorg. bases, amines, strong oxidizers, hydrocarbons, metal oxides, aluminum chloride, etc. 

All hydrocarbon fire mechanisms and estimates will be affected to some extent by flame stability features such as varying fuel composition as lighter constituents are consumed, available ambient oxygen supplies, ventilation parameters, and wind effects. Studies and experimental tests are ongoing by some research institutes and industries to provide more precise modeling techniques into the release of gas, its dispersion, fire, and explosion effects. 

The scope of this book is to provide practical knowledge on the guidance in the understanding of prevention and mitigation principals and methodologies from the effects of hydrocarbon fires and explosions. 

There are four main hazards ship collision, dropped objects, fire, and explosion. Specially, the topsides of the offshore platform, which treats combustible oil and gas, are always exposed hydrocarbon fire hazards bring out a high consequence disaster. Moreover, damages from fire accidents have increasingly been astronomical in accordance with the growing scale and complexity of the recent plants, as seen in the Deepwater Horizon incident. 

Firewater pumps should be located in the Safe Area and should be separated by adequate distance and/or by firewalls, to avoid the potential for a single fire/explosion in the Safe Area rendering firewater pumps inoperable. Firewater engine air intakes should be located in well-ventilated locations to reduce the possibility of smoke or hydrocarbon vapor ingestion. 

Hydrocarbons generally have very low electrical conductivities and manipulation of these fluids creates electrostatic charges that can result in fire or explosions. This problem is encountered with gasoline and kerosene. 

Mixing cellulose esters in nonpolar hydrocarbons, such as toluene or xylene, may result in static electricity buildup that can cause a flash fire or explosion. When adding cellulose esters to any flammable Hquid, an inert gas atmosphere should be maintained within the vessel (132). This risk may be reduced by the use of conductive solvents in combination with the hydrocarbon or by use of an antistatic additive. Protective clothing and devices should be provided. 

A common cause of a BLE T] in plants of the hydrocarbon-chemical industry is exposure to fire. With an external fire below the liquid level in a vessel, the heat of vaporization provides a heat sink, as with a teakettle evolved vapors exit tnrough the relief valve. But if the flame impinges on the vessel above the liquid level, the metal will weaken and may cause the vessel to rupture suddenly, even with the relief valve open. The explosive energy for a BLE T] comes from superheat. This energy is at a maximum at the superheat hmit temperature. (SLT is the maximum temperature to which a hquid can be heated before homogeneous nucleation occurs with explosive vaporization of the hquid and accompanying overpressure.) The SLT... 

The next simplest ether is the ether with the simplest alkane as one of the hydrocarbon backbones and the next alkane, which is methyl ethyl ether. Its molecular formula is CH3OC2H5. It is a colorless gas with the characteristic ether odor. It has a flash point of 31 °F, and an ignition temperature of only 374°F. This property, of course, makes it an extreme fire and explosion hazard. 

Not to be Used Water, foam, carbon dioxide, or halogenated hydrocarbons Special Hazards of Combustion Products No data Behavior in Fire Reacts violently with water, forming flammable and explosive hydrogen gas. This product may spontaneously ignite in air Ignition Temperature No data Electrical Hazard Not pertinent Burning Rate Not pertinent. 

J H Marsh and McLendon (M M, 1997), every five years, reviews and analyzes the 100 largest properly damage losses in the hydrocarbon- chemical industries that occurred over the previous 30 years. Most of the losses involved fires or explosions, flood, windstorm, and pressure rupture losses. 

D. K. McKibben, Safe Design of Atmospheric Pressure Vessels, Paper presented at Seminar on Prevention of Fires and Explosions in the Hydrocarbon Industries, Institute of Gas Technology, Chicago, June 21-26, 1982. 

A deflagration can best be described as a combustion mode in which the propagation rate is dominated by both molecular and turbulent transport processes. In the absence of turbulence (i.e., under laminar or near-laminar conditions), flame speeds for normal hydrocarbons are in the order of 5 to 30 meters per second. Such speeds are too low to produce any significant blast overpressure. Thus, under near-laminar-flow conditions, the vapor cloud will merely bum, and the event would simply be described as a large fiash fire. Therefore, turbulence is always present in vapor cloud explosions. Research tests have shown that turbulence will significantly enhance the combustion rate in defiagrations. 

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