Lit Cigarette and Petrol Vapour Ignition - Essay Example

Lit Cigarette and Petrol Vapour Ignition Introduction As observed, some movies are depicting scenes where cigarette has become a competitive ignitionsource resulting to explosion of any combustible materials. However, the reality seems never to go the ways cigarettes are shown to ignite some of known flammable products with industrial use. Some theories suggest that cigarette cannot be a significant ignition source of petrol vapour (Babrauskas, 2003). There are relevant theories explaining about the capacity of cigarette to ignite gasoline vapours. However, it is important to understand each of these so as to come up with specific reasons why petrol vapours do not actually ignite with cigarette as its probable ignition source. Specifically, this paper tries to investigate why cigarette cannot be a competent ignition source of petrol vapour. In this regard, it is important to understand some other substances that can be ignited by cigarettes in order to find out probable differences of petrol vapour from them. Prior to this, it is important to try to take a look at the basic of fire production and other related ignition activities. At its basic level, there are three essential components that are viewed to significantly help create a fire; oxygen, fuel and temperature are fundamentals of the production of fire. In the absence of one of them, fire is impossible. Say for instance in the case of methyl ethyl ketone peroxide (MEKP). The material is already a fuel and it must be stored at a certain temperature to prevent auto ignition. Since oxygen is everywhere, any moment when the MEKP reaches its auto ignition point will automatically ignite and even lead to further damage. Thus, one of the most effective ways to prevent it from causing unnecessary ignition is to place it at a room temperature, which is far from auto ignition point. Materials ignited and not ignited by cigarettes All materials that can be ignited are considered fuels. Fuels from our common understanding are materials that can be ignited by fire and they certainly are capable of helping the entire ignition process. Fuels are of different forms and they can be solid, liquid or gas. In either form, fuels are integral parts in creating a fire. Fuels have different properties and these make them different from each other when it comes to the level of combustibility. It is important to consider that fuels are significant reasons why there is fire. Without a fuel there can be no fire even with the presence of temperature and oxygen. Oxygen and temperature are constant because they can be everywhere. This means that the only way to control a fire is by understanding how to handle a fuel properly. This means that fuels are to be properly taken care of and the only way to do so is to follow the appropriate way to use them. For example, containers with flammable content are to be segregated and mostly they have labels showing their respective content and their potential ignitability. Thus, it is important to consider the technical specifications and other related information prior to effective and efficient usage of a certain material which can also be remarkable fuel of fire. Of all forms of fuels that can easily be ignited, the most hazardous will be the material in its vapour state, then in its solid particularly in dust state and finally in liquid state. However, despite the high level of risk associated with the combustibility of materials in its vapour state, there are still those that cannot be ignited. In the case of a cigarette and petrol vapour, widespread belief about it showed that these two components do not necessarily create ignition. It is in this regard that there is a need to closely understand what are in the hydrocarbon liquids that need to be understood why they could not be easily ignited by a smoldering cigarette. The following are materials reported to be ignited and were not ignited by cigarettes. Materials that can remarkably be ignited by a smoldering cigarette are acetylene, carbon disulfide, ethylene oxide, diethyle ether, hydrogen, hydrogen sulfide and phosphene . There are many materials that can be ignited by a cigarette but the most important point is to understand what is in them why they can be ignited by such a heat energy source. Materials such as acetylene, carbon disulfide and ethylene dioxide are composed of specific fire properties such as flash point, fire or flame point and auto-ignition point. This means that their ability to be ignited relies on the specific temperature. Materials that are ignited by cigarettes are important to be understood. According to (Cote, 2003), there are five essential dimensions that need to be investigated when it comes to understanding the cause of fire. There are five important dimensions and these include the heat source, equipment involved in the ignition, the form of material ignited, type of material ignited and ignition factor. More of these are discussed in the following section. One dimension which is clearly stated in understanding the cause of fire is the heat source. A smoldering cigarette is a heat source. Most materials or fuels ignite based on the amount of heat source (Babrauskas, 2003). Considering the capacity of cigarette to ignite a fuel would matter in this respect knowing that there are some specific temperatures particularly those combustible materials have considerable temperature needed before they finally ignite. A cigarette for instance as a heat source must necessarily have certain level of temperature in order to ignite a fuel. Considering that a fuel does not ignite with a smoldering cigarette is an indication that such material requires higher heat source in order to ignite. It is in this concern that there is a need to look closely at the heat source and the type of material in order to understand further the possible causes of ignition. On the other hand, the following are noted materials that do not ignite with a smoldering cigarette: acetone, acrolein, ammonia, benzene, butadiene, butane, butyle acetate, butylene, chlorotrifuoroethylene and more. Remarkably, there are claims that petrol vapour does not ignite with a cigarette (Babrauskas, 2003). However, evidences to support it are only few. However, the possible questions on ignition can be remarkably understood by knowing the basic principles in the creation of fire. Those materials especially petrol vapours require higher heat source in order to ignite. A smoldering cigarette may possibly have only low level of heat in order to ignite a petrol vapour (Babrauskas, 2003). If this is the case, then there is a need to increase the temperature of the environment prior to create a fire with a cigarette. For instance, a very warm environment with remarkably high temperature would mean addition of temperature produced by a smoldering cigarette. In this case, there would be enough heat which is required to ignite a petrol vapour or other hydrocarbon liquids. In the case of hydrocarbon liquids, or other liquids for instance, there is a need for them to be converted into vapour in order to ignite. Such vapour can be produced by applying the concept of evaporation which will result to the achievement of flash point, fire point or auto-ignition point in the presence of oxygen and heat energy source. Reasons for ignition and non ignition According to the review of Holleyhead (1996), a glowing tip of cigarette does not have uniform temperature while it also produces carbon dioxide and depleted reactants like oxygen. Methane, gasoline and propane according to the review are said to have upper flammable limits which cannot be ignited without sufficient oxygen. Holley emphasized that sufficient oxygen cannot be observed at the burning tip of cigarette making it unable to ignite substances that have high flammable limits. This is supported by the fact that an oxygen-enriched atmosphere or even a substance which produces oxygen has the potential for combustion (Perry, 2003). For instance, such substances like hydrocarbons (MEKP, resin and styrene) have specific oxygen in them that is why they are considered to have high potential as fire hazards. This is one of the reasons why they need to be regulated. Even if oxygen is what makes life possible on earth, it can also be the most destructive elements at the same time. In fact, it is not advisable to put off a fire through funning because it may just simply build it up more in the presence of oxygen. Though there are some other combustible gases like carbon monoxide and hydrogen that can be found at the burning tip of cigarette, the amount of depleted oxygen in it still would make it impossible to reach specific heat energy in order to burn a gasoline according to Holleyhead. Sufficient heat energy is noted to ignite the vapour produced out from the liquid surface of petrol liquid. Even if there is availability of fuel and oxygen this does not necessarily mean that a fire will be built up with only the presence of these two components. Fire is made up because specific temperature is required to be met. This is remarkably clear considering that different materials have different flash point, fire or flame point and auto-ignition temperature. All of these are significant characteristics of flammable materials which primarily consider the amount or level of temperature needed in order to ignite them (Daeid, 2004). Temperature is a very important component of ignition. Temperature can reveal meaningful ideas when understanding the ignition characteristic of a material just like how everything is presented from the study of Holleyhead and Babrauskas. Based on their studies, the most important part of temperature in the creation of fire is on its ability to aid further justification on how exactly a certain material ignites. In every product detail especially on flammable items, these materials have corresponding temperature limits in which they have to be stored. Hydrocarbons for instance such as MEKP, resin and other petrol products require specific room temperature in which they have to be stored considering they have corresponding flash point, fire point and auto-ignition point. The principle behind this is that heat energy is always transferred from one medium to another. The molecules within a medium are where the heat finds its way for the process of heat transfer (Holman, 2001). In the case of heat energy coming from the burning tip of cigarette, such amount of energy must necessarily pass through the molecules of petrol vapour in order to come up with ignition. On the other hand, there was a certain case about cigarette being lit up and significantly followed by the actual ignition of petrol vapour (Babrauskas, 2003). This actually was based on the principle of heat transfer in which the heat energy released by the heat source was enough to heat up the molecules of petrol vapour or some fuels leading to the achievement of fire point or ignition point. Heat transfer principle therefore is necessary important to be used to explain why such the amount of heat coming from a smoldering cigarette may not be enough for the ignition of petrol vapour and other liquid hydrocarbons. The case according to Babrauskas was due to the additional heat source coming from the moment cigarette was lit up. The heat release rate increased because of additional heat energy source. If there was no heat transfer and additional heat release coming from other external sources, the amount of heat produced by lit cigarette alone may not actually ignite the petrol vapour. The amount of heat produced by a lit cigarette may not be enough to ignite petrol vapour since in the first place such fuel may require certain amount of heat energy to reach its fire point or auto ignition point as pointed out by Babrauskas. On the other hand, even if the amount of heat energy produced by smoldering cigarette may be enough to ignite a fuel source but such can be affected by the way heat transfer principle works and the rate of heat release. In the case of cigarette and petrol vapour, heat transfer from the energy source through the fuel source can happen in an open air and this means wide dispersion of heat energy can be possible thereby minimizing the actual rate of heat energy released. On the other hand, since the amount of heat produced by a cigarette may not be enough to ignite some fuels, then it is important to increase the level of oxygen. Some fuels on the other hand have the capacity to produce oxygen as by product but they still require higher amount of heat which is higher than what smoldering cigarette can produce prior to undergo ignition (Babrauskas, 2003). Another point of Holleyhead was that gasoline vapour-air carbon dioxide mixture could not also be ignited when carbon dioxide exceeded 28.7% by volume. This means that since carbon dioxide can be readily produced at the burning tip of cigarette, there is a good chance that ignition of petrol vapour would be more unlikely to occur. Holleyhead added that turbulence and stagnant condition during the ignition process can probably affect ignition delay. This was remarkable when hydrogen was ignited under flowing air condition but not in stagnant condition. However, Diethy ether was ignited in a closed vessel but only after a long ignition delay. Thus, it is remarkable that ignition delay needs to be investigated further to actually explain the reason why petrol vapour cannot be significantly ignited by a lit cigarette. In addition, weather and freshpetrol could significantly affect ignition (Holleyhead, 1996; Babrauskas, 2003). A subjectively low temperature can probably affect ignition. This is to consider the fact that some substances have short ignition. According to Holleyhead, some substances with short ignition point will ignite less than one millisecond. This is true to those substances that cannot be ignited by cigarettes as pointed out by Holleyhead and Babrauskas. A study was conducted in order to prove ignition of gasoline vapour by cigarette. Various attempts were made in the said study to ignite petrol vapour but there was no remarkable result obtained (Jewell et al., 2010). This was conducted to prove further any truth behind the effect of lit cigarette to ignite petrol vapour. The gasoline for instance has remarkably 227.20K flash point and 553 to 7590K auto-ignition point (Demirbas, 2009). Ammonia on the other hand has corresponding flashpoint of 7590K (Scientific Station for Pure Products, 1920) and auto ignition point of 9240K (International Labour Organisation and International Program on Chemical Safety, 1988). All liquid fuels must necessary be converted into gas or vappour in order to be effectively ignited effectively. Thus flash point is important to know because this is the lowest temperature that a certain liquid will be able to produce sufficient vapour in order to make ignition possible (Vogel, 2005). In the case of gasoline it takes too much heat energy needed in order to have sufficient amount of vapour in the air to ignite. Thus, having a lit cigarette in the presence of gasoline does not necessarily result to ignition because there might be insufficient amount of vapour for ignition not to mention other important factors. Compared to dust on the other hand, vapour requires sufficient amount of heat from the source to be ignited. Dusts on the other hand are tiny particles that can easily be ignited because they are light, and they are easily saturated by heat from a heat source (Drysdale, 1999). It is in this reason that a petrol gas cannot be easily ignited by a cigarette compared to tiny dust particles. Gasoline vapours or petrol vapours have to be remarkably in great volume in order to create effective ignition. However, even if they are efficient enough, it is still not an assurance that they can be ignited by a lit cigarette. As mentioned earlier, they require specific amount of temperature prior to ignition which cannot be necessarily provided by the amount of heat in a smoldering cigarette. Summary There are many perspectives that can be used in order to explain why cigarette cannot be a competent heat source for ignition of petrol vapour. The science of heat transfer and the rate of heat release can be essentially applied. The basic idea on the basic components of fire can essentially be applied. Finally, the type of materials to be ignited and the type of heat source can also be another important perspective to look at. The amount or rate of heat release through heat transfer only proves that nothing can be ignited in the absence of heat source even if there are oxygen and fuel sources. Heat is necessary because this is one of the viewed important theories why petrol vapour cannot be essentially ignited by a lit cigarette. The reason lies on the fact that petrol vapour requires more heat energy prior to its fire or ignition point. On the other hand, hydrocarbons may require enough amount of heat prior to the production of enough vapour for effective ignition process. As noted, fire has to be produced by three basic important elements: fuel, oxygen and temperature. In the absence of one, fire cannot be produced at all. Temperature and oxygen are constant because they are everywhere so fuel then has to be controlled. Cigarrete is an essential source of heat and that is why it has the potential to ignite other materials. However, some studies pointed out that cigarette cannot be a competent heat source for ignition of petrol vapour because of some important reasons. Gasoline or hydrocarbons are specific types of fuel source but they cannot just be ignited by a certain heat source because they have specific chemical characteristics. On the other hand, heat sources also have physical and chemical characteristics and limitations. It seems petrol vapour and lit cigarette cannot be compatible components in order to create a fire for the reason that they have specific properties that at some point must have to be matched. Conclusion The principle behind ignition of hydrocarbons such as gasoline or petroleum product lies on the concept of how heat, fuel and oxygen work together for one certain purpose which is ignition. In the absence of one component of fire, ignition will be impossible. This is the reason why petrol products cannot be ignited by a lit cigarette because of the absence of some components. One component that can be possibly absent is the incapacity of lit cigarette to produce heat necessary for the fire point of petrol vapour. On the other hand, the other way of looking at it is to study directly the properties of petroleum products and other hydrocarbons. They can have specific properties that may never meet the need to create a fire in the presence alone of heat coming from a lit cigarette. These fuels might not have enough level of materials that can be ignited by the heat of a lit cigarette unlike any other available fuels. Thus, more studies are necessary needed in this field in order to support more evidences on existing theories. References Babrauskas, V. (2003). Ignition Handbook, WA: Fire Science Publishers. Cote, A. E. (2003) Organizing for Fire and Rescue Services. USA: Jones & Bartlett Learning. Daeid, N. N. (2004) ‘An introduction to fires and fire investigation.’ In N. N. Daeid (ed.). Fire Investigation. USA: CRC Press. Demirbas, A. (2009) Biorefinaries: For Biomass Upgrading Facilities. New York: Springer. Drysdale, D. D. (1999) An Introduction to Fire Dynamics. 2nd ed., USA: Wiley. Holleyhead, R. (1996) ‘Ignition of flammable gases and liquids by cigarettes: a review.’ Science and Justice, Vol. 36(4): 257-266. Holman, J. P. (2001) Heat Transfer. 9th ed. USA: McGraw-Hill. International Labour Organisation and International Program on Chemical Safety (1988) Major hazard control: a practical manual: an ILO contribution to the International Programme on Chemical Safety of UNEP, ILO, WHO (IPCS). UK: International Labour Organisation. Jewell. R. S., Thomas, J. D. and Dodds, R. A. (2010) ‘Attempted ignition of petrol vapour by lit cigarettes and lit cannabis resin joints.’ Science & Justice. Perry, P. (2003) Fire safety questions and answers: a practical approach. USA: Thomas Telford. Scientific Station for Pure Products (1920) ‘Pure Products.’ Scientific Station for Pure Products, Vol. 16. Vogel, G. H. (2005) Process development: from the initial idea to the chemical production plant. USA: Wiley-VCH. Read More