HEALTH, SAFETY AND ENVIRONMENT (CBB 2012) TITLE: FRACTIONAL DISTILLATION PROCESS ? CONTENTS 1. Title…………………………………………………………………………. 1 2. Summary……………………………………………………………………. 3 3. Introduction of Case Study……………. ……………………………………. 4 4. Risk Scenario Development……. …………………………………………… 5 5. Justification of Fault Tree Analysis…………………………………………6 6. Procedures of Fault Tree Analysis………………………………………….. 7 7. Fault Tree Analysis…………………………………………………………8 8. Possible Risk Associated with Hazards…. ………………………………… 11 9. Accident Consequences……………………………………………………. 13 10.
Method to Control the Risk………………………………………………… 15 11. Solution to Minimize the Risk…………………………………………….. 17 12. Conclusion…………………………………………………………………. 18 13. References…………………………………………………………………. 19 ? SUMMARY Crude oil is one the most important non-renewable sources on Earth. Demand for this black viscous liquid is growing every day in this era if modern technology. Electricity, vehicles and synthetics are among the major consumers of petroleum fluids or crude oil. Crude oil could be referred to as the ‘black gold’ due to its expensive price and complicated production process.
Unlike gold, crude oil naturally is useless in its primary form. A process called fractional distillation or petroleum refining need to be carried out onto the crude oil to separate it into various components which later could be used to supply electricity to residential houses or mobilizing vehicles. Fractional distillation or petroleum refining is the process of separating crude oil into different components based on their hydrocarbon chains. It is one of the most important major processes in the oil and gas industry.
Basically there are two types of fractional distillation which are in laboratory fractional distillation and industrial fractional distillation. Both have different method of conducting the process but utilize the similar concept. Industrial petroleum refining involves the separation of different length of hydrocarbon chain into specific refinery column which will produce products such as petrol, naphtha, kerosene and diesel. However petroleum refining has its own hazards and risk. It is highly flammable and could cause a major catastrophe to the plant.
The purpose of this report is to study a case scenario involving the fractional distillation process and its potential hazards and risks. INTRODUCTION In 1859, the petroleum industry began with the successful drilling of the first commercial oil well and the opening of the first refinery to process the crude into kerosene. The development of petroleum refining from simple distillation to today’s sophisticated processes has created a need for health and safety management procedures and safe work practices.
Refining is the processing of one complex mixture of hydrocarbons into a number of other complex mixtures of hydrocarbons. In response to changing consumer’s demand for better and different products, petroleum refining has evolved continuously. The original requirement was to produce kerosene as a cheaper and better source of light than whale oil. The production of gasoline and diesel fuels resulted from development of the internal combustion engine. Nowadays, refineries produce a variety of products. It was soon discovered that high quality lubricating oils could be produced by distilling petroleum under vacuum.
For the next 30 years kerosene was the product consumers wanted due to two significant events, first is invention of the electric light decreased the demand for kerosene and second, invention of the internal combustion engine which created a demand for diesel fuel and gasoline, also known as naphtha. Most of our modern lifestyle depends on oil. The largest oil refinery is the Paraguana Refining Complex in Venezuela, which can process 940,000 barrels of oil each day. Samuel M. Kier was the first person to refine crude oil and he used the flammable oil produced by his salt wells to light his salt works at night.
The burning crude produced an awful smell and a great deal of smoke. In 1850, Kier started experimenting with distillation and his refining experiments were successful and by 1851, Kier produced a product called Carbon Oil, a fuel oil which burned with little smoke and odor. By the end of the 1860s, Samuel M. Kier spent a great deal of his life trying to make crude oil useful and valuable and along the way he gave birth to the U. S. refining industry. A report based on fractional distillation or petroleum refining as a case study is used to determine the hazard and risk involve in the manufacturing process.
Therefore, safety precautions could be taken when countering an accident. RISK SCENARIO DEVELOPMENT Risk may be considered as the potential or adverse effects to human health or equipment loss resulting from an activity or event if exposed to a hazard. A risk scenario is an important concept before conducting a risk assessment. Based on the case study stated previously, a risk scenario involving petroleum refining processes will be developed in case of emergency situation during which time a certain procedure need to be followed to prevent any accident from happening.
There are various compartments in petroleum refining process. Instead of investigating a particular component which indicates specific process at a time, this report will generalize on all components involve in crude oil distillation. Petroleum refinery involved closed processes. Two categories of risks will be pointed out which are pollution risk and hazards risk. Pollution risk includes the release of chemicals into the atmosphere which could affect human’s health living near the refinery plant.
Apart from air pollution impacts there are also wastewater concerns. Wastewater is liquid waste discharged by domestic residences, commercial properties, industry agriculture which often contains some contaminants that result from the mixing of wastewater from different sources. Improper wastewater treatment could pose health problems to human. Noise pollution could also serves as a potential source of pollution due to industrial noise which could cause disturbance to residential area near the plant. Hazard risk involves explosion, fire and corrosion.
Heaters and exchangers in the atmospheric and vacuum distillation units could provide a source of ignition. Besides that, there is a potential for a fire to exist should a leak occur within the refinery. Wet hydrogen sulfide will cause cracks in steel which could leads to leak. The main hazard risk is corrosion which is a chemical hazard. Sections of the process susceptible to corrosion include preheat exchanger and hydrogen sulfide, preheat furnace and bottoms exchanger and atmospheric tower and vacuum furnace.
Efficiency in petroleum refinery is very crucial to reduce the cost of maintenance. Corrosion could cause efficiency decrement and the failure of equipment as well as interrupting the maintenance schedule of the refinery during which time all of the component must be shut down. Maintenance related to corrosion in the refinery is very costly and could reach up to billions of dollars. JUSTIFICATION OF FAULT TREE ANALYSIS Fault tree analysis (FTA) is used to analyze the case study. FTA is a failure analysis technique and it involves examining preceding events leading up to a system failure.
The tree starts with the accident event and working backwards through time, breaks it down into a series of contributory events that are structured according to certain rules and logic. This process of breaking down the event to identify contributory causes and their interaction continues until the root causes are identified. The logic diagram displays the various logical combinations of failures that can result in an accident. Advantages of Fault Tree Analysis 1. Easy to read and understand. 2. Can handle multiple failures or combinations of failures. 3.
Exposes the needs for control or protective actions to diminish the risk. 4. Quickly exposes critical paths. 5. The results can provide either qualitative or quantitative data for the risk assessment process. 6. Directs the analyst deductively to accident-related events. 7. Useful in investigating accidents or problems resulting from use of a complex system. 8. Excellent for ensuring interfaces are analyzed as to their contribution to the top undesired event. Weaknesses of Fault Tree Analysis 1. Though fault trees may reveal human error, they do little to determine the underlying cause. 2.
Fault trees require detailed knowledge of the design, construction and operation of the system. 3. Not suitable for assessing normal operations. 4. Fault trees may become very large and complex. 5. Significant training and experience is necessary to use this technique properly. Once the technique has been mastered, application stays time-consuming however commercial software is available. 6. Is not practical on systems with large numbers of safety critical failures. PROCEDURES OF FAULT TREE ANALYSIS 1. Identify a specific component that is to be analyzed. This will be placed at the top of the tree, in its own individual box. . Next, all the faults that are to be found within the component need to be identified. This can be done through brainstorming to identify the failures. 3. Faults each have their own box below the component. It is now necessary to work through why the faults have occurred. What were the causes? What actions resulted in these faults being created? 4. All the causes for the faults need to be identified and then set out in boxes, each one linked to the faults that are listed. 5. It is necessary to determine the root cause for each fault which may require listing several factors that contribute to the accident.
Therefore we could decide which factor that can be controlled and altered so that the fault could be avoided. Root causes are then linked to the general causes. 6. Identify countermeasures. Once all the causes and the root causes have been identified, countermeasures need to be listed. These are the antidotes to the root causes and will ensure that the faults are eliminated. Countermeasures are then linked onto the root cause boxes, because they show the actions that need to be taken. 7. There are two types of gates used in a fault analysis tree : a.
AND: where all the sub-faults and the other causative factors must co-exist so as to cause the fault for which they have been identified. b. OR: where the fault will occur even if only one of the sub-faults or the basic factors exists. ? FAULT TREE ANALYSIS In process of assessing and identifying the risks in a work environment, hazard analysis is the initial step to be taken. These are the types of hazard analysis: (i)Hazard & operability review (HAZOP) (ii)Failure mode & effect analysis (FMEA) (iii)Technique of operation review (TOR) (iv)Fault tree diagram (FTA) v)Human Error Analysis (HEA) (vi)Risk Analysis In our case scenario of the risk involving crude oil distillations processes, hazard analysis method that has been used is fault tree analysis (FTA). Definition of Fault Tree Analysis Fault tree analysis is a graphical representation of the major faults or critical failures associated with a product, the causes for the faults, and potential countermeasures. The tool helps identify areas of concern for new product design or for improvement of existing products. It also helps identify corrective actions to correct or mitigate problems.
Importance of Fault Tree Diagram FTA is the most suitable hazard analysis as it is useful both in designing new products/services and in dealing with identified problems in existing products/services. In the quality planning process, the analysis can be used to optimize process features and goals and to design for critical factors and human error. As part of process improvement, it can be used to help identify root causes of trouble and to design remedies and countermeasures. Figure 3: Fault-Tree Analysis diagram GRAPHIC SYMBOLS FOR FAULT TREE ANALYSIS EVENT SYMBOL
Function: It is divided into two:- primary and intermediate events •Primary events are not further develops one fault tree •Intermediate events are found at the output of a gate. GATE SYMBOL Function: It describes the relationship between input and output event Basic Event It is the failure or error in a system component or element. OR gate The output occurs if any of the input occurs Intermediate event Can be used immediately above a primary event to provide more room to type the event description, and also as an output of any gate AND gate The output occurs if both of the input occurs POSSIBLE RISKS ASSOCIATED WITH HAZARDS Since the process of fractional distillation undergoes the separation of the fractions are further converted using processes such as ‘cracking’ or ‘catalytic reforming’. Flammable hazards are therefore likely to be represented by many substances on a typical petrochemical refining plant. According to the Encyclopedia of The Earth, even though these are closed processes, heaters and exchangers in the atmospheric and vacuum distillation units could provide a source of ignition, and the potential for a fire exists should a leak or release occur.
In order for gas to ignite there must be an ignition source, typically a spark (or flame or hot surface) and oxygen. For ignition to take place the concentration of gas or vapor in air must be at a level such that the ‘fuel’ and oxygen can react chemically. The power of the explosion depends on the ‘fuel’ and its concentration in the atmosphere. The relationship between fuel/air/ignition is illustrated in the ‘fire triangle’. Gases and vapors’ released from crude oil refining processing activities cause harmful effects on workers exposed to them by being absorbed through the skin, inhalation or swallowed.
People exposed to harmful substances may develop illnesses such as cancer many years after the first exposure. According to Halma India News (2009) many toxic substances are dangerous to health in concentrations as little as 1ppm (parts per million). Like an example, given that 10,000 ppm is equivalent to 1% volume of any space, it can be seen that an extremely low concentration of some toxic gases can present a hazard to health. The flammable gas hazards occur when the concentration of gases or vapors exceed 10,000ppm (1%) volume in air or higher.
Furthermore, toxic gases typically need to be detected in sub-100ppm (0. 01%) volume levels to protect personnel. Gaseous toxic substances are very dangerous because of their invisibility and odorless. We cannot predict their physical behavior that can influence the properties of a gas leak. Hydrogen sulphide for example is particularly hazardous; although it has a very distinctive ‘bad egg’ odor at concentrations above 0. 1ppm, exposure to concentrations of 50ppm or higher will lead to paralysis of the olfactory glands rendering the sense of smell inactive.
This in turn may result in the assumption that the danger has cleared. Prolonged exposure to concentrations above 50ppm will result in paralysis and death. An excursion in liquids, pressure and temperature levels may also happened if automatic control devices undergo failure. The sections of the process that might be exposed to corrosion include, preheat exchanger, preheat furnace and bottom exchanger, atmospheric tower and vacuum furnace, vacuum tower, and overhead. It will also give crack in steel with the presence of H2S. The nitrogen oxides can form in the flue gases of furnaces when processing high-nitrogen crudes
ACCIDENT CONSEQUENCES According to European Agency for Safety and Health at Work (n. d) emphasized the employer should think about safety at the workplace because the employer are obliged by law to maintain a safe and healthy workplace. Besides that, most employers have a personal interest in guaranteeing the safety of their employees. In addition, the employee is responsible to think about safety at workplace. Accidents are an inevitable part of a job. However injuries not only cause loss of money but also cause pain and disruption to the workers and their family.
Actually they should know that working safely is part of their future life. Safety and health at the workplace is the responsibility of both employers and employees. European Agency for Safety and Health at Work (n. d) also said that a workplace accident is an injury or illness that occurs in relation to an employee’s job. Usually injuries occurs among workers resulted from an accident while performing duties and tasks. Through the Occupational Safety and Health Administration (OSHA) as it is commonly referred to Federal law provides employees with protection while working in a safe environment.
OSHA has enacted a set of rules and regulations that must be abided by all employers and as an alternative, the law also provide compensation for workers who have illness or injuries. David Greenberg Law (2012) explained a workplace accident that causes injury happens because of unsafe working conditions, defective equipment, lack of maintenance or a dangerous environment. There is a possibility for a worker to have the carpal tunnel syndrome due to jobs that required physical strain such as heavy lifting, working with hazardous materials or prolonged time in certain jobs such as typing.
Many factors could causes psychological illnesses such as stressful environment, discrimination or harassment, a motor vehicle accident occurring in the performance of job related duties, an injury caused by unsafe conditions or equipment and a slip and fall at work. Being injured at work has serious and sometimes permanent and irreversible effects on its victims and their families. The pain and suffering endured is not usually covered in worker compensation plans. If an accident happened, attorney from the law firm should be consulted before taking any other actions.
A workplace accident lawyer is best prepared to evaluate your particular situation and recommend the best course of action for you and your family. The workers bear about 30 percent of the total costs of workplace injury and illness. These costs include, but may not be limited to; loss of income, pain and suffering, loss of future earnings, past investment, and medical expenses. The problems created by an injury may provoke a necessity to shift to other jobs, retrain for other careers, and complete disability (handicap).
In addition, injured employee will face financial loss as a direct result of their injuries. Besides that injury or illness put a strain on relationships in a number of ways through emotional stress, financial pressure and isolation. Family and friends are deeply impacted and this eventually may lead to problems within their relationship. The injury or illness may result in a breakup or in a temporary or permanent loss of intimacy. Attitude and response received from employers, colleagues, supervisors, and others within the workplace could affect the psychological health during the physical recovery process.
The workers had to bear the risk that they need to change their lifestyle related to the injury where they and their families will endure costs, monetary losses. If you or a family member has been injured in the work place you should consult a law firm with workplace accident attorneys. ? METHOD TO CONTROL THE RISK After identifying the hazards in the industries we need to figure out a method to control the risk and therefore lower the chances of any accidents to occur. Some of the method we have managed to find is; Hierarchy of Controlling the Risk
To reduce the risk of a hazard occur during event is operated; the hierarchy of control should be used. The hierarchy represents the order of controls that need to be considered when selecting methods of controlling a risk from highest to lowest order control measure. The sequence of the hierarchy control is as below: i. Elimination of the hazards: -By getting rid of anything that can be related to the hazards such as equipment or substance completely but the elimination cannot cause the event become less effective to be operated. ii. Substitution with lesser hazard: By replacing the hazardous material into a lesser hazardous material. iii. Using engineering controls: -By redesign the hazardous material or the work processes. iv. Isolation of the hazard: -By separating the operator and the processes that being done with, such as physical barrier, or set a range of distance between the operator and the processes conducted or even by forming a hazardous area. -Example: providing a sealed cage area for fireworks. v. Using administrative controls: -Known as policy, procedure or behavior control such as time and hours of work, how to conduct the process and who can work at the specific area. By enforcing and applying the policy or the safe procedure that had been set. -Example: provide training in the work procedures and work processes. vi. Using personal protective equipment (PPE): -Last order of control in hierarchy of control. -Type of clothing or equipment or substance that can protect the operator from the hazard. However it is not highly recommended as it is not 100% guaranteed to be safe from the hazard. -Example: hearing protection, gloves, masks, hats, high visibility vest. Applying the hierarchy of controlling the risk is not enough to reduce the risk at the work place.
Therefore, other method needs to be implemented in order to create a truly safe workplace. System improvement Reduce or eliminate the possibility of a chemical release by choosing inherently safer materials and technologies. Besides that, reducing the potential severity of the impacts of a chemical release through mitigation measures (containment dikes, sprinkler systems) or emergency response plans should be carried out. Maintenances Maintenances need to be done regularly to spot any deformation or cracks in the distillation machine.
This can be done by creating a comprehensive schedule for maintenances so the machine is always working in its best condition. It is also important to make sure that the person who is in charge of the maintenance follow the schedule tightly to avoid any errors and future accidents from happening. ? SOLUTION TO MINIMIZE THE RISK Controlling of pressure, temperature and liquid levels are among the important criteria that must be taken into consideration in order to find the solution that might minimize the risk of chemical hazard in fractional distillation processes.
If automatic devices fail, an excursion could occur. We need to control devices within the operating parameters to prevent thermal cracking from happening in the distillation towers. To prevent unwanted crude from entering the reformer change, relief systems should be provided for overpressure and monitoring operations. There are some sections of the process that could easily be affected to corrosion include, preheat exchanger, preheat furnace and bottoms exchanger, atmospheric tower and vacuum furnace, vacuum tower and overhead.
When the metal temperatures exceed 450? F, some corrosion might be happened in furnace tubing and in both atmospheric and vacuum towers. This is the place where sour crudes are processed. Wet hydrogen sulfide also will cause cracks in steel. Nitrogen oxides are very corrosive with the presence of water at low temperature. Nitrogen oxide is produced from the flue of gases furnace during high-nitrogen crudes processing. We can take initiative from chemicals such as hydrochloric acid to control corrosion that produced in distillation system.
This is one of the solutions to reduce the chemical hazards. An alkaline solution such as ammonia may be injected into the overhead streams or feeding hot crude-oil to initialize the condensation process. However, usage of ammonia must be accompanied by enough supply of water. If not, ammonia chloride will be deposited which could cause severe corrosion. Appreciable amounts of water may contain in the crude feedstock that can be heated until boiling point and cause vaporization explosion when in contact with the oil in the unit. ? CONCLUSION
This report is about potential sources of hazards in a working environment. The case study chosen is related to the Oil and Gas industry which is entitled ‘Fractional Distillation’. Fractional distillation is used for separating a mixture of substances with narrow differences in boiling points and it is the most important process in the oil and gas industry. Based on this report many hazards might happen in the refinery processes especially hazards related to chemicals. Therefore chemical hazards are chosen as the main hazards in the case study.
Fault tree diagram is used to conduct the hazard analysis. This method is a graphical representation of the major faults or critical failures associated with the product, causes for the faults and potential countermeasures. It helps to identify corrective actions to correct or mitigate problems. This type of analysis can be used to optimize fractional distillation process features and goals and to determine critical factors and human error in the oil and gas refinery industry. Hence, we can find the solution for these problems if an accident occurs.
As a conclusion the chemical hazards could occur due to ignition or fire that is produce from a leakage or cracks inside the distillation units. Should an accident occur, employers must think and react quickly to contain and control the situation. Employees on the other hand need to be alert all the time about the safety condition at their workplace. Adequate rules at workplace are setup by several organizations such as European Agency for Safety and Health at Work, Occupational Safety and Health Administration (OSHA) and David Greenberg Law to increase the awareness of workers toward safety.
The solution were taken in order to minimize the risk is to stop the sources of accident which are leakage and corrosion. By using alkaline chemicals, the corrosion process of the distillation unit wall could be controlled thus reduce the number of accidents. ? REFERENCES Bastidas,L. M. (March 12,2012) . Fractional Distillation of Crude Oil. Retrieved August 11th, 2012 from http://wiki. nanjingschool. com/users/laurencemclellanbastidas/weblog/87653/Fractional_Distillation_of_crude_oil. html Fault Tree Analysis. Retrieved August 12th ,2012 from http://www. hf. faa. gov/workbenchtools/default. spx? rPage=Tooldetails&subCatId=43&toolID=120 Freudenrich,C. Howstuffworks “How oil refining Works. Retrieved August 10th ,2012 from http://science. howstuffworks. com/environmental/energy/oil-refining4. htm Gas Hazard in Petrochemical Industry. (July 2009). Retrieved August 11th, 2012 from http://halmapr. com/news/india/2009/07/03/gas-hazards-in-the-petrochemical-industry/ Health and Safety Aspects of Petroleum Refining. (October 31st,2008) Retrieved August 12th, 2012 from http://www. eoearth. org/article/Health_and_safety_aspects_of_petroleum_refining#gen8 Kinyanjui,L.
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