Times of India has reported a blast in a stores containing raw material for manufacturing explosives, in Nagpur. The reason is being investigated.. According to the article, "The blast that obliterated at AMA Industries' store in Bazargaon on Thursday morning and caused a tremor in the city, also left those in this business confused. The structure housed raw materials for making commercial explosives and did not have finished products. Experts say the thumb rule is raw materials usually would not explode unless bound into a single explosive even in case of a fire. They can burn resulting in a massive fire but not cause a blast, said industry players on condition of anonymity. "Various chemicals like ammonium nitrate, aluminium powder, sulphur when mixed in specific proportions make an explosive. However, all such chemicals stored at different places even in a single premises do not explode under normal fire. A safe distance has to be maintained for storing each of them," said an explosive maker. Aluminium powder is known to catch fire if water is sprayed on it but still a blast is not heard of, he added".
Read the article in this link
Read another article on the effect of the blast wave in this link.
May 22, 2011
Mechanical seals and flushing/cooling systems
(Diagram Courtesy Flowserve) Mechanical seals need to be understood by plant operators for their proper operation. Many times, the operations and maintenance personnel are at loggerheads because many of the operation personnel do not fully understand the principles of seal flushing/cooling systems. Flowserve has a very good mechanical seal piping plan document in this link which clearly explains the functioning for various types.
Aviation safety and Chemical Process Safety- Different approaches!
I was reading a press release by the Press Information Bureau about the improvements made by the civil aviation minsitry one year after the fatal Mangalore air crash. The report mentions the following:
"A Civil Aviation Safety Advisory Council (CASAC) was formed on May 28, 2010 with the mandate to strengthen aviation safety environment through synergisation of available expertise in areas of airlines, airworthiness, operations, air navigation, aerodromes, aircraft engineering, human performance. Special invitees to the Council include FAA, ICAO Experts, IATA, Airbus, Boeing, Bombardier etc. This is an ongoing initiative under the Chairmanship of Secretary (Civil Aviation). The Council gets its technical inputs from working groups covering Operations (Fixed wing and helicopter sub-Groups), Aerodromes, Air Navigation Services, Airworthiness General Aviation and Helicopters. Based on the reassurance drive several issues in the three areas of aerodromes, operations and airworthiness came up. Immediate actions to address the deficiencies have been taken up during the past one year. Several safety related circulars have been issued and implementation ensured. These include presence of Cabin crew in cockpit in case of one pilot leaving the cockpit, Cabin Crew to interact with pilots on intercom during period of lean cockpit activity, in the event of incapacitation of PIC, copilot to take over control and in the event of PIC not responding to calls of copilot regarding ‘go around’, assertiveness by copilot to be encouraged. Regulatory provision for penal action for reporting for duty with alcohol consumption has been made. Pilots are being subjected to Breath Analyser test prior to flights. License are being suspended for three months in case of first BA positive and on second BA positive instance, the licence is cancelled.
In a move to step up the quality of training Captains, the period of Instructorship/ Examiner-ship has been restricted to 5 years with proficiency check every 2 years. Increased oversight for selection of trainers, quality of training imparted by trainers, integrity of simulator training have been introduced. Breath Analyser Test has been mandated for approval of Training Captains and Pilots with BA ‘positive’ report have been debarred from becoming Training Captains. Existing Training Captains if found BA ‘positive’ are debarred from training Captain list for three years.The process for approval of foreign pilots has been made stringent wherein background checks are being done to ensure that these pilots have accident free record. The experience requirements for the foreign pilots have been enhanced and the pilots are subjected to Proficiency Checks before approval is granted by DGCA. These pilots are being subjected to same medical standards as the Indian pilots." Read the press release in this link
While appreciating the efforts taken by the Government in improving air safety, I could not help comparing the status of process safety management in India after the Bhopal disaster, when compared to developed nations. The PSM rule which is mandatory in USA since 1992 is still not mandatory in India......
"A Civil Aviation Safety Advisory Council (CASAC) was formed on May 28, 2010 with the mandate to strengthen aviation safety environment through synergisation of available expertise in areas of airlines, airworthiness, operations, air navigation, aerodromes, aircraft engineering, human performance. Special invitees to the Council include FAA, ICAO Experts, IATA, Airbus, Boeing, Bombardier etc. This is an ongoing initiative under the Chairmanship of Secretary (Civil Aviation). The Council gets its technical inputs from working groups covering Operations (Fixed wing and helicopter sub-Groups), Aerodromes, Air Navigation Services, Airworthiness General Aviation and Helicopters. Based on the reassurance drive several issues in the three areas of aerodromes, operations and airworthiness came up. Immediate actions to address the deficiencies have been taken up during the past one year. Several safety related circulars have been issued and implementation ensured. These include presence of Cabin crew in cockpit in case of one pilot leaving the cockpit, Cabin Crew to interact with pilots on intercom during period of lean cockpit activity, in the event of incapacitation of PIC, copilot to take over control and in the event of PIC not responding to calls of copilot regarding ‘go around’, assertiveness by copilot to be encouraged. Regulatory provision for penal action for reporting for duty with alcohol consumption has been made. Pilots are being subjected to Breath Analyser test prior to flights. License are being suspended for three months in case of first BA positive and on second BA positive instance, the licence is cancelled.
In a move to step up the quality of training Captains, the period of Instructorship/ Examiner-ship has been restricted to 5 years with proficiency check every 2 years. Increased oversight for selection of trainers, quality of training imparted by trainers, integrity of simulator training have been introduced. Breath Analyser Test has been mandated for approval of Training Captains and Pilots with BA ‘positive’ report have been debarred from becoming Training Captains. Existing Training Captains if found BA ‘positive’ are debarred from training Captain list for three years.The process for approval of foreign pilots has been made stringent wherein background checks are being done to ensure that these pilots have accident free record. The experience requirements for the foreign pilots have been enhanced and the pilots are subjected to Proficiency Checks before approval is granted by DGCA. These pilots are being subjected to same medical standards as the Indian pilots." Read the press release in this link
While appreciating the efforts taken by the Government in improving air safety, I could not help comparing the status of process safety management in India after the Bhopal disaster, when compared to developed nations. The PSM rule which is mandatory in USA since 1992 is still not mandatory in India......
Magnesium dust explosion?
An I pad manufacturing facility in China has experienced a possible magnesium dust explosion injuring 16 workers. The incident is being investigated. The news article mentions the following:
"Currently, little is known about the cause of the explosion. However, reports by the local Chinese media have stated that the explosion was caused by the ignition of magnesium dust. Magnesium is a highly flammable metal that is commonly used in industrial polishing processes. As reported by CNET, magnesium is also used in the manufacture of fireworks and flares. Faulty or deficient ventilation systems at the Chengdu plant may have allowed magnesium dust to accumulate in the atmosphere. If that was the case, even a small spark would have been enough to trigger an explosion". Read the news article in this link
"Currently, little is known about the cause of the explosion. However, reports by the local Chinese media have stated that the explosion was caused by the ignition of magnesium dust. Magnesium is a highly flammable metal that is commonly used in industrial polishing processes. As reported by CNET, magnesium is also used in the manufacture of fireworks and flares. Faulty or deficient ventilation systems at the Chengdu plant may have allowed magnesium dust to accumulate in the atmosphere. If that was the case, even a small spark would have been enough to trigger an explosion". Read the news article in this link
May 21, 2011
Learn from these process incidents
The Industrial Disaster Management Information System of the Government of Gujarat has given information about 15 process incidents. Learn from these incidents as they seem to be occurring with alarming frequency in other places too. Read about the incidents in this link.
May 19, 2011
Are we prepared to tackle a major disaster?
A news item in the Hindu newspaper indicates that a mock drill that was held in Andhra Pradesh had shortcomings. The report mentions that
"During the exercise, it was found that except fire, police, revenue, medical, and civil supplies departments, the other departments did not respond to the expected level to the crisis. According to a senior official, there was zero response from the Greater Hyderabad Municipal Corporation (GHMC) stating that the accident area did not fall under their jurisdiction.
“The officials concerned failed to respond even after information was passed on to Hyderabad. Will their reaction be the same if such an accident occurs in reality?” asked an official. He also admitted that many of the district officials failed to participate in the exercise and that there was a need to check their preparednes".
If after 27 years after the Bhopal disaster, we are still not prepared, I wonder what the situation will be when an actual disaster strikes!
Read the article in this link
May 17, 2011
Design your scrubbing systems properly
Scrubbing systems are your last line of defence. Ensure that adequate redundancy is provided to ensure that the system will work properly when needed. In an incident the CSB investigated, excess chlorine vented to a scrubber where it completely depleted the active scrubbing material (caustic soda), over-chlorinating the scrubber. The resulting decomposition reaction vented chlorine vapors to the atmosphere. Hazardous emissions continued for about six hours and led to the medical evaluation of five residents and 11 police officers, and the evacuation of 1.5 square miles. Read the CSB recommendations in this link.
May 15, 2011
Failure of UPS leading to turbine bearing damage
BHEL India has a good presentation on the importance of maintaining your UPS supply. In some of the incidents mentioned, the turbine bearing temperature increased to 140 Deg C and got damaged due to failure of UPS and auxiliary oil pump not coming in line afterthe turbine tripped. All failure modes of your UPS must be studied and corrective actions implemented. A UPS is a silent watchdog and if it malfunctions when it is required, it can cause a serious process incident. See the presentation in this link.
May 14, 2011
Combustible dust hazards - the explosions continue
The CSB has concluded that combustible iron dust has caused and explosion that killed one worker. The CSB mention the following:
"The first incident occurred on January 31 as two maintenance mechanics on the overnight shift inspected a bucket elevator that had been reported to be malfunctioning due to a misaligned belt. The bucket elevator, located downstream of an annealing furnace, conveyed fine iron powder to storage bins. The two mechanics were standing alone on an elevated platform near the top of the bucket elevator, which had been shut down and was out of service until maintenance personnel could inspect it. When the bucket elevator was restarted the movement immediately lofted combustible iron dust into the air. The dust ignited and the flames engulfed the workers causing their injuries. A dust collector associated with the elevator was reported to have been out of service for the two days leading to the incident.
The second incident occurred less than two months later on March 29 when a plant engineer, who was replacing igniters on a furnace, was engulfed in combustible dust which ignited. In the course of the furnace work, he inadvertently dislodged iron dust which had accumulated on elevated surfaces near the furnace. He experienced serious burns and bruises as a result of this second event; a contractor witnessed the fireball but escaped without injury."
Read the news release in this link.
"The first incident occurred on January 31 as two maintenance mechanics on the overnight shift inspected a bucket elevator that had been reported to be malfunctioning due to a misaligned belt. The bucket elevator, located downstream of an annealing furnace, conveyed fine iron powder to storage bins. The two mechanics were standing alone on an elevated platform near the top of the bucket elevator, which had been shut down and was out of service until maintenance personnel could inspect it. When the bucket elevator was restarted the movement immediately lofted combustible iron dust into the air. The dust ignited and the flames engulfed the workers causing their injuries. A dust collector associated with the elevator was reported to have been out of service for the two days leading to the incident.
The second incident occurred less than two months later on March 29 when a plant engineer, who was replacing igniters on a furnace, was engulfed in combustible dust which ignited. In the course of the furnace work, he inadvertently dislodged iron dust which had accumulated on elevated surfaces near the furnace. He experienced serious burns and bruises as a result of this second event; a contractor witnessed the fireball but escaped without injury."
Read the news release in this link.
May 13, 2011
The importance of properly designed back ups
A very good article by Bela Liptak about the back up systems at Fukushima mentions the following:
"The earthquake destroyed the electric power supply of the plant (the connection to the grid) which by itself should not have been a serious problem, because backup diesel generators (18) were provided. It seems they failed because they were not elevated and the 18-ft waves of the tsunami reached and damaged them. The reason for their being installed at low elevation was probably both convenience and concern for their stability. The destruction of these generators could have occurred because water entered the diesel fuel tanks and sank to the bottom because water is heavier than the diesel fuel. As the engine takes its fuel supply from the bottom of the tanks, water instead of oil reached it. It is also possible that the air intakes of the engines were not elevated and ended up under water. If either or both of these conditions existed, the engine could not operate.
The secondary battery backup (19) was of no use either because it was drastically undersized. It provided only about eight hours worth of electricity, while about ten times that would have been needed to supply the electricity needed for a safe shutdown. (It should be noted here that of the 104 American reactors, 93 are provided with only four-hour battery backups). Another problem in the Fukushima plant was the lack of automatic battery recharging. This could have been provided because the plant was still generating steam at a rate of about 5% of full capacity and, therefore, some of the turbine-generators could have been kept in operation.
No other backup was provided at the Fukushima plant. This is unfortunate, because electricity itself is not essential to cool the reactors. For example, if emergency cooling water tanks were provided on the roof, would have made it possible to charge water just by gravity, and if those tanks were properly sized, the accident could have been prevented."
Read the full article in this link
"The earthquake destroyed the electric power supply of the plant (the connection to the grid) which by itself should not have been a serious problem, because backup diesel generators (18) were provided. It seems they failed because they were not elevated and the 18-ft waves of the tsunami reached and damaged them. The reason for their being installed at low elevation was probably both convenience and concern for their stability. The destruction of these generators could have occurred because water entered the diesel fuel tanks and sank to the bottom because water is heavier than the diesel fuel. As the engine takes its fuel supply from the bottom of the tanks, water instead of oil reached it. It is also possible that the air intakes of the engines were not elevated and ended up under water. If either or both of these conditions existed, the engine could not operate.
The secondary battery backup (19) was of no use either because it was drastically undersized. It provided only about eight hours worth of electricity, while about ten times that would have been needed to supply the electricity needed for a safe shutdown. (It should be noted here that of the 104 American reactors, 93 are provided with only four-hour battery backups). Another problem in the Fukushima plant was the lack of automatic battery recharging. This could have been provided because the plant was still generating steam at a rate of about 5% of full capacity and, therefore, some of the turbine-generators could have been kept in operation.
No other backup was provided at the Fukushima plant. This is unfortunate, because electricity itself is not essential to cool the reactors. For example, if emergency cooling water tanks were provided on the roof, would have made it possible to charge water just by gravity, and if those tanks were properly sized, the accident could have been prevented."
Read the full article in this link
Transformers and process safety
Transformer fires can cause a process incident due to interruption of power to the unit. Give importance to the maintenance and fire detection and protection systems of your transformers. A good article by the US dept of interior mentions the following:
“The following devices should deenergize the transformer and trigger the transformer fire suppression system:
• Heat and/or fire sensors appropriately located near or on the transformer
• Manual discharge (control switch, pushbutton)
Depending on the type of sensors used and the details of the design, it may be desirable to require two sensors to operate before activating suppression to reduce false operation.
In addition, remote activation through the use of SCADA might be considered where operating practices permit and sufficient information is available to the remote operator.
Heat sensing fire detectors are the most reliable way of activating fire suppression for transformers. Techniques that should be considered include linear heat detectors (heat sensing cable) and infrared detectors. The appropriate method of detection is chosen when designing or re-designing the system.
Control system considerations include:
· Operation of the fire suppression system should deenergize the transformer to prevent water from discharging onto an energized transformer.
· Loss of power to fire suppression system pump motors, solenoids, and controls should be annunciated so the problem can be detected, diagnosed, and remedied.
· Activation of the suppression system should be annunciated and input to the SCADA system.
· Activation of the suppression system should block drains and pumping of oil-contaminated water from sumps into waterways.
· Activation of the suppression system should stop transformer fans and oil pumps that might feed the fire.
· Power the fire detection system from a reliable source, have continuous internal monitoring, and have sufficient output contacts for necessary alarm and control functions.
· Power the fire suppression system from a reliable source not affected by the loss of the transformer being protected.
· At unattended plants where high-volume deluge systems are retained, detection and control circuits should be designed to suppress the fire while reasonably minimizing the amount of water discharged. The purpose of this is to suppress the fire while limiting the risk of overtopping containment structures and contaminating waterways. It is reasonable to apply water for a limited time, temporarily shut down, and then reactivate water discharge to suppress any remaining fire. This might be accomplished through detectors that continue to sense fire, timers that cycle the system, or other means. In addition, high level detection in the containment structure is recommended to shut off fire suppression to prevent overflow. High level detection might be supplemented by video monitoring and remote deactivation through the use of SCADA.
Read the complete article in this link.
“The following devices should deenergize the transformer and trigger the transformer fire suppression system:
• Heat and/or fire sensors appropriately located near or on the transformer
• Manual discharge (control switch, pushbutton)
Depending on the type of sensors used and the details of the design, it may be desirable to require two sensors to operate before activating suppression to reduce false operation.
In addition, remote activation through the use of SCADA might be considered where operating practices permit and sufficient information is available to the remote operator.
Heat sensing fire detectors are the most reliable way of activating fire suppression for transformers. Techniques that should be considered include linear heat detectors (heat sensing cable) and infrared detectors. The appropriate method of detection is chosen when designing or re-designing the system.
Control system considerations include:
· Operation of the fire suppression system should deenergize the transformer to prevent water from discharging onto an energized transformer.
· Loss of power to fire suppression system pump motors, solenoids, and controls should be annunciated so the problem can be detected, diagnosed, and remedied.
· Activation of the suppression system should be annunciated and input to the SCADA system.
· Activation of the suppression system should block drains and pumping of oil-contaminated water from sumps into waterways.
· Activation of the suppression system should stop transformer fans and oil pumps that might feed the fire.
· Power the fire detection system from a reliable source, have continuous internal monitoring, and have sufficient output contacts for necessary alarm and control functions.
· Power the fire suppression system from a reliable source not affected by the loss of the transformer being protected.
· At unattended plants where high-volume deluge systems are retained, detection and control circuits should be designed to suppress the fire while reasonably minimizing the amount of water discharged. The purpose of this is to suppress the fire while limiting the risk of overtopping containment structures and contaminating waterways. It is reasonable to apply water for a limited time, temporarily shut down, and then reactivate water discharge to suppress any remaining fire. This might be accomplished through detectors that continue to sense fire, timers that cycle the system, or other means. In addition, high level detection in the containment structure is recommended to shut off fire suppression to prevent overflow. High level detection might be supplemented by video monitoring and remote deactivation through the use of SCADA.
Read the complete article in this link.
May 11, 2011
Identify chinks in your asset integrity program!
In 2004, a superheated steam pipeline in a nuclear plant in Japan ruptured, fatally killing 5 people. The rupture was 560 mm in size. The pipe wall at the rupture location had thinned from 10mm to 1.5mm. Apparently, the pipeline was never inspected since commissioning in 1976. Review your asset integrity program to ensure that there are no equipment or locations that have been skipped for inspection.In many companies having separate inspection departments, there will be a wealth of information, but soemone must be tracking the system to its logical conclusion. In today's scenario, with qualified and experienced inspection personnel in high demand, and turnover rates high in industries, it becomes imperative to have continuity in your asset integrity program. The chain is as strong only as the weakest link!
Read the article about the steam pipe rupture in this link.
Read the article about the steam pipe rupture in this link.
May 10, 2011
Tank overflows and process safety
Many atmospheric storage tanks are provided with gravity overflows which lead to a sewer or drain. Gravity overflow sizing should be carefully done. An article written in 1983 by P D Hills is a good reference. Read it in this link.
Gaskets failures
Are you giving enough importance for training your maintenance personnel on the types of gaskets used at your facility and the method of fixing them? A good article by Jim Drago mentions that out of 100 gasket failures, 68 were due to insufficient load, 14 were due to wrong selection. Crushing, cavitation, erosion and other factors contributed to the rest. Insufficient load was attributed to improper installation, misapplication, poor flange design, and/or bolt selection and rotated flanges.
Read the article in this link
Read the article in this link
May 9, 2011
Pipeline integrity
Ever since the San Bruno pipeline incident, there has been lot of debate on pileline safety in the USA. A article mentions the following
"Pipelines are by their nature distributed and remote. Having sensors and analytics available to help identify pipes at risk would be a sensible strategy. Oil and gas companies are, in fact, investing in smart technologies for safety monitoring. As part of the 2011 Vertical IT & Communications Survey conducted by IDC in January, 2011, which included 90 North American oil and gas companies, 42% stated that they would be investing in smart technologies for safety monitoring in the next one to two years. This is not surprising given the importance of safety in the upstream side of the business. But in midstream, there are a number of questions still to be answered. The major risks to pipelines are corrosion, digging and failure of materials. Is sensing technology available that can identify these potential risks to pipeline integrity? Sensors in remote locations should not have significant power requirements and should be able to be powered by long-life batteries. Are these sensors now available? Then too, is the telecommunications infrastructure available to support bringing the data back for analysis? We welcome your comments"
Read the complete article in this link..
"Pipelines are by their nature distributed and remote. Having sensors and analytics available to help identify pipes at risk would be a sensible strategy. Oil and gas companies are, in fact, investing in smart technologies for safety monitoring. As part of the 2011 Vertical IT & Communications Survey conducted by IDC in January, 2011, which included 90 North American oil and gas companies, 42% stated that they would be investing in smart technologies for safety monitoring in the next one to two years. This is not surprising given the importance of safety in the upstream side of the business. But in midstream, there are a number of questions still to be answered. The major risks to pipelines are corrosion, digging and failure of materials. Is sensing technology available that can identify these potential risks to pipeline integrity? Sensors in remote locations should not have significant power requirements and should be able to be powered by long-life batteries. Are these sensors now available? Then too, is the telecommunications infrastructure available to support bringing the data back for analysis? We welcome your comments"
Read the complete article in this link..
May 5, 2011
Process safety - what you don't see will get you!
A news article mentions that an unexploded German mine from World War Two was found near the BP Forties oil pipeline in the North Sea. The article also mentions that there is no immediate threat to the pipeline and the mine will be removed after a shutdown of the pipeline for a few days later in the year. The article reminded me of many chemical manufacturing companies taking over other organizations without doing a proper process safety due diligence. While financial due diligence is no doubt important,it becomes imperative that you also conduct a process safety due diligence to find out if you have any surprises in store!! The due diligence should cover the technical as well as the process safety cultural issues. Look before you leap and you can avoid an incident!
May 3, 2011
Fukushima and Bhopal
I have been reading with interest the interest in nuclear safety in Indian nuclear reactors after the Fukushima incident. I was wondering that if Bhopal had happened today, would the implementation of laws improve? While the West has learned from Bhopal and implemented stringent laws,we in India are yet to focus clearly on chemical process safety management. With the chemical industry set to boom in the next decade, should we wait for another Bhopal to occur before actions are taken? The current focus on process safety in India is still largely on a reactive basis. While large organisations have proactively and voluntarily taken up PSM, it is the medium and small scale organisations that are not prepared. Many of these units handle highly hazardous chemicals. It is time that the large players in the Chemical Industry start a mentoring program free of cost to enable the small and medium scale players to improve process safety. It is good for the whole industry.
May 2, 2011
Turbines and fires
According to a 1985 EPRI report, "Turbine Generator Fire Protection by Sprinkler System," by Black and Veatch, a survey of 175 generator related fires and 33 hydrogen explosions from the period 1930 to 1983 indicated that of the 119 fires involving lube oil, 39 fires occurred at the turbine bearings, 16 fires involved lube oil piping, 14 fires occurred below the turbine deck, and seven fires involved the lube oil reservoir. The exciter has also been identified as both a lube oil and an electrical hazard (seven electrical fires and two oil fires).My experience indicates that this statistic is valid even today.
Piping joint leaks, view glass leaks, piping cracks due to vibration etc all cause lube oil to leak, causing fires. These fires can stop production for quite a while as not only equipment but control and electrical cables will also get damaged. A leak of lube oil from a lube oil pump discharge line causes an atomised spray of lube oil and the source of ignition could be an uninsulated steam line. I have witnessed a major fire caused by a lube oil line leak and the damage was enormous. Train your operators to report unusual vibration, minor leaks and ensure your asset integrity program covers the lube oil system.
Piping joint leaks, view glass leaks, piping cracks due to vibration etc all cause lube oil to leak, causing fires. These fires can stop production for quite a while as not only equipment but control and electrical cables will also get damaged. A leak of lube oil from a lube oil pump discharge line causes an atomised spray of lube oil and the source of ignition could be an uninsulated steam line. I have witnessed a major fire caused by a lube oil line leak and the damage was enormous. Train your operators to report unusual vibration, minor leaks and ensure your asset integrity program covers the lube oil system.
May 1, 2011
Bhopal disaster - Police Chief's account
I met Mr Swaraj Puri, the then Chief of Bhopal Police when the Bhopal gas disaster occured, at an international conference on Bhopal gas disaster at IIT Kanpur in 2004. He recounted the horrors of that night and the difficulty he and his men faced in the aftermath of the tragedy. I chanced upon his website where he mentions all the details of that fateful night in December 1984.He mentions the following:
"The Shortcoming and the Lessons for the future
One of the first thing that struck us when the gas leak took place was our total lack of preparedness and ignorance about how to deal with such a situation.
The medical fraternity and the chemists were unaware about the effects of Methyl Isocynate on humans and also the medical treatment to deal with cases of exposure. The Chief Medical Officer of the Union Carbide Factory initially deemed MIC as only an irritant! Since the gas was of the cyanide family, Sodium Thiosulphite was administered as a probable antidote. Specifically the factory was to blame because:
Not every thing was a failure, the Police and the Medical Department with whatever meager resources at their disposal put up a tremendous immediate response. NGOs and social service organizations moved in immediately to help in the relief efforts. Local media was extremely helpful in scotching rumors and in disseminating essential information. Even the international media cooperated. The most affected area included the Bhopal Railway Station, the station master perished from the effects of the gas but the railway personnel immediately alerted the concerned, regulating the movement of trains and thus saving many lives.
FOR THE FUTURE
The Administration, the Police and other essential services must know the location and exact nature of any hazardous chemical that is stored by any industrial establishment. The procedure to be followed in case of exposure and the antidotal treatment should be known to the aforesaid. Adequate quantity of antidote should be available with the industry which stores such hazardous chemical.
"The Shortcoming and the Lessons for the future
One of the first thing that struck us when the gas leak took place was our total lack of preparedness and ignorance about how to deal with such a situation.
The medical fraternity and the chemists were unaware about the effects of Methyl Isocynate on humans and also the medical treatment to deal with cases of exposure. The Chief Medical Officer of the Union Carbide Factory initially deemed MIC as only an irritant! Since the gas was of the cyanide family, Sodium Thiosulphite was administered as a probable antidote. Specifically the factory was to blame because:
- The plant did not give vital information about the storage and handling of hazardous and dangerous materials.
- Effect of MIC on humans and the antidotal treatment was not known to the medical fraternity and such knowledge if available was not disseminated to the emergency services.
- There was a lack of appreciation of disaster management within the Government and also inadequate co-ordination between the factory and the emergency services.
- There was an absence of proper warning system in the plant. No practice drills were ever held.
- Union Carbide itself had limited data on MIC and probably had never anticipated the 'worst case scenario
- Poor plant maintenance practices. Inventory of vital spares had been depleted.
- Exodus of some of the experienced engineers and operating personnel from the plant.
- Economy measures, overriding safety concerns.
- Densely populated areas around the plant. Often shanties / slums come up on vacant areas surrounding the factories greatly increasing the danger of loss to human life. Urban planning authorities are powerless, there is an absence of political will since much of the problem is caused by the poor flocking to the cities in search of employment.
- Absence of a proper road network, rescue workers had to move on foot through densely populated areas
- Poor communications, though things have improved now.
- Lack of effective emergency medical facilities.
- Inadequate transport for emergency evacuation, even today the infrastructure is woefully in adequate.
- Cattle living in residential areas, a peculiar Indian problem, not there in the metros, but very much in existence in other urban centers.
- People sleeping on pavements/ railway platforms.
- Unidentified dead bodies. Creating difficulties in identification of religion and also medico- legal problems. Many could not be identified. They were photographed, given numbers and cremated/buried
- Along with humans a large number of animals, mostly cattle perished in the disaster. Their disposal became a serious health problem. There was a threat of an epidemic. Cranes and bulldozers had to be put in operation to remove the dead animals and then bury them in a mass grave disinfected with tonnes of bleaching powder.
- Administration collapsed with key functionaries running for their lives instead of manning key positions
- Relief operations became difficult as the disaster caused total enervation in those entrusted with emergency relief.
Not every thing was a failure, the Police and the Medical Department with whatever meager resources at their disposal put up a tremendous immediate response. NGOs and social service organizations moved in immediately to help in the relief efforts. Local media was extremely helpful in scotching rumors and in disseminating essential information. Even the international media cooperated. The most affected area included the Bhopal Railway Station, the station master perished from the effects of the gas but the railway personnel immediately alerted the concerned, regulating the movement of trains and thus saving many lives.
FOR THE FUTURE
The Administration, the Police and other essential services must know the location and exact nature of any hazardous chemical that is stored by any industrial establishment. The procedure to be followed in case of exposure and the antidotal treatment should be known to the aforesaid. Adequate quantity of antidote should be available with the industry which stores such hazardous chemical.
- The people living in the vicinity should be made aware of
- the chemicals being stored
- The likely symptoms and antidote
- Emergency procedures which should be also rehearsed
- Nearest medical facilities
- System of contacting the Factory management
- Sources of transportation for emergency evacuation and the availability of ambulances.
- Rumors and unfounded fears should countered by local Radio and TV
- NGOs and other Voluntary Organizations capable of providing help should be involved in the disaster management process and be listed and known to the administration as well as the residents of the vicinity
- Residents living in the vicinity should train with the emergency services"
April 26, 2011
Pilots and Process Safety
I am talking about Flare Pilots! Do not underestimate the need for keeping your flare systems and pilots, including their ignition systems in good condition. A working flare is a silent sentinel for process safety. For a troubleshooting guide on flare systems see this link.
April 24, 2011
Lessons from Deepwater Horzon incident investigation by USCG
The US Coast Guard has released its investigation report on the Deepwater Horizon disaster. There are lessons to be learnt for us in the chemical processing industry. The key findings from the report are given below:
"Failure to Use the Diverter Line: When the drilling crew directed the uncontrolled well flow through the Mud Gas Separator (MGS), the high pressure exceeded the system’s capabilities and caused gas to discharge on the Main Deck. Alternatively, the crew could have directed the well flow through a “diverter line” designed to send the flow over the side of the MODU (Mobile Offshore Drilling Unit). Although the diverter line also may have failed under the pressure, had it been used to direct the flow overboard, the majority of the flammable gas cloud may have formed away from the Drill Floor and the MODU, reducing the risk of an onboard explosion.
Hazardous Electrical Equipment: At the time of the explosions, the electrical equipment installed in the “hazardous” areas of the MODU (where flammable gases may be present) may not have been capable of preventing the ignition of flammable gas. Although DEEPWATER HORIZON was built to comply with IMO MODU Code standards under which such electrical equipment is required to have safeguards against possible ignition, an April 2010 audit found that DEEPWATER HORIZON lacked systems to properly track its hazardous electrical equipment, that some such equipment on board was in “bad condition” and “severely corroded,” and that a subcontractor’s equipment that was in “poor condition” had been left in hazardous areas. Because of these deficiencies, there is no assurance that the electrical equipment was safe and could not have caused the explosions.
Gas Detectors: Although gas detectors installed in the ventilation inlets and other critical locations were set to activate alarms on the bridge, they were not set to automatically activate the emergency shutdown (ESD) system for the engines or to stop the flow of outside air into the engine rooms. The bridge crew was not provided training or procedures on when conditions warranted activation of the ESD systems. Thus, when multiple gas alarms were received on the bridge, no one manually activated the ESD system to shut down the main engines. Had it been activated immediately upon the detection of gas, it is possible that the explosions in the engine room area could have been avoided or delayed.
Bypassed Systems: A number of gas detectors were bypassed or inoperable at the time of the explosions. According to the chief electronics technician, it was standard practice to set certain gas detectors in “inhibited” mode, such that gas detection would be reported to the control panel but no alarm would sound, to prevent false alarms from awakening sleeping crew members. Similarly, the crew bypassed an automatic shutdown system designed to cut off electrical power when ventilation system safety features failed, possibly allowing flammable gas to enter an enclosed area and reach an ignition source. The chief electrician had been told that it had “been in bypass for five years” and that “the entire fleet runs them in bypass.”
Design of the Main and Emergency Power Sources: Although the arrangement of main and emergency generators on DEEPWATER HORIZON met IMO MODU Code requirements to have completely independent engine-generator rooms along with independent power distribution and control systems, it did not prevent a total failure of the main electrical power system, when the explosions and fire damaged multiple generators and their related power distribution and control equipment. The design did not adequately take into account that the proximity of the air inlets to each other created a risk that flammable gases could impact all six generators at once.
Crew Blast Protection: DEEPWATER HORIZON did not have barriers sufficient to provide effective blast protection for the crew. Although the barriers separating the Drill Floor from adjacent crew quarters met the standards of the IMO MODU Code, those specifications are only designed to slow the spread of fire, not to resist an explosion. They did not prevent personnel in the crew accommodations area from sustaining injuries.
Command and Control: Because of a “clerical error,” by the Republic of the Marshall Islands, DEEPWATER HORIZON was classified in a manner that permitted it to have a dual-command organizational structure under which the OIM was in charge when the vessel was latched on to the well, but the master was in charge when the MODU was underway between locations or in an emergency situation. When the explosions began, however, there was no immediate transfer of authority from the OIM (Offshore Installation Manager) to the master, and the master asked permission from the OIM to activate the vessel’s EDS. This command confusion at a critical point in the emergency may have impacted the decision to activate the EDS".
The full report is available in this link.
"Failure to Use the Diverter Line: When the drilling crew directed the uncontrolled well flow through the Mud Gas Separator (MGS), the high pressure exceeded the system’s capabilities and caused gas to discharge on the Main Deck. Alternatively, the crew could have directed the well flow through a “diverter line” designed to send the flow over the side of the MODU (Mobile Offshore Drilling Unit). Although the diverter line also may have failed under the pressure, had it been used to direct the flow overboard, the majority of the flammable gas cloud may have formed away from the Drill Floor and the MODU, reducing the risk of an onboard explosion.
Hazardous Electrical Equipment: At the time of the explosions, the electrical equipment installed in the “hazardous” areas of the MODU (where flammable gases may be present) may not have been capable of preventing the ignition of flammable gas. Although DEEPWATER HORIZON was built to comply with IMO MODU Code standards under which such electrical equipment is required to have safeguards against possible ignition, an April 2010 audit found that DEEPWATER HORIZON lacked systems to properly track its hazardous electrical equipment, that some such equipment on board was in “bad condition” and “severely corroded,” and that a subcontractor’s equipment that was in “poor condition” had been left in hazardous areas. Because of these deficiencies, there is no assurance that the electrical equipment was safe and could not have caused the explosions.
Gas Detectors: Although gas detectors installed in the ventilation inlets and other critical locations were set to activate alarms on the bridge, they were not set to automatically activate the emergency shutdown (ESD) system for the engines or to stop the flow of outside air into the engine rooms. The bridge crew was not provided training or procedures on when conditions warranted activation of the ESD systems. Thus, when multiple gas alarms were received on the bridge, no one manually activated the ESD system to shut down the main engines. Had it been activated immediately upon the detection of gas, it is possible that the explosions in the engine room area could have been avoided or delayed.
Bypassed Systems: A number of gas detectors were bypassed or inoperable at the time of the explosions. According to the chief electronics technician, it was standard practice to set certain gas detectors in “inhibited” mode, such that gas detection would be reported to the control panel but no alarm would sound, to prevent false alarms from awakening sleeping crew members. Similarly, the crew bypassed an automatic shutdown system designed to cut off electrical power when ventilation system safety features failed, possibly allowing flammable gas to enter an enclosed area and reach an ignition source. The chief electrician had been told that it had “been in bypass for five years” and that “the entire fleet runs them in bypass.”
Design of the Main and Emergency Power Sources: Although the arrangement of main and emergency generators on DEEPWATER HORIZON met IMO MODU Code requirements to have completely independent engine-generator rooms along with independent power distribution and control systems, it did not prevent a total failure of the main electrical power system, when the explosions and fire damaged multiple generators and their related power distribution and control equipment. The design did not adequately take into account that the proximity of the air inlets to each other created a risk that flammable gases could impact all six generators at once.
Crew Blast Protection: DEEPWATER HORIZON did not have barriers sufficient to provide effective blast protection for the crew. Although the barriers separating the Drill Floor from adjacent crew quarters met the standards of the IMO MODU Code, those specifications are only designed to slow the spread of fire, not to resist an explosion. They did not prevent personnel in the crew accommodations area from sustaining injuries.
Command and Control: Because of a “clerical error,” by the Republic of the Marshall Islands, DEEPWATER HORIZON was classified in a manner that permitted it to have a dual-command organizational structure under which the OIM was in charge when the vessel was latched on to the well, but the master was in charge when the MODU was underway between locations or in an emergency situation. When the explosions began, however, there was no immediate transfer of authority from the OIM (Offshore Installation Manager) to the master, and the master asked permission from the OIM to activate the vessel’s EDS. This command confusion at a critical point in the emergency may have impacted the decision to activate the EDS".
The full report is available in this link.
Ammonia and thermal expansion
For my friends in the ammonia industry, let me remind you ammonia can also kill you in another way apart from exposure to it. 25 years ago, I witnessed a large leak due to thermal expansion of liquid ammonia which was not understood by the technical services team of the plant who had carried out an in house modification. The liquid ammonia which was blocked in, expanded due to thermal expansion and a pressure gauge in the line gave away, rocketing the gauge and causing a large leak. The flying projectile could have killed people.Airgas has published a technical bulletin about ammonia, which all personnel in ammonia facilities should read. Read it in this link.
April 23, 2011
Process Safety and Reaction calorimetry
In many batch processes, I keep observing companies hesitant to spend money to obtain reaction data prior to scale up to plant scale. The old adage "we have never done it before and nothing has happened" is often the answer. One incident that happens due to lack of understanding of reaction chemistry is enough to wipe out ALL your gains.An article written in 1991 points out the need for complete data prior to scale up to plant scale. One of the case studies mentioned is quoted below:
"A specific example of this type of approach was given by Homare Shinohara, of Eisai Chemical Co, who described the design of a manufacturing plant for pharmaceutical intermediates based on amino-thiaziazol carboxylic acid, generally known as F-15. Thiaziazol compounds are often used as a side chain at the 7-position of cephalosporin antibiotics. Thiaziazol carboxylic acid chloride (F-15Cl), for example, is being used at Eisai for the synthesis of two new antibiotics currently under development, E-1040 and E-1077. E-1040 is an injection drug, which is said to have the strongest bactericidal activity against Pseudomonas among the cephalosporins currently available, although less efficacious against Staphylococci. It is currently proceeding to Phase III testing. A development of E-1040, E-1077 is described as a fourth-generation cephalosporin having a wide spectrum of antibiotic activity from Gram-positives including Staphylococci to Gram-negatives including Pseudomonas. This compound is currently in e-phase II testing in Japan.
For the production of these compounds F-15 must be chlorinated. However, this intensely exothermic reaction can also produce two kinds of by-products: anti-F-15 acid chloride and phosphoric-amide-F-15 acid chloride. The resultant concentrations of these by-products is directly dependent upon the temperature of the reaction mass.
As a preliminary, the decomposition temperatures of the starting materials and final desired product were determined to confirm their safety. Shinohara's research team then used a Mettler Contalab to firstly determine the conditions required to suppress byproduct synthesis and then measure the heat of reaction to assist in the final plant design. To confirm the results the heats of reaction were also calculated using a Mettler RC 1.
It was determined that the reaction temperature should be maintained below -10ºC and that reaction heats generated depended upon the method of addition of phosphorus pentachloride - continuous, one or two portions. Although at 400 kJ/kg the reaction heats produced with continuous and one portion addition were 50kJ/kg higher than that for a two portion addition, possibly due to the absorption of heat by simultaneous crystallisation, it was decided to base the plant design on a 500-litre, glass-lined reactor with continuous addition of phosphorous pentachloride over a 30-minute period.
On calculation of the heat removal capacity of the jacket on the reactor using brine at -30¡C it was found to be insufficient to maintain the temperature below -10¡C. Further calculations determined the phosphorus pentachloride addition period would need to be extended to 3.3 hours, despite pilot-scale production of 5kg batches being satisfactorily achieved with additions over 30 minutes".
Read the full article with other examples in this link.
"A specific example of this type of approach was given by Homare Shinohara, of Eisai Chemical Co, who described the design of a manufacturing plant for pharmaceutical intermediates based on amino-thiaziazol carboxylic acid, generally known as F-15. Thiaziazol compounds are often used as a side chain at the 7-position of cephalosporin antibiotics. Thiaziazol carboxylic acid chloride (F-15Cl), for example, is being used at Eisai for the synthesis of two new antibiotics currently under development, E-1040 and E-1077. E-1040 is an injection drug, which is said to have the strongest bactericidal activity against Pseudomonas among the cephalosporins currently available, although less efficacious against Staphylococci. It is currently proceeding to Phase III testing. A development of E-1040, E-1077 is described as a fourth-generation cephalosporin having a wide spectrum of antibiotic activity from Gram-positives including Staphylococci to Gram-negatives including Pseudomonas. This compound is currently in e-phase II testing in Japan.
For the production of these compounds F-15 must be chlorinated. However, this intensely exothermic reaction can also produce two kinds of by-products: anti-F-15 acid chloride and phosphoric-amide-F-15 acid chloride. The resultant concentrations of these by-products is directly dependent upon the temperature of the reaction mass.
As a preliminary, the decomposition temperatures of the starting materials and final desired product were determined to confirm their safety. Shinohara's research team then used a Mettler Contalab to firstly determine the conditions required to suppress byproduct synthesis and then measure the heat of reaction to assist in the final plant design. To confirm the results the heats of reaction were also calculated using a Mettler RC 1.
It was determined that the reaction temperature should be maintained below -10ºC and that reaction heats generated depended upon the method of addition of phosphorus pentachloride - continuous, one or two portions. Although at 400 kJ/kg the reaction heats produced with continuous and one portion addition were 50kJ/kg higher than that for a two portion addition, possibly due to the absorption of heat by simultaneous crystallisation, it was decided to base the plant design on a 500-litre, glass-lined reactor with continuous addition of phosphorous pentachloride over a 30-minute period.
On calculation of the heat removal capacity of the jacket on the reactor using brine at -30¡C it was found to be insufficient to maintain the temperature below -10¡C. Further calculations determined the phosphorus pentachloride addition period would need to be extended to 3.3 hours, despite pilot-scale production of 5kg batches being satisfactorily achieved with additions over 30 minutes".
Read the full article with other examples in this link.
April 21, 2011
VFD's and process safety
VFD (Variable frequency drives) are used for conserving energy. The process safety issues when using VFD's must be considered when using them. To cut costs, some users try to install a single VFD for both the running and standby motors of a pump. This poses issues in safely locking out energy supply when one pump is given for maintenance. Read a good article on VFD's in this link.
April 19, 2011
Underground pipelines and excavation
An incident has occurred in Goa when a underground naphtha pipeline was punctured by accident by a JCB during excavation. It sparked off a major fire. As per the news item, "According to fire fighters and emergency service personnel, the incident occurred when a negligent heavy earth mover driver damaged an underground naphtha pipeline while undertaking excavation work.“It generated a spark, due to which traces in the naphtha pipeline burst into huge flames,” they informed.Immediately, after the pipeline was damaged, a blast occurred and flames reached upto 40 ft high and engulfed the earth moving excavator machine, 23 two-wheelers, six cars, three trucks, one tempo and one phosphoric acid tank, which were parked at the entrance gate of the industry.The JCB driver along with two labourers, who were standing nearby, sustained burn injuries and were rushed to a private hospital.Luckily, a major tragedy was averted, as two ammonia storage tanks of the industry are located barely 50 metres away from the entrance gate, where the fire incident occurred".
Read the news item in this link.
Read the news item in this link.
April 18, 2011
The importance of Inspection
A major fire incident in a gas turbine was traced to the improperly welded tubes in the natural gas regeneration coil section of the GT. Improper welding has given rise to many process incidents and it is important for you to have an adequately staffed inspection team to ensure proper welding procedures are followed and inspection is carried out. However, in many organisations, I observe an erosion of inspection capability as senior experienced personnel retire and are not replaced either due to lack of personnel or lack of experience. This is a recipe for disaster.
Read about the GT fire incident in this link.
Read about the GT fire incident in this link.
Subscribe to:
Posts (Atom)