Explosion in sulphuric acid tank

An explosion in a sulphuric acid tank has injured four personnel in Japan. There is the danger of presence of hydrogen in sulphuric acid tanks and when you do hot work be aware of the simple precautions like gas testing etc.
Read about the accident in this link. The Chemical Safety Board had earlier brought out a safety bulletin on the Dangers of Hot work, which is worth reading for every plant operation, maintenance and safety personnel. Read it in this link.

Fire in Pharma Plant

A fire in the vacuum dryer area of a pharma plant has reportedly seriously injured three people. As per Company press release, it states "There was a fire incident in a powder processing area at early hours on Nov 28,2011, at unit 11 which is located at Pydibhimavaram, Srikakulam near Vizag, A.P. Three persons were injured and they were taken to the hospital. The powder processing area is isolated from the intermediate block. There was no impact to the operations as well as to the assets".
Another news report indicates that the fire was caused by an explosion due to high pressure in the vacuum dryer.
Read the news reports in these links
Link 1
Link 2
Link 3

Remembering Bhopal............

Please spend December 2nd/3rd as “Process Safety Day” in your organisation. Educate your personnel on the Bhopal Gas tragedy and its lessons. 27 years ago, on the night on December 2nd/3rd, 1984, on a wintry night in Bhopal, thousands of men, women and children died an excruciating death when MIC leaked from the Union Carbide factory. The survivors and the next generation children born to those exposed to the gas still are suffering from the effects of the gas. Bhopal is an ongoing tragedy and should never be forgotten. The Bhopal gas disaster comprises actually of three disasters - the first was the actual incident, the second was the inadequate compensation received and the third is the ongoing legacy of genetic defects and effects of the hazardous waste that has seeped into the ground water. Every plant operating, maintenance and safety personnel must never forget the lessons of Bhopal. They are still relevant today:
1. Do not cut costs without looking at the effects on process safety
2. Maintain all your layers of defense including asset integrity
3. Continually ensure that competency of personnel operating and maintaining plants are updated and current
4. Be prepared for the worst case scenario.
5. Understand the risks and measures to eliminate / reduce or control them
6. Learn from your past incidents. Those who do not learn are condemned to repeat the incidents.
7. Pay heed to your process safety management system audit reports

As you are aware, this blog is also dedicated to the surviving victims of Bhopal and for my regular subscribers, I appeal to you to buy my book "Practical Process Safety Management", the proceeds from which are donated to the surviving victims of Bhopal.Contact me at bkprism@gmail.com for buying the book.

See a presentation on the Bhopal Gas Tragedy by Vijita S Aggarwal, Associate Professor, University School of Management Studies,GGS Indraprastha University,Delhi, India in this link.
Read my older post comparing the Bhopal and the BP incident of 2005 in this link
Read the then Police Chief’s account of the tragedy in this link.

Witness to a catastrophic near miss!

On 29.11.1984, I was working  in an ammonia plant when a cylcone hit the place. Management had taken advance action and instructed us to shut off the back end of ammonia plant (the back end of the ammonia plant involves high pressures). We had shut down the back end and were waiting for the cyclone to hit us. The wind speeds were very high and all of us were taking shelter in the control room. A complaint then came in from the  another plant that was located within the same complex, that they were experiencing severe ammonia odour.  Thinking that the pilot burners of the ammonia derrick supported flare that was provided for emergency venting of the ammonia storage tank was put off by the high winds, I requested operators to go out and check them. Three operators had to go, holding each other tightly,as the wind speed was so high and could blow a man off his feet. After a short while they came back and reported that the flare was missing. I went out to check with another team and we found to our horror that the flare structure had collapsed on the main ammonia vapor line coming from the tank. The derrick structure was weak and could not bear the brunt of the wind speeds, but the main flare gas pipe was in good condition and when the derrick toppled, the main gas pipe prevented it from falling all of a sudden. Instead it fell slowly and came to rest on the ammonia vapor line! The 8" main ammonia vapour line from the tank was dented, but did not leak.
When you conduct your asset integrity program, pay attention to structures. Nowadays, in many plants, painting schedules are taking a back seat, with the net result that corrosion creeps in. Corrosion is a silent killer. It will hit you one day if you don't maintain your assets.
Interestingly, recently I read an article where a complete flare structure repair was done with minimum downtime in a plant.Read the article in this link.

Escaping from steam

Many of you will be working with steam. During startups the possibility of water hammer in a steam pipeline has the potential to rupture the line or flange joints. Your SOPs must warn operators about the dangers of water hammer. An article mentions that the best way to escape from a closed space in which a steam leak has been triggered due to water hammer is to escape in the direction in which the steam is leaking through an exit. Read this article in this link

Heat transfer fluids

Paratherm have brought out a good booklet on heat transfer fluids - do's. dont's and best practices. Some of the points brought out are:
"If any hydrocarbon liquid (oil, grease, heat transfer fluid, hydraulic fluid) is allowed to enter porous insulation, it will begin to oxidize, raising the insulation’s internal temperature. If this temperature exceeds the fluid’s autoignition temperature, the fluid is likely to spontaneously combust into a smoldering fire. Thoroughly inspect all insulation for signs of wetness and other damage.Although “hydro” testing is a commonly accepted practice with heat transfer systems,alternatives such as pressure-testing with inert gas or with the heat transfer fluid itself should be considered. Water in a system can cause pump cavitation and corrosion and, if trapped in a “dead leg” and hit by high-temperature oil, can flash to steam and literally blow the pipe or tubing apart. And if the pipe doesn’t burst, the expansion can push a slug of hot oil out the expansion tank’s vent—a serious safety hazard".
Read the complete article in this link.

Blast in melamine plant kills 14

A BBC news report indicates that 14 people were killed in a blast in a melamine plant in China when work was going on an heat exchanger. Read the news report in this link. The cause of the explosion is not known.
The European agency for safety and health and work reports an incident in 2003, in Netherlands, where three maintenance workers were killed when a gas oven in a melamine plant exploded and the three workers who were standing on the cover of the oven fell into it.The gas oven was fired by natural gas and off gases from neighbouring plants. The off gases were contaminated and were filtered before use. The filters had to be cleaned regularly. A short cut taken during maintenance of these filters created a combustible mixture of gas and air in the oven which was ignited by a stray spark. Although this was the immediate cause of the explosion, investigations concluded that the underlying cause was a company culture which had allowed the untested short cut procedure to be used.
The lesson is to follow safe procedures and not to take short cuts even under time pressure. The accident also highlights the importance of the safety culture. Read the report in this link.

Chlorine leak in paper mill

Thanks to Abhay Gujjar for sending information about a chlorine leak from a chlorine dioxide storage tank in a paper mill. Four people are reported taken to hospital.
TAPPI, the leading association for the worldwide pulp, paper, packaging and converting industries has published a booklet on safe handling and storage of Chlorine dioxide. The following points are mentioned:
Chlorine dioxide gas is unstable and readily decomposes to chlorine and oxygen under upset conditions
Chlorine dioxide decomposition is a propagating reaction similar to a combustion front or flame. Providing a sweep of fresh air across the vapor space of a storage tank has shown to reduce the probability and violence of decomposition.
Read the complete guidelines in this link. 
Read about the incident in this link.

Bio Fuels and Process Safety - Ethanol Tanks

The bio fuel industry is growing at a rapid pace. However, from a process safety point of view, it is hazardous as it deals with flammable chemicals like ethanol.  An article mentions the following:
"Steel tanks containing fuel-grade ethanol develop leaks due to stress corrosion cracking, says Oliver Moghissi, president of the National Association of Corrosion Engineers. Corrosion can be an issue near vents and any external appurtenances exposed to air, allowing ethanol to pick up moisture. Storing hydrous ethanol can produce even more corrosion due to higher water content.
There are a number of corrosion mitigation strategies, he adds, drawing on technical input from Narasi Sridhar, vice president of DNV USA, a classification society, and a fellow member of NACE. Galvanic sacrificial coatings, such as zinc or aluminum, will protect steel tanks containing ethanol. The main limitation to this system of corrosion mitigation is that it could have a negative effect on product quality. “Any dissolved metal species in the ethanol can render the ethanol unacceptable to the automotive industry, its main customer,” he tells EPM. “Any galvanic coating therefore must be tested rigorously by the end-user, the automotive community, which can be time consuming and expensive.”
Cathodic protection, however, doesn’t work for the insides of metal structures containing ethanol, the corrosion engineers add. The fuel has low electrical conductivity when compared to water and, as a result, much of the applied voltage is insulated from the metal needing to be protected. “Therefore, impressed or sacrificial cathodic protection systems will not work in ethanol,” Moghissi says. “In ethanol-gasoline mixtures, the situation is even worse since gasoline has a lower electrical conductivity than ethanol.”Read the full article in this link. 

Vacuum - a deadly killer

A news article mentions that a man was sucked into a huge duct conducting gaseous silicic acid that led to his death. The duct was about three feet in diameter. Besides inhaling the gas, he had also suffered injuries on the head while being sucked in. Another employee was also partially sucked into the duct but managed to escape with minor injuries.Read the article in this link.

Dust explosions - status of regulations in USA

An AP news article mentions the lack of regulations in the USA regarding dust explosions.
"Figures compiled by the U.S. Chemical Safety Board illustrate the scope of the problem. A 2006 study reported there were at least 281 dust explosions in the U.S. between 1980 and 2005 that killed 119 workers and injured 718. In 2007, it recommended that the Occupational Health and Safety Administration create workplace rules to control dust and cut down on explosions. The Chemical Safety Board is charged with investigating industrial accidents, but it must rely on regulatory agencies like OSHA to effect change from its findings.
"Despite the seriousness of the combustible dust problem in industry, OSHA lacks a comprehensive standard to require employers in general industry to implement the dust explosion prevention and mitigation measures," the Chemical Safety Board wrote in its 2007 report".
Read the full news article in this link.

Ammonia tank safety valve release

An ammonia tank in a plant in Australia apparently released close to 1 MT of ammonia through its safety valves due to overpressure of the tank. The plant has been ordered to close down.The Government spokesperson  correctly mentions that a safety valve is the last line of defence and this is a serious incident. Many atmospheric ammonia tanks and LPG bullets have their safety valves open to atmosphere. With rampant unauthorized residential settlements still happening around chemical industries and refineries in India, is a disaster waiting to happen?
See the video and report of the incident in this link.
Read a press release of the incident by the company in this link.