Chemical Reactor Safety

The UK Health and Safety Executive has a write up on test methods for exothermicity for chemical reactors. Quoting from the article,
“The main types of test are:
1) basic screening tests;
2) isothermal calorimetry, aimed at quantifying reaction kinetics, heats of reaction, etc for particular reaction systems;
3) adiabatic calorimetry, used mainly for examining the runaway potential of reactions and individual compounds; and
4) combination instruments intended not only to give thermal data but also to calculate appropriate reactor vent sizes.
These tests tend not to give absolute results, in that the experimental conditions may affect the data obtained. Factors such as sample size, container material, heating rate, thermal inertia and endothermic effects (eg evaporation, gas evolution and phase changes) can all affect the result. The work, therefore, needs to be carried out by persons who are adequately trained and experienced in this type of investigation, to ensure that in each case suitable techniques are employed and adequate account is taken of experimental variables”.
Read the write up in this link.

Nuclear and process safety - Part 2

For those of who saw the videos of the explosion in the nuclear reactor in Japan, you must have observed the blast wave destroying the wall panels but the metal structure stayed intact. I believe the design worked as intended. But the news that sea water is being used for cooling indicates the seriousness of the situation. In a chemical plant emergency, we do not have to deal with radiation leaks but imagine the plight of the emergency responders in the Japan nuclear plant. They must wear protective clothing for the radiation and tackle the emergency also. For those of you who want to know a little more about the nuclear reactor incident, see this link
Another good article is in this link.
Read an explanation about the second reactor explosion in this link.

Earthquakes and nuclear /process safety

Our prayers are with the victims of the Japan earthquake. A BBC news article mentions the following:

"Japan's prime minister has declared a "nuclear emergency" after a number of reactors shut down in the wake of a massive earthquake hitting the country.Eleven reactors at four nuclear power stations automatically shut down, but officials said one reactor's cooling system failed to operate correctly.
Under Japanese law, an emergency must be declared if a cooling system fails.
In total, the country has 55 reactors providing about one-third of the nation's electricity.
In a statement, the Japan Atomic Industrial Forum released a statement that said Prime Minister Naoto Kan had declared the emergency "in case prompt action" had to be taken, but added that "no release of radioactive material" had been detected.
"Since emergency diesel generators at the Fukushima-1 and -2 NPPs are out of order, (energy company) TEPCO sent the emergency report to Nisa. There is no report that radiation was detected out of the site."
The reactor at the Fukushima Daiichi power station that triggered the emergency alert was the 40-year-old Reactor 1, one of six on the site.Reactors 1, 2 and 3 automatically shut down when the Magnitude 8.9 quake shook the plant, while reactors 4, 5 and 6 were not in operation as they were undergoing scheduled inspections.
It is understood that the earthquake cut electricity supplies to the power station, and the back-up generators did not come into operation when the outage occurred. As a result, not all of the cooling systems were available".
Obviously something happened to the back up generators and they could not come in line. We have to wait for the investigation report to come out.
Read the BBC article in this link.
Read an article about the seismic zoning in India in this link.

Making Process Safety Management Work

I am quoting excerpts from a recent speech by Mr Bob Dudley (Group CEO, BP) that is on the BP website
“We have created a powerful, central safety and operational risk organization headed by Mark Bly, who led our internal investigation of the accident. Mark reports directly to me and sits on our executive team.
His organization has the resources and the mandate to drive safe, reliable, and compliant operations, including intervention rights, in BP’s exploration and production operations anywhere in the world.
The new organization is now in action across BP in four main areas:
First, it is strengthening and clarifying requirements for safe, compliant and reliable operations.
Second, it is deploying around 500 specialist personnel within our businesses to guide, advise, and if necessary, intervene.
Third, it is providing deep technical expertise to our operating businesses.
And fourth, it is intervening where needed to stop operations and bring about corrective actions.
We are already seeing results.
For example, we have shut in one production platform to repair the fire water pumps. Another platform was shut down after the discovery of incorrect specifications for some fasteners. And a producing field was shut down to enable pipeline integrity work to be carried out. Further, we have decided we will not take rigs that do not conform to our standards and there are a number of cases where we have either turned away rigs or are negotiating for modifications which could bring the rig up to our standards.
We are conducting a major review of our risk management systems to ensure we have consistent standards that are applied in a disciplined way across BP.
And in support of all of this, we are linking our performance management and reward system directly to safety and risk management - as well as to key behaviours – teamwork, capability-building, listening and compliance with standards.
We will focus on the critical inputs that drive delivery, namely safety, capability, technology and relationships, rather than focussing primarily on outputs such as production barrels. If we get these right, then the outputs, including dollars, will follow. So we are emphasizing quality over quantity and value over volume.
We also learned a lot about what crisis management means in a world of 24 hour communications with massive social media coverage as well as conventional press and cable broadcasting. I saw how much pressure there is on everyone to take up polarized positions and over-simplify the issues”. 

The above points mentioned by the CEO has tremendous significance on Process Safety. I am postulating some simple rules if you want process safety to work:
1. You must be prepared to walk the talk if you want process safety to succeed.
2. Technical expertise is the key to maintaining process safety. Just having standards and a system is not enough. You must have technically competent people who understand the implications of the standards.
3. The board of directors must have direct access to technically competent people who can translate risks and their implications to them. 
4.Your organizational framework must institutionalize process safety management
5. If process safety is taken care of, profits will automatically follow. This lesson is most important for the people who control the purse strings!

Read the complete speech in this link.

Process safety - "simple" is getting lost

"I have always wished that my computer would be as easy to use as my telephone. My wish has come true. I no longer know how to use my telephone."--Bjarne Stroustrup, Danish computer scientist

I have the same feeling as the scientist when I see the modern advanced control systems. Ask any operation personnel about the meaning of all the jargon used in the current day instrumentation field - human engineered, wireless protocols, fieldbus, etc.. and I am sure he will blink at you. Today's control systems are so advanced that I suspect we are barely using 10 % of their capabilities. Does anyone think about the end user - namely the plant operating personnel? Did anyone really analyse whether we did need all the capabilities or we could have done it in a simpler way? A good example is alarm overload - today vendors sell alarm management software!! Why do we need so many alarms in the first place? When you do in house modifications, do not go overboard and suggest all the latest instrumentation. Study what is needed for you and implement only those that are needed.

Bromine leak affects many

An incident where bromine leaking from glass bottles has been reported at a chemical unit in South India. Many people were reported to be affected. Apparently the bromine leaked from glass bottles kept in the stores. If you are handling large quantities of Bromine it is always safer to use ISO containers instead of bottles. Of course this will involve costs but it is worth it. The European Bromine transportation safety forum has good details on how to handle emergencies with bromine including ISO containers. See this link for details.
Read more about the accident in these links:
Link 1
Link 2
News video
MSDS of bromine

importance of maintaining dyke / bund walls

Thanks to Abhay Gujar for sending information on a 300 MT hydrochloric acid leak at a facility in Singapore last month. The acid was contained within the bund and was later transferred safely. There were no injuries. This incident emphasizes the need to maintain your secondary and tertiary containment systems in proper condition. Read the article in this link.

New pipeline safety legislation in USA - Also needed in India?

An article mentions the following:

"Two US senators have introduced legislation to enhance pipeline safety.

The US has approximately 2.5 million miles of pipelines that transport oil, natural gas and hazardous liquids.  These pipelines are an integral component of the US economy and energy supply, and are generally considered a safer mode of transportation than other options for moving gas and liquids. 
Since 2006, there have been approximately 40 pipeline incidents each year that resulted in a fatality or injury.  Last September, a natural gas pipeline exploded in San Bruno, Calif., and quickly engulfed nearby homes in fire. The explosion, and subsequent fire, led to the death of eight people, and destroyed or damaged over 150 residences.
 The legislation introduced by Senators Lautenberg and Rockefeller would help mitigate pipeline risks through a number of measures.  The legislation would reauthorize and strengthen the authority of the Department of Transportation’s Pipeline and Hazardous Materials Safety Administration (PHMSA) through fiscal year 2014. 
Specifically, the “Pipeline Transportation Safety Improvement Act of 2011” includes provisions that would:

• Increase civil penalties for violators of pipeline regulations and add civil penalties for obstructing investigations;
• Expand excess flow valve requirements to include multi-family buildings and small commercial facilities;
• Eliminate exemptions and require all local and state government agencies, and their contractors, to notify “One-Call” notification centers before digging;
• Require the installation of automatic or remote-controlled shut-off valves on new transmission pipelines;Require the Secretary of Transportation to establish time limits on accident and leak notification by pipeline operators to local and state government officials and emergency responders;
• Require the Secretary of Transportation to evaluate whether integrity management system requirements should be expanded beyond currently defined high consequence areas and establish regulations as appropriate;
• Make pipeline information, inspections, and standards available to the public on the PHMSA’s web site
• Authorize additional pipeline inspectors and pipeline safety support employees, through a phased-in increase over the next four years;
• Allow PHMSA to recover costs for oversight of major pipeline design and construction projects; and
• Authorize appropriations for PHMSA for fiscal years 2011 through 2014."

With the natural gas pipeline network in India expanding in a big way, we should keep the above in mind.

Read the article in this link.

Learn Lessons from Incidents

The Directorate General, Factory Advice Services and Labour Insitutes (DGFASLI) has published a number of incidents on their website. I have separated the process incidents and given them below. Learn lessons from them.

Incident 1:"In a chemical factory yellow phosphorous was converted into red phosphorous in a rotary furnace. When the yellow phosphorous was cooked in the rotary furnace for its conversion to red phosphorous at 244^oc, water which was surrounding the yellow phosphorous, became steam. When steam was vented, it carried away certain amount of phosphorous and this caused the vent line choke. This ultimately increased the temperature and pressure of the vessel. Temperature shot up to 300^oC and pressure was not being monitored. Suddenly the furnace exploded and the stored up hot gases caused flash fire injury on the worker and subsequently he died. Causes :

• The outlet for the generated steam and system pressure was chocked by the phosphorous and there was a pressure and there was a pressure temperature built up in the vessel
• Pressure was not monitored by the pressure gauge installed in the furnace
• No safety valve with the proper scrubber arrangement was not installed in the furnace".

Incident 2: "On 18-07-2004 at 06.02 P,M, the Captive Power Plant feeding electrical supply to Cell House - II got tripped due to a flashover (earth fault). This resulted in the tripping of load in Cell House - II and a few motor drives in other sections. But the Cell House-I continued to function, producing Chlorine as it was being operated on EB Power. There was a Chlorine Scrubber system which was a packed column and whose function was to absorb the chlorine gas by means of the circulating lime slurry, in the event of any operational upsets in the process and chlorine free air was vented to the atmosphere. There is a chlorine gas compressor in the chlorine liquefaction section, the compressor sucks the chlorine which is evolved in the cell during electrolysis and compresses it for chlorine liquefaction. Since both the Chlorine scrubber blower and the Chlorine Compressor also got tripped along with the Cell House - II, the Chlorine gas which evolved from the Cells of Cell House – II came out freely and drifted along with the wind toward the adjoining villages. No casualty. Causes:

• Emergency power supply was not provided to the Chlorine absorption system to meet out any problem of power interruption during emergency of chlorine leak
• Cell House – I and Cell house - II were not provided with interlock arrangements in such a manner that if one cell house trips due to operational problem, the other cell house also gets tripped instantaneously".

Incident 3: "In a factory, where 10 MT weak sulphuric acid was stored, suddenly the suction line valve tank nozzle assembly got broken and through this opening sulphuric acid drained out from the tank and this resulted in vacuum formation in the tank. This FRP tank hit against the supporting channel legs due to the formation of vacuum. Causes:

• The FRP tank was not maintained with a adequate strength and stability
• The FRP tank was not tested and certified by the Competent person every year"

Incident 4:"In a fertilizer factory, as the granulator discharge chute got chocked the plant was stopped and the workers cleaned the choked discharge chute by means of poking. After cleaning, the plant was, started without feeding the raw materials namely phosphoric acid, sulphuric acid and ammonia; the granulator was put on dry run. Meanwhile, the heavy lump which caused the block in exhaust ducting fell down and consequently the unreacted ammonia, came out from the discharge end in the form of heavy puffing and injured 5 contract workers. They were given medical treatment in Government hospital and were discharged later. Cause: Un-reacted ammonia in the granulator came out from the discharge end in the form of heavy puffing and injured the workers"

Incident 5:"In a pharmaceuticals manufacturing industry, after the bulk drug is produced the solvents are recovered by distillation in solvent recovery plant. In this instance, a flash distillation still, T-302 was used for the recovery of solvent, Dimethly Sulfoxide (DMSO) in the Solvent Recovery Plant. A batch quantity of 5 KI. of 75% concentration DMSO was charged into the still T-302 in which 700 mm. of Hg vacuum using a piston vacuum pump and a temperature of 136~ were maintained. When this batch was going on and 2.5 KI. of DMSO was inside T-302, there was a hissing sound and immediately after the hissing sound was heard by the worker the still T-302 exploded with a fire ball, killing a chemist and another chemical engineer. The control room which was located very close to the Solvent Recovery Plant was heavily damaged in the explosion. There were so many joints, flanges and gaskets in the pipe line along the DMSO vapour route on the vacuum pump side. Hence failure of such parts might have led to leakage of air in the circuit and could have caused air DMSO explosive mixture. Causes:

• DMSO is a flammable liquid. It has a flash point of 80°C and flammable range from 2.6% (volume) LFL to 63% (volume) UFL. Hence when the still, T-302 is at 136°C, vacuum is absolutely necessary to rule out air entry and to prevent fire. Before the explosion, a hissing sound was heard by a witness; this indicates that vacuum still T-302 could have failed due to development of hole (s) through which air entered and formed an explosion.
• As air ingressed the still T-302, static charges could have been generated due to mixing with the DMSO. The static charges generated could have ignited the explosive mixture, leading to explosion and fire ball"

Incident 6: "In a fine chemicals manufacturing industry, chemicals like 2 – amino Di-bromo-benzly alcohol, manganese dioxide and toluene were loaded into the 4 KL stainless steel reactor (SSR5) and heated upto 65-70 degree centigrade and agitated in the above process. The resultant product layer was settled and filtered in SS nutsche filter by transferring through a HDPE hose. The remaining layer containing toluene was unloaded in a 200 litre HDPE barrel which was not provided with proper earthing or bonding to dissipate the static electric charges and hence fire broke out and spread to the nearby nutsche filter and SSR 6 reactor. Cause: HDPE barrel which was not provided with proper earthing or bonding to dissipate the static electric charges and hence fire broke out".

Incident 7: "A chemical factory had erected three MS cylindrical storage vessels with a capacity of 24 KL - 2 nos. and 30 KL - 1 no. At the time of incident, a tanker lorry with 24 KL petroleum product was brought to the premises for the purpose of unloading into the installed storage tanks. The workers tried to unload the petroleum product into the left extreme vessel of the 3 vessels (30 KL capacity) by using the rubber hose, one end of the rubber hose was connected to the outlet valve of the lorry and the other end of the rubber hose was connected to the 30 KL horizontal tank valve. While transferring the material, there was some leakage at the point of outlet valve connected to the rubber hose. In order to control the leakage, the workers decided to move the lorry to correct position. The driver started the tanker lorry and immediately there was a sudden fire noticed at the outlet valve leakage area. The workers tried to put out the fire but they could not do so. Fire spread out to the other area and consequently the storage vessel got suddenly burst out and thrown out from its foundation. Because of this explosion, the petroleum material became a fire ball, causing minor burn injury to about 23 onlookers and nearby factory workers.Causes :

• The petroleum product which is very highly flammable in nature was unloaded from the road tanker to the M.S. tanks without providing proper bonding to the road tanker and the storage tank; also earthing to avoid the risk of static electricity was not done.
• While the petroleum product was leaking through the rubber hose, the driver started the tanker lorry. The small sparks released from the exhaust pipe, ignited the petroleum product vapour, resulting in fire and tank explosion".

The above information has been obtained from this link.

Ammonia leak from storage tank vent

A leak of about 20 pounds of ammonia has been reported from a DuPont ammonia storage tank in Belle, USA. The leak was detected by a sensor which sounded an alarm. As per the article, "No one was injured in the incident.DuPont spokesman David Hastings said the incident occurred at about 2:30 a.m. and the all-clear was sounded shortly after 3:10 a.m".
It is good that the detector worked as intended. Many times, gas detectors are unreliable for detecting leaks. Some companies are now using computer modeling to determine the number of detectors and their required placement. How sure are you that your detectors will work as intended?
Read the article about the leak in this link.

Sulphuric acid tanker leak kills a woman

Thanks to Abhay Gujar for sending this info. A sulphuric acid road tanker that broke down in Jajmau area was being shifted by a crane when it reportedly got damaged and sulphuric acid got into sewers. The fumes entered a bathroom where a woman was killed. The safety of road transportation of chemicals is a big issue in India, with a number of acid tankers plying the roads. Some of them are not in road worthy condition. The onus is on both the supplier and receiver to ensure that safety rules for transport of hazardous cargo are followed to avoid such tragic deaths.

Read the article in this link.

Use of HF in refineries

An incident has been reported in a refinery in the US where a HF release reportedly occurred. The article mentions the following:
"A hydrofluoric acid leak from an oil refinery in Ohio last week sent a worker to the hospital and required the use of a “water cannon” to disperse the poisonous gas, underscoring the potentially perilous nature of a chemical used at 50 refineries across the country.
HF is used as a catalyst to make high-octane gasoline, despite the existence of a safer alternative and warnings about the chemical’s extreme toxicity and its ability to travel long distances in a cloud. The Center for Public Integrity and ABC News reported last week that at least 16 million Americans live in the potential path of an HF release".
Read the full article in this link
Read the MSDS of HF in this link.