Accidents in batch processes

The Safety, Health and Environment Association, Bharuch has posted several incidents on its website. One such incident mentions the following:
"Incident:
During nitration in reactor runaway reaction occurred and suddenly the pressure of reactor raised and explosion took place within few seconds in reactor. Manhole of reactor was opened due to high pressure. Nitric Acid, sulfuric Acid & Benzoic Acid were involved in reaction. In this incident the mixtures of acids were sprayed in process plant, company ground and nearby company. The roof sheets of plant were broken due to explosion. It was sprayed up to about 200 – 300 meters in down wind direction
Cause of Accident:
As per information received from company officials the explosion occurred due to runaway reaction during nitration from reactor of process plant.
Corrective Action
Lime was sprayed on the acidic mixture in whole the affected area in company & on the road also for neutralization. After that the road was washed out with water. Company people also sprayed lime on the acid mixture in their company ground & Process Plant.
Preventive Action
1. Process parameters to be followed strictly.
2. PRV & safety valve to be maintained in working condition with proper venting system.
3. Periodical maintenance & inspection should be done.
4. Employees should be trained in process safety.
5. Laboratory Study for knowledge relative to normal & abnormal known deviation in raw material, Process parameter"

Read more incidents on their website in this link.

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Reducing solvent in batch reactors

Have you done proper analysis before you try to reduce solvents in batch reactors and replace them with more raw material in a bid to increase capacity? An article mentions about the solvent effect on peroxide decomposition and concludes with the following:
"This study is focused on runaway decompositions as they’re more interesting in plant safety and risk analysis, because in the past they have been the cause of severe accidents. In particular solvent influence has been analyzed, proving that a solvent change has always to be tested before applied in reactor scale in order to avoid an anomalous runaway behaviour of the reaction. Screening calorimetry allowed us to analyze these processes in safety and to gain useful results such as onset temperatures, ranges of temperature and pressure evolved by reactions and others. Remember that screening equipments are not adiabatic and data have to be validated by tests run in adiabatic and reaction calorimeters, where real operational conditions (such as agitation and heat transfer) can be simulated; the use of the TSu makes it possible to save time and reduce the number of experiments with laboratory scale calorimeters".

Read the article in this link. 

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Another tank blows its roof!

An explosion in a 80KL emulsifier tank in an asphalt manufacturing tank in USA has blown the roof lid off the tank. The lid was thrown a sizable distance away causing damage to cars and structures. When you look at the video, please realize that many of your storage tanks that store flammable chemicals may be of much bigger capacity and you can imagine the consequence of an explosion in your tank. Follow all your company hot work procedures strictly.
See the news report and video in this link.


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Refinery fire - possible ignition source and some pictures

Initial investigation into the refinery fire in USA reveals that the possible ignition source could have been an idling  fire truck that was already at the scene prior to the pipe rupture. Investigators are also trying to find out why the  40 year old pipe that ruptured was not replaced even though an adjacent pipe was replaced in the turnaround a few months before the incident.
Read the news report in this link.
See "24 strangely beautiful pictures" of the  refinery fire in this link. You can see two plumes of smoke - one from the fire and one from the flare due to the emergency shutdown.

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Jaipur oil depot fire - powerpoint presentation

An excellent presentation on the IOC Jaipur oil depot fire and Government appointed Shri MB Lall's investigation committee recommendations has been made by Shri SK Roy, GM, HSE, IOC. It can be viewed in this link.

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Corrosion - cause of refinery fire?

 Preliminary investigations by the CSB indicate that corrosion could be the reason for the recent large fire at a refinery in USA. The 8" pipe that failed also had a 12" pipe connected to it. In a turnaround in 2011, the 12" pipe was replaced due to corrosion.  A news article mentions the following "The pipe that failed Monday dated back to the 1970s, investigators said, but it is still unclear whether the thickness testing conducted by Chevron in its last major inspections noted corrosion in that specific, 8-inch pipe". Read the news article in this link.


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Sulphuric acid manufacturing

You can download a good presentation by Dr Mubarak of Jordan, on sulphuric acid manufacturing and associated technical details from this link.
This will be useful for the technical training of operators in sulphuric acid plants.

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Fire in refinery

The CSB is proceeding to investigate a fire in a refinery in the US. The fire was apparently caused by a vapor leak. No one was reportedly killed. It appears that it was a cooling tower fire caused by a flammable vapour ingress. Read the news article and see pictures of the damage in this link.
Thanks to Sanjeevi for sending the link.
See a video of the press conference where the General Manager gets heckled by angry residents in this link. 

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Lessons to learn from emergency drill

An emergency drill was conducted at a production site in Terneuzen, The Netherlands.  See the photos from the drill in this link. There are lessons to learn even from the photos. Do you have the adequate emergency response equipment? Are your people trained to handle these equipment?
See the photos of the drill in this link. 

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An accident due to mixing of chemicals

An accident occurred last month on a work table where two employees were mixing red phosphorus and fiberglass powder. A news article mentions that "Investigators said the employees mix these chemicals on a daily basis in the manufacturing of igniters for military oxygen generators." Static electricity is thought to be the cause of ignition. 

Read the article and see the video in this link.

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H2S desorption incident

I came across and incident where three people died due to H2S liberation when old molecular sieves were exposed to water, that, in turn liberated H2S through a process of desorbtion. This incident highlights the need to understand the technical aspects of process safety which I had mentioned in my last post.
Read the incident in this link.

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Fire in chemical tanker threatened methanol tanks

A chemical/palm oil tanker Bunga Alpinia caught fire, while berthed alongside at Petronas Chemicals Methanol Sdn Bhd terminal in Labuan, Malaysia on the morning of 26th July. Apparently the tanker was discharging cargo when fire on board started from technical breakdown. Though the news article says the cargo was LNG, it was methanol. A lightning strike apparently was the cause of the fire.
There are a number of pictures in this link about the fire and fire fighting operations. See how close the burning tanker was to the onshore tanks containing methanol. They were lucky!

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