[Digestion] Biogas Accident

[Dr Stephen P Etheridge]

Fellow AD Listmembers

 

I wrote a note on 29th Jan re: Biogas explosions, a subject that could
potentially affect everyone in this sector. I did not realise that I would
have to revisit the subject so soon.

 

Last Friday at 4.30pm a major biogas explosion at a Tapioca Starch Factory
in Thailand injured 31, 18 seriously. Since that time 7 have died of burns
injuries and this number is expected to increase. 

 

See: 

http://www.baanmaha.com/community/blogs/entry470.html

http://www.thaivisa.com/forum/topic/446507-40-workers-injured-in-gas-explosi
on-in-chaiyaphum/

http://www.nationmultimedia.com/home/31-workers-injured-in-gas-explosion-in-
Chaiyaphum-30149629.html

http://www.ethailand.com/news/five-more-workers-killed-raising-gas-explosion
-toll-to-seven-91356.html

http://koratfart.com/isaan-news/chaiyaphum-31-workers-injured-in-gas-explosi
on/

http://www.nationmultimedia.com/2011/03/01/national/Factory-death-toll-hits-
seven-30149747.html

 

Clearly this has the potential to affect everyone in this sector but
certainly those of us woking in Thailand and S E Asia. As far as I am aware
this would be the worst biogas accident globally.

 

The biogas plant was built by P&S Designs Co., Ltd. -
http://www.psbiogas.com/eng/intro.html , however the explosion was not at
the digester, but at the starch bagging plant where the biogas is used.

 

The english language press indicates that burning wild grass entered a
biogas pipe, which seems strange since biogas pipes are sealed. The Thai
language press indicates that "hot work" (i.e. welding) was taking place
over a biogas pipe. It is common in Thailand to use HDPE pipe for biogas but
usually only up to the building where the "point of use" is. After that it
should be, and usually is, stainless steel. However, if welding was taking
place near an HDPE biogas pipe then this could have resulted in inital
ignition.

 

There have been two prior small explosions here with faulty burner gas
valves but this can happen with any gas boiler coupled with poor maintenance
(Previous explosions detailed in Appendix 2
http://www.eeec.eng.ku.ac.th/files/Handbook-BiogasSafety-IndustryFactory.pdf
). From personal experience in the Thai Tapioca sector the bagging area
rarely gets the respect it deserves as a potentially explosive area
(http://www.youtube.com/user/Jermani099#p/a/u/2/s02zYPE_AgM ). Having said
that, there are more than 200 large scale Tapioca biogas plants in Thailand
and a biogas explosion has not happened before. 

 

I suspect that biogas may have ignited and that this may have triggered a
starch explosion in the enclosed bagging area, but without substantial
information this is pure speculation at this point.

 

I will let the group know if there are substantive developments and I am
sure we would all wish to express our sympathies to those involved.

 

 

Stephen Etheridge 

spe at biotrix.asia

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.bioenergylists.org/pipermail/digestion_lists.bioenergylists.org/attachments/20110301/ca639df8/attachment.html>