P 127
Cross-Sensitivity of CO sensors
Though all the vendors have declared that there is a technical issue of cross sensitivity problem in electro-chemical sensor type,neither the supplier nor the purchaser team were aware of the involved issue while committing the order for both fixed as well as portables.
In field, while unloading the Propylene/Ethylene into Process chiller compressors in PX IV plant, safety team as a precaution hand carried a set of 4X portable gas detectors. To everybody's shock, the detectors picked up the hydrocarbon vapor presence in atmosphere as if CO is present in high value and raised alarm. Panic situation set in and they contacted me at RCP stating the detectors are defective and take up the issue with M/S MSA. Personally I had my doubt, whether the coke getting loaded in the hopper in Gasification complex would have really generated CO vapors in atmosphere! At the same time, considering the inter-distance of approx 700 Mts, whether such a possibility of CO travelling came in question.
So on SOS basis, I took up the issue with Mr Gustavo to study the issue. He reverted that the issue has arisen due to the functional characteristics of electro chemical sensor only and the detectors are not defective. Having heard that from him, I went into looking for the same issue in Honeywell supplied fixed CO detector in PX plant area. To my shock, those sensors also revealed the same characteristics. Since those fixed devices were handled by Core instrumentation group, I shared the issue with Dr. B R Mehta. That made both of us to take up with both the parties-Honeywell and MSA and made them to study/help Reliance in finding a workable resolution.
Technical Point: As we have Coke gasification complex and Syn.gas travelling all across refineries/C2 complex, tracking sensitive colorless/odourless toxic CO that too in PPM is a must. That strenuous condition ruled out usage of Infrared type sensor type for CO presence sensing in atmosphere.As it is IR sensor can sense only in % value that too with sensitivity of 10000 ppm only; whereas OSHA's recommendation is only max 50 PPM sensitivity for human being.
To validate our doubt, we referred the matter to M/S Shell Global Solutions and queried them. They responded that they do not have electro chemical type sensors at all for CO sensing! Moreover, no where else in the world, there is a combination of refinery with a petro-chemical plant and coke gasification complex all integrated in one facility! So Reliance is unique and complicated. So we took up with both the vendors to undertake a fundamental research to arrest/restrict of this hydrocarbon vapors getting converted into CO and misrepresent/create nuisance value alarm in a petrochemical complex. The research is still on when I retired from service.We have to wait&watch.It appears that direction-ally the progress is positive. Otherwise we may end up with wolf story!
Key Aspect :- Incident analysis, Lack of experience, Technical issue
Cross-Sensitivity of CO sensors
Though all the vendors have declared that there is a technical issue of cross sensitivity problem in electro-chemical sensor type,neither the supplier nor the purchaser team were aware of the involved issue while committing the order for both fixed as well as portables.
In field, while unloading the Propylene/Ethylene into Process chiller compressors in PX IV plant, safety team as a precaution hand carried a set of 4X portable gas detectors. To everybody's shock, the detectors picked up the hydrocarbon vapor presence in atmosphere as if CO is present in high value and raised alarm. Panic situation set in and they contacted me at RCP stating the detectors are defective and take up the issue with M/S MSA. Personally I had my doubt, whether the coke getting loaded in the hopper in Gasification complex would have really generated CO vapors in atmosphere! At the same time, considering the inter-distance of approx 700 Mts, whether such a possibility of CO travelling came in question.
So on SOS basis, I took up the issue with Mr Gustavo to study the issue. He reverted that the issue has arisen due to the functional characteristics of electro chemical sensor only and the detectors are not defective. Having heard that from him, I went into looking for the same issue in Honeywell supplied fixed CO detector in PX plant area. To my shock, those sensors also revealed the same characteristics. Since those fixed devices were handled by Core instrumentation group, I shared the issue with Dr. B R Mehta. That made both of us to take up with both the parties-Honeywell and MSA and made them to study/help Reliance in finding a workable resolution.
Technical Point: As we have Coke gasification complex and Syn.gas travelling all across refineries/C2 complex, tracking sensitive colorless/odourless toxic CO that too in PPM is a must. That strenuous condition ruled out usage of Infrared type sensor type for CO presence sensing in atmosphere.As it is IR sensor can sense only in % value that too with sensitivity of 10000 ppm only; whereas OSHA's recommendation is only max 50 PPM sensitivity for human being.
To validate our doubt, we referred the matter to M/S Shell Global Solutions and queried them. They responded that they do not have electro chemical type sensors at all for CO sensing! Moreover, no where else in the world, there is a combination of refinery with a petro-chemical plant and coke gasification complex all integrated in one facility! So Reliance is unique and complicated. So we took up with both the vendors to undertake a fundamental research to arrest/restrict of this hydrocarbon vapors getting converted into CO and misrepresent/create nuisance value alarm in a petrochemical complex. The research is still on when I retired from service.We have to wait&watch.It appears that direction-ally the progress is positive. Otherwise we may end up with wolf story!
Key Aspect :- Incident analysis, Lack of experience, Technical issue
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