Lubrication in H2S (Sour Gas) 2.5 % applications

Bill,
Unfortunately I can not find manufacture's requires for oil for this type engine. But let’s to ratiocinate.
On the one hand the Natural Gas Engine requires the oil with low or medium Ash levels for elimination of recession valves. But these oils have low TBN that can to fight with acid products of combustion. These oils may be will operated in your conditions at an early date. They will be requiring short oil change intervals.
On the other hand there are the motor oils, which can to work at high sulfur levels. It is Marine oils with TBN from 10 to 30 and more. However these oils have sulfated ash up to 3.5% wt. These oils can to manage with your H2S, but can to play the devil with engine.
It seems to me the best of all would be to use the oil that recommended by engine manufacturer WITH MONITORING on regular base the CONDITIONS of engine itself and motor oil using USED OIL ANALYSIS. In this case you can control engine and oil conditions and to change oil when it not operates any more (longer). Needed interval may be will shorter then manufacturer's, but your engine will be in perfect security
Regards,

Mikhail,
Sorry I didn't respond earlier. Not many people have picked up on the contradiction in the additives packages vs sulphur. To complicate matters, GM does not list reccomended oil and the oil co that do list natural gas reccomended oil show a wide variety of oil composition. The hydrogen Sulplide can do serious damage especially if the engine shuts down. It will in most cases consume the additives in as little as a hour, requiring an oil change in the event of any shut down.

Your message shows you are from Kazakstan. I know it to be one of the worlds leading oil producers. Do you have much experience with burning flare gas to produce electricity? If so what types of engines do you use. Is there a buisness opportunity to produce electricity from otherwise flared gas?

Your insights would be appreciated.

B.

Bill
You maybe consult Mobil's engineers, They always have enough experience on such industry, I met some customers(Caterpillar or GE's engine,
LNG or marsh gas) who used Mobil's products.

Bill,
Sorry, it simply an overlook on my part. I didn’t note your message and only now I saw it.
I must explain some points.
Yes, I am working in Kazakhstan. But I am Technical Specialist of ChevronTexaco Lubricants in Central Asia & Kazakhstan. I know the assortment of both Chevron and Texaco Lubricants and their applications.
I don’t work with co-generators and with Natural Gas, sorry.
So I have chemistry education I know what represents the H2S and how it impacts with metals and another materials. Maybe it is need to purify the Gas from H2S before use? I know that such technology wide use in gas-and-oil producing industry.
Regards,

Bill

Look into Mobil Peasus 426 or Mobil Pegasus 446 depending the amount of ash GM allows. We have Caterpillar engines operating with Mobil Pegasus 426 with lube oil change from 500 to 1000 hours and lube oil sampling can not be left out of the equation.

We have found that the build-up of Siloxane on the valves is a softer deposit that can be hand wiped off and with the Siloxanes being a softer deposit reducing valve guttering.

We get 8,000 hours before top-end rebuild and 40000 hours for a major. We tried extending from 40,000 to 45,000 hours and experienced rod failures.

Hope this helps you...

Good Luck,

Oil Can Hairy