Hydrogen sulfide

 

You can get all of the hydrogen sulfide that you want from refineries that
run sour crude.  However, BEWARE!!!  From a human exposure standpoint,
hydrogen sulfide is MUCH MORE hazardous than hydrogen ever thought of being.
Based on my observation of the details behind a fatality in the refinery
that I formerly worked at, at high concentrations, hydrogen sulfide is the
fastest and most deadly neurotoxin I have ever heard of.  If you inhale one
good whiff of concentrated hydrogen sulfide, you will be unconscious in a
very few seconds, and dead shortly after that.
 

H2S is nasty stuff, and having large frothed ponds of it around
represents thinking that could only come from long hours in the outhouse
alone.
 

It also stinks. Literally.
 

I suspect this is a viable lab demo that does not scale up worth a damn.
Energy going into frothing and froth production of evaporative cooling
energy loss and water vapor in the product stream are possibly likely to
be category killers.

 

Where does the hydrogen sulfide come from, and how much old energy has to go into its preparation?"
 

 

You will not like the answer.
 

Due to environmental requirements, hydrogen sulfide is concentrated before
it goes to a sulfur recovery unit for further processing.  Selling hydrogen
sulfide before the further processing would actually save refineries energy
and money.  This is a net energy gain due to the fact that the hydrogen
sulfide is an unwanted product and further processing to recover sulfur is
an unwanted process.
 

Answer - hydrogen sulfide preparation has to be done anyway in order to meet
environmental requirements.  No additional "old" energy goes into its
preparation.  If you have a refinery that runs sour crude, you can't avoid
production of high concentrations of hydrogen sulfide.
 
Large frothed ponds will never exist, for several reasons:
 

*  as you say, H2S is very toxic
*  environmental regulations require a reduction in environmental sulfur,
and I am sure beyond a reasonable doubt that EPA would not permit deliberate
"dumping" of H2S into the environment, even if it wasn't toxic to humans
*  low concentrations of H2S smell like rotten eggs, and the public would
never sit still and let a company smell up the whole neighborhood with this
stuff, even if it wasn't toxic to humans
 

I'll put the question in simpler words for you: When crude processing winds
down, with the consequential drop in production of hydrogen sulphide, what
sources will make up the difference? You said there will be such sources, so
what will they be and how much old energy will they consume?