Re: Tangent Scale Models Acid Tank Car

Cyril Durrenberger

You can learn about making sulfuric acid from
A quote from this is “Almost 70 percent of sulfuric acid manufactured is used in the production
of phosphate fertilizers. Other uses include copper leaching, inorganic pigment production, petroleum
refining, paper production, and industrial organic chemical production.”

I think the El Paso smelter began making sulfuric acid when they were required by the Texas Air Control Board (Texas air pollution control agency) to reduce their SO2 emissions in the 1970's.  The process they selected to remove the SO2 created an industrial grade sulfuric acid that they sold, but the amount received for the acid did not pay for the cost of making it.  I was on the crew that did the stack sampling of the plant that lead to the requirements to the reduction. 

It is not clear to me what, if any smelters made sulfuric acid from their SO2 emissions during the time period of this list.

Sulfuric Acid has been used for many years, perhaps over a hundred, to remove sulfur from gasoline.  So refineries used it.  In many cases the spent sulfuric acid was then recycled in an acid plant to make the acid that was used in this process.  Making the sulfuric acid often required burning sulfur containing compounds to produce SO2 which was oxidized and then combined with water to make the sulfuric acid.  It was then concentrated.  There was a large sulfuric acid plant at what is now the Exxon Baytown refinery.  Most if not all of the acid was used at the refinery. 

At one time elemental sulfur was "mined" along the Gulf Coast and other areas.  One of the uses for it was to make sulfuric acid.  The mining stopped as more and more of the refineries and natural gas processing plants were required to treat the H2S at a sulfur recovery plant rather than burning it in a flare and emitting it to the atmosphere.  The H2S is removed and converted to elemental sulfur. 

Cyril Durrenberger, P. E.
Senior Lecturer in Chemical Engineering
Research Scientist Center for Energy and Environmental Resources
The University of Texas at Austin


On Fri, 11/14/14, [STMFC] <> wrote:

Subject: [STMFC] Re: Tangent Scale Models Acid Tank Car
Date: Friday, November 14, 2014, 11:31 AM





Sulfuric acid, a by-product of copper smelting at
Asarco in El Paso, Texas,
was shipped to Minnesota for spraying on potato fields right
before harvest to
kill the vines. I'm told this facilitated mechanical
harvesting and meant less
unwanted debris among the potatoes. My observation of this
practice occurred in
the 1980s and 1990s. What I would really like to know is
when such a practice
began and if it goes back to 1950. Since I am modeling the
upper Midwest in 1950
such shipments might fit my scheme.

Gene Green

this practice on many vine-type crops goes back beyond
the 1950s.  It
was (and still is) a cheap and effective way to defoliate
plants. This was
before other compounds, such as DEF, were available,
but are typically more
expensive.  The main restrictions to using sulfuric
acid on potatoes these
days is availability and safety concerns if you aren't
rigged up to do it. 
In fact, we just sprayed a potato field with sulfuric acid
about a month
If Asarco in El Paso produced sulfuric acid, I'd
bet the plant in Amarillo
did/does the same.  Have to check that out.  As
far as uses, it is
probably easier to list industrial process that don't
use mineral acids in one
or more processes, than those that do use them.
Jerry Michels
(a research entomologist in another life)

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