Transcript Slide 1

In WWI
The Process
• Reactants = N2(g) + 3H2(g)
• Products = 2NH3(g), ΔHo =
92.4 kJ/mol
• Process is carried out at 150 250 atmospheres (atm) and
between 300 and 550 °C
• On each pass only about 15%
conversion occurs, but any
unreacted gases are recycled,
so that eventually an overall
conversion of 98% can be
achieved.
• Hydrogen
• Processed by taking
methane (CH4(g))
and reacting it with
steam (H2O(g))
• Products are carbon
dioxide (CO2(g)) and
hydrogen (H2(g)).
• Nitrogen
• (N2(g)) is obtained
from the air by
fractional distillation,
because the air is
made up of 80%
nitrogen.
• Fractional distillation is the
separation of a mixture into
its component parts, or
fractions, such as in
separating chemical
compounds by their boiling
point.
• Generally the component
parts boil at less than 25°C
from each other under a
pressure of one atmosphere
(atm).
• If the difference in boiling
points is greater than 25°C, a
simple distillation is used.
Conditions
• As the temperature
increases, the equilibrium is
shifted and hence, the
constant drops dramatically
according to the van't Hoff
equation.
• Thus one might suppose that
a low temperature is to be
used and some other means
to increase rate.
• However, the catalyst itself
requires a temperature of at
least 400 °C to be efficient.
• Pressure is the obvious choice to favour the
forward reaction because there are 4 moles
of reactant for every 2 moles of product, and
the pressure used (around 200 atm) alters the
equilibrium concentrations to give a
profitable yield.
• Economically, though, pressure is an
expensive commodity. Pipes and reaction
vessels need to be strengthened, valves
more rigorous, and there are safety
considerations of working at 200 atm. In
addition, running pumps and compressors
uses considerable energy. The compromise
used gives a single pass yield of around 15%.
Catalyst
• The catalyst has no effect on the
position of equilibrium, rather, it
provides an alternative pathway
with lower activation energy and
hence increases the reaction rate,
while remaining chemically
unchanged at the end of the
reaction.
• The first Haber–Bosch reaction
chambers used osmium and
uranium catalysts.
• However, today a much less
expensive iron catalyst is used
almost exclusively.
• The process was first patented
by Fritz Haber. In 1910 Carl
Bosch, while working for
chemical company BASF,
successfully commercialized
the process and secured
further patents.
• Haber and Bosch were later
awarded Nobel prizes, in 1918
and 1931 respectively, for their
work in overcoming the
chemical and engineering
problems posed by the use of
large-scale high-pressure
technology.
Fritz Haber
Carl Bosch
50 lbs Ammonium
Nitrate
• Ammonia was first manufactured
using the Haber process on an
industrial scale in Germany during
World War I to meet the high
demand for ammonium nitrate (for
use in explosives) at a time when
supply of Chile saltpetre from Chile
could not be guaranteed
• Had Haber not invented the
process, Germany would have
been forced to surrender years
earlier than it did. As a result the
Haber-Bosch process indirectly,
cost thousands of people their
lives.
• It has been suggested that without
this process, Germany would not
have started the war.
• "Chile saltpeter“-Sodium nitrate
is the chemical compound with
the formula NaNO3.
• Sodium nitrate is used as an
ingredient in fertilizers,
explosives, and in solid rocket
propellants.
• Many deposits were mined for
over a century, until the 1940s,
when its value declined
dramatically in the first decades
of the twentieth century (Due to
Haber Process).
• Germany could not get Chile
saltpetre from Chile because
this industry was then almost
100% in British hands.
• World War I Began in 1914 with the assassination
of the Archduke of Austria Hungary Ferdinand.
• The assassination triggered a chain of
declarations of war between the members of the
Triple Entente (England, France, and Russia) and
the Triple Alliance (Austria-Hungary, Germany,
Italy).
• The Triple Entente’s naval superiority allowed the
allies to effectively blockade the trade of the Triple
Alliance (mainly Germany).
• Following the allied blockade of the South
American ports, the supply of Saltpetre was well
and truly cut off.
• This blockade was a major contributing factor in
the Germans use of unrestricted submarine
warfare.
• Artillery: These were the new and
upgraded versions of cannons. Never in
the history of man, where there so many
cannons used in one war alone. For four
years the British had been using artillery
and firing 170 million shells in that time.
• Germany had a plan up their sleeve. For
years, German scientists were
developing the biggest artillery ever
known. It was call the ‘Big Bertha’. Big
Bertha was so powerful it could fire at
the heart of Paris from 120 kilometers
away.
• The cannons weren’t the only things that
had been improved. The shells were
upgraded as well. Instead of ordinary
shells, new High-explosive shells were
developed. The Shells were thin casings
and were filled with tiny lead pellets.
• This was so effective, that artillery fire
killed hundreds and thousands of men.
Big Bertha
• Amatol
• A highly explosive material
made from a mixture of TNT
and ammonium nitrate. Amatol
was used extensively during
the First World War and the
Second World War.
• Typically, Amatol was used as
an explosive in military
weapons such as aircraft
bombs, shells, depth charges
and naval mines.
• These were highly attractive
features during major wars,
when there was an insatiable
demand for high explosives.
•Ammonal
• An explosive made up of
ammonium nitrate, trinitrotoluene,
and aluminium powder mixed in a
ratio of roughly 22:67:11
•The ammonium nitrate functions
as an oxidizer and aluminium as a
power enhancer. To some extent
the aluminium makes it more
sensitive to detonation. The use of
the relatively cheap ammonium
nitrate and aluminium make it a
replacement for pure TNT.
•The detonation velocity of
ammonal is approximately 4,400
metres per second. (really big)
•
•
•
•
•
Mustard gas molecule
attacking skin..
(ClCH2CH2)2S
Fritz Haber is known as the
father of chemical warfare.
In addition to the invention of
the Haber process it was Haber
who first came up with the idea
of using chlorine gas as a
weapon.
He first used chlorine gas in
1915 at the battle of Ypres,
where it took the unsuspecting
(and unprotected) French
troops by surprise.
The gas killed over 10,000 of
them in in few minutes.
Over the next few years he
developed other more lethal
and nasty gases, such as
phosgene and finally mustard
gas, all of which were used
against Allied troops.
Bibliography
• http://www.chm.bris.ac.uk
• www.wikipedia.org
• www.chemistry.org/education/chemmatter
s.html
• Google.com (images)