heating. (Chap. 8) Overall however, it was remarkable just how little guidance their experiments provided regarding the uplifting of the technology to
an industrial scale. Even so their design, based on a continuous circulation
process was sound, and remains essentially that which is still used today.
With the problem identified but no clear solution yet in mind, the BASF
moved their entire research effort to a new site at Ludwigshafen, designated
Lu35. The gas preparation and cleansing system machinery, the high-pressure
reactors, circulation pumps, cryogenic separators and scrubbers.
7 were all
moved to build a new prototype plant which became operational on 10
August1910—but still using the suspect reactor tube design. The first three
months of operation saw only 100 kg of ammonia produced, but by
December 1910 a daily rate of almost 10 kg had been achieved. This rose to
18 kg day
−1 in the first two weeks of 1911.
8 In the meantime, between July
1910 and March 1911, Bosch and his team tried a number of different
solutions to obviate the problem of the burst tubes, a problem they realised
jeopardised the whole project. Initially, everything they tried was either
unsuccessful or unpromising and their conclusion was quite simple;
We assumed…. that the diffusion of hydrogen into the iron, the de-carburisation of
the perlite, and the formation of brittle iron hydride are just unavoidable. They had
to be rendered harmless by a modification in design…
1
Bosch focussed on the role of the reactor walls. These he concluded served
two purposes viz, to act as a gas tight seal, and to mechanically withstand the
extreme pressure. He ingeniously decided to separate these two roles by
designing a reactor made of two tubes, an outer pressure bearing steel jacket
and a quite thin inner ‘sacrificial’ lining of soft steel in such a way that;
As the hydrogen… diffuses [and] passes through the thin lining it is able to escape
without building up pressure before it can attack the outer steel jacket at the high
temperature. This is readily achieved by grooves produced on the outside when the
[inner] tube is being turned and by a large number of holes drilled in the steel jacket
through which the hydrogen is free to emerge… the thin lining tube fits tightly
against the jacket under the high pressure and… when it has become brittle there is
no way of expanding it… so that no cracks occur.
1
The early recognition of ‘hydrogen attack’ of course had already led to the
submission of the supplementary ‘diffusion’ patent, (Chap. 8) whilst the first
reactor based on the twin tube proposal—which provided the ‘protection’
mentioned in the patent application—became operational from March 1911.
11 From Karlsruhe to Oppau
217
an industrial scale. Even so their design, based on a continuous circulation
process was sound, and remains essentially that which is still used today.
With the problem identified but no clear solution yet in mind, the BASF
moved their entire research effort to a new site at Ludwigshafen, designated
Lu35. The gas preparation and cleansing system machinery, the high-pressure
reactors, circulation pumps, cryogenic separators and scrubbers.
7 were all
moved to build a new prototype plant which became operational on 10
August1910—but still using the suspect reactor tube design. The first three
months of operation saw only 100 kg of ammonia produced, but by
December 1910 a daily rate of almost 10 kg had been achieved. This rose to
18 kg day
−1 in the first two weeks of 1911.
8 In the meantime, between July
1910 and March 1911, Bosch and his team tried a number of different
solutions to obviate the problem of the burst tubes, a problem they realised
jeopardised the whole project. Initially, everything they tried was either
unsuccessful or unpromising and their conclusion was quite simple;
We assumed…. that the diffusion of hydrogen into the iron, the de-carburisation of
the perlite, and the formation of brittle iron hydride are just unavoidable. They had
to be rendered harmless by a modification in design…
1
Bosch focussed on the role of the reactor walls. These he concluded served
two purposes viz, to act as a gas tight seal, and to mechanically withstand the
extreme pressure. He ingeniously decided to separate these two roles by
designing a reactor made of two tubes, an outer pressure bearing steel jacket
and a quite thin inner ‘sacrificial’ lining of soft steel in such a way that;
As the hydrogen… diffuses [and] passes through the thin lining it is able to escape
without building up pressure before it can attack the outer steel jacket at the high
temperature. This is readily achieved by grooves produced on the outside when the
[inner] tube is being turned and by a large number of holes drilled in the steel jacket
through which the hydrogen is free to emerge… the thin lining tube fits tightly
against the jacket under the high pressure and… when it has become brittle there is
no way of expanding it… so that no cracks occur.
1
The early recognition of ‘hydrogen attack’ of course had already led to the
submission of the supplementary ‘diffusion’ patent, (Chap. 8) whilst the first
reactor based on the twin tube proposal—which provided the ‘protection’
mentioned in the patent application—became operational from March 1911.
11 From Karlsruhe to Oppau
217