formaldehyde - Sciencemadness Dot Org

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POEM ALDEHYDE
30-cm hard-glass tube containing a cylinder of coarse copper gauze o cm
long. Bra?? gauze surrounding that portion of the tube which contained
the copper catalyst was gently heated. Passage of the mixed reaction
gases over the catalyst caused it to glow with a brightness which depended
upon the rate of flow. The reaction products emerging from the glass tube
were conducted through a large empty vessel and two flasks half-filled with
water. Continuous operation of the process yielded solutions containing
as much as 15-20 per cent formaldehyde. When the methanol was heated
by Tollens 33 to 45-5G°C and the reaction gases passed over the copper
catalyst (surrounded hy asbestos diaphragms to prevent explosions), a 30
per cent conversion to formaldehyde was obtained.
With the pioneering study on the preparation of formaldehyde completed
by the demonstration in 1886 that it could be produced in continuous manner
24 - 35 production on a commercial scale became feasible. Industrial
developments are difficult to trace in detail, since practical advances are
usually kept secret. It therefore becomes necessary to rely on patent literature
for such information, which is fragmentary at best.
In 1889, both France and Germany granted August Trillat 35 the first
patents to cover a process for the manufacture of formaldehyde. The procedure,
which represented little improvement over the methods of Loew 24
and Tollens 35 , consisted in discharging methanol vapors in the form of a
spray into the open end of an externally heated copper tube packed with
coke or broken tile, both the coke and the copper serving as catalysts.
Although rights under these patents were sold to Meister, Lucius and
Bruning at Hochst a.M.? the process does not appear to have been employed
commercially.
According to Bugge 10 , the firm of Mercklin and Losekann, founded in
1S88 at Seelze, near Hannover, Germany, starred the commercial manufacture
of formaldehyde in 1889. Shipments of 5-20 kg were made to
various factories and to university laboratories. Also prepared for the
chemical market were such formaldehyde derivatives as paraformaldehyde,
hexamethylenetetraroine, and anhydroformaldehyde aniline.
At approximately this period, investigations were being conducted on
the use of formaldehyde as a disinfectant. Meister, Lucius, and Bruning
were customers of Mercklin and Losekann, although the former company
also carried out work of their own on formaldehyde manufacture. Formaldehyde
purchases of the Badische Aniline and Soda Fabrik amounted
to 1000 marks per month as early as 1891. The aldehyde was used chiefly
for hardening gelatin films and for syntheses in the medicinal and dyestuff
fields. With the patenting in 1901 15 of a method for synthesizing phenylglycine
(an intermediate for indigo) from aniline, formaldehyde, and an
alkali or alkaline-earth cyanide, there resulted a marked increase in the
demand for formaldehyde.