Carbon Disulphide Engines.

Updated: 16 Oct 2008
Fell & Bunster method added
A rather exotic and dangerous working fluid. Back to Home PageBack to The Museum

The Method of Fell & Bunster: carbon disulphide & glycerine New
Colwell's carbon disulphide locomotive
The Ellis Arrangement
Carbon disulphide as a substance

This is a very obscure corner of technology indeed, and I can only offer a few crumbs of information at present. If anyone knows more, I would be most gratified to hear from them.

The boiling point of carbon disulphide is only 46.3C at atmospheric pressure, so it can be made to boil by heat rejected from other processes,in a "bottoming cycle".

Unfortunately, any stand-alone cycle using volatile liquids is doomed to inefficiency because the temperature at which the heat is taken up is low. See: Thermodynamics: Carnot efficiency.


Left: The Fell & Bunster patent

Thomas Fell and Henry Bunster explain in their patent that all previous attempts at carbon disulphide engines have failed because when the hot CS2 vapour contacts metal in the presence of water, it reacts, leaving the sulphide of the metal and liberating carbon. (I have no idea if this is correct- just quoting) Their idea was to use glycerine to heat the CS2 vapour and cover the metal parts with a thin protective film. They say "The properties of bisulphide of carbon are well known. It is easily evaporated into a dense vapour, the gravity of which is 2.621, by a heat of 110 Fahrenheit. The latent heat absorbed for vaporization is about 280 Fahrenheit, that of steam being nearly 1000, or a saving in fuel of 71 per cent."
The saving of fuel is of course thermodynamically infeasible, and saying that latent heat is measured in units of temperature does not inspire confidence.

A is the boiler, part-filled with glycerine, B the condenser, C the boiler feed pump, and E "an ordinary engine". The liquid CS2 was sprayed onto the surface of the glycerine in the boiler. The safet-valve on top of the boiler does not exhaust to the air (for which we may be thankful) but connects with the exhaust pipe from the engine to the condenser.

The patent gives no clue as to whether this scheme was ever constructed and tested.

The F & B patent mentions the exploits of Bernard Hughes, who in 1854 patented a method of injecting carbon disulphide into water, and used the resulting vapour to propel machinery. The Museum staff are hot on the trail of that one, as the earliest carbon disulphide engine so far discovered.


This remarkable proposal for a locomotive driven by carbon disulphide vapour is taken from US patent 225689, filed in October 1879, William S Colwell of Pittsburgh, Pennsylvania. It uses steam to heat the liquid carbon disulphide indirectly.

Left: The Colwell locomotive in section

Colwell says in his patent that carbon disulphide vapourises at 118 degrees Fahrenheit, (the modern figure quoted above is equivalent to 115.3 degF) and will generate a pressure of 186 psi when heated to 295 degrees F.

The design is as follows: B is a conventional firebox surrounded by water-space C, connected to two small water boilers D with conventional fire-tubes e; a Y-piece f connects them to chimney g. The water-space is fitted with a steam dome h, pressure gauge j, and safety valve k, all of which are conventional.

s' is an air-cooled condenser for the vapour from the engine cylinders.

Left: The Colwell locomotive in section

The two lower boilers D generate steam which passes through the tubes m and r in the carbon disulphide boiler l at the top, which Colwell calls "the evolving chamber". This boiler is surrounded by another space q, which is filled with a non-inflammable liquid. Colwell seems to have thought this was a sufficient protection against fire, though he does not specify what liquid is to be used; presumably not water as that would be boiled off by the steam tubes. The carbon disulphide boiler has an outer dome s which encloses the inner carbon disulphide dome t. A regulator valve in dome t controlled the flow of carbon disulphide vapour to two outside cylinders with slide valves.

The the inner carbon disulphide dome t has a so-called "safety-valve" that presumably blasted out poisonous and inflammable carbon disulphide vapour when the pressure became excessive; this is perhaps better than an explosion, though maybe not by much, bearing in mind that this valve is only a few feet from the furnace. Quite possibly there would be an explosion anyway.

In his patent Colwell admits to two problems with his exotic working fluid. The first was corrosion of the engine valves and cylinders, the second was loss of the lubricant properties of oil as carbon disulphide reacted with it. He claimed to have solved both difficulties by using finely-ground graphite mixed with oil, as a lubricant. This does seem to indicate that he had at least done some real experiments with carbon disulphide.

Colwell claimed his engine would operate "with great economy and perfect safety". Perhaps surprisingly, he lived to take out more patents for carbon disulphide prime movers in 1882 and 1885.

It is not currently known if anyone tried to actually build and operate this locomotive. One hopes not.

Left: The Ellis Arrangement

"With very little loss", eh? I do hope so, because carbon disulphide is poisonous. See below.

Carbon disulphide and bisulphide of carbon are of course two names for the same stuff.

This is an example of using a volatile liquid in a "bottoming cycle", which is not an indelicate mode of transport, but a way of getting more work out of the same amount of heat. Ammonia has also been used for this purpose.

I have so far found no case in which carbon disulphide is used directly in a single cycle.

From Knight's American Mechanical Dictionary, 1881 Edition.


There are lots of reasons why using carbon disulphide as a working fluid is not a good idea. As soon as you depart from water or air, you find yourself dealing with something that is expensive, explosive, poisonous, or all three. So what about carbon disulphide?

I don't have any figures to hand for the cost of carbon disulphide, but it is clearly going to cost a lot more than water.

Carbon disulphide evaporates at room temperature, and the vapour is more than twice as heavy as air. Carbon disulphide easily forms explosive mixtures with air and ignites very easily; it is dangerous when exposed to heat, flame, sparks, or friction. Vapors can be ignited by contact with an ordinary light bulb.

Acute carbon disulphide poisoning is very dangerous. Absorption can occur through the skin, by ingestion or by inhalation. In severe poisoning, the subject quickly becomes comatose and death occurs in a few hours, usually due to respiratory depression and convulsions. In less severe cases local irritation, nausea, vomiting and abdominal pain are followed by headache, euphoria, hallucinations, panic delirium, paranoid reactions and suicidal tendencies. In other words, your typical engineering development project...

Another opinion:

"A low boiling point, high toxicity and an exceptional fire hazard make carbon disulphide an extremely dangerous substance; its use should be avoided wherever possible; usually a less dangerous substitute can be found."
From Safety In The Chemical Laboratory" by Pieters & Creyghton, pub Butterworth 1957.

And yet I can remember using it in the chemistry lab at school...

Not for the first time, it occurs to me that water is a really good choice as a working fluid.

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