eS OT ea TSC 
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TRANSACTIONS OF SECTION B. 433 
proportion of this huge total which in the light of the best knowledge of to-day 
ought to be subjected to the preliminary treatment by distillation before it is 
used for heating purposes ? 
One of the largest items of the national consumption is the 35 million tons 
used for domestic heating. As this is the item which in use produces town 
smoke in its more unmanageable form, we naturally turn to it as one of the most 
important fields for reform. Let us first inquire what is actually being done in 
this direction. 
In March of the present year Mr. F. W. Goodenough, in his Cantor Lectures 
on ‘Coal Gas as a Fuel for Domestic Purposes,’ gave a most encouraging account 
of splendid work which is being done by the Gas Light and Coke and the other 
London gas companies in the introduction of gas for domestic cooking and heating. 
From these and similar statistics supplied by other cities, we are entitled to 
conclude that the increasing quantity of coal which is being distilled by the gas 
companies is going towards the replacement of raw coal by gas and coke, and we 
are confirmed in the belief that the treatment of coal by distillation is one of 
the most hopeful directions in which to seek for increased economy and efficiency. 
This raises again the previous question: are we to rest satisfied that in these 
admirable achievements of the gas engineer the last word has been spoken from 
the fuel reformer’s point of view? 
It is now about eight years since Mr. Parker brought forward a scheme for 
the production of ‘ Coalite,’ a smokeless domestic fuel made by the distillation 
of coal at a temperature of 400° to 450° C., in contrast to the gas-retort method 
of distillation at 900° to 1,000°. Professor Vivian B. Lewes, in supporting this 
scheme, showed the immense significance of the changes in the proportions as 
well as in the qualities of the products of distillation which would result from 
this radical change in the conditions of distillation. The keynote of the scheme 
from the chemist’s point of view was the conservation of the saturated and allied 
hydrocarbons in the liquid and gaseous distillate, in contrast to the modern 
gas-works practice in which these hydrocarbons are sacrificed to the production 
of a large volume of poor gas. This policy of conservation had already found 
its fullest expression in the shale-oil industry, in which the chief aim had 
always been to preserve the maximum quantity of paraffin wax in the distillate ; 
but from the gas engineer’s point of view Mr. Parker’s proposal was regarded 
as revolutionary and hardly worth serious consideration. 
A fairly extensive experience of low-temperature distillation as applied to 
coal as well as to oil shale led me from the outset to question whether the 
proposal to distil bituminous coal in long vertical tubes of small diameter would 
be industrially successful. With the assistance of Mr. H. N. Beilby, and later 
also of Mr. G. Weller, an experimental inquiry into the possibilities of other 
methods of distilling coal at a low temperature was carried on in the works of 
the Cassel Cyanide Company in Glasgow. 
By freely exposing small cubes of coal to radiant heat at a temperature of 
450° C., it was found that the gases were driven off in about an hour. It seemed 
reasonable, therefore, to conclude that under practical conditions the time of 
exposure to heat need not exceed one and a half to two hours. It had been 
stated in published reports that the time of exposure to heat in the small vertical 
tubes of Mr. Parker’s apparatus was four hours, and at a later stage it was 
suggested that even this time was not long enough to complete the distillation 
in the centre of the mass. The object we now set before us was to devise a 
form of apparatus in which the coal could be exposed to the action of heat in 
thin layers. The first practical apparatus consisted of a column heated externally 
in a gas-fired oven, and fitted internally with a series of sloping shelves. 
Mechanical arrangements were made for feeding the small coal in to the top of 
the column and for mechanically jolting the shelves so that the coal passed 
over the whole series from top to bottom in a sheet two to two and a half inches in 
thickness. The coke was mechanically withdrawn from the bottom of the 
column. The volatile products of distillation were removed by an exit pipe to 
suitable condensers and receivers. The performance of this apparatus fully 
justified our expectations as to the rate at which coal could be exhausted of its 
gases at 400° to 450°. The time required did not exceed the one and a half 
hours of our estimate. ; Z 
The further evolution of the apparatus passed through various stages till a 
1913, FF 
