TURNING OLD OIL INTO NEW
Oil is the blood of industry. Do we ever pause to reflect as to what
would happen if we were suddenly to be deprived of our supplies of this
commodity? Do we realize that without oil every machine would instantly
be condemned to idleness, that our clocks would stop, and that it would
be impossible for a train, steamship, tram, or omnibus to move a yard?
The probability is that we have never given a thought to the subject,
otherwise we should scarcely be so extravagant in our use of the
article. Certainly we would not hesitate to expend appreciable effort
in the recovery of as much of the waste as possible for further use.
Britain’s normal importations of lubricating oil are in the
neighbourhood of 68,000,000 gallons a year, and they cost us a round
£2,500,000--$12,500,000. The tendency in regard to consumption is
upwards owing to our enhanced industrial activity, so that we are
becoming more and more dependent upon extraneous sources of supply for
our requirements.
But the wastage is colossal. Rags and cotton waste, after becoming so
soddened with oil as to be incapable of absorbing another drop, are
discarded without compunction. There is scarcely a workshop, factory
or office in the country which cannot point to improvidence in this
direction. Such absence of thought is deplorable for more reasons than
one. Not only is the oil, which might be recovered, irretrievably lost,
but the very absorbent which from its textile nature might prove of
distinct value for other applications shares a similar fate. Were only
50 per cent. of the oil wasted in this country during the course of
the year recovered, it would be possible to reduce our imports to a
very pronounced degree. The reclaimed oil might not be of any value for
its avowed purpose, but it must be remembered that lubrication does not
constitute the one and only purpose to which oil can be applied.
The remarkable development of mechanical traction upon our highroads
has been responsible to a marked degree for our increased consumption
of this commodity, and this is the very field in which the greatest
losses are incurred. There are thousands of garages scattered over the
country. Many are of unpretentious calibre, but even the smallest of
these establishments contributes its quota to the oil wastage issue.
In cleaning operations oil is drawn off from engine crank-chambers and
gear-boxes to run to waste. Rags are used for wiping and cleaning to be
perfunctorily thrown away or burned when they have become too saturated
for further use. The private motor-owner is probably as pronounced a
contributory source of waste as the small garage, because he, too,
is prodigal in his use of oil in every direction, and scarcely ever
gives a thought to the retention of the waste for treatment to recover
the oil and to release the rag for other duty, even if it be only for
making paper.
At the moment the losses in this direction may not be so heavy as they
have been in the past, for the simple reason that oil, in common with
other commodities and in compliance with the inexorable law of supply
and demand, has become more expensive. As the price rises the tendency
to be sparing and careful becomes more marked, which only serves to
prove that cheapness is the primary incentive to waste.
Wherever machinery has to be kept steadily and rhythmically moving
oil is indispensable, so that it is not a difficult matter, when we
recall the immense quantity of machinery which is kept running in these
islands to maintain our industries, and to furnish our homes with
such amenities as water, gas, and electricity, to recognize that our
consumption of this article must necessarily run into huge figures.
Our imports do not extend the true index to our dependence upon this
article, because appreciable quantities thereof are derived from
domestic sources of supply, such as coal and shales.
Machinery is insatiable in its hunger for oil. This circumstance,
combined with the increasing price of the article, has been responsible
for the display of striking fruitful thought and experiment in the
discovery of effective substitutes. This is particularly noticeable in
our machine-shops. A lubricating agent must be utilized to facilitate
the cutting of metals. Oil is admittedly the most efficient and best
suited for the purpose, but many excellent compounds have been evolved
to consummate the desired end and to conspicuous advantage. In one
machine-shop the consumption of oil by the large automatic tools became
so heavy as to prompt experiment. Many expedients were evolved and
submitted to practical test, but they failed from some peculiar cause
or other. However, perseverance brought its due reward. A substitute at
last was found, with the result that oil for cutting was abandoned. By
the change over the firm in question succeeded in effecting a saving of
£30--$150--per month on each large automatic machine it had in use by
the supercession of oil for cutting.
Doubtless opportunities for substitutes still exist in many other
directions, but commercial rivalry under normal conditions, with
enhanced prices prevailing in regard to costs of production, has not
yet been sufficiently encountered to compel the use of the substitute
in preference to the ostensible staple to secure manufacturing
economies. But changes will, and must of necessity, be recorded as the
struggle for trade develops.
In order to encourage the more economical use of oil in industry
many interesting and to a certain degree efficient devices have been
introduced. But for the most part these apparatus are devoted to the
filtering of what may be described as dirty free oil. They scarcely
venture beyond the removal of whatever impurities may be associated
with the product in the suspensory form. They do not attempt to
reclaim waste oil. Such timid treatment is readily explicable. Oil is
a somewhat sensitive product. Its inherent qualities may be easily
impaired. For example, oil prepared essentially for lubricating
purposes must be possessed of specific qualities, of which viscosity
is one and the most important. Then the requirements of lubricating
oil fluctuate so widely. An oil designed for use with a high-speed
engine, such as the petrol motor, is not adapted to the lubrication of
a slow-moving steam engine. Yet the depreciation of one single quality
in any one grade is adequate to render the oil unsuited to the purpose
for which it has been specially prepared.
The consumption of lubricating oil by the authorities during the war
ran into imposing figures, and the liability to waste was proportionate
to the consumption. Aeroplane engines and lorry motors, together with
their auxiliary gearing, were in a constant condition of overhaul.
Every time an engine or gearbox had to be dismantled many gallons of
oil had to be drawn off. Consequently the handling of this enormous
quantity of material to frustrate waste demanded special consideration,
inasmuch as the oil could not be put back into the machinery after the
latter had been reassembled. The authorities solved the problem by the
perfection of an organization for the collection of this oil, which
was returned to the oil-refinery to be re-conditioned, that is to be
cleaned thoroughly and to have its original properties restored. By the
observance of this practice of turning old oil into new the country was
saved huge sums.
But there is a vast difference between official and civil conditions.
So far as the former is concerned it was a comparatively simple matter
to introduce an efficient organization to cope with the problem, while
the waste oil was recovered in bulk, the hospitals for treating the
engines of the aeroplanes and motor vehicles being centralized. It is
the degree to which facilities for satisfying the civil demand are
scattered which renders collection and handling of the waste along
inexpensive lines so perplexing. It might be satisfactorily overcome
if each garage and private owner undertook to maintain a waste-bin and
to commit all oil-soddened rags thereto for periodical collection by a
centralized authority, either municipal or private. The waste would be
obtainable at a low figure, possibly free, inasmuch as the majority of
garage owners would only be too glad to be rid of it. Possibly it would
be found profitable to strike a bargain along the lines of free waste
in return for the de-oiled rags, particularly if they were dusters or
cloths. In this event the waste oil exploiter would only be called upon
to incur the expense of collection and the treatment of the spoil. The
return of the cloths would not entail further expense, because they
could be returned in exchange for another consignment of waste. The
vehicle would have to make the journey in any event, and it might just
as well make the outward trip laden as empty. It is quite possible,
moreover, that the garage would be readily disposed to pay a slight
charge for the cleaning of this material, particularly of cloths,
so long as the sum was attractively below the price ruling for new
supplies of the article. To the waste exploiter the value of the oil
recovered should be adequate to defray all expenses of collection and
treatment, and then leave a handsome profit capable of accretion from
the disposal of the cleaned rags, which the garage did not require, for
paper-making. It is merely a question of enterprise and organization,
and in a large centre could be rendered a highly attractive and
profitable venture.
This fact is borne out by the experience of private firms. Of course,
it is essential that the volume of spoil handled should be of
sufficient bulk to keep the plant installed for the reclamation of the
oil going to its full capacity, or to one approaching the maximum. This
is possible in the case of a large private company, such as a railway,
electric-generating station, or even industrial plant.
One of the largest motor omnibus companies in the world was induced to
consider the possibilities of this issue, and finally was induced to
make the experiment. The “Iwel” plant in question was designed to turn
out 6 tons of clean dry rags per week. This may seem to be an enormous
quantity to accumulate during a period of seven days, but it must be
pointed out that the company in question maintains 2,000 to 3,000
public vehicles upon the roads, as well as several garages and repair
shops.
The first three months’ experience served to bring home the economic
advantages accruing from the scientific exploitation of this form
of waste. During this brief period the company reclaimed 67 tons of
rags for further use, the value of which at the time was set down at
£1,007 7s. 1d.--over $5,000--while from this waste 4,080 gallons of
oil, valued at £59 10s.--$297.50--were recovered. Here was a distinct
gross saving of £1,066 17s. 1d.--$5,334--which figure was increased
to £1,489 15s. 7d.--$7,449--on the credit side by the delivery of new
rags to depots valued at £419 12s. 6d.--$2,098--and the sale of small
rags unsuited to further work for £3 6s.--$16.50. On the debit side
the heaviest expenses were incurred in connection with the purchase of
new rags, valued at £405 12s. 9d.--$2,028, cartage of the waste £152
17s. 10d.--$764.44, wages and salaries £157 15s. 1d.--$788.74, and coal
£105 0s. 11d.--$525.22. The total outgoings amounted to £1,038 16s.
7d.--$5,194.14, which left a balance of £450 19s.--$2,254.72--actual
saving recorded by the treatment of the waste. So far as the reclaimed
oil was concerned, while this was unsuited to further utilization in
its original province, it was found to form an excellent fuel for the
operation of the Diesel engines, and consequently reduced the fuel bill
on this account by a corresponding amount.
Another illuminating instance of the value of such waste is afforded
by the working account for one year, furnished by one of the foremost
British chemical manufacturers. The plant acquired in this instance
comprised two turbine centrifugal separators, one washing machine,
and one drying cabinet, the cost of which complete was £210--$1,050.
In the course of the twelve months 350,000 wiping and other cloths
were treated, and the losses incurred therewith were so slender as to
demand renewals to the extent of only 15,000 new cloths, which, at
2s. 1¹⁄₄d.--52.5 cents--per dozen came out at £131 10s. 2¹⁄₂d.--about
$657.55. The heaviest item in the operating account was wages--£132
12s. ($663). Other expenditure, including repairs, fuel, and
interest on the first cost of plant, brought the total to £324 2s.
2¹⁄₂d.--$1,620.55. From the treatment of the 350,000 cloths 125 casks,
or 5,000 gallons, of oil were recovered, which, at 10d.--20 cents--per
gallon, represented £208 6s. 8d.--$1,041.64. The saving in cotton
waste due to the soiled cloths being rendered available for further
duty, set down at 392 lb. at £4 4s.--$21--per week, came out at £218
8s.--$1,092. Thus the total value of the waste recovered was £426 14s.
8d.--$2,133.64, leaving a saving, after deducting expenditure, of £102
12s. 5¹⁄₂d.--$533.11. The results of the year’s working, therefore,
enabled the firm to recoup approximately 50 per cent. of its original
outlay, while the value of the oil recovered was only a little below
the cost of the plant. The saving in cotton-waste--material which
otherwise would have had to be provided--actually exceeded the capital
outlay upon the plant.
The Lancashire and Yorkshire Railway Company, in consonance with the
general practice, formerly utilized cotton-waste in its works for
cleaning purposes. In these operations the material becomes saturated
with ordinary lubricating, cylinder, and other oils, as well as grease
from rubbing down the locomotives and parts. Some years ago it decided
to abandon cotton-waste in lieu of sponge cloths, at the same time
installing a plant for the recovery of the oil and grease from the
soiled materials. During the year these sponge cloths are passed over
and over again through the cleansing process, the operations being
equivalent to the treatment of 6,500,000 cloths, and in this manner
approximately 45,000 to 56,000 gallons of oil are reclaimed.
It does not matter to what phase of industry one turns, a certain
amount of oil is possible of reclamation from the waste employed
in connection with the conduct of the work. The volume recoverable
naturally varies widely according to the nature of the trade
pursued, and in some instances the individual yield may appear to be
insignificant. But, during the course of the year, even in a small
shop, the figure is certain to become impressive and well worth the
efforts expended, as well as the money invested in the requisite plant,
while, if the one instance be multiplied by the number of other similar
establishments distributed throughout the country, the aggregate must
necessarily be formidable. The table opposite furnishes a few actual
results in the selection of industries specified.
It will be observed that the yield varies widely according to the
industry concerned, but in every instance it will be observed that the
figure is such as to render the process profitable, not only on account
of the oil thus procured, but from the release of the waste or other
absorbent for a further spell of useful service. If the waste, or other
material, has been employed only for wiping parts, or mopping up free
oil, passage through the oil separator will suffice, but if it has been
utilized for general work and has become badly soiled, it requires
washing. The sludge resulting from this process is subsequently
passed through the oil-recovery plant instead of being thrown away,
the reclamation thus being complete, while the rags or other textiles
are passed through cabinets or other suitable facilities to be dried
quickly.
----------------+-----------------+----------+--------------+---------
Industry. |Material Treated.| Quantity.|Oil Recovered.|Per Cent.
----------------+-----------------+----------+--------------+---------
| | | Pints. |
Agricultural | Cotton-waste | 18 lb. | 9·75 | 54·16
machinery | | | |
Biscuit | Cotton-waste[1] | 10 lb. | 4 | 40
manufacture | | | |
Colliery |{Cotton-waste[2] | 39·75 lb.| 63 | 158·69
|{Cotton-waste[3] | 15·75 lb.| 10 | 57·5
| | | |
Cycle and parts |{Rags |112 lb. | 80 | 71·42
|{Sponge cloths | 1 gross | 8 | --
Foundry | Cotton-waste | 13 lb. | 11·25 | 86·53
Machine-tool | Cotton-waste | 8·25 lb.| 2·75 | 33·33
manufacture | | | |
Motor-car |{Cotton-waste | 16 lb. | 1·25 | 7·81
|{Rags | 12 lb. | 2·75 | 22·91
| | | |
Railway |{Cotton-waste | 14 lb. | 2·625 | 13·75
|{Cotton-waste[4] | 10 lb. | 13 | 130
| | | |
Steel and |{Cotton-waste | 8·25 lb.| 9·25 | 112·12
iron-works | | | |
|{Mutton cloths | 2 lb. | 1·5 | 75
Tramway | Cotton-waste | 13 lb. | 1·25 | 9·61
Wood screw | Cotton-waste | 21 lb. | 13·75 | 65·47
manufacture | | | |
----------------+-----------------+----------+--------------+---------
But so far as industrial operations are concerned oil reclamation is by
no means confined to the treatment of the waste and cloths. As already
mentioned, oil is freely used in working metal, acting as the lubricant
to the cutting tool. While trough facilities are provided to catch
the oil to enable it to be used again, much clings to the turnings
and other refuse. Even where works are not equipped with oil-recovery
apparatus of some description or another an attempt to secure a
proportion of what would otherwise be lost is made. The turnings are
permitted to drain. The quantity of oil recovered in this manner,
however, is very low. Certainly it does not exceed 40 per cent.,
because the oil clings somewhat readily and freely to the metallic
surface.
Accordingly, in the best equipped factories, the practice is to submit
the turnings to treatment. It is passed through the extractors and in
this way at least all but 10 per cent. of the oil is recovered. When
the solvent extraction process is exploited the recovery can be carried
as far as 99 per cent., the fraction resisting recovery thus being
extremely small. The yield obtainable from such metallic residue from
the machines is certainly sufficient to justify the treatment. In one
shop, devoted to the manufacture of cycles and cycle parts, the oil
recovery averaged 22 pints per 112 lb. of turnings treated. In another
instance, where the production of agricultural machinery is conducted,
26 lb. of steel turnings and 23 lb. 9 oz. of brass turnings yielded
1·75 and 1·125 pints of oil respectively. One motor-car manufacturing
firm recovers 1,200 gallons of cutting oil from the treatment of its
weekly accumulation of turnings. This becomes available for re-use,
and the absolute loss recorded is only about 10 per cent. In another
instance, 2,440 gallons of oil were recovered from the treatment of
41 tons 17 cwt. of metal turnings, 900 lb. of rags, and 19,300 sponge
cloths in the course of six months.
Another interesting experience in this field is worthy of record.
It was found that the sawdust in the vicinity of certain machines,
provided as an absorbent, became somewhat heavily charged with oil
splashed and otherwise discharged from the machines. The presence of
the oil-soaked refuse on the floor was construed as being a menace
to the establishment, the hazard of fire being regarded as thereby
increased. Accordingly, the floor was swept more frequently than
otherwise would have been the case, the refuse being promptly shovelled
into the furnace merely to secure its prompt and complete riddance.
The sawdust was examined by a waste expert upon the occasion of a
visit to the works, and he suggested, from the fact that oil oozed
from a handful of the sawdust when squeezed, that the waste should
be subjected to the “Iwel” oil-reclamation process, instead of being
burned. The recommendation was followed, and the volume of oil thus
recovered was found to be of surprising quantity. In fact, its value
more than defrayed the cost of the small plant which was installed to
treat it. So effectively was the sawdust found to be cleaned of the
oil as to be redistributed time after time upon the floor around the
machines. In this instance destruction of the oil-soaked refuse by fire
represented a material loss in more senses than one.
While it is only within the past few years that the possibility of
reclaiming oil from cotton-waste has aroused such earnest attention,
it must be acknowledged that many firms sought to reduce their
expenditure by submitting their cloths and waste to a laundrying
process. Of course, by this practice the textiles were recovered, but
the oil was lost, while material expense was incurred in the conduct of
the laundrying operations and the acquisition of suitable detergents.
An interesting record of the cost of the respective processes is
forthcoming from a certain firm in the South of England. It refers to
two years’ operations, the one referring to straight laundrying of the
sponge cloths and waste, while the other refers to the latest method
of dealing with such materials. Under the former _régime_ the cost for
the year was £219 9s. 2d.--$1,097.28. The heaviest items were for the
purchase of sponge cloths and waste, the figures for which were £62
17s. and £137--$314.25 and $685--respectively. The cost of washing the
dirty cloths at 7s. 3d.--$1.78--per week was £18 17s.--$94.25.
The firm then acquired a small oil reclamation and cloths-cleaning
plant at a cost of £125--$625. During the year, under the new
conditions, the expenditure on account of sponge cloths and waste
was £25 16s. and £85 15s.--$129 and $428.75--respectively, but, for
purposes of comparison, one-fifth was added to each item to counteract
the slackness encountered, and to bring the subject more in line with
the experience of the previous year. But even after making these
allowances the total expenditure for these two articles came out at
only £133 17s. 2d.--$669.28--against £199 17s.--$999.25--when the
textiles were laundered. Inclusive of all expenditure, including wages,
washing materials, power, and interest at 5 per cent. upon the first
cost of the plant, the total cost was £199 4s. 4d.--$996.8--as compared
with £219 9s. 2d.--$1,097.28--for the previous year--a saving of £20
4s. 10d.--$101.20. But under the new system 716 gallons of oil, totally
lost under the previous method, were reclaimed, which represented £11
15s.--$58.75, so that the total saving was £31 19s. 10d.--$159.98,
representing approximately 25 per cent. on the capital outlay incurred
for the installation of the plant.
In view of the economies possible from the practice of such a system as
I have described, it is somewhat surprising that manufacturing firms
should hesitate to include an oil-reclamation plant in the equipment
of their establishments. It is likewise somewhat difficult to bring
home to them what really can be achieved by the scientific treatment
of their waste. In order to popularize the practice, and to further
the observance of economies which are inseparable from industrial
operations under contemporary conditions, more than one British firm
is prepared to advance an attractive commercial proposal. This is
that the equipment should be installed and its cost defrayed out of
the actual savings effected. Thus, in the case of the installation to
which I have made reference, and which deals with the rags accumulating
from the maintenance of public service vehicles, such a procedure
was initiated. The capital expenditure involved in this instance was
approximately £2,200--$11,000, but as the plant recorded a net saving
of £450--$2,250--as a result of three months’ work, which is equivalent
to £1,800--$9,000--a year, it should be able to defray the whole of the
initial outlay within about 16 months. However, all things being equal,
it is computed that a reclamation plant submitted to the work which
I have described should pay for itself within two years. Experience
serves to support this contention, although, under the conditions
which at present prevail, the possibility is that such a gratifying
achievement would be fulfilled within a shorter period.
FOOTNOTES:
[1] From engine-room.
[2] From blast-furnaces.
[3] From power-station.
[4] Axle-box waste.