HARDWOOD RECORD 



Evaporation of the water from the acetate solution, leaving behind a 

 solid vphich is commercial acetate of lime. 



From the foregoing, it will be seen that in order to reclaim 

 finished products from the (originally dilute) pyroligneous acid, 

 it is necessary to evaporate the whole original volume three times. 

 This takes fuel, labor and apparatus, all of which can be econo- 

 mized in direct proportion to any concentration whatever of the 

 original pyroligneous acid. This fact should be noted for future 

 reference. 



We have now reviewed the cardinal points and shown some of 

 the problems which confront the wood distiller of to-day with 

 constantly increasing force. 



The methods to be described deal only with the first step of 

 the process, i. e., carbonization, which has long been carried on 

 with little or no improvement in apparatus or methods. 



Before discussing the "remed}', " let us consider the possible 

 sources of the raw material, wood, its distribution and use. 



In the United States to-day there are in operation about eighty 

 firms making acetate of lime, charcoal and crude wood alcohol. 

 Some of these own several plants. These plants are grouped in 

 the original centers of the industry, !New York, Pennsylvania and 

 Michigan. They use much forest waste and also mill waste in 

 the form of slabs, but, unfortunately, they use also much good 

 "body wood" which should go for other purposes. The existing 

 plant must have wood as raw material, in relativeh' large pieces, 

 such as cordwood or slabs. 



Great sums of money have been spent in efforts to use finely 

 divided wood such as sawdust, shavings or hog-chips. These efforts 

 have until now been uniformly unsuccessful, partly because of the 

 difficulty of obtaining heat penetration either of the sawdust itself, 

 or of any portion of it which the operator might succeed in car- 

 bonizing. The man, therefore, who can use sawdust for carboni- 

 zation will be enabled to literally "play the game with the 

 discard." 



Of the vast quantity of sawdust and shavings now going to 

 waste, a considerable percentage is made in connection with the 

 manufacture of flooring, vehicles, farm machinery, and the like. 

 It is obvious that, chemically, the sawdust is exactly like the 

 wood from which it came. Therefore, the out-turn of sawdust 

 from high-class stock, like the above, is dry, well seasoned, of 

 the right age for distillation, and is free from bark, decay and 

 dirt, which are present in such objectionable quantities in the 

 cordwood and slabs now being used. 



This chemically superior material may be bought for a fraction 

 of the cost of cordwood and would long since have replaced it 

 entirely had it not been for certain mechanical difficulties which 

 have stubbornly resisted the efforts of all who sought its utiliza- 

 tion by older methods: difficulties so great as without exception 

 to result in failure. 



The history of these failures would form a technical obituary 

 too bulky for the present article. In justice to the workers in this 

 branch of the art, it should be said that they have, in general, 

 used well and intelligently those elements and appliances possessed 

 by them at the time. The successful method of carbonizing saw- 

 dust (about to be described) has been made possible only by 

 the advent of radically new apparatus. 



The cordwood being used costs the operators more each year. 

 The reason for this is not far to see: it must be bought from the 

 forest owner at fifty to seventy-five cents per cord standing; 

 then it must be cut and piled in the woods at about one dollar and 

 twenty-five cents per cord. There it is left for a year or so to 

 season and during that period is subject to very serious shrinkage 

 caused by theft, fire, decay, falling off of the bark, floods and 

 insects. Such wood as escapes these hazards must be hauled out 

 of the woods to the distillation plant, an increased distance each 

 year, as the supply diminishes. After hauling, it must again be 

 piled on the yard or storing ground ready for re-handling to the 

 industrial cars which carry it to its final destination, the retorts. 

 Even where this complicated performance is conducted in con- 

 nection with a lumbering operation and where every possible econ- 



omy is exercised, the cost of the wood per cord at the retort is 

 three dollars and fifty cents; oftener, it is four dollars and over. 

 Compare this with the problem involved in the use of sawdust, 

 which may be bought at a price no greater than its fuel value, 

 say one dollar per cord, at point of production. The distillation 

 plant (located close to the mill) receives its sawdust ready for 

 immediate use, direct from the chains of the mill, from which it 

 feeds automatically into the mechanism of the distillation plant, 

 never once being touched by hand, so that the expense beyond 

 the bare cost of sawdust is too small to calculate. 



By the perfected process of the American Wood Eeduction 

 Company, the formerly rejected sawdust becomes the preferred 

 material. It is taken in a reasonably dry state, passed through a 

 press of unique construction, which has a new and peculiar action 

 on the wood, reducing it to a condition vastly better suited for 

 carbonization than any other form which has ever been available. 

 The wooden blocks resulting are of uniform size, quality and density. 

 The.v may be handled automatically throughout the remainder of the 

 process. For carbonizing them, there has been designed and con- 

 structed a simple retort of low cost, so arranged that each block 

 is in intimate contact with a heat radiating surface, and which 

 heat needs penetrate only to a depth of two inches in order to 

 carbonize completely the entire contents of the retort. Owing to 

 the great density of these blocks, their heat conductivity is very 

 high, hence the whole mass is at practically the same tempera- 

 ture at any given point of time. Thus, when the exothermic period 

 is reached, it is effective in the whole mass and the applied heat 

 may be reduced and thus economized. 



Because of the high heat conductivity of the mass under treat- 

 ment and because of the intimate contact, the applied heat reaches 

 and permeates the entire mass with a very little lag. Hence, there 

 is at no time in the entire apparatus a heat zone materially higher 

 than that at which the vapors are being evolved. It is, therefore, 

 obviously impossible for these vapors to be overheated and thus 

 reduced in value or, worse still, split into a fixed gas. 



When the chemist or gas engineer desires to "split" any hydro- 

 carbon into a fixed gas, he does exactly what we are thus avoiding, 

 viz., he brings the vapors of the hydro-carbon into a zone of high 

 temperature and preferably into contact with highly heated carbon 

 such as charcoal. This splitting or critical point of temperature 

 has been well known, but we are now able for the first time with 

 absolute correctness to avoid this splitting, causing those elements 

 of the wood which are sensitive to its influence to be driven off 

 and then condensed in their most valuable form, viz., wood alcohol 

 and acetic acid. 



As a matter of record, this system makes from a given unit of 

 wood less than half the fixed gas which is regularly made in older 

 plants. The elements of the wood, thus conserved, become mar- 

 ketable products of many times the worth of the gas. 



Distillation engineers may be somewhat incredulous with reason 

 when told that carbonization which takes twenty-four hours by 

 regular methods can now be accomplished in two to three hours 

 and yet produce yields vastly better than existing methods. 



Kiln-dried sawdust contains only about five per cent of moisture, 

 while cordwood often carries thirty per cent. When either mate- 

 rial is carbonized, its water content becomes a part of the distillate, 

 diluting the pyroligneous acid, which must be evaporated in the 

 refining step three times. The saving due to the use of a dry raw 

 material is thus seen to be great. 



It has been known for a long time that the fixed gas from a 

 retort carries with it clear through the condenser a certain part 

 of the valuable volatiles generated in the retort. It should, there- 

 fore, be plain that a process making but half the volume of gas 

 from a unit of wood has an advantage. 



The perfection of heat control enables the operator to obtain a 

 higher yield and to do the work in from eight per cent to twelve 

 per cent of the time required by former methods. Nearly every 

 that a rapid carbonization results in a decrease of valuable prod- 

 authority on distillation, notably Muspratt and also Senff, states 

 nets and an increase of non-condensable gas. Under the changed 



