INDUSTRIAL A N D ENGINEERING CHEMISTRY
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Vol. 15, No. 1
Method in Research’ By D. B. Keyes U. S.
INDUSTRIAL ALCOROL Co.,27
W I L ~ I A ST., M NEW YORK,N. Y.
OUNG men beginning nitric acid, and potassium Research methods as applied to the everyday problems of the the study of research dichromate, need not be conchemical plant are somewhat digerent from thosefollowed in the colmethods have a right sidered unless the yields oblege laboratory-as the differencesbetween the two types of problems t o know those general printained are unusually good. dictate. This article presents an outline of the steps that must ciples that will help them in Processes involving chlorine be followed if the worker is to ham reasonable assurance of success. the solution of any research point to a high equipment Its value lies rather in the expression of a tried and trusty method problem; yet, few are given cost and upkeep, and therethan in the presentation of revolutionary ideas. I t is hoped that this opportunity. Educafore can be eliminated. Catthe younger generation of chemists going into research laboratories tional men and research alyzers such as platinum need will find food for substantial thought in the scheme presented. chemists have rarely brought not be considered if the yields forward clearly defined and are poor or if the catalyzer workable plans of attack for research problems in general. Most is delicate and easily poisoned, because the cost of the material research chemists a t the beginning of their training are either would make the cost of the process prohibitive. We have left left strictly alone and allowed to flounder as best they may, or the oxidation of acetaldehyde with air in the presence of vanathey are told explicitly what to do and how to do it by someone dium pentoxide. The result of this elimination is not the only else, without being allowed to develop their own ideas. Ultione possible, because many factors will influence the researcher’s mately, each investigatcr devises some plan of his own which is opinion bdt the existing economics of the question will play the usually more dependent on “hunches” that cannot be explained leading role. than upon any definite scheme of procedure. CONSIDERATION O F CHANCES IN METHOD SELECTED A few definite principles similar to those developed in patent practice form the basis of every successful plan. Research men Having the nucleus for the research work, we must now see familiar with patent procedure generally show a remarkable where changes can be made, or, in other words, what are the degree of accomplishment compared with those who do not have the advantages of such experience. It is our purpose to factors involved in the process chosen. By factors are meant not only the chemical and physical characteristics of the constitpresent a plan developed from experience with commercial and of the reaction, but all such conditions as are variable. uents industrial research which has resulted in successful, practical The principal factors involved in our hypothetical example operation and the issue of broad basic patents. can be considered as follows: SEARCH 01‘ LITERATURE
Y
The collection of all available information bearing either directly or indirectly on the problem in hand is recognized as the first step in any research. The importance of indirect bearings on the problem cannot be over-estimated, for analogy is a powerful weapon when properly applied. Let us suppose, by way of illustration, that a new and more efficient process for the oxidation of acetaldehyde to acetic acid is desired in order to dispose of a plentiful supply of the former and t o fill an existing demand for the latter. The literature search should cover, not only the particular, oxidation in question, but also the oxidation of related compounds to their corresponding acids. Ketones, alcohols, hydrocarbons, and other aldehydes might conceivably act similarly under similar circumstances. As the problem begins to take more definite shape in the mind of the worker, leads along this line will be developed and should be carried through. ~$,IMINATION
OF UNSUITABLE PROCESSES
From the mass of information thus collected, some more or less definitely applicable processes must next be selected with a view to their commercial possibilities. To continue the hypothetical case, let us suppose that the methods found for carrying out the oxidation were, among others; 1-In aqueous solution using nitric acid, hypochlorous acid, potassium permanganate, or potassium bichromate. 2-In the vapor phase using air as the oxidizing agent in the presence of a catalyst such as platinum black or vanadium pentoxide. Others may be found in this case, but the examples given may be considered typical. The elimination of those unsuited to the present case may be done without experimentation. Oxidizing agents that are too costly, such as potassium permanganate, 1
Received June 24, 1922.
Catalyzer: Oxidizer: Acetaldehyde:
Physical characteristics Chemical characteristics Physical characteristics Chemical characteristics Physical characteristics Chemical characteristics
Temperature Pressure Concentration Velocity
It is of great importance to consider every factor possible because actual laboratory work is still not necessary and no “good bets” should be overlooked. The preparation of this list of variables is one of the most difficult, as well as important, parts of the problem. When these changes are actually to be made, we must limit the number of variable factors and also the number of variations to those for which we have the time and money available. We must also remember that no change shall be made for which there is no sound and substantial reason. Our variations must be based upon logical principles rather than upon guesswork. Let us first consider a change in the physical character of the catalyzer. It is well known that the greater the catalyzer surface the greater its activity, Bvidently, if vanadium pentoxide is more finely divided it will have more surface and more activity. The same result can be obtained by placing the catalyzer on a porous body such as pumice stone, but the physical properties of the foundation material in any catalysis are of extreme importance. Pumice stone is a poor heat conductor, and this will prevent a fine temperature control. The reaction is exothermic and large quantities of heat must be conducted away rapidly. If this were not done the temperature would rise, and complete oxidation to carbon dioxide would result. A foundation material having both high .porosity and high heat conductivity is needed.
January, 1923
INDUSTRIAL A N D ENGINEERING CHEMISTRY
In recent years methods have been described in the literature for making metals, such as copper and aluminium, very porous. Vanadium pentoxide can be replaced for trial purposes by other oxides in the same periodic group or by any other oxide catalyzer that might act similarly. Combinations using two or more compounds as a catalyzer work better than any one alone. Energy in the forms OF light and electricity work well in many cases. Enzymes act as catalyzers in fermentation processes. All such principles should be considered, even though time permit only a few changes based on such principles. Though we have picked out of the literature as the most feasible process the oxidation of acetaldehyde in the vapor phase by means of air, it is not necessary to limit experiments to this oxidizer. If experience or the literature has shown that other oxidizers have worked unusually well in other instances, it might be worth while to try them. Compounds liberating oxygen are not the only oxidizing agents. Oxidation is an electrical phenomenon, therefore an electric current and also the halogens may be considered. The physical character of the oxidizing agent is very important. Oxygen in the atomic state is much more reactive than in the molecular state. The research man may discover that the base material acetaldehyde may be replaced by acetylene, ethylene, or ethyl alcohol, and a distinct economic advantage be gained thereby. Though such a change is not within the scope of his problem, this line of investigation should be followed if time permits. The hie hest yields along with a practical velocity occur within a definite temperature, pressure, and concentration range. The control of the temperature is especially important in catalytic work. The literature is full of methods that have been used to control accurately the temperature of gaseous, exothermic, catalytic reactions. It must be admitted that most of the methods so far devised are poor, but good pointers may be obtained by reading about these failures. Boiling liquid jackets, elimination of dead air space, metallic supports for the catalyzer, and dilution of reacting gases, are a few of the means described to overcome this difficulty. Changing pressure and concentration in order to take advantage of a possible equilibrium is a common means for increasing the conversion factor. The rapid removal of the finished product is especially advantageous. A factor which influences the temperature, and indirectly the yield, is the time of contact of the reacting gases with the catalyzer, or, in other words, the velocity with which the gases are passed across the catalyzer. In this connection yield and not conversion factor is the important thing. That is to say, a conversion of 70 per cent with 30 per cent waste of raw material by passing the catalyzer once is far less advantageous than a conversion of 10 per cent which results in practically no loss through complete oxidation to carbon dioxide and water. It is conceivablethat the same gases may be passed over the catalyzer many times and still maintain an economical advantage provided the over-all yield is materially increased.
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the laboratory process to fit the standard plant equipment than, to experiment with new and unique plant design. Standard chemical engineering operations give enough trouble without borrowing troubles from the unknown. The real experimenting should be done in the laboratory, not in the plant. A fullsized unit should not be made a t first, but rather a semicommercial unit. These points cannot be over-emphasized. SELLING THE PRODUCT
The research man’s work carries him into a t least one more field. If he has developed a new product he.must go with the salesman and help overcome the difficulties experienced by the customer. The research man can remedy the troubles more quickly than anyone else, and, furthermore, he will learn economic principles that are essential in his work. The customer’s requirements, the shipping requisites, and the sales field should be thoroughly appreciated by the research man. The customer is, after all, the person who supplies the money for research work, and his wishes should be carefully considered. Business principles and production methods have never injured the highly scientific research chemist, but rather have broadened his viewpoint and increased his productive ability. The plan of research outlined is not one that is offered as a tentative scheme, but it is one that has proved its value in the cold gray dawn of industry. It is recognized that the ideas expressed are not in themselves new, but an attempt has been made to crystallize these ideas so that all may benefit by them.
Lexington Section Officers The election of officers of the Lexington Section resulted a s follows: President: JOHN A. GUNTON, Transylvania College, Lexington, Ry. 1st Vice President: L. A. BROWN,Experiment Station, University 0% Kentucky, Lexington, Ky. 2nd Vice President: J. R. MITCHELL, University of Kentucky. Councilor: H. P. NEWTON, Georgetown College, Georgetown, K y . Secretary- Treasurer: E. L. JACKSON, Experiment Station, University of Kentucky.
South Jersey Section Officers The following officers of the South Jersey Section have been elected for the coming year: Chairman: H. W. MAHR Vice Chairman: A. F. ODELL Secretary-Treasurer: W. FLETCHER TWOMBLY, care of E. I. du Pout de Nemours & Co., Box 526, Wilmington, Del. Councilor: W. S . CALCOTT
EXPERIMENTS ON SEMICOMMERCIAL SCALE: After the process has been pronounced a success upon a laboratory scale, the research chemist’s work has not been completedoftentinies it is really just begun. He must now collaborate with the mechanical engineer and work out the process on a semicommercial scale. Large-scale apparatus is a “bird of another color,” and new troubles arise. The research chemist should never be allowed to turn over his laboratory process to others. He must be held responsible t o the very end, because it is only with this experience well in mind that he can develop in the laboratory the nucleus of a commercial process. He will soon learn that laboratory processes are usually only successful when standard pieces of equipment are needed for industrial scale work. The time necessary to produce special plant equipment may be longer than can be allowed. It is easier to change
Officers of New York Section At the meeting of the New York Section a t Rumford Hall, ”NewYork City, on December 8, 1922, the following officers for 1923 were elected : Chairman: C . A. BROWNE, New York Sugar Trade Laboratory. Vice Chairman: C. E. DAVIS,National Biscuit Company. Secretary-TYeasuuer: B . T.BROOKS, The Mathieson Alkali Works, Inc. Executive Committee: M. H . ITTNER, Colgate Co.; JAMESKENDALL, Columbia University; H. C. PARMELEE, Chemical and Metallurgical EngiJayne & Sidebottom, Inc. neering; and H . G . SIDEBOTTOM, Councilors: C. A. BROWNE, C. E. DAVIS,B. T. BROOKS, JAMESKENDALL, H . C. PARMELEE, H . G. SIDEBOTTOM, R. G . WRIGHT,F. H.GETMAN, ELLWOOD HENDRICK, K . G. MCKENZIE,DAVIDWESSON,H. R . MOODY, M. H. ITTNER,A. C. LANGMUIR, D. W. JAYNE,B. R . TUNISON,A. W. THOMAS, WILLIAMSHAYNES,LOIS M. WOODFORD, MARYE . PENNINGTON, and F. M. TURNER.
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