ENGINEERING, DESIGN, AND PROCESS DEVELOPMENT a fair rewaid for the volume of business transacted and thus ia n-ell managed. If it cannot show a good return on sales while demand is still high it will find the situation greatly aggravated when demand is less. Third, has the company evpanded a t a rate commensurate with the trend for the industry as a whole or has i t been deficient in opportunism even after meeting the first two tests? In other words, can the company be enveloped by competition? Perhaps the answers to these three points will serve as much in establishing expansion policy as the researches of the chemical technologists. The future 01 ill see a higher degree of selectivity of processes to increase profits per dollar of sales rather than the volume of sales. A s a corollary, old procesqes will be scrapped in order to use the equipment on improved or even entirely new products. Today, however, there is added impetus to discard a going plant. The tax structure has changed considerably. The manulacturer receives little tax credit for new capital inveatment. It is money taken out of profits and dividends on JT hich the t a w s have been paid. The compan) only receives a small increase in its tax deduction in succeeding years for having made the investment today. If a manufacturer takes a written-off plant and revamps it for another service he need only capitalize the value of the labor used t o revamp the plant and such supplementary equipment a4 he supplies. H e may also be obliged t o adjust depreciation where i t proved excessive, but on this score he usually comes out ahead. Consider the fact that as a result of equipment price changes from 1939-54 equipment which is obsolete processwise but still capable of function may now be worth twice what its owner paid for it. .4dd to this the fact that a piece of installed
equipment is rr-orth an additional 20 to 30% by virtue ol being erected in place. From these facts it should no loiiger be difficult to just,ify the abandonment of obsolete processes where a siibstaritial part, of the equipment is reclaimable. Chemical technology should soon be faced with a growing necessity to evaluate the good t h a t remains in a worn-out procew rat'her than the bad that is in it. For the research chemist i t means development wit8hthe prospect of reclaiming t,tiat equipmeni; which has already been built rather than exploration in t h r realm of unfettered science. For the chemical erigiiieer, t,ltei,e is the challenge of re-engineering and redesign. One of the problems of re-engineering is the disruption in output which may result from the down time during change-over. However, as demand and price weaken it should be possible to stock-pile for the period of conversion without excessively efl'eccing the marketing pict'ure or product cost. Facilities which arp re-engineered can usually be placed on stream in shorter titrir wit'h less capital tie-up t,han new facilities. Here lies the new great, phase of chemical technology. T o evaluate the direction of research and development in terms of its nianagement implications. T o search a t the start for those products which hold bright prospects in t e r n s of t,he act,ivecapital facilit,ies of a specific company rather than from the &,lidpoint of general scientific interest. A product which may be attractive to produce in t,erms of one company's re-engineerable facilities may be unattractive t o another. But most important a greater degree of management, and economics must be built into even the least specialized levels of research, developriient, and engineering. Perhaps then, the technologist will reach his highest achievement--as a businessman as well BB a scholar. RECEIVED for review April 7, 19S4.
AccormD Sei)texnber. 30, l Q J 4
Converting Plants for New Products c. 8. WAGNER,
Koppers Co., Inc., Piftsburgh, Pa.
The rewards that may be expected from a well-engineered plant designed to produce a special product are maximum efficiency, minimum maintenance costs, and minimum material handling and operating labor costs. There are times, however, when acceptance of less than these ideals i s justified. Fortunately, chemical process equipment is flexible and can be adapted for uses rather remote from those for which they were designed. The arguments favoring conversion of plants are reviewed, and the pitfalls in such practices are emphasized. A check list covers the elements to be considered, and these are illustrated b y a discussion of their application in the Koppers Co., when an oil refinery unit was converted to B multiprocess chemical plant. Some experiences of other companies are also cited. The paper i s concluded with a challenge for the future.
T
HE general theme of this symposium contends that chemical process equipment is adaptable. It need not be discarded when its original use-that for which it was designed-no longer exists. The equipment, as is or mith minor changes, can be substituted in other places, perhaps a ith some sacrifice to efficiency or operating costs. This paper extends this idea one step in stating t h a t not only cansinglepiecesof equipmentbe adapted but t h a t whole operating units or plants (consisting of many pieces of equipment) can be altered to perform tasks other than those in the original plan. Again i t must be added, "perhaps with some sacrifice t o efficiency or operating costs." It is fortunate t h a t chemical process plants are versatile and need not be discarded when they are out of date. Vaddell 2466
(3) says, "A plant is out of date when the estimated anniini saving made possible by a n s v plant equals or exceeds the anriiiul cost of financing t h a t plant." This point is often re:tcliiaci quickly in the chemical industry. Particularly is this true when plants are built in periods of national e~nergency~-wl~rn the cost of operating the plant is not the prime consideration. If it is true t h a t chemical plants become obsolete quiclilg even when well engineered, the chances are even greater that this st,age will be reached in a short' time if engineering sacrifices :LE made in order to use an existing process unit or plant. Such :L glum outlook poees a question as t o whether consideration 3houlti ever be given to converting a chemical plant. The answer is that there are occasions when efficiency of operation is second in importnnce. For example,
INDUSTRIAL AND ENGINEERING CHEMISTRY
Vol. 46, No. 12
PLANT ADAPTATION 1. Keed for quick conversion to meet a national emergency. 2. Need to use existing equipment to conserve metals in time of national emergency. 3. Need to reach markets quickly. This includes satisfying a market that is expanding so rapidly that there is not sufficient time for delivery of new equipment. 4. Shortage of availablc capital to be invested in a plant. MONTHS
2
ment. Figures 2 and 3, from a major equipment supplier, illustrate the performance on compressors and steam ejectors. If the time required to prepare purchase specifications and to install the equipment after delivery is added to these figures, it is easy to visualize the pressure on engineers to consider used equipment and plants in periods such as 1946-47. A similar period was reached in 1951 a t the start of the Korean hostilities, but a t that time the shortages were not so acute for some types of equipment* (Figure 3). Although capital was readily available in this postwar period (compared to other periods), potential markets encouraged manufacturers to stretch capital dollars to cover as many new ventures as possible. All these factors were favorable to the sale of war surplus plants. On September 30, 1952, the General Services Adniinistration published a list of sales of surplus real property by GSA or its predecessor agencies. This listing included sales at 1068 locations where 83,741,500,000 of surplus industrial property was MONTHS
1946
1947
1948
1949
-DELIVERY OF PUMPS _.-.-
I950
1951
1952
1953
--- DELIVERY OF TANKS
DELIVERY OF COMPRESSORS
Figure 1.
10
Delivery o f Equipment
8
At the cnd of World K a r 11, conditione werc particularly favorablc for plant conversion. Cheniical plants had been built at odd locations for security reasons, and some were designed to operate 011 high priced raw materials in order to conserve more logical raw materials for production of other necessities. Some plants were designed to produce chemicals for which there is little peacetime demand. These reasons, and others, resulted in the postwar necessity of disposing of process units that would not be used to make the products for which they were designed. Most of thcse plants were well built, and ninny had been operated only a short period of timr. MONTHS
l4
:
4
I 4 I
2
1946
1947
Figure 3.
1
I
I
I
1
1948
1949
1950
1951
1952
1953
Delivery o f Steam Jet Ejectors with Inter- and Aftercondensers
sold for $1,313,700,000,an average realization of 35.1%. This was exclusive of property worth approximately $500,000,000 transferred to state or local instrumentalities. Many of these sales mere to industrial firms that converted thc property t o new uses. In this category was the sale to Koppers Co. of Plancor 1044 a t Oil City, Pa., which constitutes the main case study in this report.
From Aviation Gasoline to Coal Chemicals
j
2 1946
1947
Figure
1948
2.
I
DUP(EX OPPOSEDSTEAM D ~ I V E
1 7 1
1949
1950
1951
1952
1953
Delivery of Compressors
This availability of surplus equipment was coupled' with a pent-up desire on the part of chemical companies to expand their operations and t o promote new products. Heavy demands for process equipment were placed on equipment manufacturers n-hcn they also were in the process of converting from wartime to peacetime production. Delivery of special design work required a year or more, and equipment which normally would be delivered in 6 months required 9 months to a year. Figure 1, prepared from data in Koppers Go. procurement files, illustrates the changc in availability of thrce classes of chemical plant equip-
December 1954
Plancor 1044 was an aviation gasoline plant built by the Government at Oil City in 1943-44 and operated for approximately 18 months by The Pennzoil Co. The plant was located midway between the two privately owned plants of The Pennaoil Co. Feedstocks for the plant were delivered by pipeline from Pennzoil'~No. 2 plant, a distance of about a quarter of a mile. Isobutane was alkylated with butylene to form iso-octane for blending with other refinery products to give a high octane military aviation fuel. The United States production of aviation gasoline underwent a 14-fold increase during World War I1 to a peak production in excess of 500,000 barrels a day. Demand in 1946 had dropped below 100,000 barrels a day. There were fourteen government-owned aviation gasoline plants of this type east of the Rocky Mountains. The Oil City plant was one of the smallest units and was the only one situated in the Pennsylvania oil fields; other plants were located in Texas, Oklahoma, Louisiana, and other states where the crude oil supply is lower priced, more available, and generally recognized as better suited for gasoline production than is the Pennsylvania crude oil. For these reasons neither the wartime operator of the plant nor any other refiner was interested in operating the plant in competition with the larger aviation gasoline refineries. Pennzoil did have
INDUSTRIAL AND ENGINEERING CHEMISTRY
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‘ENGINEERING, DESIGN, AND PROCESS DEVELOPMENT an interest in the steam plant since it also was supplying st,eani to their KO. 2 refinery. Later an agreement was made to have the supply of st’eam to the refinery continued by Koppers. Koppers had for a long time been considering the construction of a plant to upgrade a portion of the phenol and cresol products produced in its tar p l a n k They proposed to alkylate these materials with olefins to form products that could be sold as antioxidants, oil additives, det’ergent intermediates, pharmaceutical intermediates, and other industrial chemicals. The following discussion covers the factors that were evaluated in considering the purchase and reconversion of this plant. In general, the same check list may be used in considering similar venturey. Location-Raw Materials and Markets. Raw materials supply and eliniination of freight costs represented major considerations in the decision to purchase the Oil City plant. I t was possible to contract iyith the refinery for the purchase of hydrocarbon streams t o be supplied through already e x i d n g pipelines. With the C4 stream, it was possible to remove the desired isobutylene and sell the unused butylenes back t’o the refinery as feed to their polymerization unit. Propylene coulcl he similarly extracted and t,he remaining gases used for fuel. If a plant being considered for conversion is not located in approximately the best spot relative to the market freight, costs to move the products to the market become a significant cost factor that may well offset many of t>headvantages of the conversion plan. If the products are new and their market potential is somewhat speculative, less n-eight can be put on the product freight fact,or. A survq- of the potential markets for Koppers alkylated products indicated the area around Philadelphia to he the best, location in respect to the market. S o w , 7 years later, the Oil City location is practically as good in regard to freight on products as would be a location near Philadelphia. Proximity t,o other operations is, of course, minor compared to location in respect to raw materials and markets. However, there are savings to be realized through sharing overhead coda and costs of travel and cominunications ivhen a plant is near other plant>sor offices operated by the same company. Room to Expand. One problem in purchasing a used plant or unit concerns its location in respect to other operat,ing units that are not for sale. One of the worst mist’akes that can be made is to move into an area where there is no room to expand. Koppers’ managenlent would not consider the purchaPe of Plancor 1044 until an option to purchase some adjoining vacant land could be obtained. Thiy is a point, that government agencies building emergency plants might keep in mind. -4fen- extra acres of land around a plant, will make it more salable after the emergency. Equipment That Can Be Used. Preliminary specifications for the process to be used probably are available. Preliminary specifications are possibly better than final specifications in t,liat,they allow more latitude in thinking. This problem is, “what can he used?” rather than, “what is there that is exactly fitted to the job?” Some sacrifices must be made. A 4-foot-diameter distillation column may be indica.t,ed,but ’ou may have to ;.et,tle for a 5 - or even 6-foot, column. The que tion ic whether it will do the job-not necessarily the best job. Conversion is not a project for an engineer who lacks imagination. The alkylate distillation column at Oil City furnishe9 an example of t,he extent of such changes as shown in Table I . This is about as radical a change from original design as can be imagined. The operation of this column has been succeseful, and the separation of products has been as good as espect’ed and required. In converting the alkylate distillation column there was no anxiety concerning performance of t,he equipment in the new assignment. This is not always the case. For example, the Oil City equipment included two Stratford Engineering Co.
2468
alkylation reactors. Each of these consisted of a tank (about 2000-gallon capacity) with an internal bundle of G-fin tubes for cooling and an internal circulating pump with marine-type impeller. These were decidedly different from the type reactors used by Koppers in pilot plant studies of the process to be used. The process was discussed with the Stratford engineers who believed the equipment could be used. The outcome vias that Koppers purchased a %gallon prototype from Stratford Engineering C,o. and used it to recheck the pilot plant data before making a decision to use the large reactors. Corrosion problems caused the internal tube bundles to fail soon after the start-up of the plant. It was decided a t that time to change to external cooling exchangers because they were available in unused equipment a t the plant. Later tests proved that internal circulation was not necessary but that sufficient agitation could be obtained by proper introduction of the olefin as a fine stream a t the bottom of the reactor. As new equipment became available the external circulating pumps and coolers TTere replaced with equipment properly designed to do the job. The reactor vessels are still bcing used.
Table I Column diameter Column height Overhead pipe diameter Operating prgssure Heating medium Condensing system Operation Material distilled Internal changes
Present Use 7 feet 120 feet 18 inches 50 m m . €10 abs. Dowtherm Condenser from another p a r t of plant Continuous Batch (10,000gal. kettle substituted for reboiler) Isobutylene Dibutyl cresols Height of overflow weirs on trays reduced Original Design 7 feet 120 feet 8 inches 350 lb./sq. inch Steam Condenser-suhcooler
These two examples illustrate several practices that folloved in converting a plant:
citri
be
1. Be willing to make radical changes in equipment if calculations shorn it d l do the job. 2. If equipment is different from t,hat,used in the pilot plant, check the results on a prot,otype. 3. When sacrifices are made in operating efficiency in order to use available equipment, start making plans to correct these defects as soon as proper equipment is available.
An excessive number of major pieces of equipment that are of no use in conversion may present obstacles in purchasing a plant. Disposal of t8he equipment, may necessitate sales agreements before any offer is made to purchase the plant,. Some governmenb-owned plants sold wit,h the restriction that the plant be maintained for reconversion if it becomes necessary during a st,ated number of years. Much of the equipment in a purchased chemical plant may be standard, and although it may not be needed for the new process it will in all probability eventually find use somewhere in the company’s operations. This equipment can be evaluated a t a reduced figure that alloivs for cost of storage, cost of dismantling and moving, possibility of never being used, and for the risk of obsolescence. Equipment To Be Purchased. If there are one or more key pieces of equipment missing and delivery cannot be obtained on these for long periods, all the time advantage gained by conversion mag be lost. This is when the engineer’s ingenuity must produce temporary arrangements until delivery is obtained. If a t,eniporary solution can be found, often it is possible to expedite the delivery of a single piece of needed equipment far beyond the possibilities when dealing with a whole new plant. At Oil City the product,s could not be distilled a t t.he temperatures obtained
INDUSTRIAL AND ENGINEERING CHEMISTRY
Vol. 46, No. 12
PLANT ADAPTATION with 275-pound-per-square-inch steam. The plant was useless R ithout higher temperatures for heat exchange. Two vertical tube-fired boilers were obtained from a second-hand dealer to start the operations in mid-1947. Promised delivery dates on standard Dowtherm boilers were beyond the endurance that could be expected of the temporary boilers. Furthermore, the second operating unit was scheduled for December 1947 and could not start up without additional Dowtherm capacity. The orders for the permanent Dowtherm system were placed. I n order to bridge the gap between the period when the scrap boilers would be inadequate and when the Dowtherm system would be installed, it was necessary to purchase several hot oil type units which were of simpler design and could be delivered on shorter notice than the larger Dowtherm units. These intermediate units consisted of a continuous welded 4-inch pipe in a firebox baffled to give three passes of the hot combustion product gases over the pipe. Regulation was difficult and heat efficiency low, but production was continuous from July 1947 to Xovember 1948, when the Dowtherm unit was ready to operate. Thus, the heating problem was solved in three stages: a poor setup which was immediately available; an intermediate setup which was operable but costly; and finally the well designed unit when the equipment was available. Condition of the Equipment. Internal inspection of the equipment prior to making a purchase agreement is a “must.” A proper inspection can only be based on knowledge of the details of the process that was formerly used. With this information, possible corrosion sites can be checked, and better estimates can be made of the cost and difficulty of cleaning the equipment. Previous operators may make available their inspection records. If dangerous chemicals were used in the original process, extra precautions must be taken in converting the plant. Hydrofluoric acid had been used as a catalyst in the alkylation unit a t Oil City, but with precaution, there were no injuries from this cause while cleaning and altering the equipment. A tetraethyllead weighing tank and addition equipment were dismantled under the supervision of the Ethyl Corp. safety engineer, and the equipment was resold to the Ethyl Corp. Location of Equipment. In any original plant layout there is a plan by which the equipment is arranged for ease of operation of the process or processes planned. There are two general methods of arrangement which are followed in chemical plants. 1. 411 equipment of one type is grouped together-for example, the stills in a plant may be all in one group even though they may be for different processes or different steps in the process. 2. All equipment for a single step in the process may be grouped and the operators have control of all the manufacturing in that step. The intermediate product is then transferred to the next unit.
The question of which arrangement to use depends upon factors peculiar to the process being engineered, and what is best for one process may be cumbersome for another. Since there are two general arrangements, the converter faces a 50:50 chance that the arrangement inherited is not the one that is best for his process. Bt the Oil City plant, the equipment was grouped by types-stills in one section, reactors in another, tanks in another, etc. Koppers’ plans called for a multiprocess plant and a t times as many as five processes were being operated a t the same time. This arrangement was satisfactory as two trained operators could man the stills for all the processes, etc. At other times only one process was operating, and a larger number of operators was required than would be needed for a unit operation. There were other objections such as more difficult communications and excessive material handling. Even assuming that the general type of arrangement is satisfactory, the location of individual pieces of equipment may be wrong. For example, take the simple arrangement: December 1954
Stills Reactors Tanks
1 2 3 4 1 2 3 4 1 2 3 4
5 6 5 6 7 8
One may find that for a new process the equipment best adapted is :
Raw material tanks Still Reactor Product tank
2 8 1
4 7
Intersperse this with other processes, and the operation becomes difficult. Pumps, small compressors, scrubbers, and other small equipment can be relocated without too much cost or time delay. However, moving a 20-ton reactor or an 80-foot distillation column is another matter. -4s mentioned before, some sacrifice in the efficiency of t h e operation is almost certain to be the price that must be paid when a plant is converted t o a new use. This is difficult to measure. One can figure the increased pumping costs, the added utility costs, and other added processing costs, but there still exist intangibles such as the frequency and cost of operating errors due to overcomplication of the process. Utilities. The problem of available utilities is not likely to be overlooked by a prospective buyer. A water supply that may have been adequate (in quality as well as quantity) for one operation may be just a drop in the bucket for another. In a period of rapid expansion, additional power and steam facilities could mean as much delay as the purchase of new process equipment. Options on contracts with local fuel suppliers must be arranged early in planning. Heating a t the Oil City plant was entirely by steam when it was operated as a gasoline refinery. The planned chemicals operations required higher heat transEer temperatures. Makeshift facilities for Dowtherm heating hampered operations in the early months while the plant waited for delivery of a proper Dowtherm system. Land Surface. In evaluating an established plant against the alternative of building a new plant, an important factor in favor of the used plant is that the ground has been prepared. This can mean a sizable saving in time and investment for leveling the land, filling in low spots, building intraplant roadways and parking areas, and landscaping around the office buildings. 9study of government-financed chemical plants during World War I1 disclosed that 30y0of the total cost was accounted for in the selection and preparation of the site, This included the installation of basic utilities. Perhaps 20 to 25% is more accurate for chemical plants if installation of utilities is excluded. Subsurface conditions should be investigated. Future additions may prove costly if piling, additional filling, or drainage are necessary. Two years after purchasing the Oil City plant, the area was flooded by the adjoining creek. Anyone not thoroughly acquainted with the area would have believed this to be inipossible from the normal size of the stream. Fortunately, the damage to the plant was slight, but expenditures had to be made to prevent future occurrence. Another point to remember is that, in taking over an established plant, you are not choosing your neighbors. The cooperation of other Oil City industries was all that could be desired, but the location of a woodworking shop next to the plant has always been a concern of the insurance companies. It will pay t o look beyond the plant a t the neighboring area and industries. Traffic. In purchasing a plant, the railroad and truck loading facilities can be considered at some amount close to full value. Every plant needs them and they are essentially the same for all plants. The existence of railroad siding and traffic lights saves a. lot of red tape that must be endured if they were being installed in a new plant.
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ENGINEERING, DESIGN, AND PROCESS DEVELOPMENT Labor Supply. One of t,he greatest intangible gains in purchasing an existing plant comes if you inherit a t,rained labor force. If the plant is operating and employing trained firemen in the boiler plant, t'rained still operators, skilled mechanics, etc., you are well on your way toward smooth operatiom. They not only know t,he skills of their trades, but they actuallv know the applications of t'hose trades to the specific pieces of equipment in the plant,. Men who know the history of previous repairs and failures of the equipment are valuable. This advantage may estend to the office jobs as well. Y o u may acquire v i t h the plant an employee who knows the traffic personnel of t,he area or perhaps another who is acquainted with local purchasing. It is not necessary to dwell further on the obvious personnel advantages in buying an operating unit for conversion as against building a new- plant in a new area. If the plant has been shut down prior to its purchase, you may still be able to locate former employees in the area who are willing to return. This was the situation a t the Oil City plant. The general labor market for the area must supplement these of course, whether the unit is newly constructed or converted. Legal Restrictions. I t should be remembered that during a war period code relaxations are permitted t,o expedite complet,ion of war-necessary projects. Coded vessels were not always so stamped, and records were difficult to trace after World War 11. The change in intended use of the equipment may change its inspection requirements. Vessels intended for use in refineries may be permitted to use the API code, whereas the same vessel in n similar use in a chemical plant may be required to fit a state code patterned after the ASME code. The small differences can cause considerable legal trouble and require special operating permits from the state officers. Municipalities may permit' one type of operation and restrict a similar t.ype so that occupation of a previous operating site does not forego the need to check with local authorities and ordinances. Piping. Placing a value on piping is a big job. The quest'ion of what pipe can be used is only part of the task. The cost of removing pipe must be figured, and the cost of cleaning pipelines may also be a large factor. Accurate piping drawings are an asset. Consideration can be given to removing most of the piping and reinstalling what is needed. Operations probably would be simplified by such a procedure. One company operating a revamped plant writes as follows about this phase of the problem: "Piping arrangements which were found suitable for one type of operation are seldom convenient when adapted to another process. The misplacenient of valves and t,he installation of additional lines lead to unfortunate operat,ing errors particularly during the start-up period." Cleanout Costs. The necessit,y of a physical inspection to determine the extent of corrosion and wear has already been mentioned. This same inspection can be used to est,irnate the cost of cleaning equipment for new operations. Costs will include labor, cleaning solutions, new gaskets, and the cost of retesting equipment after assembly. Consideration can be given to obtaining a preliminary quotation from a firm that specializes in cleaning chemical equipment.
Making the Decision Having assembled the answers t o the questions in the preceding check list, final calculations can be made: 1. The first step is to estimate a start-up date that can be realized by revamping the plant. If negotiations for purchase of the plant are required, allowance must be made to complete this transaction. It may be necessary to work with several alternative dates based on several proposed dates of acquisition of the plant. At the same time the estimating department should determine a realistic start-up date for a new plant. Obviously for the two estimates to be comparable, they should be made by the same group of estimators. It is preferable that the estimating group
2470
be detached from the operating management so that personal preferences do not enter into the comparison at this stage. 2. The tangib!e costs of revamping the plant should be compared directly with the cost of building a rieiv plant. Credits should be applied to cover escess equipment that would I)? acquired. At, this point, the questions of availability of capital, current cost of borroiving money, and the relation to an over-all expansion program are considered. If the process and inarket are not cornpletely developed and indications are that tjhe new plant might have to be revised or enlarged in a short time, then there are good arguments for investing as little capital as possilile in thi3 initial st,age. 3. Operating costs sheet's should be prepared for both plants under consideration. It is to be expected that the operating costs of the specifically dFsigned plant will be lower than those for the revamped plant. r h e best plan is to have two figures for each item, representing the operating cost with and without, depreciation included, The reason for this is that capital costs have already been considered in the first comparison and ineluding depreciation again in operating coste tends to overemphasize this point. The reason for including depreciation is t o make these costs estimates consistent with Ytitridard cost reports which will be issued when the operation is a fact. 4. The costs set forth in paragraph 3 should be translated into estimated profit,. The profit t o be ree,lieed from an earlier start-up date should be calculated. 5 , Finally, the intangible or less tangible factors should be considered. This is the time to tabulate and consider such items as t,iming on the introduction of a new product before competition; differences in morale of employees working in a new plant as compared with an old plant; valuable employees who might be trarisferred as a result of taking over another operation; a good or bad labor situation which might be inherited; possible lack of space to expand; and the many similar quest,ions previously mentioned in this discussion. When all these points are considered the chances are that any individual will see a clear pat,h of desirable action. Unfortunately, different individuals may come to different conclusions. I t might be valuable to have a composite reaction as to the success chemical 1iiaIiufacturers have had in converting plants in the past. Such an opinion would be difficult t o obtain; we do not publicize our errors, and one is likely to read only about the suecessful ventures. Xevertheless, it might be int,eresting t,o briefly review a fev cases. 1. Conversion from coke to natural gas in ammonia production: This subject is covered in by Burt ( 1 ) and is ineritioiied here only to call your attent,ion to this type of conversion. 2. Conversion of ammonia plants to production of methanol: l\n example of this was a t the Jayhawk Works of Spencer Cheniical C o . in southeastern Kansas. When the demand for animonia in that area was less than the production capacity, a portion of the plant was switched to the production of methanol. The changes required were not major in scope and consided of the elimination of process equipment for converting carbon 1no11oxide to carbon dioxide in the gas preparation step and the elimination of carbon monoxide scrubbers in the gas purification step. ArrangerneIits had to be made for t,he inclusion of carbon dioxide feed in the original gas preparation equipment, and minor. changes were effected in the compression equipment required by Ihe variance in gas coniposition and redesign of reactor interrials including a change of catalyst. The reaction charactcristics varied substantially, and much closer control of the reaction \-vas necessary. The project \vas reported as entirely succes~fulfrom the standpoint, of efIicient production of methanol. This conversion from ammonia to methanol was made earlier by Commercial Solvents Corp. a t its Peoria, Ill., works, and the original work on this methanol process was carried out by ote, Inc., a t Belle, W. Va., in an ammonia plant. After iVorld r 11, Solvay Process Co. made a similar conversion a t South Point, Ohio, and Commercial Solvents at' Sterlington, I,a. 3. Conversion of a magnesium plant to the production of titaiiiuni: The Titanium Metals Corp. of America found that the basic facility %-aspeculiarly well adapted for the change a t the plant, a t Henderson, Xev. The basic magnesium plant was designed for the inanufacture of magnesium chloride. Magnesium chloride is a by-product of the titanium process since titanium is produced by the reduction of its tetrachloride by magnesium metal. Therefore, part of the original plant could be used as designed to recover magnesium and chlorine from the by-product. Other factors favoring the conversion of this plant were its favorable location for purchasing make-up chlorine by pipeline and purchasing low cost power from Hoover Dam. T h e site nets
INDUSTRIAL AND ENGINEERING CHEMISTRY
Vol. 46, No, 12
PLANT ADAPTATION
Lakc hlead also offered a substantial supply of fresh water, which is always an asset t o a chemical plant. 4. Conversion of an unused bromide plant to the production of lithium carbonate: In order to avoid writing entirely about work that was done 6 or 8 years ago in the postwar period, the author looked for a more recent example and found that the American Potash and Chemical Co. is using a bromide plant a t Trona, Calif., to produce lithium carbonate ( 2 ) . The conversion (meant to save time and money) was made in less than 3 months. The report of this conversion ( 2 )states that it is a relatively simple trick to engineer a new process into a plant built specificall for the process, particularly if you can draw on extensive pi& plant work and have a wide choice of new equipment. But squrezing into an existing plant, and making old equipment do, all without benefit of a pilot plant, requires a firm grasp of the fundamentals of chemical engineering. Correspondence with an officer of the American Potash and Chemical Co. brings this later reaction. While they are “quite happy with the conversion of this plant,” such a conversion generally results in a crowded plant with less than ideal material flow arrangements. They would far prefer a plant specifically designed for the purpose. It is doubtful if anyone would attempt this type of conversion exccpt where the economic and/or time factors are of considerable importance.
looking A h e a d Finally, we come to the question of opportunities in this field today. Certainly most of the war plants have been disposed of and delivery of equipment is generally not delayed. The opportunities lie in our own backyards. What new chemicals can be made with minor changes to some nonprofitable unit? Can engineering departments be challenged by the chance to try out production of a new chemical that may not justify the cost of a new plant? This type of experience may be just what young engineers need to wean them from lazy thinking habits that may have developed during a period of rapid expansion and easy capital. Literature Cited (1) Burt, R. B . , IND. ENC.CHEM.,46, 2479 (1954). (2) Chem. Eng., 60, 144 (1953). (3) Waddell, H. L., Factory Managenaant and Maintenance, 108, No. 4, B-59 (1950). RECEIVED for roview April 13, 1954. .4CCEPTED August 30, 1964.
Engineering in Plant Revamp Work J. M. BLACK The M. W. Kellogg Co., 225 Broadway, New York, N. Y.
Available figures covering the cost of a new plant built from the ground up are apt to be fairly accurate. When it appears that an alternate program of plant adaptation or revamp is possible, then a similarly accurate comparative estimate should be prepared. This i s a difficult assignment. The purpose of this paper i s to highlight the engineering and construction factors that greatly influence the correctness of revamp estimated costs.
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T H E coinparatively young and rapidly advancing fields of the petroleum and petrochemical industries, new processes are often developed in the laboratory faster than commercial aize plants can be built. In fact companies in these industries sometimcs find that a plant under construction is already outmoded Fortunately, this represent6 extreme rather than averagc rate of obsolescence so that usually amortization is substantially accomplished. However, the outmoding often occurs long before the useful lifc of the physical equipment has been realized. Therefore, probably without parallel in other industries, refiners may be confronted 15 ith acres of installed vessels, pumps, piping, supporting structures, buildings, power generating equipment, and attendant water and waste handling facilities and are faced with the pi essing economic question, should u-e revamp? The first blush reaction of management is apt to be “why not?” This response results from being influenced by assumed iuvestment and calendar time advantages over competitors who will have to build entirely new plants from scratch. There is only one way t o find out, and that is by means of a very careful survey. Obtaining proposals for new plant construction is comparatively simple and routine. With fixed price bids, the figures arc apt t o be quite accurate and can only be affected by inflation and strikes, which are common to all new construction. This is not true of thc so-called revamp project. Here fixed bids are less practical and estimates can be grossly in error unless all the problems peculiar to this type n orlc are carefully studied and taken into consideration. I t is the purpose of this paper to highlight those items which most greatly influence the final dollar figure in revamp ~ o r by k December 1954
citing a few case histories in the oil refining field and to signal engineering and construction pitfalls. The writer is not aware of any conversion job that did not prove to be a successful financial venture finally. However, the tendency is to underestimate the original cost of the reinvestment. It is this point that is emphasized-stressing what might be overlooked, or insufficicntly appreciated.
Exampies The majority of so-called revamp projects in oil refineries basically involve plant capacity increase by enlargement or modernization of equipment to remove bottlenecks. There are also many projects where the feed and/or type product characteristics are altered sometimes by established means and other times by completclp new process approaches. The following are typical: 1. Existing catalytic cracker vapor recovery unit revamped for greater propylene production t o product improved aviation gasoline blending stock and ethylene feed stock for petrochemical processes. 2 . Portion of combination thermal cracking unit revamped to a vacuum distillation unit to supply catalytic cracker feed stock. 3. Portion of combination thermal cracking unit revamped into a n atmospheric distillation unit to supply highly fractionated straight run distillates plus reduced crude feed t o a vacuum unit for catalytic cracker feed stock. 4. Entire hydrofluoric acid alkylation aviation gasoline plant built for Defense Plants Corp. during war converted to lube oil plant. The last mentioned case represents a good cxample of plant adaptation. Right after Korld War 11, demands for aviation
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