Ft-AT LI R E S THE IMPORTANCE OF CHEMICAL ENGINEERING AND THE CHEMICAL INDUSTRY IN THE ECONOMY OF SRI LANKA WJ.N. Fernando This evaluation of the requirement and demand fof chemical engineers "and the extent of involvement of chemical engineering in Sri Lankan Industries was carried out by Dr. WJJtt. Fernando, Head of the Department of Chemical Engineering, University of Peradeniya, His survey reveals that at least 45 percent of chemical engineering opera­ tions are presently carried out by teams of chemists and mechanical engineers. This situation which has arisen as a result of the shortage of chemical engineers* is shown to be unsatisfactory. Capacity under-utiiization of Sri Lanka's chemical and allied industries In partly attributed to the lack of chemical engineering, expertise iii such industries. Contributions which could have been made to the national economy by way of improvement of capacity ,' utilization and saving of power and fuel of the existing chemical and allied industries If the necessary chemical engineering expertise were available Is shown to be substantial The important role of the chemical .industry within and outside the Greater Colombo Economic Commission; and the potential of-participation of the chemical industry and the chemical engineering profession in the future ^development of Sri Lanka is also discussed. - * INTRODUCTION During the inception of the profession of Chemical Engineering in the developed world, Chemical Engineering has been defined as the combination of disciplines of Chemistry and Mechanical Engine­ ering. Consequently, Chemists and Mechanical Engineers are regarded as a sufficient substitute for Chemi­ cal Engineers. However this has been proved to be a fallacy long time back in industrialised coun tries. (1) A commonly known process of manufacturing sugar from sugar cane can be taken as one of the examples to illustrate this fallacy. A Chemist, whose-work is usually confined to a laboratory in a re­ search/teaching organisation or in an industry obtains sugar juice by crushing and squeezing a few pieces of sugar cane. Sugar is then produc­ ed by evaporating sugar juice in a vessel. Under proper controlled conditions sugar crystallizes out. Study of molecular composition and crystal structure form part of their work. For the Chemist, the energy for the evaporation which is usually obtained by a lighted bunsen burner or an electric ele­ ment is quite abundant. He is not concerned of the efficiency or the economy of extraction of the juice. However, industrial produc­ tion of sugar needs much more skills and machinery than those mentioned above. A shredder or a crusiier and several pressure mills are needed to extract the juice from the sugar cane. Conveying equip­ ment for transport of sugar cane, pulp and syrup are needed. The juice which flows in large quantities is usually clarified by means of chemical treatment and settling in order to remove impurities and suspended matter. Settling is usual­ ly carried out in settling chambers. The clarified liquor. is then evaporated and crystallized. Some of the streams are recycled for better recovery of products and energy. Mechanical Engineers are needed for this production process in order to design, operate and maintain mechanical equipments such as power drive's,'boilers, heat exchangers, coolers. The scope of a Mechanical Engineer usually does not embrace operations of equip­ ment such as crystallizers, evapora­ tors, clarifiers, settlers, extractors, and also of recycle streams. So it can be seen that a gap exists between the expertise needed for a sugar industry in addition to the expertise contributed by Chem­ ists and Mechanical Engineers. This is the case in nearly all Chemical and allied industries. The gap can be termed as Chemical Engineering. The definition of Chemical Engineering has varied from one institution to another and from one country to another. It would be appropriate if Chemical Engine­ ering is defined as that part of Engineering other than Mechanical/ Civil/Electrical/ Production or any other defined branch of Engineer­ ing encountered in Processing/ Manufacturing industries in which physical and or chemical changes occur within the processes. CHEMICAL ENGINEERING IN RELATION TO SRI LANKA Present Position Chemical Engineering em­ braces a wide range of engineering operations known as unit opera­ tions (1). A survey was carried out 4 by the Department of Chemical ^ Engineering of the University of Perdadeniya in order to evaluate the importance of Chemical Engine­ ering operations and their national importance. Table 1 shows a list of important Chemical Engineering operations and their relative na­ tional importance in Sri Lanka as evaluated by the survey. The survey showed that approximately 45% of the Chemic­ al Engineering operations in Sri Lanka are being carried out at present by teams of Chemists and Mechanical Engineers. As a result, ECONOMIC REVIEW FEB/MARCH'85 20 TABLE 1 RELATIVE IMPORTANCE OF SOME CHEMICAL ENGINEERING OPERATIONS Operation Estimate as a Percentage 1. Cooling/A ir Conditioning 9.49 2. Feed/Effluent treatment 9.31 3. Solids treatment 8.58 4. Heat transfer 8.17 5. Drying 7.21 6. Filtration 6.91 7. Evaporation 6.22 8. Mixing/Agitation 5.87 9. Conveying 5.37 10. Centrifugation 5.01 11. Fluidisation 4.27 12. Chemical reaction 3.41 13. Boiling 2.92 14. Ion exchange 2.20 15. Sedimentation 2.17 16. Thickening 2.12 17. Absorption 2.10 18. Distillation 2.00 19. Bio-chemical reactions 1.96 20. Crystallization 1.88 21 . Extraction 1.54 22. Absorption 0.64 23. Flotation 0.35 24. Osmosis 0.30 i malfunctioning of equipment with­ out proper care ani maintenance, underutilization of equipment, wastage of energy and other resour­ ces due- to unawareness or incapa­ bilities could be expected from our Chemical and allied industries. Production Aspects Table 2 shows the percent­ age utilization of capacities of our industries for years 1976 to 1982 (both years inclusive). Out of these, industries belonging to categories 1,4, 5 and 6 could be regarded as industries of Chemical and allied nature. The value of industrial pro­ duction for these four categories of industries over the above period are shown in Table 3. Table 4 shows the addi- * tional production capabilities of our Chemical and allied industries for each of the years 1976 to 1982. This analysis shows that products of Chemical and allied nature worth Rs. 22,313 million which could have been produced in Sri Lanka for the seven year period 1976-1982 (in­ clusive) had not been produced due to under-utilization of our Chemical and allied industries. In 1982 alone this amounts to Rs. 5,954 million this is 5.9 percent of the gross domestic product of Sri Lanka in 1982. The capacity under-utiliza­ tion of Chemical and allied indus­ tries can be attributed to the fol­ lowing reasons. 1. Unavailability of raw mat erials and energy. 2. Short of markets for pro­ ducts. 3. Malfunctioning of mach­ inery or deterioration of machinery to production rates lower than designed values. 4. Lack of expertise for proper care, maintenance and deve­ lopment of machinery. If factors (3) and (4) are assum­ ed to be equally responsible for under-utilization as much as factors (1) and (2) then it could be argued that an extra production of at least Rs. 2977 million (i.e. 50% of Rs. 5954 million) could have been achieved in 1982 if the necessary expertise were available for the existing Chemical and allied in­ dustries. The figure could be of the same order'or of larger mag­ nitude in 1983. The overall figure for the seven year period 1976- 1982 (inclusive) is Rs. 11,156.5 million. Table 5 shows the values of industrial production of Sri Lanka for the seven years 1976 to 1982. Items 1, .4, 5, and 6 being Chemical and allied industries represent 76. f, 77.7 77.5, 79.0, 81.6, 79.9 and 78.9 percent of the gross industrial production in each of the years 1976 to 1982 respectively. Energy Aspects Equipment associated with chemical industries usually con­ sume large quantities of energies compared with other industries. To demonstrate this fact, take the single unit operation of dn'in". T»ble 6 shows the pro­ duction rates of six selected indus­ tries of Sri Lanka in 1983. Products of these indus­ tries usually have to be dried through moisture contents of at least 40 - 60%. If 50% moisture content is taken as an average figure, amount of moisture eva­ porated by the six industries in 1983 estimates to at least 397, 525.5 metric tonnes of water (Le. 50 per cent of 795 ,051 metric tonnes). If the latent heat of evapo­ ration of moisture is assumed to be 2256.7 kJ/kg, the total energy requirement by the industries for evaporation alone amounts to at least 8.97 x 10" k J . This amounts to 249 million kWh of energy. The power generated in 1983 by ther­ mal power stations of the stations of the Sri Lanka Electricity Board amounts to 897.2 million kWh. It is therefore seen that the energy consumed for the unit operation of drying for these sjx 21 ECONOMIC REVIEW FEB/MARCH185 TABLE 2 Category 1976 Food, beverages and 75 tobacco Textile, wearing apparel 56 and leather products Wood and wood 45 products (including- furniture) Paper and paper 58 products Chemicals, petroleum 66 coal, rubber and' plastic products Non metallic mineral 76 products (except petroleum and coal) Basic metal products 39 Fabricated metal 53 products, machinery and transport equipment Manufactured products 45 n.e.s. % Utilization of capacity 1977 1978 1979 1980 1981 69 70 72 70 66 55 71 62 78 67 84 70 87 89 81 70 72 70 68 75 61 67 65 79 76 61 77 80 82 83 40 63 68 62 53 54 64 60 58 68 57 79 < 74 70 69 1982 77 94 92 70 77 86 33 83 73 TABLE 3 VALUE OF INDUSTRIAL PRODUCTION OF CHEMICAL AND ALLIED INDUSTRIES (RS. MILLION) 1976 TO 1982 Category 1976 1977 1. Food, beverages 1715 2295 and tobacco 4. Paper and paper 203 270 products Chemicals, petroleum, coal, rubber and plastic products 1978 1979 1980 1981 1982 2609 2856 3899 4496 5246 376 445 476 626 725 2336 2469 3279 4508 9416 12106 13099 6. Non metallic mineral 360 411 products except petroleum and coal 592 710 1156 1250 1370 ECONOMIC REVIEW FEB/MARCH'85 CAPACITY UTILIZATION IN INDUSTRY 1976 -1982 industries alone is about twenty eight .percent of the energy generat­ ed by thermal power generating units of the Ceylon Electricity Board in 1983. Table 7 shows the cost of power and fuel used by industries in 1982. It can be seen that a major portion of the fuels amounting to Rs. 1714 million have been used by Chemical and allied industries. This amounts to approximately 79 per­ cent of the cost of the total energy consumed in 1982. The figure for the year' 1983 should riot be too different. Modern researches and deve­ lopments of unit operations have shown possibilities to reduce the energy requirements in respective operations. Savings up to 10-15% have been shown to be possible compared with the older unit operation equipment (6). As a result energy saving techniques if employed in existing operating could have yielded a national saving of around Rs. 170-250 million in 1982 alone. Table 8 shows the estimated national saving which could have been made if proper expertise for Chemical and allied industries were available. Overall Considerations Therefore a national con- tribution of at least Rs. 300 million could have been made available in 1982, by way of increase of pro­ duction and fuel saving if proper expertise in Chemical Engineering were employed in our Chemical and allied industries. As a comparison of the magnitude of this figure, it repre­ sents approximately 11% of the total production, in 1982. These figures should not deviate much for the years 1983 and 19.84. TABLE4 ADDITIONAL PRODUCTION CAPABILITIES OF CHEMICAL AND ALLIED INDUSTRIES (RS. MILLION) 1976 TO 1982 Category 1976 1977 1978 1980 1981 1982 1. Food, beverages and 426 711 tobacco 4. Paper and paper products 85 81 5. Chemical, petroleum, /94 963 coal rubber and plastic products 6. Non metallic mineral 86 160 products except petroleum and coal Total 1394 1915 783 105 1082 136 2106 800 134 1578 142 26S4 1170 1529 152 157 1977 2884 208 213 3607 4783 1983 Grand Total : 22313 Rs. Million TABLE 5 VALUE OF INDUSTRIAL PRODUCTION 1976 -1982 Category 1. Food, beverages and and tobacco 1976 1977 1978 1715 2295 2609 2 Textile, wearing apparel 680 698 1008 and leather products 3. Wood and wood products 129 127 124 (Including furniture) 4. Paper and paper products 203 270 376 5. Chemicals, petroleum, 2336 2469 3279 coal/ rubber and plastic products 6. Non-metallic products 360 411 592 (except petroleum and coal. 7. Basic metal products 1979 2856 1128 Rs. Million 1980 1981 3899 4496 1923 3040 138 132 219 . 166 289 315 445 476 626 4508 9416 12015 710 1156 1250 349 478 428 FUTURE TRENDS Forthcoming Industries 8. Fabricated metal products, machinery and transport equiprnsnt 474 571 590 34 55 In addition to the factors 9 Mahufectu«rrproducts 26 discussed earlier, other contribu- (n.e.s) tions which the Chemical Engineer­ ing profession could make available T ° t a l 6061 7007 8852 50 10781 620 54 782 58 18311 23010 1982 6246 3863 361 725 13099 1370 262 904 74 25904 ECONOMIC REVIEW FEB/MARCH'85 23 1207 218 4323 206 S954 to the national development of the future depend on the forthcoming expansion and development schem­ es in the fields of Chemical and allied industries of Sri Lanka. Table 9 shows the invest­ ment approvals contracted within the GCEC (Greater Colombo Eco­ nomic Commission) for various categories of industries from 1979- 1983. The investments made on already contracted Chemical and allied industries as a percentage of the total investment have been 21.6 percent for the whole five year period (1979-1983) and 28.2 percent for 1983 alone. The total investments approved and con­ tracted was 3662 million rupees for the five year period. 790 million rupees have been allocated for Chemical and allied industries. Major Chemical industries for which agreements were signed, in 1982 arc the manufacturing project for phosphate fertilizer using F.ppawala rock phosphate deposits. This is with the collaboration of Agrico Group of Companies of USA and the State Mining and Mineral Development Corporation of Sri Lanka. Another is the Seva- nagala sugar development project with the collaboration of KCP Ltd of India and Sri Lanka Govern­ ment. The annual capacity of the project was to be 27,000 t/y. Other projects such as acti­ vated Carbon, P V C blown con­ tainers and oil palm have already taken off the ground prior to 1982. The investments on Chemi­ cal and allied industries outside the GCEC have been substantial over the last five year. Table 10 shows the total investments outside the greater Colombo Economic Commission approved by the foreign invest­ ments advisory committee for the five years 1979-1983. 43.5 percent of total investments for the five years up to 1983 and 44.9 percent of the total investment in 1983 hare been for Chemical and allied industries. The total investment TABLE 6 Metric Tonnes 1. Sri Lanka Sugar Corporation 22044 2. National Paper Corporation 22262 3. Ceylon Ceramic Corporation 44498 4. Sri Lanka Cement Corporation 479568 5. Tea 179300 6. Desiccated Coconut 43529 (4) Copra 3850 (4) Total 795051 TABLE 7 COST OF POWER AND FUEL USED IN INDUSTRY 1982 (5) Category Rs. Million 1. Food, beverages and tobacco 307 2. Textile, wearing apparel and leather 314 products 3. Wood and wood products 26 (including furniture) 4. Paper and paper products 232 5. Chemicals, petroleum, coal, rubber 814 and plastic products 6. Non-metallic mineral products 361 (except petroleum and coal) 7. Basic metal products 57 8. Fabricated metal products, machinery 41 and transport equipment 9. Products n.e.s. 5 Total 2157 ECONOMIC REVIEW FEB/MARCH'R5 PRODUCTION RATES OF EIGHT SELECTED INDUSTRIES OF SRI LANKA IN 1983(3) 24 TABLE 8 Contribution with respect to proper utilization of capacity Contribution from saving power and fuel Total Its. Million 2977 170-250 3147-3227 TABLE 9 INVESTMENT APPROVALS AND CONTRACTED WITHIN GCEC* (RS. MILLION) Year (9) 1 9 8 ^ 9 ) 1981<5> 1 9 8 2 ( 4 ) 1 9 8 3 ( 4 ) 45 934 153 128 91 Category of Industry 1 . Food, beverages and tobacco 2. Textiles, weaving apparel and leather products 3. Wood and wood products 4. Paper and paper products 5. Chemical, petroleum, coal, rubber and plastic products 6. Non metallic mineral products (except petroleum) 7. Baste metal products 8. Fabricated metal products, machinery and transport equipment 1979' 180 86 426 13 9. Other Total 619 488 134 1689 55 35 54 196 493 79 14 20 30 461 684 36 177 Greater Colombo Economic Commission • being S7S6 million rjpees for four years and 1031 million rupees for. 1983. Out of the 56 industrial projects, approved in 1983, 29 perujects have been in the Chemical and allied industries (4). . Table 11 shows the appro­ vals by the local investment advi­ sory committee for industries out­ side the Greater Colombo Econo­ mic Commission. 44.5 percent of the total investment for the five year period and 58.8' percent for 1983 have been for Chemical and allied industries. The total invest­ ments, being 2112 million rupees for the five years and 415 million rupees for 1983. The total' investments ap­ proved and 'contracted by GCEC and approved by FIAC and LIAC for the establishment of Chemical and allied industries have been 4S37 million rupees. Other Opportunities Suitability of a given chemi­ cal industry for a particular country is determined by numerous, com­ plex and interdependent factors. Most important of all is the market for the products envisaged. The market could be either' national, regional or export. The size of Sri Lankan national market is small. The coun­ try had sometimes already witness­ ed low efficiency, poor quality control and high prices as a result of conflict between small size market and the need for an effi­ cient scale production of some industries (11). Leaving aside the possibility of small scale chemical industries at appropriate level for local markets, planning for export markets therefore become very essential for many of the. future chemical industries in Sri Lanka. The second governing factor which determines the setting up of future chemical industries in Sri Lanka is the availability of resourc­ es. Apart from .Capital, and man­ power resources, availability of raw materials is a prime factor of impor­ tance. Sri Lanka being a country surrounded by seas, raw materials for chemical industries could be tapped from and across the seas around, in addition to resources from the ground beneath and skies above. Resources from the ground are available from two main sourc­ es; 'the- agricultural resources and minerals resources. 25 ECONOMIC REVIEW FEB/MARCH'85 ANTICIPATED APPROXIMATE NATIONAL SAVING IN 1982 IF PROPER CHEMICAL ENGINEERING EXPERTISE WERE AVAILABLE FOR EXISTING INDUSTRIES TABLE 10 INVESTMENTS APPROVED BY THE FIAC** OUTSIDE THE GCEC * (RS. MILLION) Category of Industry , 9 7 9 ( 9 ) 1 9 8 0 (10) 1 • Food, beverages and tobacco 77 650 2. Textiles, weaving and leather 688 38 products 3 . Wood and wood products 4. Peper and paper products 12 6. Chemicals, petroleum, coel, 75 rubber and plastic products 6. Non metallic mineral 12 products (except petroleum ' and coal) 7. Basic metal products 6. Fabricated metal products 97 machinery and transport equipment 9- Other 10 Total 60 Yew 1981 ( 5 ) 229 55 20* 210 235 264 776 971 1792 362 50 1161 *• Foreign Investment Advisory Committee * Greater Colombo Economic Commission p provisional 1982' 258 162 (4) 151 70 136 17 801 I 9 8 J ( 4 ) (p> 235 140 123 64 164 242 63 1031 percent from 1983 to 1987 in value (11). The anticipated increase of exports of instant tea is 200 percent during the same period (11). The increased earnings from exports of desiccated coconut, and shell charcoal/activated carbon envisaged during the above period are 3 percent and 58.1 percent respectively. Products from rubber which have good export potential has now been identified (11). Manufacture of household rubber gloves, non- industrial rubber footwear, bicycle tyres and tubes, rubber hose and rubber protective clothing and moulded products has been identi­ fied as viable export oriented rub­ ber based chemical industries of the future (11). It is anticipated (11) that a growth rate of 35 percent be main­ tained for export of essential oils. Such growth of the essential oil industry will be necessary as value added products such as extracts, tinctures and essential oils would enhance Sri Lanka's expot earnings rather than by export of raw mater­ ials. Chemical and allied indus­ tries which could be based on agricultural resources are (12). (1) Food and beverages indus­ tries (2) Tea, rubber and coconut products industries (3) Pulp and paper industries (4) Essential Oils industries (5) Tans and Dyes industries (6) Oils and Fats industries (7) Gums, resins and oleo-rcsins industries (8) Sugar and Alchohol indus­ tries (9) Indigenous medicine manu­ facture industries (10) Industries based on agri­ cultural wastes The main chemical industry associated with food and beverages in Sri Lanka has been the process­ ing and canning of fruit juices and canned fruits. It is anticipated that the exports of products of this industry would increase by 47.6 The export market of soap and allied products is expected to increase (11) from Rs. 10 million in 1983 to Rs. 40 million in 1*8 7. The glycerine export market de­ pends on the future improvements of technology of production of glycerine and the quality of pro­ duction. However, with the increase in manufacture of soap, the exports of glycerine could be reduced. During the years 1977 to 1983 sugar imports have risen by 703 percent by value (4). paper and paper products imports nIOMIC R E V I E W F t B / M A R C H ' 8 5 26 have risen by 187 percent by value. It is therefore seen that additional sugar and paper industries could become worthwhile industries for the future. Out of chemical industries based on Minerals, the joint venture project for the manufacture of phosphatic fertilizers envisages pro­ duction of ammonium phosphate and triple superphosphate to the extent of 399,000 tonnes and 37,500 tonnes respectively in 1986 and. 480,500 tonnes and 45,000 tonnes respectively in 1987. Pro­ duction and export of wall tiles, porcelain and other products is to rise from 200 million rupees in 1983 to 473 million rupees in 1987. the total minerals exported from Sri Lanka in-1982 have been 48,893 mT of ilemehite, 153.0 mT *f Rutile,' 3024 mT of graphite, 292 mT of mica and some metallic iron pyrites (5). It is a well known fact that beneficiated minerals are several folds valuable than the respective raw minerals. As a result, beneficiation projects for minerals will have to be given consideration. Such projects are basically chemical industries. Out of the sea-based indus­ tries, it is reported that new ven­ tures like the manufacture of refined salt and enhanced produc­ tion pf chlorine and 'caustic soda could be beneficial. The magnesium content of 0.13 percent oCour sea waters is reported (7) to be promis­ ing for exploitation. Extraction of antibacterial agents from marine natural products could become viable. Nitrogen based industries such as ammonia, nitric acid and ammonium nitrate can form part of the Chemical industries of'the fut­ ure. One of the neglected areas in the development of chemical industries has-been the field of manufacture of pharmaceuticals. ECONOMIC REVIEW FEB/MARCH'85 TABLE 11 INVESTMENTS APPROVED BY THE L IAC** OUTSIDE - CCEC* (RS. MILLION) Category of Industry Year 1979 (9) 1 • Food, beverages and tobacco 103 Textile, wearing apparel and 504 leather products 3- Wood and wood products **• Paper and paper products 21 5-Chemical, petroleum, 7 4 ' coal, rubber and plastic 6- Non metallic minerals 45 products (except petroleum and coal) 7 - Basic metal products 8 - Fabricated metal products 123 machinery and transport equipment 1980 34 (10) 51 17 105 44 1981 32 22 18 88 22 (5) 1982 (4) 15 60 1983(4)(p) 61 82 13 52 72 33 176 66 9 - Other Total 5 875 64 18 337 69 3 254 231 415 P - Local Investment Advisory Committee Greater Colombo Economic Commission provisional Manufacture of synthetic pharma­ ceuticals and pharmaceuticals from natural products are some possibili­ ties. The import expenditures in­ curred by Sri. Lanka for the four years 1979 to 1982 have been Rs. 135 million and approximately Rs. 34 million in each respective year (5). A large portion on this expenditure has been for the import of antibiotics. Since penicil­ lin still holds the reputation of being a reliable antibiotic and since most other antibiotics can be manufactured with penicillin fer­ mentation, equipment with or with­ out minor modifications and since capital investment in the anti­ biotic industry seems to be safe and markets stable (8), such in­ dustries could become worthwhile chemical industries in the future. Use of alternate sources'of fuel and utilization of energy saving techniques-in- chemical and agricultural processing industries could be considered useful in order to curb the rising costs of production in such industries. In­ troduction of .fluid bed drying techniques for tea is an example of an emergence of this trend in the agricultural sector. CONCLUSION From the above analysis it is seen that the chemical industry plays an important role in the overall production and economy of Sri Lanka at present. Approximate­ ly 79 percent of the industrieal production accounts for production . from chemical and allied industries. During the five year period 1979 to 1983, approximately 36.5 percent of the total investment within and outside GCEC has been envisaged for 'chemical and allied industries. It is also seen that possibilities for numerous chemical and allied industries exist for the future development of Sri Lanka. It Is 27 also seen that the Chemical Engine­ ering profession could play an active and important role in chemi­ cal and allied industries at present. However there exists a shortage of personnel in the field of Chemical Engineering. REFERENCES 1. Ibl, N., 'Trends in Chemical Engineering' Eight Marchon Lecture:, The University of Newcastle Upon Tyne, Ruari McLean. 1968. 2. Centaral Bank of Ceylon, Annual Report 1981. 3. Central Bank of Ceylon, The Bulletin June 1984. 4. . Central Bank of Ceylon Annual Report 1983. 5. Central Bank of Ceylon, Review of the Economy 1982. 6. Potter, O.E., et aL, Proc. 3rd Int. Symp. on Drying, 12-15 September 1982, Bir­ mingham, U.K. 7. Herath, J.W., 'Mineral Re­ sources of Sri Lanka' Eco­ nomic Bulletin No. 2, Geo­ logical Survey Department, Colombo 1980. 8. Dryden., C.E., 'Outlines of Chemical Technology' Affi­ liated East-West Press, New Delhi, 1969. 9. Central Bank of Ceylon, Review of the Economy, 1980. 10. Central Bank of Ceylon, Review of the Economy, 1981. ' 11. Sri Lanka Export Develop­ ment Board, 'National Ex : port Development Plan 1983-1987' VoL I I . 1984. 12. Seneviratne, E.W., Proc. Int. Symp. on the Industrial Utilization of Tropical Pro­ ducts, Tsukuba 1980 pp. 156-220. ? 8 ECONOMIC REVIEW FEB/MARCH'85