Industrial charcoal and chemicals from Ipil Ipil wood

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Title: Industrial charcoal and chemicals from Ipil Ipil wood
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Fulltext: Industrial Charcoal and Chemicals From hy lpil lpil Wood SUMMARY Pilot-plant studies on the carbonization of ipil-ipil wood indicated the possibility of producing an industrial-grade charcoal containing 87.23 per cent fixed carbon, 10.45 per cent volatiles, and 2.32 per cent ash. The charcoal has a heating value of 7 470 calories per gram. lpil-ipil wood yielded about 9.21 per cent wood tar and wood-tar oils, 25.46 per cent pyroligneous liquor and 34.42 per cent charcoal. The pyroligneous liquor recovered contained 1.76 per cent acetic acid, 0.81 per cent methanol and 3.73 per cent soluble tar, based on oven-dry wood. INTRODUCTION There is perhaps no other Philippine tree as common as ipil-ipil ( Leucaena leucocephala (Lam.) cle Wit). It could be found in practically every part of the country ( 10) 2 • It grows sturdily and abundantly in any condition, whether it be in the fertile soils d the farms and valleys or in the rocky cliffs of hills and riverbanks. Ipil-ipil could well be the Philippine wonder wood for charcoal production because despite its comp'lratively fast growth and short rotation age, the charcoal produced from its wood is hard and heavy. 1 Forest Products Technologist and Jr. Forest Products Technologist, respectively Forest Products Research Institute, College, Lagun~. 2 Numbers in parentheses refer to Literature Cited. MOVING-UP DAY ISSUE-1965 E. P. VILLANUEVA & N. B. LAXAMANA1 A hard, heavy charcoal which meets the limiting requirements for volatiles is applicable for industrial purposes. According to Beglinger ( 2), unlike most other industrial raw materials, charcoal is seldom sold ;:in specifications. The usual market guarantees relate only to the weight per bushel and to the percentage of contained volatile matter. Limiting values for volatile matter and for moisture are that they be not more than 14 per cent and 2 per cent, respectively ( 2). The Forests Commission of Victoria ( 5) theorized that the ultimate test of charcoal quality is its performance in a gas producer. W. Atkinson Wood ( 5) showed that a suitable producer-gas charcoal when burnt, should not cause blackening of a tin plate placed directly over the embers. Laboratory tests at the Institute showed that this corresponds to charcoal containing volatiles less than 20 per cent. The volatiles are chemicals which are formed during the carbonization process. They escape from the burning wood as smoke. When ipil-ipil wood is carbonized, about 60 per cent of its original weight is lost as smolw ( 1 ) . However, when the vapors are passed through a condenser, a liquid product called pyroligneous liquor and a black, waxy residue called settled tar are recovered. The chief components of the pyroligneous liquor are acetic acid, methanol and soluble ltar ( 11 ) . The commercial recovery of these chemicals have largely augmented the wood Page 41 distillation industry of the United States and Germany during World War II (7, 11). Acetic acid is presently, one of the chief chemical imports of the Philippines ( 3). The settled tar contains wood-tar oils ( 4 J. It is not definitely known how wood tar and wood-tar oils are used in Philippine industry but they are imported into the country in large quantities. In 1962, 1,047 tons worth P238,000.00 were imported. Until lately, there is an apparent increasing price trend of this product. In June 1963, 163 tons worth 'P'53,000.00 were imported, and in July 1963, only 33 tons came into the country but at a total cost of 'P'87,000.00 ( 3). The operation of some Philippine industries depends on wood-carbonization products. Certain metallurgicaL chemical and home industries need industrial-grade charcoal as fuel and raw material (Table 1). The manufactures of plastics, textiles, paints, rubber and pharmaceutical products need acetic acid, methanol and probably wood tar and wood-tar oils. This study is therefore aimed to develop a process of producing an industrial-grade charcoal from ipil-ipil wood. Experiments were conducted to evaluate the smoke chemicals in terms of its acetic acid, methanol, wood tar and wood-tar oil contents. EXPERIMENT AL Raw Material Matured ipil-ipil trees obtained from the Mt. Makiling area, Los Bafios, Laguna were used in the study. Round woods were split and cut to uniform sizes, about 2 in. x 2 in. x 12 in. and air-dried. The average moisture content of the wood charge in every run was determined. The wood samples, analyzed according to the methods suggested by the Technical Association of the Pulp and Paper Industry Page 42 ( 12), showed the following chemical compositions: ' (a) Ash _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 2.25% ( b) Alcohol-benzene extract _ 5.09% (c) Hot-water extract ( w Io prior leaching) - 11.60% ( d) Hot-water extract (leached) ----------- 6.95% (e) Lignin (corrected for ash) 23.90% (f) Solubility in 1% NaOH __ 16.35% ( g) Pentosan -------------- 15.24% ( h) Holocellulose (by difference) ---------- 62.17% Carbonization The carbonization runs were made in a stainless s t e e l , electrically-heated retort, equipped with a water-cooled condenser (Fig. 1). At tight-fitting steel cover was used to seal the wood charge completely in the coaling chamber. The retort was fitted with a temperaturerecorder controller. In all runs, this was set at 900 deg. F to allow carbonization to proceed as fast as possible. Three thermocouples extending into the coaling chamber were fitted at strategic positions, so that the temperature in every part of the chamber may be determined (Fig. 2). Heating was terminated when no more smoke came out of the flue. At the completion of a run, cooling water was allowed to continue flowing through the conden.,er for another half hour before the contr0l valves for hot gases and water were closed. The weight of the condensate was determined 15 hours after heating was stopped. The settled tar was separated from the pyroligneous liquor by settling and decantation. After cooling for 20 hours, the steel cover was opened and charcoal yield was determined. 3 Percenlages are on oven-dry weight basis. FORESTRY LEAVES Pyroligneous Liquor Analysis 1. Methanol. -The methanol content was determined by the specific gravity method. 2. Total acids. - The total acid content of the pyroligneous liquor was determined on a redistilled sample as acetic acid by direct titration with standard base using phenolpthalein as indicator. 3. Soluble tar. - The black residue left in the flask after redistilling the clear pyroligneous liquor was considered as soluble tar. The weight of soluble tar was obtained by difference. Chemical Analysis and Calorimetric Determinations Chemical analyses of the charcoals were made according to the methods of Moore and Beglinger ( 8). The amount of volatile matter was reported as the percentage of loss in weight of oven-dry charcoal after heating for 11 minutes in a covered crucible at 950 deg. C. The weight of residue, after completely burning the charcoal for 6 hours at 750 deg. C, was reported as the ash content of the charcoal. The fixed carbon content was obtained by difference. A Parr peroxide bomb calorimeter was used in determining· the heating value nf the charcoals ( 6, 9). Re distillation of Settled Tar The settled tars were subjected to a secondary distillation in Pyrex distilling flasks at atmospheric pressure. By careful, controlled heating, the distillation-temperature schedules below were followed: APPROXIMATE DISTILLATION TEMPERATURE RANGE, DEGREES C DURATION, HOURS Room temperature to 210 210 to 235 235 to 270 270 to 315 MOVING-UP DAY ISSUE-1965 1.5 1.0 1.0 1.5 The distillates at different temperature ranges were collected separately. The color and other physical properties of the liquids were observed. Their specific gravities, using the pycnometer method, were determined. RESULTS AND DISCUSSIONS Charcoal Yield and Quality The carbonization process used in this study was based on a controlled pyrolysis 'lt a temperature range of 800 to 900 deg. F. The heat generated at this range seemed sufficient to carbonize the wood and "refine" the charcoal by vaporizing the complex organic chemicals, thereby leaving a product rich in carbon content. The maximum temperature was low enough to eliminate the danger of incurring unnecessary deterioration on the equipment. A ~harcoal yield of 34.42 per cent was obtained at the above conditions (Table 2). The charcoal analysis of 87.23 per cent fixed carbon and 10.45 per cent volatiles (Table 3) substantially met the limiting chemical requirements of industrial-grade charcoal. Its heating value of 7470 calories per gram compared favorably with coke and the industrial "white charcoal" of Japan (Table 6). The indicated carbonization process has produced a hard and dense but cracked charcoal. The ruptures probably resulted from rapid drying coupled with the violent expulsion of hot gases from the interior of the wood during carbonization. However, this condition has not affected the utility of the products to an appreciable extent. Investigations on the Pyroligneous Liquor The composite sample of pyroligneous liquor, obtained from the carbonization of ipil1ipil wood, was a Lurbid, hr.own liquid having a distinctly pungent odor. It contained a dye Page 43 which left a dirty brown stain on the hanos and clothes. The stain cannot be removed by rinsing with ordinary soap and water. On an oven-dry wood basis, about 25.413 per cent pyroligneous liquor was obtained (Table 2). The chemical analysis of this liquid indicated that the carbonization .Jf one ton of oven-dry ipil-ipil wood would yield approximately 17.60 kilos acetic acid, 8.10 kilos methanol, and 37 .30 kilos soluble tar (Table 4). Wood Tar and Wood-Tar Oils Laboratory studies at the Institute showed that one ton of oven-dry wood could produce 90.20 kilos of wood tar. This tar contained 7.14 per cent light oils (specific gravity range 0.90 to 1.0) distilling below 200 deg. C and 9.91 per cent heavy oils (specific gravity range 1.01 to 1.03) distilling from 200 deg. C to 315 deg. C (Table 5). The greater fraction of wood tar is pitch. CONCLUSION 1. The carbonization of ipil-ipil wood, at the conditions used in this study, produced charcoal that may be suitable for industrial application. This charcoal had an average volatile matter content of 10.45 per cent, which is much lower than the limiting value of the contained-volatile-matter requirement of industrial-grade charcoal. 2. If the smoke that escapes during the carbonization of ipil-ipil wood is condensed, it is possible to recover 254 kilos pyroligneous liquor and 92 kilos wood tar and wood-tar oils, per ton of oven-dry ,wood. 3. The pyroligneous liquor may be processed to yield about 17.60 kilos acetic acid and 8.10 kilos methanol, per ton of oven-dry wood. Page 44 LITERATURE CITED 1. Bawagan, P.. V. 1000. Charcoal production in a two-cord, double-walled, three-chimney charcoal kiln, 1st Progress Report, FPRI Project No. 33-1-1. College, Laguna. 2. Beglinger, E. 1952. Charcoal production. U. S. Forest Products Laboratory Report No. Rl666-ll. Madison, Wisconsin. ~- Bureau of Census and Statistics. 1962, 1963. Foreign trade statistics of the Philippines. Manila. 4. Food and Agricultural Organization of the United Nations. 1956. Charcoal from portable kiln and fixed installations. Rome, Italy. 5. Forests Commission of Victoria. 1941. The manufacture of wood charcoal. Melbourne, Australia. 6. Furman, N. H., ed. 1936. Scott's standard methods of chemical analysis. 5th ed. v. 8. Van Nostrand Co., Inc., New Jersey. 7. Locke, E. G. and J. F. Saeman. 1945. Wood carbonization industry of Germany. FIAT Final Report No 444. Joint Intelligence Objectives Agency, Washington, D. C. 8. Moore, W. W. and E. Beglinger. 1961. A method of charcoal analysis. Fore:>t Prod. J. 11: 17. 9. Parr Instrument Company. 1961. Parr peroxide bomb calorimeter manual. Moline, Illinois, U.S.A. 10. Reyes, L. 1938. Philippine woods. Technical Bulletin 7. Bureau of Forestry, Manila. 11. Shreve, R. N. 1956. The chemical process industries. 2nd ed. McGraw-Hill Book Co., Inc., New York. 12. Technical Association of the Pulp and Paper Industry. 1963. Testing methods, recommended practices, specifications, New York, U.S.A. FORESTRY LEAVES Table 1. Some common industrial outlets for charcoal in. the form of lumps, screenings, powder and briquettes. Metallurgical Chemical Aluminum metal Armor plate Case hardening Cobalt metal Copper, brass and bronze Electro manganese Foundry molds Magnesium metal Mining Molybdenum Nickel Pig Iron Powdered iron Special alloys Steel Specialized Fuel Citrus growers Foundries Meat and fish curing Tobacco curing Activated carbon Black powder Brake linings Carbon disulfide Carbon monoxide Catalyst reactor Electrodes Fertilizer Galvanizing Gas cylinders Glass Glues Graphite Molding resins Nursery mulch Pharmaceuticals Plastics Poultry and stock feeds Potassium cyanide Rubber Sodium cyanide Source: Beglinger, E. 1952. Charcoal production. U. S. Forest Products Laboratory Report No. Rl666-ll. Madison, Wisconsin. Table 2. Carbonization products of ipil-ipil wood NoTE: All samples were carbonized in an electrically-heated retort at a maximum temperature of 900 deg. F. The carbonization time was 8 hours. Sample Moisture Oven-dry Pyroligneous Settled tarb Uncondensible gases content" Weight of wood Charcoalb liquor" and lossesd per cent kg. per cent per cent per cent per cent A 22.87 17.49 36.30 20.89 4.17 38.64 B 17.80 15.04 31.00 22.40 6.05 40.55 c 25.30 13.56 33.82 30.60 6.25 29.33 D 25.00 16.50 36.81 28.60 5.35 29.24 E 23.51 15.36 34.20 24.80 5.60 35.40 Average 22.90 15.59 34.42 25.46 5.48 34.04 " Percentage was based on the weight of wood as received. b Percentage was based on the oven-dry weight of wood charge. c The weight of water in the wood charge was subtracted from the total weight of liquid product recovered. d Percentage of uncondensible gases and losses =' 1100- ( % charcoal _.,... % pyroligneous liquor_.,... % settled tar).] MOVING-UP DAY ISSUE-1965 Page 45 Table 3. Proximate chemical analysis of charcoal of ipil-ipil u;oodc Sample Moisture1 Volatile matterg A.s hg Fixed carbong per cent per cent per cent per cent A 0.44 9.20 1.93 88.87 B 5.00h 13.20 2.30 84.60 c 1.74 10.58 2.78 86.64 D 4.78h 8.80 2.46 88.74 E 0.97 10.45 2.12 87.43 Average 10.45 2.32 87.23 - ·------- --e Unless otherwise stated, the charcoal samples were obtained immediately after opening the retort. r Percentage was based on charcoal as received. g Percentage was based on moisture-free charcoal. h Charcoal samples were obtained after a stabilization period of at least 24 hours at room temperature. Table 4. Pyroligneous liquor analysisi Samples Methanol per cent A 0.65 B 0.74 c 0.86 D 0.96 E 0.84 Average 0.81 i All percentages are based on the oven-dry weight of wood charge. Acidity as acetic per cent 1.28 1.32 2.16 2.30 1.74 1.76 acid Table 5. Fractional distillation of settled tari Temperature range Average weight Average specific deg. C Percentage of fraction Gravity of fraction 150-210 3.41 0.913 210-235 3.73 1.010 235-270 4.76 1.025 270-315 5.15 1.031 (Residue) 64.40 xxxxx Soluble tar per cent 3.66 3.50 3.56 3.94 4.01 3.73 REMARKS straw-yellow oil orange oil reddish-orange oil reddish-brown oil waxy, black oil i All percentages are based on the weight ofsettled tar. (Continued on page 52) Page 46 FORESTRY LEAVES tractives, and other important characteristics of potential hybrids should be known through an effective research of the institute. The wood-using industries should also conduct studies on the quality and saleability of the finished products, together with the economics of the improved varieties and species, like the inbreds and hybrids. An alternative but a philanthropic contribution would be a financial support to the various projects within the scope of the program. SUMMARY The Philippines today is destroying its forest faster than any country in the world. Illegal kaifigin, timber smuggling, and indiscriminate logging have drained much of the forest resource .. However, no immediate measures of tree improvement are taken to check this critical forest problem. Agriculture has long developed high-yielding varieties of rice, corn, abaca, and other crops but practically no improved tree varieties or hybrids could be brought to light yet, after more than half a century of forestry practice in the Philippines. A solution to the foreseeable problem of timber shortage has been proposed through the implementation of a well-planned fore'it Industrial Charcoal . . (Continued from page 46) tree improvement research. This involves studies o.n t_he genetic and silvicultural aspects of improving the quality of existing tree species that are of commercial importance. Efforts would be exerted to creale a population of genetically superior trees that are expected to answer the dire neeus of the wood-using industries. Attainment ·A this objective calls for the production of hybrids that are characteristically fast-growing, resistant to pests and diseases, of wider ecological adaptation, and superior wood qua· lity. The castle of this dream could be built up through the cooperative efforts of the various forestry agencies that would undertake the different phases of the research program. Most possibly, the creation of a Committee on Forest Tree Improvement couid be an incendiary step to keep the ball rolling. To begin with, the committee would explore the possibilities of securing the necessary research fund which is considered as the lifeblood of the proposed undertakings. On the whole, the time is already ripe; hence, the Filipino Foresters should appropriately act now in order to create and per· petuate better trees for . tomorrow and a greener Philippine forest. Table 6. Calorific value of coke, coking coal and wood charcoals Kind of Fuel Volatile matter Fixed carbon Heating value per centk per centk per centk Coking coaF 19.0 76.0 7500 Coke1 5.0 87.0 7100 Black charcoal (Japan)m 12.0 86.0 7158 White charcoal (Japan) m 5.0 93.0 7235 Spruce wood charcoal (U.S.A.) 1 14.4 83.6 7310 Coconut shell charcoal (Philippines) 0 18.8 77.4 6700 lpil-ipil wood charcoal (Philippines) 0 11.0 86.7 7472 -----k Based on moisture-free charcoal. 1 Anonymous. 1955. Wood burning. Food and Agricultural Organization of the United Nations, Rome, Italy. p. 4 m Kishimoto, S. 1961. Firewood and charcoal. Chemical utilization of wood. Overseas Technical Cooperation Agency, Ministry of Agriculture and Forestry, Japan. pp. 272-273. n Coconut shell charcoal was obtained from a commercial sample. 0 Average of 6 distillation runs. The calorific values of coconut shell and ipil-ipil charcoals were determined by the sodium peroxide method at the Institute. Page 52 FORESTRY LEAVES