Japanese Cedar Wood Research Articles

Raman spectroscopic study on pyrolyzed wood and bark of Japanese cedar: temperature dependence of Raman parameters

Raman spectra were measured for Japanese cedar wood and bark pyrolyzed in a nitrogen atmosphere at various temperatures (200°–1100°C). Two characteristic bands, near 1340 and 1590 cm−1, denoted as the D-band and G-band due to graphitic carbon, respectively, appeared on all the spectra; and the spectral features changed markedly with increasing heat-treatment temperature (HTT). The Raman parameters (band position, band width, D/G ratio) of the bands were deconvolved using of a curve-fitting method. There was no significant difference in the values of the parameters between the wood and bark. The D-band position and the G-band width showed a marked HTT dependence in the region of 400°–800°C. We described the correlations of the Raman parameters with HTT and investigated the availability of Raman spectroscopy as a means for evaluating HTT.

Pyrolysis of lignin in the presence of tetramethylammonium hydroxide (TMAH): products stemming from beta-5 substructures.

Lignin model compounds, synthetic lignins, and cedar wood have been analyzed by pyrolysis-gas chromatography(-mass spectrometry) in the presence of tetramethylammonium hydroxide (TMAH) to examine the behavior of beta-5 substructures specifically under these conditions. Two model compounds contained a beta-5 linkage and a gamma-CH2OH group. The phenolic model compound produced stilbene products by way of a formaldehyde elimination of the gamma-CH2OH. The nonphenolic model compound underwent dehydration to give arylbenzofuran products. Dehydrogenation polymers of coniferyl alcohol gave a large amount of stilbene products in TMAH/pyrolysis. TMAH/pyrolysis of a Japanese cedar (Cryptomeria japonica) wood yielded a very small amount of stilbene products. The results demonstrated that synthetic lignins are rich in terminal beta-5 substructures, but cedar (a softwood) contains a paucity of the terminal beta-5 substructures.

Effect of pyrofoil composition on pyrolysis of lignin

The effect of pyrofoil compositions was examined on pyrolysis of lignocellulosic materials. The pyrofoil, which is an alloy of 60% of nickel and 40% of iron (Ni–Fe) having a Curie-point temperature of 500 °C, was coated with different metals (gold, platinum and aluminium). Lignin model compounds, coniferyl alcohol and guaiacylglycerol-β-guaiacyl ether, were pyrolyzed using Pyrofoil Ni–Fe and the metal-coated pyrofoils. The model compound product profiles were quite similar for Pyrofoil Ni–Fe and platinum. This close similarity suggests that lignin pyrolyses performed with Pyrofoil Ni–Fe and platinum, which is widely used as a heating source or a crucible because of the less catalytic effect, can be cross-referenced. Pyrolysis using the gold-coated Ni–Fe pyrofoil (G) produced a product profile greatly different from the other pyrofoils. Dihydroconiferaldehyde was a characteristic product of both the model compound pyrolysis experiments with Pyrofoil G. With the aid of Pyrofoil G, a Japanese cedar ( Cryptomeria japonica D. Don) wood also produced dihydroconiferaldehyde in an appreciable abundance.

Pyrolysis-trimethylsilylation analysis of lignin: preferential formation of cinnamyl alcohol derivatives

This paper describes a pyrolysis-trimethylsilylation procedure that is a new pyrolysis-derivatization thermochemolysis procedure of lignin. N, O-Bis(trimethylsilyl)trifluoroacetamide (BSTFA) was used as a trimethylsilylating reagent. A bulk dehydrogenative polymer of coniferyl alcohol (G-DHP) and a Japanese cedar ( Cryptomeria japonica D. Don) wood were pyrolyzed in the presence of BSTFA at 500°C for 4 s. The resultant volatile products were analyzed by gas chromatography/mass spectrometry (GC/MS). The G-DHP and the wood produced large abundances of trimethylsilyl (TMS) derivatized coniferyl alcohol (CA-(TMS) 2), in which both the phenolic and alcoholic hydroxyl groups are derivatized with TMS. CA-(TMS) 2 accounted for about 68% of the TMS derivatized products in the G-DHP pyrolysis, and about 24% of those in the wood pyrolysis. The results indicated that pyrolysis in the presence of trimethylsilylating reagents such as BSTFA is a potentially useful technique for drawing information on the pyrolytic precursors of cinnamyl alcohols (such as cinnamyl alcohol-end groups) from lignin. Pyrolysis-trimethylsilylation occurs in a one-step process and provides the TMS derivatives that are immediately available for the subsequent GC(/MS) analysis. This method is applicable to all lignocellulosic materials.

Analytical pyrolysis products derived from cinnamyl alcohol-end groups in lignins

The contributions of cinnamyl alcohol-end groups to lignin-derived pyrolysis products were studied using coniferyl alcohol benzyl ether I, a model compound for cinnamyl alcohol-end groups. The profile of the pyrolysis product distribution of I demonstrated that cinnamyl alcohol-end groups are greatly responsible for the formation of propenylphenols, and cinnamyl compounds (dihydrocinnamyl alcohols, cinnamaldehydes, and cinnamyl alcohols), but play a small role in the formation of the products with a short side-chain (<C3). The contributions of coniferyl alcohol-end groups were examined in pyrolyses of reference lignins, a bulk dehydrogenative polymer of coniferyl alcohol (DHP), a Japanese cedar ( Cryptomeria japonica D. Don) wood and its milled wood lignin. Large similarity of the distribution profile of the cinnamyl compounds in the DHP pyrolyzate to that in the I pyrolyzate showed that coniferyl alcohol-end groups play a large role in the DHP pyrolyzate. The distribution profiles of the cinnamyl compounds in the cedar wood and its lignin pyrolyzates were greatly differed from that of the I pyrolyzate.

Removal of mercury by carbonized wood materials from aqueous solutions of different types of mercury compounds.

Japanese cedar (Cryptomeria japonica D. Don) wood powder carbonized at varying temperatures was used to remove mercury from aqueous solutions of different types of mercury compounds. Aqueous solutions of different types of mercury compounds were prepared at 5 ppm to determine the amounts of mercury removed by these materials. In all cases, wood powder carbonized at 1000°C performed best among the carbonized wood materials examined, even better than activated carbon. Mercury was removed even when ovendried wood powder and wood powder carbonized at 200°C were used. The ability of wood powder carbonized at 600°C to remove mercury was also promising.

Analytical pyrolysis of alcohol bisulfite lignin

A high molecular weight lignin fraction, alcohol bisulfite lignin, was isolated from the spent liquor of alcohol bisulfite pulping of Japanese cedar ( Cryptomeria japonica D. Don) wood and subjected to analytical pyrolysis. The resulting products were compared with those from the original wood, its milled wood lignin and a synthetic lignin. The alcohol bisulfite lignin yielded several characteristic pyrolysis products compared with the other samples: a large yield of 4-propylguaiacol and small amounts of methylated compounds. Furthermore, analytical pyrolysis of the alcohol bisulfite lignin gave a much smaller yield of coniferyl alcohol than that from Japanese cedar wood. These differences are due to the chemical change in the lignin structure as a result of the alcohol bisulfite treatment.

Dilatometry of wood: Part II. Longitudinal dilatometry of wood treated with sodium borate, ammonium bromide, and sodium chloride

Dilatometry of Japanese cedar wood treated with sodium borate, ammonium bromide and sodium chloride was carried out according to the procedure described previously. The sodium borate-treated wood first underwent shrinkage due to bond formation in hemicelluloses, such as cross-linking and grafting, then elongation due to the chain scission of cellulose, and finally shrinkage due to bond formation in cellulose. The ammonium bromide-treated wood first revealed elongation, secondly shrinkage, then elongation again, and finally shrinkage. These changes are respectively ascribable to the chain scission of cellulose, the cross-linking or grafting of cellulose, the chain scission of cellulose accelerated by the increase in tensile stress from the decrease in cross-sectional area of the specimens, and the cross-linking or grafting of cellulose after active weight loss. The dimensional changes of the sodium chloride-treated wood followed basically the same pattern as that for the ammonium bromide-treated wood, although the first elongation occurred at higher temperatures and progressed through two steps which were attributable to the scissions of linkages in the lignin network and in cellulose, respectively. The activation energies determined for dimensional changes are discussed in relation to the applied tensile loads. Activation energies for weight losses are also presented.

Dilatometry of wood: Part I. Longitudinal dilatometry of wood untreated and treated with ammonium phosphate

In order to obtain information about the dimensional changes of wood at high temperatures, dilatometry of untreated and ammonium phosphate-treated Japanese cedar wood (25×5.0×0.2 mm) under constant tensile loads was carried out with uniform heating rates in a vacuum. The untreated sample first underwent elongation, due probably because of scission of linkages in the lignin network and then shrinkage due to bond formation in cellulose, such as cross-linking and grafting. With high heating rates or large loads the shrinkage was followed by another stage of elongation and then shrinkage which could be ascribed to the chain scission of cellulose accelerated by the increase in tensile stress and to bond formation in cellulose. The dimensional changes of ammonium phosphate-treated wood were first elongation due to the scission of cellulose and then shrinkage due to bond formation in cellulose. With large loads, the elongation stage progressed through two steps which were ascribable to the scission of linkages in lignin and cellulose, respectively. The activation energies for the dimensional changes were obtained and the effects of tensile loads on them are discussed. Also the activation energies of weight loss are determined.

魚味噌製造に關する研究第1報魚味噌の製造について

(1) We tried to manufacture the Japanese Miso from fish meat instead of soy beans. This Miso we call Gyomiso (Fermented fish paste). (2) We tried various methods to obtain Gyomiso resembling soy-Miso (Sop cheese), and met with a successful manufacturing method. (3) To manufacture Gyomiso, crushed fish meat (75%) is mixed with wheat bran (10%) inoculated with Aspergillus oryzae and salt (15%). This mixture is kept about 2 weeks at 25-30°C to ripen by the action of the auto-digestive enzyme of fish meat and the action of the enzymes of Aspergillus oryzae. After 2 weeks the mixture should be cooked to stop the action of enzymes. For 3 days after the mixing of fish meat, wheat bran and salt, the mixture was too hard to disturb, but after the 4th day the mixture became soft. On the 5th day, a bag which was filled with Japanese cedar wood dust was immersed into the mixture, then the mixture gave off the cedar flavour. From the 7th day, the fermentation of the mixture became stronger, and the juice increased. The hydrogen ion concentration of the mixture was 6 at the beginning, pH 6.5 during the fermentation and became pH 4.5 at the end of the fermentation. If the fermentation goes on excessively, the pH value becomes greater than 6.5 and at this time ammonia smell is given off. Therefore, when the mixture indicates pH 5.5, it should be boiled to sterilize it, and to decrease the water content of the goods to 40%. And then it blends homogeneously togather. The percentage of yield of the products was from 45 to 50 4 of the weight of the raw fish bodies.