Pyrolysis of wood

Arima [32-34] performed simultaneous TG and DSC investigations on the thermal decomposition of various tropical soft- and hardwoods in air and in nitrogen. Under air, two main exothermic peaks and an exothermic shoulder were ob- 

Stems and leaves of the Chilean Euphorbia copiapina were analyzed by means of TG, DSC and combustion calorimetry to evaluate their quality as a source of botanochemical compounds and fuels, using various zeolitic catalysts [36]. The applied catalysts shifted the pyrolysis to mixtures with interest as fuels and indu-stnal chemicals. 

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Chemicals have long been manufactured from biomass, especially wood (sHvichemicals), by many different fermentation and thermochemical methods. For example, continuous pyrolysis of wood was used by the Ford Motor Co. in 1929 for the manufacture of various chemicals (Table 20) (47). Wood alcohol (methanol) was manufactured on a large scale by destmctive distillation of wood for many years until the 1930s and early 1940s, when the economics became more favorable for methanol manufacture from fossil fuel-derived synthesis gas. 

This paper discusses the effects of the pyrolysis of wood and paper treated with pentachlorophenol or sodium pentachlorophenate along with the exposure of sodium pentachlorophenate to ultraviolet light. The effect of heat, light, and air with respect to some of the chlorinated dibenzo-p-dioxins will be considered. 

Slow pyrolysis, also called carbonization, is characterized by a high charcoal yield and is not considered for hydrogen production processes. The slow pyrolysis of wood (24 h typical residence time) was a common industrial technology to produce charcoal, acetic acid, methanol, and ethanol from wood until the early 1900s. 

Tang, W. K., H. W. Eickner. Effect of Inorganic Salts on Pyrolysis of Wood, Cellulose, and Lignin Determined by Differential Thermal Analysis FPL Research Paper 82, U.S.D.A., 1967. 

The pyrolysis of wood, oxygen chemisorption and oxidation of wood chars were carried out in a computerized coupled TG-FTIR system containing Cahn-R-100 electric balance, DuPont Model 990 thermal analyzer and Nicolet MX-1 Fourier transform infrared spectrometer. All of these sequential processes are carried out within the thermal balance without interruption. 

Figure 1. Pyrolysis of wood heated from 100 C to the final temperature in ten hours.

In the 1920s the catalytic synthesis of methanol was commercialized in Germany. Even before that, methane was distilled from wood, but this pyrolysis of wood was relatively inefficient. 

Guo, J. Pyrolysis of wood powder and gasification of wood-derived char,... 

Mohan, D., Pittman, C.U., Steele, PH. 2006. Pyrolysis of wood/biomass for bio-oil a critical review. Energy Euels 20 848-889. 

Roberts A.F , A Review of Kinetics Data for the Pyrolysis of Wood and Related Substances , Combustion and Flame 14, 261-272 (1970). 

Methanol was first produced commercially in 1830 by the pyrolysis of wood to produce wood alcohol. Almost a century later, a process was developed in Germany by BASF to produce synthetic methanol from coal synthesis gas. The first synthetic methanol plant was introduced by BASF in 1923 and in the United States by DuPont in 1927. In the late 1940s, natural gas replaced coal synthesis gas as the primary feedstock for methanol production. In 1966, ICI announced the development of a copper-based catalyst for use in the low-pressure synthesis of methanol. 

The most important and frequently used terpene esters in flavours are the acetates of nerol, geraniol, citronellol, linalool and isoborneol [12], As discussed before, all these terpene alcohols are available both from renewable resources and from petrochemical origin. Acetic acid can be obtained from renewable resources by pyrolysis of wood as wood vinegar, and also by synthesis from petrochemical origin. 

Twenty-five years ago the only oxygenated aliphatics produced in important quantities were ethyl and n-butyl alcohols and acetone made by the fermentation of molasses and grain, glycerol made from fats and oils, and methanol and acetic acid made by the pyrolysis of wood. In 1927 the production of acetic acid (from acetylene) and methanol (from synthesis gas) was begun, both made fundamentally from coal. All these oxygenated products are still made from the old raw materials by the same or similar processes, but the amount so made has changed very little in the past quarter century. Nearly all the tremendous growth in the production of this class of compounds has come from petroleum hydrocarbons. 

Methanol, also called methyl alcohol and once commonly know as wood alcohol, is a clear, volatile liquid mp, -98°C bp, 65°C). Until the early 1900s, the major commercial source of methanol was the destructive distillation (pyrolysis) of wood, a process that yields a product contaminated with allyl alcohol, acetone, and acetic acid. Now methanol is synthesized by the following reaction of hydrogen gas and carbon monoxide, both readily obtained from natural gas or coal gasification ... 

Considering the volatiles that evolve from hot pressing and heat-treating operations, it is concluded that the major chemical changes occurring in this stage are pyrolytic. Methanol, acetic acid, furfural, and ligneous tars are the common volatiles produced by the slow pyrolysis of wood practiced in destructive-distillation processes. The temperatures used in the board conversion operations approach pyrolysis temperatures of wood and the evidence indicates that pyrolysis is indeed active in board conversion. 

Soltes, E. I. (1980). Pyrolysis of wood residues. A route to chemical and energy products for the forest products industry Tappi 63(7), 75-77. 

Richards, G. N. and Zheng, G. C., Influence of metal-ions and of salts on products from pyrolysis of wood -Applications to thermochemical processing of newsprint and biomass. J Analytical Appl Pyrolysis 1991, 21 (1-2), 133-146. 

Ltndberg JJ, Ratsanen S, Niemt R (1982) GC-MS studies on the pyrolysis of wood and lignin Gov Rep Announce Index (US) 1984 84 163-173 Linskens HF, Jackson JF (1986) Gas chromatography/mass spectrometry Springer, Berlin Heidelberg New York Tokyo, 304 pp... 

All of the studies mentioned are directed to lignins derived from pulp and paper manufacture. This requires that a traditionally conservative pulp and paper industry embark on further development as a chemical producer. However, Helena Chum and her colleagues (Chapter 11) derive their phenolics from lignin by fast pyrolysis of wood rather than as byproducts from the pulp and paper industry. Opportunities might be better for development of adhesives from a chemical manufacturer drawing on waste wood as a raw material much the same as has developed in the production of furan resins derived from agricultural residues described by Bill McKillip (Chapter 29). 

Due to the novelty of the microwave pyrolysis process, there are no other reports in the scientific literature, with details of equipment for the degradation of plastics. However, for the degradation of other materials, details of the apparatus utilized for the microwave pyrolysis of wood have been presented [50, 51]. 

M. Miura et al.. Rapid pyrolysis of wood block by microwave heating. Journal of Analytical and Applied Pyrolysis, 71, 187-199 (2004). 

M. Miura et al. Rapid microwave pyrolysis of wood. Journal of Chemical Engineering of Japan, 33, 299-302 (2000). 

Lindberg JJ, Raisancn S, Nicmi R (1982) GC-MS studies on the pyrolysis of wood and lignin. 

Ohta K. and Venkatesan M. I. (1992) Pyrolysis of wood specimens with and without minerals implications for lignin diagenesis. Energy Fuels 6, 271-277. 

Since biomass pyrolysis product mixtures are very complex and selectivities are low for specific products, considerable effort has been devoted to improving selectivities. Selectivities can sometimes be increased by addition of coreactants or catalysts, or by changing the pyrolysis conditions (cf. Nikitin et al, 1962). For example, the pyrolysis of maplewood impregnated with phosphoric acid increased the yield of methanol to 2.2 wt % of the wood as compared to 1.3 wt % obtained on dry distillation of the untreated wood. Addition of sodium carbonate to oak and maple increased the yield of methanol by 100 and 60%, respectively, compared to pyrolysis yields without sodium carbonate. Other weakly alkaline reagents exhibited a similar effect. Pyrolysis of wood in a stream of benzene, xylene, or kerosine increased the yields of acetic acid, aldehydes, and phenols and reduced the yield of tars. Optimization of pyrolysis conditions will be shown later to have large effects on product distributions and yields. 

Much of the technology discussed in previous chapters can be applied to the synthesis of organic chemicals from biomass. The pyrolysis of wood described in Chapter 8 illustrates how several commodity chemicals were manufactured in the 1920s and 1930s by the Ford Motor Company. The yields and selectivities... 

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