Pyrolysis of cellulose in a vacuum

Abstract

Samples of cotton , cotton h ydrocelJulose, and viscose rayo n, both by t hemselves an d impreg nat;ed with sod ium carbonate or sodium chloride, were p yl'Olyzed at 250 0 to 397 0 C in a lli g h vacuum. The volatile products were fractionated a nd t he fractio ns analyzed in th e m ass spectrometer a nd by inf rared absorpt ion. Th e volatile fraction s co nsisted mainly of CO, CO2, water, and levoglucosan (tar). The residue consisted main ly of carbon (cha r).Imp reg na t ion of the cellulosic m aterials with salt s caused a decrease in t he y ield of tar and an increase in t he yields of CO, CO" H 20 , a nd char. R ates of thermal degradation of the sam e materials were in vcstigated in the range 245 0 to 305 0 C by a loss-of-w eight m ethod, usin g a ver y sensitive t ungste n spring bala ncc enclosed in a vac uum. Plots of rates of loss of " 'eigh t versus percentage of loss of ' weight, in t h e case of pure cellulosic materials, p ass th rough maxima at a bout 13 to 23 percent loss of " 'eigh t, t he n drop graduall y to t he carb onization end point. In the case of sampl es impreg nated with sodium carbonate or sod ium chlorid e, t he initial ra tes of loss of weight are very hi gh , but drop rapidly to the carbon izatio n end p oi11 t . Th e activation energies o f thermal d egradation of t h e pure cellulosic mater ials are much greate r than t hose of t he sa me material s impregnated with sod ium carbo nate or sodium ch lor ide .

Thermal Characteristics of Coated Textile Fabrics

“…Corresponding peaks in the three chromatograms are indicated by the same number and the products that have been identified are listed by peak number in Table XIV. A minimum of 37 different volatile products is indicated whereas earlier studies using other analytical methods have indicated from 8 to 18 products [14,16] and the recent studies on cellulose pyrolysis by isothermal gas chromatography [17,18] have indicated no more than 18 decomposition products. These results indicate the same products irrespective of the pyrolysis conditions but significant differences in product distribution are shown.…”

Evaluation of Exothermic Reactions from Bulk-Vitrification Melter Feeds Containing Cellulose

“…Using the ARC, they observed this decomposition near 180°C. Madorsky et al (1956) found that cellulose decomposed, producing tars composed of levogucosan and small amounts of 1,6 anhydro-β-D-glucofuranose, 5-(hydroxymethyl)-2-furaldehyde, 2-furyl hydroxymethyl ketone, and 1,4: 3.6-dianhydro-α-D-glocopyranose; these tars were 65 wt% of the original cellulose mass. Dollimore and Hoath's (1981) review of literature on cellulose decomposition reports that over 60 secondary products have been identified.…”

Competitive Reactions in the Thermal Decomposition of Cellulose

“…The combustion of cellulose has been studied quite frequently during recent years (1)(2)(3)(4)(5)(6)(7), and several reviews have appeared (8,9). Much of the evidence strongly suggested that when the cellulose is heated, the following sequence of reactions occurs (1):…”