Steam explosion techniques

Dekker, R. F. H. 1991. Steam explosion an effective pretreatment method for use in the bioconversion of lignocellulosic materials. In Focher, B., Marzetti, A., and Crescenzi, V. (Eds.), Steam Explosion Techniques Fundamental Principles and Industrial Applications (pp. 277-305). Philadlphia PA Gordon and Breach Scientific Publishers-. 

AFEX is the pretreatment method that utilizes steam explosion techniques using ammonia as the chemical reagent [38-41]. The intended biomass material is placed in a pressure vessel with liquid ammonia (1 1 basis) and treated... 

Focher, B. Marzetti, A. Crescenzi, V. eds. Steam Explosion Techniques-, Gordon and Breach Sci. Publ, Philadelphia, PA, 1991,413 pp. 

Physical methods such as ultrasonication [57, 58], microwave [59, 60] and gamma radiation have also been reported. Steam explosion is reported to be an excellent alternative to the conventional methods such as CMP (chemical mechanical pulps) and chemical thermomechanical processes. The principle of steam explosion technique are that the steam xmder pressure with increased temperature penetrates through the space between the fibers, thus the middle lamella and the fiber adherent substance become soft and water soluble [61,62]. Marchessault [63] described the steam explosion... 

G. Excoffier, A. Peguy, M. Rinaudo, and M. R. Vignon, evolution of lingo cellulosic components during steam explosion, in Potential applications steam explosion techniques, fundamentals and industrial applications, B. Focher, A. Marzetti and V. Crescenzi (Eds.), pp. 83-95, Gordon and Breach Science Publisher, Philadelphia. (1991). 

We have previously reported the design of mixed hydrophilic/hydrophobic hydrogels containing PHEMA and polysaccharide segments, in which the polysaccharide structure is a hydrosoluble hemicellulose with a comparatively low molecular weight obtained from spruce chips by a steam explosion technique and fractionated by size exclusion chromatography (SEC) (1), In this paper we summarize earlier work and add some new results concerning controllability. 

M Avella, E Martuscelli, B Pascucci, M Raimo, B Focher, A Marzetti. J Appl Polym Sci 49 2091, 1983. B Focher, A Marzetti, V Crescenzi. Steam Explosion Techniques Fundamentals and Application,... 

Possible hazards introduced by variations in experimental techniques in Kjeldahl nitrogen determination were discussed [1]. Modem variations involving use of improved catalysts and hydrogen peroxide to increase reaction rates, and of automated methods, have considerably improved safety aspects [2], An anecdote is given of the classic technique when sodium hydroxide was to be added to the sulphuric acid digestion and was allowed to trickle down the wall of the flask. It layered over the sulphuric acid. Gentle mixing then provoked rapid reaction and a steam explosion [3],... 

The direct extraction and reuse of the metals from treated wood has been proposed. These include acid extraction, fungal degradation, bacterial degradation, digestion, steam explosion, or some combination of these techniques. All of these approaches show some potential, but none are currently economic (Helsen and Van den Belk, 2005). 

Cherian et al. [119] also extracted cellulose nanofibres from pineapple leaf fibres using acid-coupled steam treatment. The strucmral and physicochemical properties of the pineapple leaf fibres were studied by environmental scanning electron microscopy (ESEM), AFM and TEM and X-ray diffi action (XRD) techniques. The acid-coupled steam explosion process resulted in the isolation of PALF nanofibres having a diameter range of 5-60 nm. Figure 1.24a and b shows the AFM and TEM images of nano fibres obtained from pineapple leaf fibres. AFM and TEM support the evidence for the isolation of individual nanofibres from PALF. 

Kessler RW, Kohler BU, Rgoth B et al (1998) Steam explosion of flax- a superior technique for upgrading fibre value. Biomass Bioenergy 14 237-249... 

Physical modification involves thermal treatments such as plasma or nonthermal treatments like application of electric discharge, ultrasound, ultraviolet, or high-frequency cold plasma to the fiber surface. Stmctural and surface properties of the fibers are changed by these treatments, which result in improved mechanical bonding to polymers. These treatments are apphed to separate the fiber bundles into individual filaments and modify the fiber surface for more compatibility with the matrix in the composite [6]. If separation of the fiber bundles is desired, methods like steam explosion and thermomechanical processing are adopted. Methods like plasma (thermal) treatment, dielectric barrier techniques, or corona discharge (nonthermal) treatments (CDT) are anployed to modify the fiber surface. 

Essentially, physical methods are employed on natural fiber during processing in order to separate natural fiber bundles into individual filaments and also to modify the surface structure of the fibers so as to improve the use of natural fibers in composites. Physical methods can be divided into two categories viz (1) steam explosion and thermomechanical processes and (2) plasma, dielectric barrier techniques, radiation modification, ultrasonic treatment, and corona discharge. In an effort to impart and improve reactivity, these physical treatments have been used to modify thermoplastic polymeric films like polyethylene and polypropylene and thermosets, such as epoxy. 

A variety of methods have been demonstrated for biomass deconstruction. These can be broadly classified as chemical, biological, physical, and physicochemical [155]. Chemical methods include steam, lime, liquid hot water, ionic liquids, organosolve, ammonia, oxidative delignification, and ozonolysis [150, 155]. Physical and physiochemical methods include milling, steam explosion (autohydrolysis), ammonia fiber explosion (AFEX), microwave, extrusion, pulsed electric field, pyrolysis, and ultrasound. Consistent with the theme of this chapter, the first description of a novel non-enzymatic biomass deconstruction technique demonstrated the effectiveness of this method by producing ethanol [156]. 

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