title: Overcoming the recalcitrance for the conversion of kenaf pulp to glucose via microwave-assisted pre-treatment processes.
abstract: This study evaluates the pre-treatment of cellulose from kenaf plant to yield sugar precursors for the production of ethanol or butanol for use as biofuel additives. In order to convert the crystalline cellulosic form to the amorphous form that can undergo enzymatic hydrolysis of the glycosidic bond to yield sugars, kenaf pulp samples were subjected to two different pre-treatment processes. In the acid pre-treatment, the pulp samples were treated with 37.5% hydrochloric acid in the presence of FeCl(3) at 50 °C or 90 °C whereas in the alkaline method, the pulp samples were treated with 25% sodium hydroxide at room temperature and with 2% or 5% sodium hydroxide at 50 °C. Microwave-assisted NaOH-treatment of the cellulose was also investigated and demonstrated to be capable of producing high glucose yield without adverse environmental impact by circumventing the use of large amounts of concentrated acids i.e., 83-85% phosphoric acid employed in most digestion processes. The treated samples were digested with the cellulase enzyme from Trichoderma reesei. The amount of glucose produced was quantified using the Quantichrom(™) glucose bioassay for assessing the efficiency of glucose production for each of the treatment processes. The microwave-assisted alkaline pre-treatment processes conducted at 50 °C were found to be the most effective in the conversion of the crystalline cellulose to the amorphous form based on the significantly higher yields of sugar produced by enzymatic hydrolysis compared to the untreated sample.
authors.affiliation: Department of Chemistry, Middle Tennessee State University, P.O. Box 68, Murfreesboro, TN 37132, USA; E-Mail: mah5a@mtmail.mtsu.edu.
authors.forename: Beng Guat
authors.initials: BG
authors.lastname: Ooi
authors.forename: Ashley L
authors.initials: AL
authors.lastname: Rambo
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Hurtado
mesh_terms: D056804:Biofuels; D002480:Cellulase / Q000378:metabolism; D002482:Cellulose / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism*; D031584:Hibiscus / Q000737:chemistry / Q000378:metabolism*; D006851:Hydrochloric Acid / Q000737:chemistry; D006868:Hydrolysis; D008872:Microwaves; D012972:Sodium Hydroxide / Q000737:chemistry; D013059:Spectrum Analysis, Raman; D014242:Trichoderma / Q000201:enzymology
chemical_list: D056804:Biofuels; D012972:Sodium Hydroxide; D002482:Cellulose; D002480:Cellulase; D005947:Glucose; D006851:Hydrochloric Acid