Selectivity and delignification kinetics for oxidative and nonoxidative lime pretreatment of poplar wood, part III: Long-term

• Published in: Biotechnology progress Vol. 26; no. 6; pp. 1685 - 1694
• Main Authors: Sierra, Rocio, Garcia, Laura A., Holtzapple, Mark Thomas
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.11.2010; Wiley
• Subjects: biofuels; Biological and medical sciences; biomass; Biotechnology; Calcium Compounds - chemistry; Calcium Compounds - metabolism; Carbohydrates - chemistry; delignification; Fundamental and applied biological sciences. Psychology; Kinetics; long-term; modeling; Oxidation-Reduction; Oxides - chemistry; Oxides - metabolism; poplar wood; Populus - chemistry; Wood - chemistry; Delignification; Selectivity; Kinetics; Pretreatment; Wood; Long term
• ISSN: 8756-7938; 1520-6033; 1520-6033
• DOI: 10.1002/btpr.493

Lime pretreatment is an effective method for improving lignocellulose digestibility by removing lignin. For several weeks, mixtures of poplar wood, water, and calcium hydroxide (lime) were submitted to temperatures from 25 to 65°C, with and without aeration. Kinetic models for lignin and carbohydrate degradation were obtained as functions of temperature, time, and aeration using first‐order kinetics in lignin and carbohydrates. Model 1 considered two reacting moieties (slow and fast), and Model 2 considered three (slow, medium, and fast). Model 1 was statistically better and was employed to determine differential and integral selectivities, which measure the ability of pretreatment to retain carbohydrates while removing lignin. During the first 2 weeks, when lignin content ≥0.80 g/g lignin in raw biomass, both glucan and xylan differential and integral selectivities decreased rapidly. Afterwards, selectivities were nearly constant ranging between 0 and 3 g lignin removed/g carbohydrate degraded. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010