Preparation of Concrete Superplasticizer by Oxidation-Sulfomethylation of Sodium Lignosulfonate

Yu, Guang; Li, Bin; Wang, Haisong; Liu, Chao; Mu, Xindong

doi:10.15376/biores.8.1.1055-1063

Cited by 61 publications

(70 citation statements)

References 8 publications

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“…The lignin was recovered with a spray dryer (FH-1500, Shanghai Gaoji, China) without any purification. The M w , M n , and PDI (polydispersity index) of the recovered lignin are 22780, 16430, and 1.386, respectively, and the measurement procedure of molecular weight was reported previously [24]. Also, the recovered lignin with relatively larger molecular and small PDI could be modified to value-added products, such as concrete additives and phenol-formaldehyde resins [25].…”

Section: Resultsmentioning

confidence: 86%

Alkaline twin-screw extrusion pretreatment for fermentable sugar production

Liu

Heide

Wang

et al. 2013

Biotechnol Biofuels

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BackgroundThe inevitable depletion of fossil fuels has resulted in an increasing worldwide interest in exploring alternative and sustainable energy sources. Lignocellulose, which is the most abundant biomass on earth, is widely regarded as a promising raw material to produce fuel ethanol. Pretreatment is an essential step to disrupt the recalcitrance of lignocellulosic matrix for enzymatic saccharification and bioethanol production. This paper established an ATSE (alkaline twin-screw extrusion pretreatment) process using a specially designed twin-screw extruder in the presence of alkaline solution to improve the enzymatic hydrolysis efficiency of corn stover for the production of fermentable sugars.ResultsThe ATSE pretreatment was conducted with a biomass/liquid ratio of 1/2 (w/w) at a temperature of 99°C without heating equipment. The results indicated that ATSE pretreatment is effective in improving the enzymatic digestibility of corn stover. Sodium hydroxide loading is more influential factor affecting both sugar yield and lignin degradation than heat preservation time. After ATSE pretreatment under the proper conditions (NaOH loading of 0.06 g/g biomass during ATSE and 1 hour heat preservation after extrusion), 71% lignin removal was achieved and the conversions of glucan and xylan in the pretreated biomass can reach to 83% and 89% respectively via subsequent enzymatic hydrolysis (cellulase loading of 20 FPU/g-biomass and substrate consistency of 2%). About 78% of the original polysaccharides were converted into fermentable sugars.ConclusionsWith the physicochemical functions in extrusion, the ATSE method can effectively overcome the recalcitrance of lignocellulose for the production of fermentable sugars from corn stover. This process can be considered as a promising pretreatment method due to its relatively low temperature (99°C), high biomass/liquid ratio (1/2) and satisfied total sugar yield (78%), despite further study is needed for process optimization and cost reduction.

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Section: Resultsmentioning

confidence: 86%

Alkaline twin-screw extrusion pretreatment for fermentable sugar production

Liu

Heide

Wang

et al. 2013

Biotechnol Biofuels

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“…[95,96] Sulfomethylation was then carried out with 20 wt %C H 2 Oa nd 30 wt % Na 2 SO 3 for 3h at 95 8C. Scheme 10 presents ap rocess for the oxidation and sulfomethylation of lignosulfonates.…”

Section: Sulfomethylationmentioning

confidence: 99%

Production and Application of Lignosulfonates and Sulfonated Lignin

2017

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Lignin is the largest reservoir of aromatic compounds on earth and has great potential to be used in many industrial applications. Alternative methods to produce lignosulfonates from spent sulfite pulping liquors and kraft lignin from black liquor of kraft pulping process are critically reviewed herein. Furthermore, options to increase the sulfonate contents of lignin-based products are outlined and the industrial attractiveness of them is evaluated. This evaluation includes sulfonation and sulfomethylation of lignin. To increase the sulfomethylation efficiency of lignin, various scenarios, including hydrolysis, oxidation, and hydroxymethylation, were compared. The application of sulfonated lignin-based products is assessed and the impact of the properties of these products on the characteristics of their end-use application is critically evaluated. Sulfonated lignin-based products have been used as dispersants in cement admixtures and dye solutions more than other applications, and their molecular weight and degree of sulfonation were crucial in determining their efficiency. The use of lignin-based sulfonated products in composites may result in an increase in the hydrophilicity of some composites, but the sulfonated products may need to be desulfonated with an alkali and/or oxygen prior to their use in composites. To be used as a flocculant, sulfonated lignin-based products may need to be cross-linked to increase their molecular weight. The challenges associated with the use of lignin-based products in these applications are comprehensively discussed herein.

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“…A 45° pulse flipping angle, a 4.6 µs pulse width, a 2.05 s acquisition time, and 1 s relaxation delay time were considered for this analysis.The formation of a by-product, i.e. glycolic acid, of the carboxymethylation reaction was confirmed using a Varian Unity INOVA 500 MHz spectrometer[26]. The carboxymethylated reaction medium was centrifuged at 1000 rpm for 5 min after the reaction.…”

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confidence: 99%