Preparation and evaluation of a dispersant for gypsum paste from acid hydrolysis lignin

Abstract

ABSTRACT:The preparation of dispersants with carboxyl groups from acid lignin (a byproduct in the saccharification process of woody materials that are renewable resources) was investigated, and their dispersion efficiency was evaluated. In this study, sulfuric acid lignin (SAL) was selected as a representative acid lignin. To convert SAL to water-soluble polymers, it was first subjected to phenolation with sulfuric acid to enhance its chemical reactivity. The introduction of a carboxy group was carried out with two methods. One was carboxymethylation with bromoacetic acid, and the other was the Mannich reaction with glycine, sarcosine, and iminodiacetic acid. The carboxymethylation product [carboxymethylated phenolized sulfuric acid lignin (CP-SAL)] with 1.4 carboxymethyl groups per phenolated phenylpropane lignin base unit was soluble in water. The Mannich reaction products were also soluble in water with a lower addition of carboxyl groups than that for CP-SAL. Surprisingly, all the prepared water-soluble polymers possessed a higher dispersibility for gypsum paste than commercial lignosulfate. This may be due to the higher molecular weights of acid lignin derivatives.

Production of carboxymethylated lignin and its application as a dispersant

“…Similarly, an increase in peak intensity at 1600, 1263 and 1030 cm -1 corresponds to the introduction of carboxylate group at the para position of aromatic rings in the modified lignin [18]. Thus, FTIR results confirm that there was an introduction of carboxylate group to the modified lignin due to the carboxymethylation of lignin with sodium chloroacetate.…”

“…Straw soda aqueous lignin was also modified to form chelating resins for binding to copper metals [17]. In another report, an acetone-based lignin model compound was carboxymethylated using bromoacetic acid to prepare carboxymethylated lignin, which was also used as dispersant for gypsum paste [18].…”

Adsorption–Desorption of Surfactant for Enhanced Oil Recovery

“…SLs are by-product of sulfite cellulose pulp production, they contain hydrophilic groups which make them water soluble (Dawy et al 1998;Telysheva et al 2001;Wang 2002). They can be described as anionic surfactants, which are relatively low cost and are widely used in many applications (Li et al 2007;Matsushita et al 2005;Pei et al 2008;Gogoi 2009). Studies have shown that aqueous solution of SL could reduce the IFT between oil and water thereby releasing the captured oil blobs from the porous media (Son et al 1982;Hornof et al 1982;Babu et al 1984;Gogoi 2010).…”

Aggregation and adsorption behaviors of carboxymethylated lignin (CML) in aqueous solution

“…An optimal lignin management is part of this strategy. Acid lignin is, for example, generated as a by-product of bioethanol production using acid saccharification of woody biomass (Matsushita et al 2005 ;Da Silva et al 2011 ;Cerrutti et al 2012 ). There is a large amount alkali lignin (AL) available in the waste liquor of soda pulping .…”