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Acidification has been commercialized for producing kraft lignin from black liquor of kraft pulping process. This work intended to evaluate the effectiveness of acidification in extracting lignocelluloses from the spent liquor of neutral sulfite semichemical pulping (NSSC) process and from prehydrolysis liquor (PHL) of kraft-based dissolving pulp production process. The results showed that the NSSC and PHL spent liquors had some lignin-carbohydrate complexes (LCC), and that the square weighted counts of particles with a chord length of 50–150 μm in the spent liquors were significantly increased as pH dropped to 1.5. Interestingly, the acidification reduced the lignosulfonate/lignin content of NSSC and PHL by 13% or 20%, while dropped their oligosugars content by 75% and 38%, respectively. On a dry basis, the precipitates had more carbon, hydrogen and a high heating value of 18–22 MJ/kg, but less oxygen, than spent liquors. The precipitates of PHL could be used as fuel. [ABSTRACT FROM AUTHOR]

In this work, the adsorption of lignocelluloses from spent liquor (SL) of neutral sulfite semi chemical (NSSC) pulping process on bentonite was investigated. It was observed that 0.26 g/g of lignin and 0.27 g/g of hemicelluloses from SL were adsorbed on bentonite under the conditions of 50 °C, 100 rpm and 40 g/g SL/bentonite after 3 h of treatment. The adsorptions of lignin and hemicellulose were increased to 1.8 g/g and 0.45 g/g, respectively, via adding 15 mg/g of polydiallyldimethylammonium chloride (PDADMAC) in the system of SL/bentonite. The turbidity and COD removals were improved from 69% to 93% and from 25% to 38% by adding PDADMAC to the SL/bentonite system, respectively. The increase in the heating value of bentonite (from 0 to 15.4 MJ/kg) confirmed the adsorption of lignocelluloses. The modified bentonite can be used as filler in corrugated medium paper production or as fuel. [ABSTRACT FROM AUTHOR]

• LignoTall process was introduced to produce tall oil, salt and tall oil lignin. • Lignotall process can be integrated into kraft pulping process. • The physicochemical characteristics of tall oil lignin and kraft lignin are different. • Spent liquor of the process can be reused in pulping or treated in wastewater system. • Tall oil lignin could be used in the production of rubber and epoxy resins. The aim of this work was to study the production and characterization of tall oil lignin (TOL) from tall oil soap (TOS) of the kraft pulping process following a new process (i.e., LignoTall). Also, the properties of the TOL and kraft lignin (KL) produced via LignoForce technology were compared. Although TOL and KL were generated from the same black liquor and softwood species, they had remarkably different characteristics, confirming the impact of the production methods on the physicochemical properties of the isolated lignin. TOL had higher molecular weight, O/C elemental ratio, sulfur content, and carboxylate-OH content but lower methoxy group content than did KL. The high sulfur group content (7.3%) of TOL can be very useful for the vulcanization process. Moreover, the high carboxylate-OH content of TOL (0.56 mmol/g) is desirable for its utilization in epoxy resin production. [ABSTRACT FROM AUTHOR]

This study undertakes a state-of-the-art review on thermophilic membrane bioreactors (ThMBRs). Thermophilic aerobic membrane bioreactors (ThAeMBR) and thermophilic anaerobic membrane bioreactors (ThAnMBR) have been widely tested for various high-temperature industrial wastewater treatments at lab- and pilot-scale studies and full-scale applications. The biological and membrane performances of the ThAeMBRs and ThAnMBRs could be better, comparable or poorer, as compared to the mesophilic ones. In general, sludge yield was much lower, biodegradation kinetic was higher, and microbial community was less diversity in the ThAeMBR and ThAnMBR systems. The results from the literature show that ThMBR technology has demonstrated many advantages and is a promising technology for industrial wastewater treatment and sludge digestion. Furthermore, challenges and opportunities of various ThMBRs for industrial applications are identified and discussed. [ABSTRACT FROM AUTHOR]

[Display omitted] • β-O-4 decreased with intensifying autohydrolysis intensity of wood chips. • Lignin was deposited on wood chip surface via intensifying autohydrolysis. • Phenolic OH had a correlation with enzymatic hydrolysis of autohydrolyzed chips. • Binding of lignin and enzyme was increased with intensifying autohydrolysis. Enzymatic hydrolysis is a method to generate biofuel from biomass, and autohydrolysis is a popular method to pretreat biomass prior to enzymatic hydrolysis. The primary aim of the present study was to determine the role of lignin produced in the autohydrolysis process on the enzymatic hydrolysis of biomass. The HSQC and 31P NMR analyses confirmed that β-O-4 of lignin was reduced, while β-5, β-β, and S/G-ratio of lignin were increased with intensifying the hydrolysis intensity. The increase in the hydrolysis intensity significantly enhanced the condensed and non-condensed phenolic OH group of lignin. Interestingly, the cellulase enzyme adsorbed more on lignin that had more phenolic content, and its association with lignin reduced its activity for hydrolyzing cellulose microcrystals. Strong negative correlations were observed between the enzymatic hydrolysis yield and the condensed S-OH (r 2 = 0.978) and G-OH (r 2 = 0.961) of lignin generated in the autohydrolysis process. [ABSTRACT FROM AUTHOR]