-->High-value Application of Lignin

Innovative Development to Build A New Pattern for High-quality Utilization of Waste Paper Fiber in China

WAN Jinquan — 2022/9/27 18:30:33

This study summarized the current situation of waste paper in papermaking industry， analyzed the impact and challenge of the “Zero Import” policy of solid waste on the supply chain of papermaking raw materials in China. It was proposed that domestic waste paper and imported recycled fiber pulp board will still be an important proportion of China's papermaking raw materials in the future， which is of great significance to ensure the effective supply of fiber raw materials for China's paper industry. On this basis， the technical problems emerged during the high-quality recycling of waste paper fibers in terms of restraining strength performance decay， deinking， bleaching， and stickies control were reviewed， and the scientific research pertaining to the basic theory of waste paper fiber application and innovative solutions to the abovementioned technical problems in recent years were accentuated.

Research Progress on Application of Enzyme in Waste Paper Recycling

LYU Wenzhi,CAO Shuangfeng,LI Xiaofeng,WANG Runping,WANG Fang,WU Qiyin,LONG Zhu — 2022/9/27 18:30:23

With the transition of China's economy from high-speed development to high-quality development stage， as well as the promulgation and implementation of national restrictions on foreign waste import， the price of waste paper is rising， therefore， the efficient and intensive utilization of waste paper is particularly important. The application research and development of various enzymes in waste paper recycling production were introduced in this review， accentuating its application and research progress in waste paper deinking， stickies controlling， bleaching， beating， and wastewater treatment. Furthermore， the main issues and application prospects of enzymes in the field of waste paper recycling were discussed and prospected.

High-value Utilization of Waste Paper and Its Research Progress in Materials Research Area

ZHANG Xiaolin,DI Jingjing,BO Xiangfeng,LYU Jinyan,DUAN Jingting,XU Long — 2022/9/27 18:30:36

The efficient utilization of renewable resources is an important part in the construction of ecological civilization. Waste paper （recycled fiber） is an important waste resource in the field of waste polymer materials with a large amount and a wide range. At present， the production of recycled paper using waste paper is still the prevalent way of its recycling， and the development of high-value and efficient utilization technology of waste paper has attracted wide attention. This review briefly introduced the current recycling situation of waste paper in China， summarized the research achievements of high value-added products such as the preparation of waste paper fiber derivatives， waste paper-based engineering filler， and waste paper fiber composite material， and analyzed the high-value utilization of waste paper and the development prospect of its application in material field.

Review on Recent Development in Utilization of Deinking Sludge

LIU Junjie,XIA Jie,ZHANG Hongjie,HU Xin,SHEN Yuehao,ZHANG Wenhui — 2022/9/27 18:30:34

The producing of huge amount of deinking sludge is currently one of the important environmental problems faced by waste paper mills. The reasonable utilization of deinking sludge is an effective way to solve the current contradictions. The basic properties of deinking sludge， including the main components， metal ion content， and organic pollutants of deinking sludge produced from different pulping process using waste paper as raw material were summarized. Based on the relative research findings at home and abroad， the latest research progress and application prospect of resource utilization for deinking sludge in biochar， bio-oil， organic and inorganic substance recovery， composting and anaerobic digestion， nutrition substrate and biocomposite materials were reviewed as well.

Study on Polymeric Ionic Liquid Modified Waste Newspaper-based Cellulosic Aerogel and Its Dye Adsorption Performance

2022/9/27 18:30:25

In this study， the waste newspaper （WNP） was purified via ultrasonic deinking to obtain the deinked cellulose fiber which was then dissolved in alkaline solvent system and cross-linked to prepare regenerated cellulose aerogel （WNCA）. The poly（1-vinyl-3-butylimidazole bromide） brush modified cellulosic aerogel adsorbent （WNCA-g-PBVIMBr） was obtained by chemical grafting. The chemical structure and physical morphology of WNCA-g-PBVIMBr were studied， and the adsorption performance and mechanism towards acid orange II （AO II） were explored as well. The results showed that the PBVIMBr polymer brush with an average molecular weight of 3780 g/mol was uniformly grafted on the surface of WNCA， of which the maximum adsorption capacity towards AO II could reach 351 mg/g. The adsorption process conformed to the pseudo-second-order kinetic model and Langmuir adsorption isotherm model， indicating chemical adsorption played a key role in the adsorption process.

DCS Analysis in the Tissue Packaging Paper Manufacturing System Using Deinked Pulp

MIAO Qingxian,ZHANG Chen,GUO Xingji,HUANG Liulian,CHEN Lihui — 2022/9/27 18:30:33

The characterization analysis of dissolved and colloidal substances （DCS） existing in the tissue packaging paper manufacturing system using deinked pulp as raw material was conducted. The results showed that all the performance indicators of DCS in the bleached pulp were the highest compared with other deinked pulp samples， which was due to the alkaline peroxide bleaching extracting more DCS from the deinked pulp. All the performance indicators of DCS in the headbox ranked the first compared with other paper stocks located in different spots， which was ascribed to the circulation of white water. The main components of carbohydrates in DCS were sugars and aldehyde acids， while the methyl tert-butyl ether （MTBE） extractives mainly comprised different fatty acids， resin acids， glyceride， sterol ester， and lignin-degraded substances.

Study on Deinkability and Properties of Deinked Pulp of CaSiO₃-filled Paper

FAN Shujie,SU Zhenhua,ZHANG Yu — 2022/9/27 18:30:22

The deinking properties of two types of CaSiO₃-filled paper were discussed. The results showed that both CaSiO₃-filled paper （1^#） and CaSiO₃/talc-filled paper （2^#） had good deinking effect， with comparable flotation deinking yields. The brightness of 1^# flotation deinking pulp was 77.5% ISO， slightly higher than that of 2^# flotation deinking pulp， which was 73.9% ISO. The ERIC of 1^# flotation deinking pulp was 81.24 mm²/m²， slightly lower than that of 2^#flotation deinking pulp of 115.96 mm²/m². In the deinking process， the removal effect of stickies of 1^# pulp was slightly better than 2^# pulp. The stickies contents of both 1^#and 2^# pulp were low and would not affect the production. After flotation deinking， the fiber lengths of 1^# and 2^# repulping pulp decreased，while the content of fines increased. The decrease of fiber length of 1^# pulp was slightly more than that of the 2^# pulp. Due to the ash existing in the pulp， the intensity index of 1^# paper was slightly lower than those of the 2^# paper.

Study on the Synergistic Removal of Micro-stickies and Ca²⁺ from OCC Wastewater

LIU Hui,YANG Xiao,FU Wencai,DANG Wenhao,WANG Zhiwei — 2022/9/27 18:30:31

There are two problems in the reusing process of OCC papermaking wastewater， i.e.， the deposition of micro stickies and the calcification of anaerobic granular sludge caused by high Ca²⁺ concentration. The effects of electrocoagulation， physical， chemical， and biological enzymatic treatments towards OCC papermaking wastewater were compared in this study. The results showed that the electrocoagulation treatment could remove more micro-stickies and Ca²⁺ compared with other methods. The optimal conditions of electrocoagulation treatment were further explored： aluminum used as the anode， the current density， electrode distance， and reaction time were 115 A/m²， 5 cm， and 60 min， respectively. The relative contents of Al³⁺ and Ca²⁺ in flocs after electrocoagulation treatment （under the optimum conditions） were higher than those in the control group， indicating that the micro-stickies， COD， and Ca²⁺ in OCC wastewater were removed by electrocoagulation effectively， which is a green and non-pollutant process conforming to the requirements of sustainable development.

Phosphate Inhibition for Calcification of Anaerobic Granule Sludge in Waste Paper Pulping Wastewater

2022/9/27 18:30:21

The phosphate—the nutrient in wastewater treatment， was used to block calcification in this study. The ability of phosphate in lattice deformation and surface corrosion were explored and the feasibility of phosphate inhibition for calcification in anaerobic reactor was tested in industrial scale. The results showed that calcium retention rate in the anaerobic reactor can be reduced from 38% to <8% with the addition of phosphate into the pre-acidification tank. In this way， calcified sludge replacement and alkali-precipitation calcium removal which would cause production of unnecessary chemicals and destruction of sludge structure would be avoided by retrofitting the nutrient supply strategy in wastewater treatment. Therefore， the proposed phosphate inhibition for calcification would provide an eco-tech feasible solution for waste paper pulping enterprises.

Bibliometric-based Analysis of the Development and Research Focus in the Field of Recycled Fiber Pulping and Papermaking Technologies

ZHOU Zaifeng,ZHOU Qiuju,FAN Yongming — 2022/9/27 18:30:19

Using bibliometric methods and knowledge mapping tools such as VOSviewer and CiteSpace， taking Web of Science （WOS）（1946 to 2020） and CNKI （1973 to 2020） as data sources， this paper comprehensively analyzes the progresses， research hotspots， and development trends in the field of recycled fiber pulping and papermaking technology in China and in the Globe from the perspective of publishing years， geographical distribution， journals， high-yielding institutions， high-yielding authors， and research topics. The results show that， in recent years， pulping and papermaking technology related to the recycled fiber resources is entering a new development period. The relevant research is mainly in the United States， Germany， China， and Canada， etc. The research focus has gradually shifted from waste paper deinking and adhesive removal to the utilization of recycled fiber. In addition， due to environmental protection and the need to further the utilization of waste paper， fine fiber reclamation and wastewater treatment technology has become a new research hot spot.

Efficient Preparation of Activated Carbon with High Adsorption Capacity Using Lignin-Zn Complex from Black Liquor

WANG Lulu,WANG Guanhua,SUI Wenjie,SI Chuanling — 2023/6/20 0:00:00

Lignin-Zn complex isolated from black liquor by ZnCl₂ complexation was used as the carbon precursor to prepare activated carbon with high adsorption performance. The results showed that after ZnCl₂ complexation （0.5 mol/L ZnCl₂， 0.6 mL/mL black liquor）， 89.5% of lignin in black liquor was isolated accompanied with COD_Cr reduction of 72.4% and neutral pH value for the treated black liquor. Meanwhile， the metal complexation rendered Zn²⁺ distributing evenly in the lignin-Zn complex， facilitating the well-proportioned formation of porous structure during carbonization process. The activated carbon prepared from lignin-Zn complex had higher specific surface area and adsorption capacity， compared with the conventional process of acid-precipitated lignin by impregnation. Moreover， maximum equilibrium adsorption capacities of the as-prepared activated carbon were 1046.8 mg/g and 263.6 mg/g for cationic methylene blue and anionic methyl orange， respectively， which were higher than those absorbents prepared in previous reports.

Study on Preparation and Application of Flax Lignosulfonate-based Dye Dispersants

WANG Junhao,LI Jinsong,LI Hongyan,HOU Qingxi,LIU Wei — 2023/6/20 0:00:00

The dye dispersants were prepared by combining separation and purification and chemical modification using flax lignosulfonates as raw materials. Fourier transform infrared spectroscopy， ultraviolet spectrum， and particle size analysis were conducted to investigate the structure and stability of the dye dispersants. The as-prepared dye dispersants were added into disperse blue 79 and disperse red 73 to investigate the effects of different pretreatment methods and epichlorohydrin （ECH） dosage on properties of the dye dispersants. The results showed that ultrafiltration greatly improved the performance of the dye dispersants， endowing them with good dispersibility and thermostability. After ultrafiltration of flax lignosulfonates using ultrafiltration membrane with molecular weight of 1000， the resultant dye dispersants prepared with 3 mmol/g of ECH showed the best performance， with dye uptake in disperse blue 79 and disperse red 73 of 91% and 88%， and reduction hydrolysis rate of 15% and 11%， respectively.

Research Progress on Lignin Fractionation by Green Organic Solvent

LI Changgeng,JIN Huiqi,YANG Chenfeng,JIA Wenchao,SUN Yanning,SHI Haiqiang — 2023/6/20 0:00:00

Industrial alkali lignin and solvent-extracted lignin have the defects of complex structure and poor molecular weight homogeneity. The use of organic solvents such as ethanol， γ-valerolactone， ethyl acetate， and butanone to fractionate lignin is one of the effective ways to solve the abovementioned problems. In this review， the research progress of lignin fractionation methods using green organic solvent was briefly introduced. The fractionation methods， types of solvents used， and fractionation effects and its impact on lignin applications were analyzed. Current problems and shortcomings pertaining to lignin fractionation using organic solvents were proposed； future research directions and prospects of lignin fractionation using organic solvent were summarized and prospected. It's expected this review could provide references for the fractionation using green organic solvents and high-value application of lignin.

Research Progress in Lignin-based pH-Sensitive Smart Materials

JIN Jianhao,LI Wei,ZHENG Qian,ZHANG He,CHEN Xiaohong,SUN Runcang — 2023/6/20 0:00:00

Preparation of lignin-based smart materials to meet the increasing technological needs is a significant branch of the present lignin-related research. Among them， lignin-based pH-responsive smart materials have been rapidly developed in recent years， the structure， shape， or performance of which would vary as the pH value changes. This property renders lignin-based pH-responsive smart materials with potential application prospects in novel materials. This review summarizes the research process of lignin-based pH-sensitive smart materials in the fields of biomass refining， pharmaceuticals， actuators， and lignin fractionation， presents existing problems pertaining to its R & D and application， and prospects its future research and industrial applications.