scholarly journals Paper Mill Sludge as a Source of Sugars for Use in the Production of Bioethanol and Isoprene

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4662
Author(s):  
Shona M. Duncan ◽  
Malek Alkasrawi ◽  
Raghu Gurram ◽  
Fares Almomani ◽  
Amy E Wiberley-Bradford ◽  
...  

Paper mill sludge (PMS) solids are predominantly comprised of cellulosic fibers and fillers rejected during the pulping or paper making process. Most sludges are dewatered and discharged into landfills or land spread at a cost to the mill; creating large economic and environmental burdens. This lignocellulosic residual stream can be used as a source of sugars for microbial fermentation to renewable chemicals. The aim of this study was to determine the possibility of converting mill sludge to sugars and then fermentation to either isoprene or ethanol. Chemical analysis indicated that the cellulosic fiber composition between 28 to 68% and hemicellulose content ranged from 8.4 to 10.7%. Calcium carbonate concentration in the sludge ranged from 0.4 to 34%. Sludge samples were enzyme hydrolyzed to convert cellulose fibers to glucose, percent conversion ranged from 10.5 to 98%. Calcium carbonate present with the sludge resulted in low hydrolysis rates; washing of sludge with hydrochloric acid to neutralize the calcium carbonate, increased hydrolysis rates by 50 to 88%. The production of isoprene “very low” (190 to 470 nmol) because the isoprene yields were little. Using an industrial yeast strain for fermentation of the sludge sugars obtained from all sludge samples, the maximum conversion efficiency was achieved with productivity ranging from 0.18 to 1.64 g L−1 h−1. Our data demonstrates that PMS can be converted into sugars that can be fermented to renewable chemicals for industry.

Author(s):  
Zhiyong Xu ◽  
Yunqin Lin ◽  
Yuejin Lin ◽  
De Yang ◽  
Haomin Zheng

Energy ◽  
2022 ◽  
Vol 239 ◽  
pp. 121925
Author(s):  
Zhongzhe Liu ◽  
Matthew Hughes ◽  
Yiran Tong ◽  
Jizhi Zhou ◽  
William Kreutter ◽  
...  

1982 ◽  
Vol 108 (1) ◽  
pp. 1-15
Author(s):  
Orlando B. Andersland ◽  
Abdul-Amir W.N. Al-Khafaji ◽  
Richard K. Lowe
Keyword(s):  

2014 ◽  
Vol 40 (1) ◽  
pp. 33-40
Author(s):  
Nurdan Aycan ◽  
Nurdan Gamze Turan

Abstract The effects of different volumetric ratios of bulking agents to pulp/paper-mill sludge on composting were studied. Rice husk and corncob were used as bulking agents. Volumetric ratios of bulking agents to pulp/paper-mill sludge were used as 10:100 and 25:100. To monitor the evolution of the composting systems, routine parameters such as temperature, moisture, pH, total N, NH4 +-N, NO3 --N, total C, and C/N ratio were analyzed. The results indicated that the agro-based materials significantly affected compost maturity parameters. Moreover, the quality of the product obtained in the composting process treated with the agro-based materials achieved satisfactory stabilization and sanitation for application to land.


2014 ◽  
Vol 955-959 ◽  
pp. 711-715 ◽  
Author(s):  
Li Li Qian ◽  
Shu Zhong Wang ◽  
Jie Zhang

Paper industry produces large amounts of sludge with about 65wt% moisture content. Due to its complex composition, the charge of traditional disposal method is high and easy to bring about secondary pollution. In this paper, the influences of temperature, oxidation coefficient and residence time on the performance of supercritical water oxidation (SCWO) of paper mill sludge were investigated. The results show that SCWO can almost completely eliminate organics in sludge and obtain transparent liquid products meeting relative national standards at 550°C, 5min with an oxidation coefficient of 3.0. However, during this process, TN changes to NH3-N, so NH3-N in liquid products increases with operation parameters, indicating the recalcitrant nature of NH3-N, and which needs further treatment.


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