Energy recovery from secondary pulp/paper-mill sludge and sewage sludge with supercritical water treatment☆

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.

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Experimental Study on Supercritical Water Oxidation of Paper Mill Sludge

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.955-959.711 ◽

2014 ◽

Vol 955-959 ◽

pp. 711-715 ◽

Cited By ~ 1

Author(s):

Li Li Qian ◽

Shu Zhong Wang ◽

Jie Zhang

Keyword(s):

Supercritical Water ◽

Water Oxidation ◽

Paper Industry ◽

Paper Mill ◽

National Standards ◽

Supercritical Water Oxidation ◽

Paper Mill Sludge ◽

Temperature Oxidation ◽

Liquid Products ◽

Transparent Liquid

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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NOx and N2O Emission Characteristics From Circulation Fluidized Bed Combustion of Blends of Paper Mill Sludge and Coal

18th International Conference on Fluidized Bed Combustion ◽

10.1115/fbc2005-78032 ◽

2005 ◽

Author(s):

Xiao-Ping Chen ◽

Li-Feng Gu ◽

Chang-Sui Zhao ◽

Ai-Qiang Zhu ◽

Xin Sun

Keyword(s):

Sewage Sludge ◽

Fluidized Bed ◽

Paper Mill ◽

N2o Emission ◽

Municipal Sewage ◽

Municipal Sewage Sludge ◽

Emission Characteristics ◽

Fluidized Bed Combustion ◽

Paper Mill Sludge ◽

Excess Air

With the rapid economic development and the increase in population in the whole world, the amount of municipal sewage (MS) is increasing and lead to a rapid increasing in amount of municipal sewage sludge (MSS). Combustion of municipal sewage sludge may be a viable solution for its disposal in some cases and so is its co-combustion with coal. Whereas significant information is available on NOx and N2O emissions characteristics of sludge and coal individually, not much has been reported on sludge/coal blends. In the present paper, investigations in NOx and N2O emission characteristics from circulation fluidized bed combustion of blends of municipal sewage sludge and coal were conducted in a 0.2MWth circulating fluidized bed test facility with cross section of 0.23×0.23m2 and height of 5.9m. Coal sample selected was a kind of lignite, while a kind of paper mill sludge was used as sludge sample. The influences of sludge/coal mixing rate, excess air ratio and second air ratio on NOx and N2O emission characteristics have been studied. Test results show that co-combustion of sewage sludge and coal is feasible. With the increasing in proportion of sludge of the sludge/coal blends, the temperatures in dense bed and freeboard decrease rapidly, and the emissions of NOx decrease while the emission of N2O increases obviously. With the increasing in excess air ratio, the emission concentrations of NOx and N2O increase. While with the increasing in secondary air ratio, the emission concentrations of NOx and N2O decrease.

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