Accepted Manuscript Investigation on thermochemical behavior of co-pyrolysis between oil-palm solid wastes and paper sludge Yousheng Lin, Xiaoqian Ma, Zhaosheng Yu, Yawen Cao PII: DOI: Reference:

S0960-8524(14)00809-8 http://dx.doi.org/10.1016/j.biortech.2014.05.101 BITE 13509

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Bioresource Technology

Received Date: Revised Date: Accepted Date:

22 April 2014 22 May 2014 23 May 2014

Please cite this article as: Lin, Y., Ma, X., Yu, Z., Cao, Y., Investigation on thermochemical behavior of co-pyrolysis between oil-palm solid wastes and paper sludge, Bioresource Technology (2014), doi: http://dx.doi.org/10.1016/ j.biortech.2014.05.101

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Investigation on thermochemical behavior of co-pyrolysis between oil-palm solid wastes and paper sludge Yousheng Lin, Xiaoqian Ma*, Zhaosheng Yu, Yawen Cao School of Electric Power, South China University of Technology, Guangzhou 510640, China Postal address: School of Electric Power, South China University of Technology, No. 381, Wushan Road, Tianhe District, Guangzhou, 510640, China *Corresponding author Tel.: +86 20 87110232; fax: +86 20 87110613. E-mail address: [email protected] Abstract: :The pyrolysis characteristics of oil-palm solid wastes, paper sludge and their blends were studied via thermogravimetric analysis. Blends ranging from 10wt.% to 90wt.% on dosage ratio were prepared to investigate their co-pyrolysis behavior and kinetics. There was a synergistic interaction at low temperature during co-pyrolysis between oil-palm solid wastes and paper sludge. The synergistic interaction would improve thermochemical pyrolysis reactivity of the blends, which could be attributed to the hydrogenation role and the potential mineral catalytic effects on paper sludge pyrolysis. The value of average activation energy obtained by Starink and Friedmen methods did not gradually decline with the increasing proportion of oil-palm solid wastes in the blends. The lowest average activation energy was achieved when the percentage of oil-palm solid wastes was 70%, which was 152kJ/mol by Starink and 149kJ/mol by Friedmen, respectively.

Keywords : Co-pyrolysis; oil-palm solid wastes; paper sludge; thermogravimetric analysis; kinetics 1. Introduction Energy shortage is increasingly becoming the bottleneck which restricts the economic development in many countries. To deal with the energy crisis, modern industries promoted the development and utilization of renewable energy such as solar energy, biomass energy and wind energy. Oil palm biomass was employed as major alternative source for renewable energy because of its abundant and renewable supply (Idris et al., 2010). Meanwhile, approximately 154.2 megatons annually worldwide of oil-palm solid wastes (including empty fruit bunches, kernel shell and palm fibre) were produced during palm oil milling process (Luangkiattikhun et al., 2008). According to (Yusoff, 2006), agriculture solid biomass residues from oil palm industries consist of 22% empty fruit bunches, 13.5% palm fibre and 5.5% kernel shell. About 80% of these solid wastes are incinerated directly or processed into the activated carbon and fiber products while the rest 20% are abandoned casually (Luangkiattikhun et al., 2008). However, low energy efficiency of these processes leads to high emission of dust and CO2, which contributed to environmental pollution and global warming. Therefore, if these oil-palm solid wastes are used as a potential bioenergy, not only could the energy dependence on fossil fuels be weakened, but also environmental pollution lessens (Lu et al., 2013). The co-utilization technology of wastes and solid fuels such as coal, sludge and

MSW, is an interesting disposal way to solve these problems. Recently, a number of investigations have reported synergetic effects on co-processing of solid fuels and biomass, in particular co-combustion and co-pyrolysis(Çepelioğullar & Pütün, 2013; Ding & Jiang, 2013; Idris et al., 2010; Kılıç et al., 2014; Masnadi et al., 2014; Yin et al., 2010). Idris et al. (2012) reported blending oil palm biomass wastes with coal could reduce the apparent activation during co-combustion process. Parshetti et al. (2014) observed that co-combustion of oil palm biomass wastes and coal significantly reduced the level of gaseous pollutant emissions detected by TGA-FTIR. Shuang-quan et al. (2009) found that there existed a synergistic effect between sludge and rice straw in co-pyrolysis process. Ding & Jiang. (2013) studied the co-pyrolysis of excessively activated sludge with waste biomass, the results suggested that it was feasible to reduce sludge without external energy supply. The above findings revealed that co-pyrolysis is a promising, economic and environmental friendly technology for both energy production and waste remediation. Co-pyrolysis technology is a relatively new area, and it can be applied to any type of fuel in principle. In China, the pyrolysis is currently one of the most efficient treatments because of its validity for disposal volume reduction and complete destruction of pathogen agents (Ji et al., 2010; Zhang et al., 2014). However, co-pyrolysis technology of paper sludge with biomass wastes may have more advantages than the sole pyrolysis of the paper sludge, considering their low calorific value, high moisture content, high ash content and high density (Ding & Jiang, 2013).

Due to the structural differences, the pyrolysis characteristics of oil-palm solid wastes are completely different from paper sludge, so the adjunction of biomass wastes into paper sludge may affect the whole pyrolysis process. Since the co-pyrolysis technology is still in development, and most of the current investigations are focusing on the co-pyrolysis of oil-palm solid wastes and coal or sludge and coal, co-pyrolysis behavior between oil-palm solid wastes and paper sludge has seldom been investigated. As a potential energy method with high utilization value, further understanding about co-pyrolysis of oil-palm solid wastes and paper sludge, chemical reaction kinetics as well as the interaction between the constituents, for instance, is of paramount importance. Therefore, the driving force of this work is to research the co-pyrolysis thermal behavior of oil-palm solid wastes, paper sludge and their respective blends under N2 atmosphere at different heating rates via thermogravimetric analyzer. Two non-isothermal thermogravimetric methods -- Starink method and Friedmen method were used to obtain the apparent activation energy. The results could provide a detailed observation on co-pyrolysis process of oil-palm solid wastes/paper sludge blends, thus offering referential information for designing and optimizing the co-pyrolysis technology for these blends. 2. Methods 2.1 Materials and experimental facility The oil-palm solid wastes (OSW) and paper sludge (PS) investigated in this study were collected from Zhanjiang oil palm plantation and Jiangmen paper Mill

(Guangdong Province, China), respectively. After air-dried at 105 ºC for 24h, the samples were crushed and sieved to the desired particle size (

Investigation on thermochemical behavior of co-pyrolysis between oil-palm solid wastes and paper sludge.

The pyrolysis characteristics of oil-palm solid wastes, paper sludge and their blends were studied via thermogravimetric analysis. Blends ranging from...
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