| dc.description.abstract | This research investigates that automobile shredder residue (ASR) and paper mill sludge converted into energy by co gasification with controlling at equilibrium ratio (ER), temperature (700 ℃), and ASR amended ratio (0%~15%) in lab scale and full scale gasifier. The producer gas composition, product distribution, energy yield efficiency, pollutants (heavy metal and chlorine) partitioning characterization, and dioxin characteristics analysis were all evaluated.
In the case of co gasification of 10% ASR mixed paper mill sludge, the H2 and CO composition were 4.91 vol.% and 2.06 vol.%, respectively. With 15 %ASR amended ratio, the H2 and CO composition were varied to 4.80 vol.% and 2.62 vol.%, respectively. The average heat value of syngas increased from 1.93 MJ/Nm3 to 2.50 MJ/Nm3 with an increase in ASR addition from 10% to 15% as well as the cold gas efficiency (CGE) increased from 22.67 % to 37.81 %.Based on energy conversion results,increasing the ASR amended ratio, it could enhance the energy yield efficiency in co-gasification of ASR and paper mill sludge.According to the a full scale gasifier, the H2 and CH4 production were increased from 2.99 vol.% to 3.45 vol.% and from 1.79 vol.% to 2.10 vol.% with an increase in ASR addition ratio from 5 % to 15 %, respectively. The heating value of gas production was increased from 1.64 MJ/Nm3 to 1.83 MJ/Nm3 with ASR addition ratio increasing from 5 % to 15 %. Cold gas efficiency (CGE) was also increased from 0.17 % to 0.29 % with an increase in ASR addition ratio. By increasing ASR addition ratio, it could enhance the heating value in co-gasification, especially for 10% ASR addition ratio. The average heating value of gas production was 1.83 MJ/Nm3 and the CGE was 0.29 %.
The heavy metal partitioning characteristics results indicated that Cu, Zn and Cr were mainly partitioned in residue phase during the lab-scale and full-scale gasification. The Cu, Zn and Cr partitioning percentages of residue phase were increased with increasing ASR amended ratio. On the other hand, the.low volatility heavy metals, such as Cu and Cr. Cu and Cr were mainly partitioned in residue phase and were approximately 98 % and above.
According to the results of the chlorine emission characteristics, in the case of without ASR addition ratio, the chlorine partitioned in the solid phase and liquid phase were 85.61 % and 14.39 %, respectively. However, in the case of 10% ASR addition amended ratio, the chlorine in the solid phase and liquid phase were decreased to 57.55 % and 32.12 %, respectively. Meanwhile, the chlorine partitoned in the gas phase was significantly increased from N.D to 10.33 % with an increase in ASR addition ratio. This was because increasing ASR addition ratio resulted in the paper mill sludge containing calcium content decreased. In case of the full-scale test, the chlorine were approximately 98 % partitioned in solid.
According to analysis results of dioxin equivalence concentration of produced gas, the dioxin concentration of syngas was 6.129 ng-TEQ /Nm3 in the gasifier that had high concentration than other facilities. After air pollution control devices (APCDs), the dioxin equivalence concentration of the flue gas sampled from combustion furnace and stack were all in compliance with regulatory thresholds (0.5 ng-TEQ/Nm3). Therefore, the feasibility of co-gasified ASR and paper mill sludge was proved by full scale plant,.
In summary, the research has proved the ASR could co-gasify paper mill sludge. It could enhance the energy conversion from co-gasification, but also could reduce air pollutants emission during co-gasification process. Therefore, the results of this study could provide the helpful information for the selection of ASR energy conversion technologies and control strategies of pollutants emission in the future.
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