| 1. |
- Chen, Fangjun, et al.
(författare)
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Comprehensive kinetic modeling and product distribution for pyrolysis of pulp and paper mill sludge
- 2024
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Ingår i: Science of the Total Environment. - 0048-9697 .- 1879-1026. ; 924
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Tidskriftsartikel (refereegranskat)abstract
- Pyrolysis holds immense potential for clean treatment of pulp and paper mill sludge (PPMS), enabling efficient energy and chemical recovery. However, current understanding of PPMS pyrolysis kinetics and product characteristics remains incomplete. This study conducted detailed modeling of pyrolysis kinetics for two typical PPMSs from a wastepaper pulp and paper mill, namely, deinking sludge (PPMS-DS) and sewage sludge (PPMS-SS), and analyzed comprehensively pyrolysis products. The results show that apparent activation energy of PPMS-DS (169.25–226.82 kJ/mol) and PPMS-SS (189.29–411.21 kJ/mol) pyrolysis undergoes significant change, with numerous parallel reactions present. A distributed activation energy model with dual logistic distributions proves to be suitable for modeling thermal decomposition kinetics of both PPMS-DS and PPMS-SS, with coefficient of determination >0.999 and relative root mean square error <1.99 %. High temperature promotes decomposition of solid organic materials in PPMS, and maximum tar yield for both PPMS-DS (53.90 wt%, daf) and PPMS-SS (56.48 wt%, daf) is achieved at around 500 °C. Higher levels of styrene (24.45 % for PPMS-DS and 14.71 % for PPMS-SS) and ethylbenzene (8.61 % for PPMS-DS and 8.33 % for PPMS-SS) are detected in tar and could be used as chemicals. This work shows great potential to propel development of PPMS pyrolysis technology, enabling green and sustainable production in pulp and paper industry.
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| 2. |
- Ren, Guanlong, et al.
(författare)
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CFD investigation of structural effects of internal gas intake on powder conveying performance in fuel supply systems for aerospace engines
- 2024
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Ingår i: Particuology. - 2210-4291 .- 1674-2001. ; 92, s. 140-154
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Tidskriftsartikel (refereegranskat)abstract
- Optimal design of gas intake in powder fuel supply systems is crucial for performance of aerospace engines. There is little research on the impact of intake structure on powder conveying performance. Three novel internal intakes were proposed, which are spherical, cube-shaped, and dome-shaped. After validation, CFD simulations demonstrate that fluctuation of mass flow rate of powders in the dome-shaped intake is reduced by about 73.3% compared with the annular external one. Variation trends of phase velocities are similar for the spherical and cube-shaped intakes, while those are similar for the annular external and dome-shaped internal intakes. Fluctuation of area of gas zone for the annular external and spherical internal intakes is larger than that for the cube-shaped and dome-shaped internal intakes. Pressure and relative pressure drop in the fluidization chamber have a stable stage, and fluctuation of relative pressure drop is small when dome-shaped internal intake is used.
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