Co-pyrolysis of food waste and wood bark to produce hydrogen with minimizing pollutant emissions

• Published in: Environmental pollution (1987) 2021-02, Vol.270, p.116045, Article 116045
• Main Authors: Park, Chanyeong, Lee, Nahyeon, Kim, Jisu, Lee, Jechan
• Format: Article
• Language: English
• Subjects: Biomass; Co-pyrolysis; Environmental Pollutants; Food; Food waste; Hot Temperature; Hydrogen; Lignocellulosic biomass; Plant Bark; Pyrolysis; Refuse Disposal; Waste valorization; Waste-to-energy; Wood
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2020.116045

In this study, the co-pyrolysis of food waste with lignocellulosic biomass (wood bark) in a continuous-flow pyrolysis reactor was considered as an effective strategy for the clean disposal and value-added utilization of the biowaste. To achieve this aim, the effects of major co-pyrolysis parameters such as pyrolysis temperature, the flow rate of the pyrolysis medium (nitrogen (N2) gas), and the blending ratio of food waste/wood bark on the yields, compositions, and properties of three-phase pyrolytic products (i.e., non-condensable gases, condensable compounds, and char) were investigated. The temperature and the food waste/wood bark ratio were found to affect the pyrolytic product yields, while the N2 flow rate did not. More non-condensable gases and less char were produced at higher temperatures. For example, as the temperature was increased from 300 °C to 700 °C, the yield of non-condensable gases increased from 6.3 to 17.5 wt%, while the yield of char decreased from 63.6 to 30.6 wt% for the co-pyrolysis of food waste and wood bark at a weight ratio of 1:1. Both the highest yield of hydrogen (H2) gas and the most significant suppression of the formation of phenolic and polycyclic aromatic hydrocarbon (PAH) compounds were achieved with a combination of food waste and wood bark at a weight ratio of 1:1 at 700 °C. The results suggest that the synergetic effect of food waste and lignocellulosic biomass during co-pyrolysis can be exploited to increase the H2 yield while limiting the formation of phenolic compounds and PAH derivatives. This study has also proven the effectiveness of co-pyrolysis as a process for the valorization of biowaste that is produced by agriculture, forestry, and the food industry, while reducing the formation of harmful chemicals. [Display omitted] •Co-pyrolysis of food waste (FW) and wood bark (WB) was performed.•Effects of various parameters on the pyrolytic products obtained were studied.•Systematic study characterized the three-phase pyrolytic products in detail.•Temperature and FW/WB ratio affected co-pyrolytic products (quality and quantity).•Co-pyrolysis (FW:WB, 1:1) increased H2 yield with minimal phenol and PAH formation. Co-pyrolysis of food waste and lignocellulosic biomass at an appropriate ratio enhances H2 production while minimizing the formation of harmful pollutants.