Sørmo Erlend, Krahn Katinka M, Flatabø Gudny Øyre, Hartnik Thomas, Arp Hans Peter H, Cornelissen Gerard
Norwegian Geotechnical Institute (NGI), 0484 Oslo, Norway; Norwegian University of Life Sciences (NMBU), 1430 Ås, Norway.
Lindum AS, 3036 Drammen, Norway.
J Hazard Mater. 2024 Jan 5;461:132546. doi: 10.1016/j.jhazmat.2023.132546. Epub 2023 Sep 12.
Biomass pyrolysis is the anoxic thermal conversion of biomass into a carbon rich, porous solid, often called biochar. This could be a better waste management alternative for contaminated organic wastes than incineration, due to the useful properties of biochar and potential for carbon sequestration. There are, however, concerns about the potential formation/destruction of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs). Six organic wastes, including digested sewage sludges, wood wastes, and food waste reject, were pyrolyzed (500-800°C) in a full-scale relevant unit (1-5 kg biochar hr). Removal efficiencies for PCBs and PCDD/Fs were > 99% in the produced biochars. Biochar PAH-content (2.7-118 mgkg) was not significantly correlated to feedstock or temperature. PAHs (2563-8285 mgkg), PCBs (22-113 µgkg), and PCDD/Fs (1.8-50 ngTEQ kg) accumulated in the pyrolysis condensate, making this a hazardous waste best handled as a fuel for high temperature combustion. Emission concentrations for PAHs (0.22-421 µgNm) and PCDD/Fs (≤2.7 pgTEQ Nm) were mainly associated with particles and were below the European Union's waste incineration thresholds. Emission factors ranged from 0.0002 to 78 mg tonne biochar for PAHs and 0.002-0.45 µgTEQ tonne biochar for PCDD/Fs. PCDD/F-formation was negligible during high temperature (≥500 °C) biomass pyrolysis (69-90% net loss).
生物质热解是指生物质在缺氧条件下热转化为富含碳的多孔固体，通常称为生物炭。由于生物炭具有有用的特性以及碳固存潜力，对于受污染的有机废物而言，这可能是比焚烧更好的废物管理替代方案。然而，人们担心多环芳烃（PAHs）、多氯联苯（PCBs）以及多氯二苯并对二恶英和呋喃（PCDD/Fs）可能会形成或被破坏。六种有机废物，包括消化后的污水污泥、木材废料和食品垃圾残渣，在一个全尺寸相关装置（每小时生产1 - 5千克生物炭）中进行热解（500 - 800°C）。所产生的生物炭中多氯联苯和多氯二苯并对二恶英和呋喃的去除效率> 99%。生物炭中的多环芳烃含量（2.7 - 118毫克/千克）与原料或温度没有显著相关性。多环芳烃（2563 - 8285毫克/千克）、多氯联苯（22 - 113微克/千克）和多氯二苯并对二恶英和呋喃（1.8 - 50纳克毒性当量/千克）在热解冷凝物中积累，这使得热解冷凝物成为一种危险废物，最好作为高温燃烧的燃料来处理。多环芳烃（0.22 - 421微克/标准立方米）和多氯二苯并对二恶英和呋喃（≤2.7皮克毒性当量/标准立方米）的排放浓度主要与颗粒物有关，并且低于欧盟的废物焚烧阈值。多环芳烃的排放因子范围为0.0002至78毫克/吨生物炭，多氯二苯并对二恶英和呋喃的排放因子范围为0.002至0.45微克毒性当量/吨生物炭。在高温（≥500°C）生物质热解过程中，多氯二苯并对二恶英和呋喃的形成可以忽略不计（净损失69 - 90%）。
