基于国际碳足迹标准的中国人造板产业碳减排路径研究

Study on carbon emission reduction path of China's wood-based panel industry based on international carbon footprint standards

基于生命周期分析的碳足迹评估,量化产品从原材料获取到最终处理各个阶段的温室气体排放,已在多个产业和产品间得到应用和实践。碳足迹评估的标准化对碳足迹核算提出指导,减排承诺背景下林产品兼具碳储减排和替代减排的双重效益,规范和统一其碳足迹评估标准并挖掘减排潜力,对于统一中国产业间的碳足迹评估有借鉴意义。本文聚焦国际主流且关联度较高的产品碳足迹核算标准(PAS 2050和GHG Protocol),以在中国人造板产业占支柱地位的胶合板为研究对象,量化国际碳足迹标准方法学的差异性。具体涉及系统界限、取舍原则、分配方法、碳储存及其延迟排放等。为综合分析国际碳足迹标准的适用性,通过"摇篮到大门"和"摇篮到坟墓"系统模型进行评价。结果表明:①PAS 2050和GHG Protocol对中国胶合板产业的碳足迹核算,结果分别为-1 123. 46 kg CO_2e和-1 117. 63 kg CO_2e,在应对气候减排的背景下,PAS 2050标准的应用对胶合板生产企业承受的减排压力较小。②PAS 2050对评估实质的环境影响提供了具体的指导,尤其是对区别于石化产品的林产品碳储功能,PAS 2050提供了测算延迟排放的具体方法,从产品生产企业和政策制定的视角,PAS 2050对胶合板的碳足迹核算也更具普适性。国际碳足迹标准对中国人造板产业的碳减排提供了可供借鉴的改进路径:①气候减排能力发掘。产品的填埋处理相对燃烧处理可实现549. 32%的减排效果。②能源结构调整。现场生产阶段采用木质生物质能源替代化石能源可显著减少36. 99%～38. 24%的温室气体排放。③产业链优化。木质原料获取端应推进林板一体化战略,废旧产品处理端应加快产品回收利用及政策设计。④市场结构调整。林木资源稀缺,胶合板面临被定向刨花板等对木质原材料要求较低的新型木质复合材料替代的趋势,人造板产业结构的升级亟待完善。

Based on the life cycle assessment( LCA),carbon footprint( CF),being a quantitative expression of greenhouse gas( GHG) emissions from raw material extraction to the end-of-life treatment has been widely used in many industries and products. The standardization provides guidance for carbon footprint accounting. Forest products have dual benefits of carbon storage and substitution effects in climate change mitigation. Owing to China’s commitment to reduce greenhouse gas emissions,unifying the carbon footprint standards and identifying the potentials of emission reduction of forest products are of great significance to the whole industrial sector.This study focused on the two international leading product carbon footprint standards( PAS 2050 and GHG Protocol),which are highly relevant to each other. A case study was performed in plywood industry which is the pillar of China’s wood-based panel industry according to the analyzed standards. The first aim was to quantify the differences in methodological issues including the treatment of system boundaries,cut-off criteria,allocation rules,carbon storage and its delayed emissions. Both cradle-to-gate and cradle-to-grave models were developed to enable a more comprehensive assessment. The obtained carbon footprint of plywood was-1 123. 46 kg CO2 e and-1 117. 63 kg CO2 e,respectively,with the PAS 2050 and GHG Protocol. Under the background of emission reduction,the application of PAS 2050 allows plywood manufactures to bear less pressure on reducing emissions. Besides,PAS 2050 provides more specific guidance for assessing the actual environmental impacts. In particular,PAS 2050 provides a method for measuring the delayed emissions of carbon storage. Therefore,both from the perspective of product manufactures and policy makers,PAS 2050 is more preferable for plywood industry. Another purpose of this study was to put forward an improved path for China’s wood-based panel industry: ①climate change mitigation capacity: landfill can achieve 549. 32% of total emission reduction compared with combustion.②Energy structure adjustment: by substituting fossil fuels with wood biomass energy,greenhouse gas emissions can be reduced by36. 99% ~ 38. 24% and the energy consumption structure for the on-site manufacturing can be improved. ③ Industrial chain optimization: the strategy of forest-panel integration should be promoted to reduce emissions from the acquisition of wood raw materials,and the pace of recycling and reuse should be speed up to achieve emission reduction from the disposal of waste products. ④Market structure adjustment: plywood has been replaced by other wood composite materials like orientated particleboard,which requires less wood raw materials,due to the scarcity of forest resources. There is an urgent need to upgrade the market structure of China’s woodbased panel industry.