Norwegian Geotechnical Institute (NGI) , Oslo NO-0806, Norway.
Environ Sci Technol. 2014 May 6;48(9):4664-71. doi: 10.1021/es405190q. Epub 2014 Apr 10.
Biochar is the product of incomplete combustion (pyrolysis) of organic material. In rural areas, it can be used as a soil amendment to increase soil fertility. Fuel-constrained villagers may however prefer to use biochar briquettes as a higher-value fuel for cooking over applying it to soils. A systems-oriented analysis using life cycle assessment (LCA) and cost benefit analysis (CBA) was conducted to analyze these two alternative uses of biochar, applying the study to a rural village system in Indonesia. The results showed soil amendment for enhanced agricultural production to be the preferential choice with a positive benefit to the baseline scenario of -26 ecopoints (LCA) and -173 USD (CBA) annually pr. household. In this case, the positive effects of carbon sequestration to the soil and the economic value of the increased agricultural production outweighed the negative environmental impacts from biochar production and the related production costs. Use of biochar in briquettes for cooking fuel yielded negative net effects in both the LCA and CBA (85 ecopoints and 176 USD), even when positive health effects from reduced indoor air pollution were included. The main reasons for this are that emissions during biochar production are not compensated by carbon sequestration and that briquette making is labor-intensive. The results emphasize the importance of investigating and documenting the carbon storage effect and the agricultural benefit in biochar production-utilization systems for a sustainable use. Further research focus on efficient production is necessary due to the large environmental impact of biochar production. In addition, biochar should continue to be used in those soils where the agricultural effect is most beneficial.
生物炭是有机物质不完全燃烧（热解）的产物。在农村地区，它可用作土壤改良剂，以提高土壤肥力。然而，燃料受限的村民可能更愿意将生物炭制成棒状燃料用于烹饪，而不是将其应用于土壤。本研究采用生命周期评价（LCA）和成本效益分析（CBA）进行了系统分析，以分析生物炭的这两种替代用途，将研究应用于印度尼西亚的一个农村村庄系统。结果表明，为提高农业生产而进行土壤改良是首选，与基线情景相比每年每户可带来-26 个生态点（LCA）和-173 美元（CBA）的积极效益。在这种情况下，生物炭对土壤的固碳效应和增加农业生产的经济价值超过了生物炭生产的负面环境影响和相关生产成本。将生物炭用于制造棒状燃料作为烹饪燃料在 LCA 和 CBA 中都产生了负面的净影响（分别为 85 个生态点和 176 美元），即使考虑到减少室内空气污染带来的积极健康影响也是如此。主要原因是生物炭生产过程中的排放没有被碳封存所补偿，而且制造棒状燃料需要大量劳动力。研究结果强调了在生物炭生产-利用系统中调查和记录碳储存效应和农业效益的重要性，以实现可持续利用。由于生物炭生产的环境影响较大，因此需要进一步研究如何提高生产效率。此外，应继续将生物炭用于农业效益最大的土壤中。
