Galgani Pietro, van der Voet Ester, Korevaar Gijsbert
Department of Industrial Ecology, Institute of Environmental Sciences, Leiden University, Van Steenis gebouw, Einsteinweg 2, 2333CC Leiden, The Netherlands.
Department of Industrial Ecology, Institute of Environmental Sciences, Leiden University, Van Steenis gebouw, Einsteinweg 2, 2333CC Leiden, The Netherlands.
Waste Manag. 2014 Dec;34(12):2454-65. doi: 10.1016/j.wasman.2014.07.027. Epub 2014 Sep 6.
In some areas of Sub-Saharan Africa appropriate organic waste management technology could address development issues such as soil degradation, unemployment and energy scarcity, while at the same time reducing emissions of greenhouse gases. This paper investigates the role that carbon markets could have in facilitating the implementation of composting, anaerobic digestion and biochar production, in the city of Tamale, in the North of Ghana. Through a life cycle assessment of implementation scenarios for low-tech, small scale variants of the above mentioned three technologies, the potential contribution they could give to climate change mitigation was assessed. Furthermore an economic assessment was carried out to study their viability and the impact thereon of accessing carbon markets. It was found that substantial climate benefits can be achieved by avoiding landfilling of organic waste, producing electricity and substituting the use of chemical fertilizer. Biochar production could result in a net carbon sequestration. These technologies were however found not to be economically viable without external subsidies, and access to carbon markets at the considered carbon price of 7 EUR/ton of carbon would not change the situation significantly. Carbon markets could help the realization of the considered composting and anaerobic digestion systems only if the carbon price will rise above 75-84 EUR/t of carbon (respectively for anaerobic digestion and composting). Biochar production could achieve large climate benefits and, if approved as a land based climate mitigation mechanism in carbon markets, it would become economically viable at the lower carbon price of 30 EUR/t of carbon.
在撒哈拉以南非洲的一些地区，适当的有机废物管理技术可以解决诸如土壤退化、失业和能源短缺等发展问题，同时减少温室气体排放。本文研究了碳市场在促进加纳北部塔马利市堆肥、厌氧消化和生物炭生产实施方面可能发挥的作用。通过对上述三种技术的低技术、小规模变体实施情景的生命周期评估，评估了它们对缓解气候变化的潜在贡献。此外，还进行了经济评估，以研究它们的可行性以及进入碳市场对其产生的影响。研究发现，通过避免有机废物填埋、发电和替代化肥使用，可以实现显著的气候效益。生物炭生产可以实现净碳固存。然而，发现如果没有外部补贴，这些技术在经济上不可行，以7欧元/吨碳的考虑碳价格进入碳市场不会显著改变这种情况。只有当碳价格升至75 - 8欧元/吨碳以上（分别针对厌氧消化和堆肥）时，碳市场才能帮助实现所考虑的堆肥和厌氧消化系统。生物炭生产可以实现巨大的气候效益，如果在碳市场上被批准为基于土地的气候缓解机制，它将在30欧元/吨碳的较低碳价格下在经济上可行。
