Hanifzadeh Mohammadmatin, Nabati Zahra, Longka Pairote, Malakul Pomthong, Apul Defne, Kim Dong-Shik
Department of Chemical Engineering, The University of Toledo, OH 43606, USA.
The Petroleum and Petrochemical College, Chulalongkorn University, Bangkok 10330, Thailand.
J Environ Manage. 2017 Sep 1;199:83-90. doi: 10.1016/j.jenvman.2017.05.018. Epub 2017 May 17.
Common methods of managing dairy manure are directly applying it to the farm field as a fertilizer. For direct application without any type of treatment, the majority of nutrients in the manure run off to the local river and lake during precipitation periods. The algae bloom is one of the environmental outcomes due to eutrophication of the lakes, which may jeopardize the quality of drinking water. In this study, superheated steam drying (SSD) technology is investigated as an alternative manure management method. Rapidly dried cow manure can be used as alternative fuel. Evaluations of energy payback time (EPBT) and life cycle assessment (LCA) of the SSD technology are presented in the SSD scenario and the results are compared with those of the direct field application (FA) of fresh manure and anaerobic digestion (AD). The heat required for the generation of superheated steam in the SSD scenario is provided from combustion of the dry manure to reduce energy costs. The results for the SSD process show 95% and 70% lower eutrophication and global warming potential in comparison to the FA scenario. Acidification potential for SSD turned out to be 35% higher than FA. The comparison of SSD with AD for their EPBT and normalized impacts indicated that the proposed SSD scenario has higher environmental sustainability than AD (70% lower impact), and is likely an economically better choice compared to conventional AD method (87% lower EPBT) for the future investment.
处理奶牛粪便的常见方法是将其直接作为肥料施用于农田。对于未经任何处理的直接施用，粪便中的大部分养分在降雨期间会流入当地的河流和湖泊。藻类大量繁殖是湖泊富营养化导致的环境后果之一，这可能会危及饮用水质量。在本研究中，对过热蒸汽干燥（SSD）技术作为一种替代粪便管理方法进行了研究。快速干燥的牛粪可用作替代燃料。在SSD方案中给出了SSD技术的能源回收期（EPBT）和生命周期评估（LCA）的评估结果，并将结果与新鲜粪便直接田间施用（FA）和厌氧消化（AD）的结果进行了比较。SSD方案中产生过热蒸汽所需的热量由干粪便燃烧提供，以降低能源成本。SSD工艺的结果表明，与FA方案相比，富营养化和全球变暖潜力分别降低了95%和70%。SSD的酸化潜力比FA高35%。SSD与AD在EPBT和归一化影响方面的比较表明，所提出的SSD方案比AD具有更高的环境可持续性（影响降低70%），并且与传统AD方法相比，对于未来投资可能是一个经济上更好的选择（EPBT降低87%）。
