†Division of Environmental Systems Analysis, Department of Energy and Environment, Chalmers University of Technology, Rännvägen 6, SE 412 96 Gothenburg, Sweden.
‡Chemical Environmental Science, Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Kemivägen 4, SE 412 96 Gothenburg, Sweden.
Environ Sci Technol. 2015 Jun 2;49(11):6881-90. doi: 10.1021/acs.est.5b00888. Epub 2015 May 15.
Nanocellulose is a bionanomaterial with many promising applications, but high energy use in production has been described as a potential obstacle for future use. In fact, life cycle assessment studies have indicated high life cycle energy use for nanocellulose. In this study, we assess the cradle-to-gate environmental impacts of three production routes for a particular type of nanocellulose called cellulose nanofibrils (CNF) made from wood pulp. The three production routes are (1) the enzymatic production route, which includes an enzymatic pretreatment, (2) the carboxymethylation route, which includes a carboxymethylation pretreatment, and (3) one route without pretreatment, here called the no pretreatment route. The results show that CNF produced via the carboxymethylation route clearly has the highest environmental impacts due to large use of solvents made from crude oil. The enzymatic and no pretreatment routes both have lower environmental impacts, of similar magnitude. A sensitivity analysis showed that the no pretreatment route was sensitive to the electricity mix, and the carboxymethylation route to solvent recovery. When comparing the results to those of other carbon nanomaterials, it was shown that in particular CNF produced via the enzymatic and no pretreatment routes had comparatively low environmental impacts.
纳米纤维素是一种具有许多有前途应用的生物纳米材料，但生产过程中的高能耗被描述为未来应用的潜在障碍。事实上，生命周期评估研究表明，纳米纤维素的生命周期能耗很高。在这项研究中，我们评估了三种生产途径的从摇篮到大门的环境影响，这三种生产途径用于生产一种特殊类型的纳米纤维素，称为纤维素纳米纤维（CNF），由木浆制成。这三种生产途径是：（1）酶法生产途径，包括酶预处理，（2）羧甲基化途径，包括羧甲基化预处理，（3）一种无预处理途径，这里称为无预处理途径。结果表明，由于大量使用来自原油的溶剂，通过羧甲基化途径生产的 CNF 显然具有最高的环境影响。酶法和无预处理途径的环境影响都较低，程度相似。敏感性分析表明，无预处理途径对电力组合敏感，而羧甲基化途径对溶剂回收敏感。当将结果与其他碳纳米材料进行比较时，表明特别是通过酶法和无预处理途径生产的 CNF 具有相对较低的环境影响。
