Efficiency and sustainability indicators for papermaking from virgin pulp—An emergy-based case study

The pulp and paper sector is the fourth-largest industrial sector worldwide in terms of energy use, accounting for approximately 6% of the total industrial energy consumption and contributing to 2% of direct carbon dioxide (CO₂) emissions produced by industries. The definition of the environmental profile of this industrial sector is crucial, due to the high market demand of paper and the increasing concern for the environmental costs of the whole papermaking process. A sustainability perspective should rely on a wider and holistic viewpoint, properly including all direct and indirect interactions with the environment. To this purpose, the Emergy (spelled with “m”) Accounting method (EMA) is very appropriate for the evaluation of the efficiency, effectiveness and sustainability of the papermaking process under different perspectives (resource quality, fossil energy and material consumption, environmental and human-driven support). Several studies concerning environmental impacts, eco-efficiency, and cleaner technologies in the pulp and paper sector have already been carried out, but none of them addressed resource quality and resource generation costs from a supply-side point of view. This study aims to fill this gap in the literature by highlighting the direct and indirect contribution in terms of natural capital and ecosystem services to the pulp and paper production process. By means of EMA performance indices, this paper aims to assess the environmental sustainability associated to the production of pulp and paper, so as to identify those process steps that entail the highest environmental costs and require improvements. Three forest management scenarios − based on Spruce/Pine, Eucalyptus and Poplar production for raw material supply − were evaluated to assess the sustainability and the efficiency of each species. Moreover, the marginal costs of achieving higher energy and material efficiency are investigated, with a special focus placed on the identification of the effects of energy input flows on additional demand for environmental services. The research results show that the largest supply-side environmental costs are generated by the industrial processing activities, due to high energy, water and chemicals consumption. Only a minor role is played by forestry activities that supply the raw feedstock, although forestry management practices certainly affect both the final productivity and the energy balance, through the amount and use efficiency of the farm inputs. Additionally, among the three forest systems under study, Spruce/Pine forest management displays the most sustainable option for paper production because, basing on the emergy indices, it presents the best sustainable contribution to both the economy and the environment of the investigated region. In conclusion, the application of EMA approach allowed a more comprehensive assessment of forestry and industrial operations, contributing to assist decision makers in implementing the best environmental management of papermaking process.