Wood and Other Renewable Resources Medium Density Fibreboard

Goal, Scope and Background. Wood is the most important renewable material. The management of wood appears to be a key action to optimise the use of resources and to reduce the environmental impact associated with mankind's activities. Wood-based products must be analysed considering the twofold nature of wood, commonly used as a renewable material or regenerative fuel. Relevant, up-to-date environmental data are needed to allow the analysis of wood-based products. The main focus of this study is to provide comprehensive data of one key wood board industry such as the Medium Density Fibreboard (MDF). Moreover, the influence of factors with strong geographical dependence, such as the electricity profile and final transport of the product, is analysed. In this work, International Organization for Standardization standards (ISO 14040-43) and Ecoindicator 99 methodology have been considered to quantify the potential environmental impact associated to the system under study. Three factories, considered representative of the 'state of art', were selected to study the process in detail: two Spanish factories and a Chilean one, with a process production of around 150,000 m3 per year. The system boundaries included all the activities taking place into the factory as well as the activities linked to the production of the main chemicals used in the process, energy inputs and transport. All the data related to the inputs and outputs of the process were obtained by on-site measurements during a oneyear period. A sensitive analysis was carried out taking into account the influence of the final transport of the product and the dependence on the electricity generation profile. Life Cycle Inventory Analysis. LCI methodology has been used for the quantification of the impacts of the MDF manufacture. The process chain can be subdivided in three main subsystems: wood preparation, board shaping and board finishing. The final transport of the product was studied as a different subsystem, considering scenarios from local to transoceanic distribution and three scenarios of electricity generation profile were assessed. The system was characterised with Ecoindicator 99 methodology (hierarchic version) in order to identify the 'hot spots'. Damage to Human Health, Ecosystem Quality and Resources are mainly produced by the subsystem of Wood Preparation (91.1%, 94.8% and 94.1%, respectively). The contribution of the subsystem of Board Finishing is considerably lower, but also significant, standing for the 5.8% of the damage to HH and 5.5% of the damage to Resources. Introduction Wood is the most important, renewable material and regenerative fuel [1]. As a material, wood is one of the resources most widely used for its remarkable properties, i.e. high strength, low specific weight, good insulation properties, availability, etc. [2]. Due to a broad of potential applications, it is often in competition with other materials such as concrete, steel or plastics [3–4]. However, this material is not only used as raw material for manufacture of different tools. Its use as biomass fuel accounts for 14% of the worldwide energy consumption and demand continues to increase for the use of biomass for energy, partly driven by the targets to fulfil national commitments under the Kyoto Protocol [5–6]. The wood panels market in the Economic Commission for Europe region fared better than other primary sectors, as measured by the largest increases in consumption coupled with higher prices [5]. The main breakdown of wood-based panels is presented in Fig. 1. The main panels in Europe are particleboard, which figures for approximately 65% of the total panel production and Medium Density Fibreboard (MDF), which accounts for 20%. The MDF industry has continued its solid growth for the last ten years in the 19 countries of the European Free Trade Association (EFTA), with an MDF consumption of 8.7 million cubic metres reported in 2003, as well as 2.3 million cubic metres for other Europe regions (22 countries) [5]. MDF consumption in the United States has also been increasing during last years, rising to 4.3 million cubic metres in 2004 [5]. Medium Density Fibreboard Wood and Other Renewable Resources 144 Int J LCA 12 (3) 2007 Wood management is a key action to optimise the use of resources and to reduce the environmental impact associated with mankind activities. In this sense, Life Cycle Assessment (LCA) methodology has proved to be a valuable tool to evidence and analyse the environmental impacts of products and services systems that need to be part of decisionmaking process towards sustainability [7]. However, it is not possible to determine the specific causes of the greatest environmental burdens in the life cycle until all the stages have been evaluated and the quality of data used has been fully verified. Wood-based products must be analysed considering the twofold nature of wood, commonly used as renewable material or regenerative fuel. As a first priority, allocation should be avoided by system expansion, thus adding additional functions to the functional unit [8–9]. Since LCA application began to be significant during the 1990s, efforts have been made to make progress in this area specifically in relation to forest operations [10–12]. So far, no comprehensive Life Cycle Inventory (LCI) for wood board manufacture, the most common items of wood-based materials, was available in the literature [13]. In previous work, we analysed the particleboard industry in detail [13]. The main focus of this study is to provide complete data of the other main wood board produced in the MDF industry.