Environmental Sustainability ofBIOPLASTICS

The aim of this study is to define the eco-compatibility of biopolymers, the so called "green plastics" with a view extended to all phases of life in order to quantify the environmental impact of these materials. Nowadays, biopolymers represent the most widespread materials when it comes to replace the conventional polymers and they are considered particularly promising in terms of environmental sustainability. Indeed, the production of plastics from renewable sources in recent years has had an exponential growth (from 180 ton in 2008 to 1 million of ton in 2011). This rise is due to the market demand of products and materials with an increased environmental performance compared to “traditional plastics”, it is also due to the necessity to find alternatives to fossil fuel and to split the price of manufacturing to the fossil fuel cost. Therefore, the need to quantify the biopolymer environmental impact is becoming meaningful in order to give a concrete and objective answer to the market. However, even if there is the rapid growth on the market, the environmental data are still ambiguous and not well established. It is necessary to stress that the term “biopolymers” does not correspond to a precise and (internationally) recognized definition. In fact, This term is used both to indicate the raw material biologic origin (from biomass) and to report the information about the biodegradability in the biopolymers end of life contest. As a matter of fact, it must be specified that: - the biodegradability can be a characteristic both for a polymer coming from biomass and for one coming from fossil fuel source; - it does not exist a direct correlation between renewable source and biodegradability: a biopolymer from renewable sources is not necessarily biodegradable; - biopolymers are already implemented in the market to produces goods, for example in the packaging sector, but very often only a small percentage of their composition comes from a renewable source. In order to outline the effective sustainability when conventional polymers are replaced with biopolymers, it is necessary to consider the environmental burden related to the entire life cycle. In particular, it has to be considered: the biomass growing phase, the pellet and manufacturing production, the use phase and the end of life scenarios. Many evaluation methods are nowadays available to assess the environmental sustainability, but above all Life Cycle Assessment (LCA) remains the most reliable. LCA is in fact one of the most internationally recognized methodology for the evaluation of environmental burdens, related to a product or a service during all life cycle stages, from the extraction of raw materials to the end of life. In the specific case of biopolymers, the quantification of the environmental burdens through the application of the LCA methodology is a complex target because many are the issues to be considered for each phase and data availability is very little. In order to reach this target, a deep data collection from scientific studies and main LCA databases allowed to precisely detect specific issues concerning each of the different life cycle phases. In particular, the main issues are: the description of the parameters from the Marina Foschia Environmental Sustainability of BIOPLASTICS 3 sowing to the harvest step (raw material cultivation, carbon storage, land use change, agriculture management, transport) in biomass growing phase; the investigation of LCA data availability in the pellet production and manufacturing phase and the analysis of the existing data coming from chemical recycling plant (one of the possible end of life scenarios). It has to be mentioned that one of the most widespread biopolymer used in the market is the Polylactic acid (PLA): most of the information and data used in this study are referred to PLA life cycle.