Techno-economic risk assessment, life cycle analysis and life cycle costing for poly(butylene succinate) and poly(lactic acid) production using renewable resources.

The sustainable production of poly(lactic acid) (PLA) or poly(butylene succinate) (PBS) from corn glucose syrup, corn stover and sugar beet pulp (SBP) have been assessed via process design, preliminary techno-economic evaluation, life cycle assessment and life cycle costing (LCC). Cost-competitive PLA and PBS production can be achieved in a SBP-based biorefinery, including separation of crude pectin-rich extract as co-product, leading to minimum selling prices of $1.14/kgPLA and $1.37/kgPBS. Acidification Potential, Eutrophication Potential and Human Toxicity Potential are lower when SBP is used. The LCC of PLA ($1.42/kgPLA) and PBS ($1.72/kgPBS) production from SBP are lower than biaxial oriented polypropylene (BOPP, $1.66/kg) and general purpose polystyrene (GPPS, $2.04/kg) at pectin-rich extract market prices of $3/kg and $4/kg, respectively. Techno-economic risk assessment via Monte-Carlo simulations showed that PLA and PBS could be produced from SBP at the market prices of BOPP ($1.4/kg) and GPPS ($1.72/kg) with 100% probability to achieve a positive Net Present Value at pectin-rich extract market prices of $3/kg and $4/kg, respectively. This study demonstrated that SBP-based biorefinery development ensures sustainable production of PLA and PBS as compared to fossil-derived counterparts and single product bioprocesses using glucose syrup and corn stover.

Environmental consequences of wheat-based crop rotation in potato farming systems in galicia, Spain.

Intensive agricultural farming systems have negative impacts on the ecosystem. Therefore, the use of crop rotation emerges as an opportunity to improve the environmental sustainability of agricultural systems. In the region of Galicia in north-western Spain, potato and wheat are important commodities and essential foods in the diet. Hence, it is interesting to investigate the environmental profile of these crops to improve the understanding of local agrosystems. This study evaluated three agricultural crops managed under a crop rotation system and following a conventional arable farming: the main rotation crop, which is the potato in the first year (cP), followed by a second year of commercial wheat (cW) and autochthonous Galician wheat (GcW) in the third year. The Life Cycle Assessment (LCA) methodology was performed using four types of functional units: in terms of productivity (kg-1); land management (ha-1∙year-1); a financial function (euros €-1 of income from sales) and energetic value (MJ-1). The environmental indicators selected are Climate Change (CC), Particulate Matter (PM), Terrestrial Acidification (TA), Freshwater Eutrophication (FE), Marine Eutrophication (ME), Human Toxicity (HT), Land Use (LU) and Fossil Depletion (FD). The figures show that the GcW has the lowest environmental impact when the functional units refer to land management, financial function and energetic value. However, if analysed in terms of productivity, cP is presented as the best crop due to its comparatively higher yield, reaching a production ratio 10 times higher than wheat. In the specific case of wheat, compared to a previous study in the same region, the environmental impacts are lower when grown in a crop rotation system in contrast to monoculture. This article demonstrates the relevance of using LCA for diverse stakeholders (e.g., farmers, consumers and researchers) to understand the environmental impacts of regional agricultural systems. In addition, it serves as a basis for future work aimed at comparing rotational agricultural systems in this region, integrating economic and social aspects.

Life cycle assessment of autochthonous varieties of wheat and artisanal bread production in Galicia, Spain.

For millennia, bread and wheat have been one of the most important sources of nutrients in many civilizations. Today, mechanization and evolution in agriculture and food processing have intensified yields and modified the biological and nutritional aspects of multiple crops and foods. The Galician bread is a reference value of food heritage in Spain, which is made from common wheat grain and is a mixture of indigenous Galician wheat and conventional Spanish wheat. In the pursuit of product excellence, it is interesting to identify the environmental profile as support criteria in decision-making, not only to analyse product environmental sustainability, but also as a marketing element to improve consumer awareness. The paper has a twofold perspective to analyse the environmental burdens of wheat cultivation and the bread sector, using life cycle assessment approach: 1) the comparison of the different types of agricultural systems, i.e. the cultivation of Galician wheat following a strategy of monoculture and crop rotation, certified Galician seed production and its comparison with conventional wheat cultivation and 2) the environmental profile of Galician bread. The functional units chosen were 1 kg of wheat grain transported to the milling facility and 1 kg of Galician bread. The results show that wheat cultivation presents the main environmental impacts of bread production, mainly due to the use of agrochemicals and field emissions. The best cultivation scenario corresponds to a crop rotation system, since chemical fertilisation is not applied. In comparative terms with many staple foods produced in Europe, Galician bread has a low environmental impact. The overall environmental results of bread production draw attention to the dependence of bread and flour manufacturers on the agricultural sector, highlighting the need to share responsibilities across the supply chain. In addition, this study contributes to the stakeholder debate on environmental impacts related to food heritage.