Biological fermentation pilot-scale systems and evaluation for commercial viability towards sustainable biohydrogen production.

Featuring high caloric value, clean-burning, and renewability, hydrogen is a fuel believed to be able to change energy structure worldwide. Biohydrogen production technologies effectively utilize waste biomass resources and produce high-purity hydrogen. Improvements have been made in the biohydrogen production process in recent years. However, there is a lack of operational data and sustainability analysis from pilot plants to provide a reference for commercial operations. In this report, based on spectrum coupling, thermal effect, and multiphase flow properties of hydrogen production, continuous pilot-scale biohydrogen production systems (dark and photo-fermentation) are established as a research subject. Then, pilot-scale hydrogen production systems are assessed in terms of sustainability. The system being evaluated, consumes 171,530 MJ of energy and emits 9.37 t of CO2 eq when producing 1 t H2, and has a payback period of 6.86 years. Our analysis also suggests future pathways towards effective biohydrogen production technology development and real-world implementation.

Combining organizational and product life cycle perspective to explore the environmental benefits of steel slag recovery practices.

Sustainability in steel production is considered a global challenge which needs to be faced with coordinated actions. The aim of this study is to assess the environmental improvements of a steel mill in a circular economy perspective, through the Organizational Life Cycle Assessment (O-LCA) and the Product Life Cycle Assessment (P-LCA) methodologies. This study explores to what extent the improvements and the efforts to recover the steel slag can be detected using an organization perspective and making a comparison with the more traditional product perspective. The results obtained show that the case in which the steel slag is recovered has lower impacts than the case in which it is landfilled through both O-LCA and P-LCA applications and that the percentage variations are similar for 8 categories out of 10 demonstrating that for our case study, O-LCA and P-LCA can detect the efforts to recover slag similarly. Two categories, namely ADP-minerals&metals and EP-freshwater, are affected by the greater amount of metal and mineral raw materials needed if the slag is not treated and by the steel slag landfill disposal more significantly. What the results tell us is that the variations obtained for this study in the P-LCA application are greater than those obtained in O-LCA application, due to two methodological aspects, namely the application of allocation procedures and the choice of the system boundaries. Finally, it emerges that O-LCA methodology can detect environmental improvements of circularity practices, but the reduction of the impacts is less clear than P-LCA application. What is transferable is that O-LCA and P-LCA methodologies are not interchangeable to quantify the environmental benefits and address the efforts to improve a process in terms of circularity.

Life cycle assessment applied to waste management in Italy: A mini-review of characteristics and methodological perspectives for local assessment.

Life cycle assessment (LCA) and related tools are commonly used to evaluate the potential environmental impacts of waste treatment scenarios. This manuscript presents a mini-review of studies published over the last 10 years in Italy and aims to investigate how life cycle thinking tools are applied to assess the environmental sustainability of local-level waste policies. Results reveal that different waste flows, technologies and policies have been investigated independently and in varying detail. Review suggests that boundary selection significantly affects LCA results; integration of different waste systems is therefore crucial to avoid spatial or temporal shifts of environmental impacts. Moreover, the description of methodological characteristics, limitations and transversal aspects of Italian waste management studies allows various stakeholders to assess the reliability of past and future research for waste policy planning and rebound effects prevention. This review also highlights the need to define minimum requirements of transparency and ease of reporting of the studies to private and public stakeholders. Finally, the paper investigates whether using both the organisational LCA and the life cycle sustainability approach for the overall waste management process may be useful to develop a standard method to address multi-functionalities and multiple sites.

Design and modeling of sustainable bioethanol supply chain by minimizing the total ecological footprint in life cycle perspective.

The purpose of this paper is to develop a model for designing the most sustainable bioethanol supply chain. Taking into consideration of the possibility of multiple-feedstock, multiple transportation modes, multiple alternative technologies, multiple transport patterns and multiple waste disposal manners in bioethanol systems, this study developed a model for designing the most sustainable bioethanol supply chain by minimizing the total ecological footprint under some prerequisite constraints including satisfying the goal of the stakeholders', the limitation of resources and energy, the capacity of warehouses, the market demand and some technological constraints. And an illustrative case of multiple-feedstock bioethanol system has been studied by the proposed method, and a global best solution by which the total ecological footprint is the minimal has been obtained.