Circularity measurement of external resource flows in companies: The circular flow tool.

Unlike the linear model "take-make-use-dispose", the circular economy model "grow-make-use-restore" intends to potentiate material and energy flows within a system with the premise of increasing environmental gains. Moreover, circular economy practices can be alternatives for closing loops in companies from different sectors, with material-, waste-, and energy-related initiatives towards promoting greater internal value-adding. However, the lack of consistent tools for measuring circularity of processes and companies is a gap yet to be covered. To tackle this gap, this paper's aims are: (i) to build a new tool, called Circular Flow, for generating greater internal value and competitive advantage in organizations and identify potential circular economy-related opportunities for closing loops based on external flows, (ii) to apply the tool in a case study, an organization that presents material and energy (electricity) flows and exchanges with other organizations, and (iii) to discuss the integration and potential opportunities for the tool in organizations. The novel, Circular Flow, tool is based on a set of circular graph visualizations, and quantitative circularity indicators. For the graphical visualization, the software tool R (using the Circlize package) was used. The graphs aid the visualization of several interconnected pieces of information, allowing to show all quantitative flows of inputs and outputs, intuitively showing the paths (origin and destination of each flow) within the boundaries of the system under study. The quantitative indicators, e.g. Circularity of the organization (Circ p) and Circularity of each process (Circ o), show a circularity index ranging from 0% to 100%, which can be assessed at different levels. The criteria to select these indicators are based on quantities of inputs and outputs regarding mass and electricity. The tool has been applied in a case study of a rural property in southern Brazil, which region holds a tradition for milk and pig farming. The use of the tool showed the involvement of the rural property with its neighbors and with an agroindustrial cooperative. Keeping these flows within the system may increase environmental gains by reducing transportation, using renewable sources of energy, reducing costs, and boosting the generation of jobs and income in the region due to new market opportunities and business models.

Sustainability of sugarcane lignocellulosic biomass pretreatment for the production of bioethanol.

The sustainability of a biofuel is severely affected by the technological route of its production. Chemical pretreatment can be considered the traditional method of decomposition of the lignocellulose into its mono and oligomeric units, which can be further bioconverted to ethanol. The evaluation of the recent advances in chemical pretreatments of sugarcane bagasse, especially diluted acids, alkaline, organosolv and ionic liquids, identified the critical points for sustainability. In this context, chemicals recovery and reutilization or their substitution by green solvents, heat and electricity generation through bioenergy, reutilization of water from evaporators, vinasse concentration and the upgrading of lignin were discussed as strategic routes for developing sustainable chemical-based lignocellulose pretreatment. The advances in the technologies that allow greater fractionation of lignocellulosic biomass should be focused on the minimization of the use of natural resources, effluent generation and energy expenditure.

Life cycle assessment of medium-density fiberboard (MDF) manufacturing process in Brazil.

Brazil is one of the largest producers of medium-density fibreboard (MDF) in the world, and also the MDF has the highest domestic consumption and production rate in the country. MDF applications are highlighted into residential and commercial furniture design and also a wide participation in the building sector. This study aimed to propose ways of improving the environmental cradle-to-gate life-cycle of one cubic meter MDF panel by means of a life-cycle assessment (LCA) study. Complying with requirements of ISO 14040 and 14,044 standards, different MDF manufacturing scenarios were modelled using Umberto® v.5.6 software and the Ecoinvent v.2.2 life-cycle inventory (LCI) database for the Brazilian context. Environmental and human health impacts were assessed by using the CML (2001) and USEtox (2008) methods. The evaluated impact categories were: acidification, global warming, ozone layer depletion, abiotic resource depletion, photochemical formation of tropospheric ozone, ecotoxicity, eutrophication and human toxicity. Results identified the following hotspots: gas consumption at the thermal plant, urea-formaldehyde resin, power consumption, wood chip consumption and wood chip transportation to the plant. The improvement scenario proposals comprised the following actions: eliminate natural gas consumption at the thermal plant, reduce electrical power consumption, reduce or replace urea-formaldehyde resin consumption, reduce wood consumption and minimize the distance to wood chip suppliers. The proposed actions were analysed to verify the influence of each action on the set of impact categories. Among the results, it can be noted that a joint action of the proposed improvements can result in a total reduction of up to 38.5% of impacts to OD, 34.4% to AD, 31.2% to ET, and 30.4% to HT. Finally, MDF was compared with particleboard production in Brazil, and additional opportunities to improve the MDF environmental profile were identified.