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Used cooking oil (UCO) is a domestic waste generated daily by food industries, restaurants, and households. It is estimated that in Europe 5 kg of UCO are generated per inhabitant, totalling 2.5 million metric tons per year. Recovering UCO for the production of biodiesel offers a way of minimizing and avoiding this waste and related pollution. An exergy analysis of the integrated waste management (IWM) scheme for UCO is used to evaluate such a possibility by accounting for inputs and outputs in each stage, calculating the exergy loss and the resource input and quantifying the possible improvements. The IWM includes the collection, pretreatment, and delivery of UCO and the production of biodiesel. The results show that the greatest exergy loss occurs during the transport stages (57%). Such exergy loss can be minimized to 20% by exploiting the full capacity of collecting vans and using biodiesel in the transport stages. Further, the cumulative exergy consumption helps study how the exergy consumption of biodiesel can be further reduced by using methanol obtained from biogas in the transesterification stage. Finally, the paper discusses how increasing the collection of UCO helps minimize uncontrolled used oil disposal and consequently provides a sustainable process for biodiesel production.

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Summary We used a thermodynamic framework to characterize the resource consumption of the construction sector in 2001 in Catalonia, the northeast region of Spain. The analysis was done with a cradle‐to‐product life cycle approach using material flow analysis (MFA) and exergy accounting methodologies to quantify the total material and energy inputs in the sector. The aim was to identify the limitations of resource metabolism in the sector and to pinpoint the opportunities for improved material selection criteria, processing, reuse, and recycling for sustainable resource use. The results obtained from MFA showed that nonrenewables such as minerals and natural rocks, cement and derivatives, ceramics, glass, metals, plastics, paints and other chemicals, electric and lighting products, and bituminous mix products accounted for more than 98% of the input materials in the construction sector. The exergy analysis quantified a total 113.1 petajoules (PJ) of exergy inputs in the sector; utilities accounted for 57% of this exergy. Besides exergy inputs, a total of 6.85 million metric tons of construction and demolition waste was generated in 2001. With a recycling rate of 6.5%, the sector recovered 1.3 PJ of exergy. If the sector were able to recycle 80% of construction and demolition waste, then exergy recovery would be 10.3 PJ. Hence the results of this analysis indicate that improvements are required in manufacturing processes and recycling activities, especially of energy‐intensive materials, in order to reduce the inputs of utilities and the extraction of primary materials from the environment.

Industrial parks have been used to promote the economic development of countries. However, its rapid growth has generated environmental problems related to the depletion of natural resources and pollution. Consequently, the network analysis and the bibliometric analysis applied in this research generated qualitative and quantitative information from a systemic perspective on the thematic and community evolution of research on industrial parks (IP) performed to improve its negative environmental impact and reach sustainability. This study used the Web of Science (WoS) database from 1996 – 2019. The main trends and critical research points were identified in four periods of 6-year each. Social network analysis (SNA) was used to identify the intellectual structure main and the academic collaboration networks established among countries/territories, institutions, and authors. The most productive country in articles is currently China (882), however, when we consider the frequency of articles per million inhabitants, it ranks seventh. The WoS database grouped 63.6 ​% of the articles published in the subjects of “Environmental Sciences & Ecology”, “Engineering”, and “Science & Technology - Other Topics”. Industrial Ecology (IE), Industrial Symbiosis (IS), and Circular Economy (CE) were the author keywords with the highest frequency, indicating that IP research has focused from these perspectives to promote the exchange of byproducts and to evaluate the performance and environmental impact of industrial areas through the use of methodologies such as carbon footprints, emergy analysis, and life cycle analysis (LCA). Finally, some themes were identified and proposed for future research based on analyzing research trends and hot spots from the literature review on industrial parks.