• Energy Research
• 2021-2025close
• Restricted close
• ES close
• CA close
• AU close

The building and construction sector is a large contributor to anthropogenic greenhouse gas emissions and consumes vast natural resources. Improvements in this sector are of fundamental importance for national and global targets to combat climate change. In this context, vertical greenery systems (VGS) in buildings have become popular in urban areas to restore green space in cities and be an adaptation strategy for challenges such as climate change. However, only a small amount of knowledge is available on the different VGS environmental impacts. This paper discusses a comparative life cycle assessment (LCA) between a building with green walls, a building with green facades and a reference building without any greenery system in the continental Mediterranean climate. This life cycle assessment is carried according to ISO 14040/44 using ReCiPe and GWP indicators. Moreover, this study fills this gap by thoroughly tracking and quantifying all impacts in all phases of the building life cycle related to the manufacturing and construction stage, maintenance, use stage (operational energy use experimentally tested), and final disposal. The adopted functional unit is the square meter of the facade. Results showed that the operational stage had the highest impact contributing by up to 90% of the total environmental impacts during its 50 years life cycle. Moreover, when considering VGS, there is an annual reduction of about 1% in the environmental burdens. However, in summer, the reduction is almost 50%. Finally, if the use stage is excluded, the manufacturing and the maintenance stage are the most significant contributors, especially in the green wall system.

The building and construction sector is a large contributor to anthropogenic greenhouse gas emissions and consumes vast natural resources. Improvements in this sector are of fundamental importance for national and global targets to combat climate change. In this context, vertical greenery systems (VGS) in buildings have become popular in urban areas to restore green space in cities and be an adaptation strategy for challenges such as climate change. However, only a small amount of knowledge is available on the different VGS environmental impacts. This paper discusses a comparative life cycle assessment (LCA) between a building with green walls, a building with green facades and a reference building without any greenery system in the continental Mediterranean climate. This life cycle assessment is carried according to ISO 14040/44 using ReCiPe and GWP indicators. Moreover, this study fills this gap by thoroughly tracking and quantifying all impacts in all phases of the building life cycle related to the manufacturing and construction stage, maintenance, use stage (operational energy use experimentally tested), and final disposal. The adopted functional unit is the square meter of the facade. Results showed that the operational stage had the highest impact contributing by up to 90% of the total environmental impacts during its 50 years life cycle. Moreover, when considering VGS, there is an annual reduction of about 1% in the environmental burdens. However, in summer, the reduction is almost 50%. Finally, if the use stage is excluded, the manufacturing and the maintenance stage are the most significant contributors, especially in the green wall system.

Thermokinetics of Biochar production.

Thermokinetics of Biochar production.

Common hornbeam (Carpinus betulus) is one of the most important spring pollen allergens widespread in the Czech Republic. This study evaluates the changes in Carpinus betulus flowering and the length of the blooming period in the Czech Republic during 1991-2020. Temporal and spatial evaluations in the timing of the flowering and the length of the blooming period were investigated at different altitudinal levels. Moreover, the changes in mean air temperature and precipitation total in spring months (March-April-May) were assessed, including the correlation with phenological data. Geographic Information System methods, the Mann-Kendall test and Pearson's correlation coefficient were used for processing. The flowering of Carpinus betulus changed significantly over time during the 1991-2020 period. The linear models predicted early flowering in Carpinus betulus at different altitudes (27 days at > 701 m 18 days at 501-700 m and 13 days at 301-500 m) significantly (p<0.001) over the last three decades. Furthermore, the length of the blooming period of Carpinus betulus has been shortened (4 days) at the 301-500 m a.s.l. altitudinal level significantly (p<0.05). The strongest correlation was predominantly observed between flowering and the mean air temperature (March-April-May).

Common hornbeam (Carpinus betulus) is one of the most important spring pollen allergens widespread in the Czech Republic. This study evaluates the changes in Carpinus betulus flowering and the length of the blooming period in the Czech Republic during 1991-2020. Temporal and spatial evaluations in the timing of the flowering and the length of the blooming period were investigated at different altitudinal levels. Moreover, the changes in mean air temperature and precipitation total in spring months (March-April-May) were assessed, including the correlation with phenological data. Geographic Information System methods, the Mann-Kendall test and Pearson's correlation coefficient were used for processing. The flowering of Carpinus betulus changed significantly over time during the 1991-2020 period. The linear models predicted early flowering in Carpinus betulus at different altitudes (27 days at > 701 m 18 days at 501-700 m and 13 days at 301-500 m) significantly (p<0.001) over the last three decades. Furthermore, the length of the blooming period of Carpinus betulus has been shortened (4 days) at the 301-500 m a.s.l. altitudinal level significantly (p<0.05). The strongest correlation was predominantly observed between flowering and the mean air temperature (March-April-May).

This study aimed to evaluate the potential of microalgae grown in wastewater to recover carotenoids and biogas in a biorefinery approach. To this end, two pilot raceway ponds treating real wastewater were operated with a hydraulic retention time (HRT) of 8 and 6 days. The maximum total carotenoid content in harvested biomass was 4.3 mg·gDW-1 with a HRT of 8 days, while it stabilized at 1.5–2.2 mg·gDW-1 with a HRT of 6 days. Biochemical methane potential tests were then run to quantify the biogas production from carotenoid-extracted biomass (136.3 mLCH4·gVS-1), which corresponded to 86% of the methane yield achievable from raw microalgal biomass. Co-digestion with primary sludge increased the methane yield production both for raw and carotenoid-extracted biomass by 58 and 86%, respectively, when a 75:25 ratio was employed and by 28 and 44%, respectively, when a 50:50 ratio (VS basis) was used. This approach is promising for recovering resources (bio-based products and bioenergy) in the framework of a circular bioeconomy. This research has received funding from MCIN/AEI/10.13039/501100011033 and “ERDF A way of making Europe’’ under the projects AL4BIO (RTI2018-099495-B-C21) and Cyan2Bio (PID2021-126564OB-C32). E. Ruales acknowledges her grant 2020 FISDUR 00592 funded by AGAUR (Generalitat de Catalunya). M. Bellver acknowledges her grant PRE2019-091552 funded by MCIN/AEI/ 10.13039/501100011033 and “ESF Investing in your future”.

This study aimed to evaluate the potential of microalgae grown in wastewater to recover carotenoids and biogas in a biorefinery approach. To this end, two pilot raceway ponds treating real wastewater were operated with a hydraulic retention time (HRT) of 8 and 6 days. The maximum total carotenoid content in harvested biomass was 4.3 mg·gDW-1 with a HRT of 8 days, while it stabilized at 1.5–2.2 mg·gDW-1 with a HRT of 6 days. Biochemical methane potential tests were then run to quantify the biogas production from carotenoid-extracted biomass (136.3 mLCH4·gVS-1), which corresponded to 86% of the methane yield achievable from raw microalgal biomass. Co-digestion with primary sludge increased the methane yield production both for raw and carotenoid-extracted biomass by 58 and 86%, respectively, when a 75:25 ratio was employed and by 28 and 44%, respectively, when a 50:50 ratio (VS basis) was used. This approach is promising for recovering resources (bio-based products and bioenergy) in the framework of a circular bioeconomy. This research has received funding from MCIN/AEI/10.13039/501100011033 and “ERDF A way of making Europe’’ under the projects AL4BIO (RTI2018-099495-B-C21) and Cyan2Bio (PID2021-126564OB-C32). E. Ruales acknowledges her grant 2020 FISDUR 00592 funded by AGAUR (Generalitat de Catalunya). M. Bellver acknowledges her grant PRE2019-091552 funded by MCIN/AEI/ 10.13039/501100011033 and “ESF Investing in your future”.

Abstract Volumetric solar receivers are essential components in high-temperature concentrated solar power plants. Their optical design is crucial for achieving efficient photon-thermal energy conversion; however, their three-dimensional geometry complicates a reliable and accurate optical characterization. This work proposes a new methodology for the 3D optical-performance analysis of the volumetric absorber having an open hierarchical structure. Firstly, the solar absorber is optically characterized using a test bench that mainly comprises a solar simulator and a customized instrument equipped with single-photon avalanche diodes, which holds the absorber and measures light flux on its external surface. Then experimental measurements are compared with a Monte Carlo ray-tracing numerical model. The results are consequently employed to understand light propagation in the absorber. This procedure is successfully applied to characterize a complex three-dimensional self-similar structure manufactured by Selective Laser Melting. The proposed experimental technique is a promising candidate for becoming a robust in operando method to characterize the radiation propagation within the complex porous structures employed for volumetric receivers.