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Recycled polylactic acid (PLAr) was reinforced with treated nanocellulosic hemp fibers for biocomposite fabrication. Cellulosic fibers were extracted from hemp fibers chemically and treated enzymatically. Treated nanocellulosic fibers (NCF) were analyzed by Fourier-transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. Biocomposite fabrication was done with PLAr and three concentrations of treated NCF (0.1%, 0.25%, and 1% (v/v)) and then studied for thermal stability and mechanical properties. Increased thermal stability was observed with increasing NCF concentrations. The highest value for Young’s modulus was for PLAr + 0.25% (v/v) NCF (250.28 ± 5.47 MPa), which was significantly increased compared to PLAr (p = 0.022). There was a significant decrease in the tensile stress at break point for PLAr + 0.25% (v/v) NCF and PLAr + 1% (v/v) NCF as compared to control (p = 0.006 and 0.002, respectively). No significant difference was observed between treatments for tensile stress at yield.

This study aims to overview the U.S. sustainable development by measuring the environmental performance of 50 states over the period of 2009–2018. To attain the objective, we employ data envelopment analysis for environmental assessment where we prioritize the minimization of CO2 emissions first and the maximization of gross state product later under the concept of managerial disposability (i.e., an environment-based performance measure). Then, we examine how the state-level environmental performance measures are associated with their political and spatial contexts. For the purpose, we conduct the Kruskal-Wallis rank sum test across groups of states characterized by their political transitions in the presidential and gubernatorial elections and defined by the regions of the U.S. Economic Development Administration and Environmental Protection Agency. Based on our empirical results, we find that (a) overall environmental performance has gradually enhanced over time, (b) there are statistically significant differences in the environmental performance measures along with the political transitions, and (c) states on both coasts have outperformed those of the middle in the measurement.

The beginning of the 21st century for the fuel and energy complexes of most countries is characterized as a period of active restructuring and a fundamental shift in developmental priorities. The basis of these changes is technological development. Industry 4.0 technologies have particular importance in achieving maximum optimization of production processes. In the same way, they are applicable in establishing effective interaction between the energy sector and other sectors of the economy. The authors outline an approach to assessing the country’s fuel and energy balance state through the selected properties: sustainability, accessibility, efficiency, adaptability and reliability. Hence, a model of the fuel and energy complex was created on the example of the Russian Federation, considering the country’s territorial and functional division. The methodology is based on scenario modeling of the influence level of external challenges in conjunction with the accompanying technological development. The mathematical model allowed forecasting changes in the properties of the energy system. The scientific significance of the work lies in the application of a consistent hybrid modeling approach to forecast the state of the fuel and energy balance. The results of the study are useful in compiling scenarios for the regional and entire development of the fuel and energy complex. Further model improvements should include an expansion of the number of counted industries and their relations.

Energy performance contracts are a very promising area for attracting private investment in the renewable energy sector. The concept of energy performance contracting is a well-established mechanism aimed at increasing the energy efficiency of a facility and reducing annual maintenance costs. This paper presents a hierarchical model of a decentralized energy system with renewable energy sources and a battery energy storage system under an energy service agreement. This model reflects the interaction between the client and the performance company. The model includes the main parameters characterizing the energy service contract, such as net present value, contract duration and levelized cost of energy. As an example, a real decentralized power system is considered, which currently only uses diesel generation. In the case of building a photovoltaic system, the optimal equipment composition consists of a 100 kW solar station and storage batteries with a capacity of 240 kW·h. The optimal contract term is 5 years, and diesel fuel savings are 69%.

Building energy efficiency is strongly linked to the operations and control systems, together with the integrated performance of passive and active systems. In new high quality buildings in particular, where these two latter aspects have been already implemented at the design stage, users’ perspective, obtained through post-occupancy assessment, has to be considered to reduce whole energy requirement during service life. This research presents an innovative and low-cost methodology to reduce buildings’ energy requirements through post-occupancy assessment and optimization of energy operations using effective users’ attitudes and requirements as feedback. As a meaningful example, the proposed method is applied to a multipurpose building located in New York City, NY, USA, where real occupancy conditions are assessed. The effectiveness of the method is tested through dynamic simulations using a numerical model of the case study, calibrated through real monitoring data collected on the building. Results show that, for the chosen case study, the method provides optimized building energy operations which allow a reduction of primary energy requirements for HVAC, lighting, room-electricity, and auxiliary supply by about 21%. This paper shows that the proposed strategy represents an effective way to reduce buildings’ energy waste, in particular in those complex and high-efficiency buildings that are not performing as well as expected during the concept-design-commissioning stage, in particular due to the lack of feedback after the building handover.

The novel life cycle assessment (LCA)-based carbon handprint indicator represents a potential carbon footprint reduction that producers/products create for customers who use the(ir) product instead of a baseline product. The research question is how to consider a situation in which multiple customers use a product for different purposes to provide a carbon handprint quantification and the associated communication. The study further provides new insight into the greenhouse gas (GHG) emissions reduction potential within the mobile telecommunications and energy sectors. The carbon handprint of a novel Finnish liquid-cooled base station technology is quantified. The liquid-cooled base station provides a telecommunications service and waste heat that is recoverable through the cooling liquid for heating purposes. The baseline solutions are an air-cooled base station, and district and electrical heating. The liquid-cooled base station creates a carbon handprint, both through energy savings in telecommunications and additional waste heat reuse, replacing other energy production methods. A large-scale climate change mitigation potential through a liquid-cooled base station expansion could be significant. Different supply chain operators’ contributions to the total carbon handprint could be terminologically distinguished in communications to emphasize their roles in a shared handprint. The handprint should be transparently communicated for each customer and function.

Biomass can be considered an alternative to coal in the production of heat and electricity. Many types of biomass are waste from agriculture and the food industry. This waste is cheap, readily available, and replenished annually. However, most agricultural and food industry wastes (sugar cane pulp, olive and sunflower oil production wastes, straw, etc.) have ash with a low melting point. This leads to a rapid growth of ash deposits on the heating surfaces of boilers; as a result, the actual efficiency of boilers in which waste from agriculture and the food industry is burned is 45–50%. Known biomass pre-treatment technologies that allow for the fuel characteristics of biowaste. For example, leaching of biowaste in water at a temperature of 80–240 °C makes it possible to drastically reduce the content of alkali metal compounds in the ash, the presence of which reduces the melting point of the ash. However, this biomass pre-treatment technology is complex and requires additional costs for drying the treated biomass. We proposed to use torrefaction for pre-treatment of biomass, which makes it possible to increase the heat of combustion of biomass, increase the hydrophobicity of biomass, and reduce the cost of grinding it. However, we are not aware of studies that have studied the effect of torrefaction on the chemical composition of ash from the point of view of solving the problem of preventing the formation of agglomerates and reducing the growth rate of ash deposits on the convective heating surfaces of boilers. In this paper, the characteristics of sunflower husk subjected to torrefaction in an environment of superheated steam at a temperature of 300 °C and in an environment of gaseous products at a temperature of 250 °C are studied. All experiments were conducted using fluidized bed technology. The resulting biochar has a calorific value of 14.8–23% higher than the initial husk. To assess the behavior of sunflower husk ash, predictive coefficients were calculated. Torrefaction of sunflower husks does not exclude the possibility of slagging of the furnace but reduces the likelihood of slagging by 2.31–7.27 times. According to calculations, the torrefaction of sunflower husks reduces the likelihood of ash deposits on the convective heating surfaces of the boiler by 2.1–12.2 times. According to its fuel characteristics, the husk, after torrefaction in an environment of superheated steam, approaches wood waste, i.e., can be burned separately without additives or mixtures with other fuels with refractory ash.

Brazil’s status as a rapidly developing country is visible in its need for more energy, including electricity. While the current electricity generation mix is primarily hydropower based, high-quality dam sites are diminishing and diversification to other sources is likely. We combined life-cycle data for electricity production with scenarios developed using the IAEA’s MESSAGE model to examine environmental impacts of future electricity generation under a baseline case and four side cases, using a Monte-Carlo approach to incorporate uncertainty in power plant performance and LCA impacts. Our results show that, under the cost-optimal base case scenario, Brazil’s GHGs from electricity (excluding hydroelectric reservoir emissions) rise 370% by 2040 relative to 2010, with the carbon intensity per MWh rising 100%. This rise would make Brazil’s carbon emissions targets difficult to meet without demand-side programs. Our results show a future electricity mix dominated by environmental tradeoffs in the use of large-scale renewables, questioning the use tropical hydropower and highlighting the need for additional work to assess and include ecosystem and social impacts, where information is currently sparse.