A novel complex absorbent composed of polyethylene glycol 200 (PEG200) and ionic liquids (ILs) was prepared for the absorption of volatile organic compounds (VOCs) such as dichloromethane (DCM) and benzene. We prepared complex absorbents composed of [EMIM][Cl], [BMIM][Cl], [HMIM][Cl], [BMIM][BF4], [BMIM][PF6], [BMIM][NTF2], and PEG200, respectively, and studied the absorption properties of these six complex absorbents for DCM and benzene. The results show that under the optimized situation, the absorptivity of [HMIM][Cl]−PEG200 complex absorbent for DCM is 85.46% in the first 5 min, and 87.15% for benzene. No obvious decay in the absorptivity of [HMIM][Cl]−PEG200 for DCM and benzene was observed in five cycles, indicating an impressive regeneration performance. Furthermore, the mechanism of ionic liquid absorption for VOC is explored by thermodynamic analysis and quantum chemical calculations. The theoretical calculation results show that the [HMIM][Cl]−DCM interaction is stronger than... [more]

The marine-terminating glaciers are one of the biggest contributors to global sea-level rise. Research on this aspect of the effects of global climate change is developing nowadays in several directions. One of them is monitoring of glaciers movements, especially with satellite data. In addition to well-known analyzes based on radar data from available satellites, the possibility of studying glacier displacements from new sensors, the so-called microsatellites need to be studied. The main purpose of research was evaluation of the possibility of applying new high-resolution ICEYE radar data to observe glacier motion. Stripmap High mode were used to obtain velocities for the Jakobshavn glacier with an Offset-Tracking method. Obtained results were compared with displacements obtained from the Sentinel-1 data. The comparative analysis was performed on displacements in range and azimuth directions and for maximum velocity values. Moreover, correlation plots showed that in different parts of... [more]

CO2 diffusion coefficient plays a crucial part in saline aquifers for the CO2 storage and the safety of long-term sequestration. Therefore, it is particularly important to measure the diffusion coefficient accurately. As far as we know, there are currently no CO2 brine diffusion data in real cores under reservoir temperature and pressure conditions. In this paper, a study on the CO2 diffusion coefficient diffused in a brine-saturated Berea core along the radial direction was conducted at temperatures of 313.15 K to 373.15 K and pressures of 8 MPa to 30 MPa. On account of the experimental results, the effect of permeability, NaCl concentration, temperature and pressure on the CO2 diffusivity is analyzed. The results in this study indicate that the diffusion coefficient increases with increasing permeability, pressure and temperature and decreases with increasing NaCl concentration. However, the relationship between pressure and the diffusion coefficient is not linear. As the pressure gr... [more]

Carbon emission reduction is now a global issue, and the prediction of carbon trading market prices is an important means of reducing emissions. This paper innovatively proposes a second decomposition carbon price prediction model based on the nuclear extreme learning machine optimized by the Sparrow search algorithm and considers the structural and nonstructural influencing factors in the model. Firstly, empirical mode decomposition (EMD) is used to decompose the carbon price data and variational mode decomposition (VMD) is used to decompose Intrinsic Mode Function 1 (IMF1), and the decomposition of carbon prices is used as part of the input of the prediction model. Then, a maximum correlation minimum redundancy algorithm (mRMR) is used to preprocess the structural and nonstructural factors as another part of the input of the prediction model. After the Sparrow search algorithm (SSA) optimizes the relevant parameters of Extreme Learning Machine with Kernel (KELM), the model is used fo... [more]

The Paris Agreement was signed by 195 nations in December 2015 to strengthen the global response to the threat of climate change following the 1992 United Nations Framework Convention on Climate Change (UNFCC) and the 1997 Kyoto Protocol [...]

This study investigates the influence of moisture content on the potential oxidation efficiency of methane (CH4) of biofiltration systems treating landfill gas containing high oxygen concentrations. Column tests filled with compost with different moisture contents (20%, 30%, and 40%) loaded with different methane flows were set up on a laboratory scale. Analyzing the results the following evidences can be summarized: With low methane load (<100 g CH4 m−2 d−1), a moisture content of 20% was not enough to support bacterial activity, while a moisture content of 40% advantaged the compost respiration assisting it to become the dominating process; with higher methane load (100−300 g CH4 m−2 d−1), a moisture content of 30% resulted in an optimal value to support methanotrophic activity showing the highest CH4 concentration reduction; moving on to a CH4 load above 300 g CH4 m−2 d−1, the inhibition of methanotrophic activity emerged independently to the moisture content of the filter media.... [more]

This paper reports the regulated, unregulated, and particle number emissions from six high-mileage, China-4 compliant, dedicated methanol taxis over the new European driving cycle. Compared to new vehicles, carbon monoxide, total hydrocarbons, and nitrogen oxides emissions from in-use methanol taxis increased by 76.1%, 40.2%, and 179.8%, respectively. Still, they managed to meet China-4, indicating good in-service conformity. In the test fleet, the test vehicles with longer mileage inclined to emit higher carbon monoxide and total hydrocarbons emissions. Formaldehyde emissions from these field-aged taxis ranged from 1.06 to 2.33 mg/km, which were similar to or lower than those from previously reported pre-Euro-5 gasoline vehicles. One of the six test vehicles produced extraordinarily high unburned methanol emissions, which was about ten times higher than the rest of the properly operating vehicles due to possible misfire, suggesting that unburned methanol will be the primary stress for... [more]

Thermal interactions through longwave radiation exchange between buildings, especially in a dense urban environment, can strongly influence a building’s energy use and environmental impact. However, these interactions are either neglected or oversimplified in urban building energy modeling. We developed a new feature in EnergyPlus to explicitly consider this term in the surface heat balance calculations and developed an algorithm to batch calculating the surrounding surfaces’ view factors using a ray-tracing technique. We conducted a case study with a district in the Chicago downtown area to evaluate the longwave radiant heat exchange effects between urban buildings. Results show that the impact of the longwave radiant effects on annual energy use ranges from 0.1% to 3.3% increase for cooling and 0.3% to 3.6% decrease for heating, varying among individual buildings. At the district level, the total energy demand increases by 1.39% for cooling and decreases 0.45% for heating. We also ob... [more]

Glazing is considered as a preferred solution for the buildability, aesthetic, and comfort of commercial buildings since glass cover can protect occupants from external environmental conditions, ensure the light transmission, and provide view and ventilation. At the same time, in the context of climate change and global warming, the use of renewable solar energy, such as solar and wind power, are encouraged to be utilized. Specifically, solar energy has become a renewable energy source that is clean and endless, at reasonable cost, to contribute to energy security as well as ensure sustainable development. Therefore, the study proposes a method for supporting the decision making in installing solar panels on vertical glazing façades of the building in the worst case that the remaining radiant energy from the sun was only transferred to the inside of the building. The Life Cycle Assessment and the Life Cycle Costing methodologies are applied to consider both environmental and economic a... [more]

To resolve the protection issues caused by high penetration of distributed energy resources, this paper proposes an efficient protection scheme for microgrids based on the autocorrelation of three-phase current envelopes. The proposed strategy uses a squaring and low-pass filtering approach for evaluating the envelope of the current signal. Then, the variance of the autocorrelation function is used to extract the hidden information of the distorted envelope to detect the fault signatures in the microgrid. Furthermore, the reactive power is used for determining the fault direction. The performance of the proposed protection scheme was verified on a standard medium-voltage microgrid by performing simulations in the MATLAB/Simulink environment (Version: R2017b). The proposed scheme was shown to be easy to implement and have good performance under looped and radial configuration for both grid-connected and islanded operation modes. The simulation results showed that the scheme could not on... [more]

A bi-level electricity market clearing process was developed for energy and reserve allocation in the day-ahead market using AC Optimal Power Flow (ACOPF). An energy-consuming entity (ECE) which does not want its cleared demand to be curtailed, even if any contingency occurs, purchases power from the reserve market at a higher rate. The proposed model helps the ECE to secure a reserve market allocation at the price of the energy market in the real-time market settlement. Various market models were formulated for the evaluation of locational marginal pricing (LMP) in the energy market and locational contingency marginal reserve pricing (LCMRP) in the reserve market. The impact of wind farms on LMP, LCMRP, and negative LMP was analyzed. The increase in demand requirement in the deregulated environment was balanced in the proposed models by the thermal−wind coordination dispatch. The market models were illustrated with the IEEE 30 bus system.

Even if current action towards sustainability in architecture mainly concerns single buildings, the responsibility of the urban shape on local microclimate has largely been ascertained. In fact, it heavily affects the energy performances of the buildings and their environmental behaviour. This produces the necessity to broaden the field of intervention toward the urban scale, involving in the process different disciplines, from architecture to fluid dynamics and physics. Following these ideas, the Masterplan for the Campus of the University Eduardo Mondlane in Maputo (Mozambique) develops a methodology that integrates microclimatic data and analyses from the initial design model. The already validated software ENVI-met (Version 4.4, ENVI_MET GmbH, Essen, Germany) acts as a useful ‘feedback’ tool that is able to assess the microclimatic behaviour of the design concept, also in terms of outdoor comfort. In particular, the analysis focused on the microclimatic performances of a ‘C’ block... [more]

The development of new climate change policies has increased the motivation to reduce energy use in buildings, as reflected by a stringent regulatory landscape. The construction industry is expected to adopt new methods and strategies to address such requirements, focusing primarily on reducing energy demand, improving process efficiency and reducing carbon emissions. However, the realisation of these emerging requirements has been constrained by the highly fragmented nature of the industry, which is often portrayed as involving a culture of adversarial relationships and risk avoidance, which is exacerbated by a linear workflow. Recurring problems include low process efficiency, delays and construction waste. Building information modelling (BIM) provides a unique opportunity to enhance building energy efficiency (EE) and to open new pathways towards a more digitalised industry and society. BIM has the potential to reduce (a) waste and carbon emissions, (b) the endemic performance gap,... [more]

This paper focuses on Hilton’s proprietary sustainability performance measurement system (SPMS) called LightStay (2010−2017). It draws on the case-study method and relies on three principal sources of information: in-house documents, a questionnaire completed by users of LightStay and interviews conducted with external experts. Specifically, the paper traces the system’s evolution and highlights its distinctive features, exploring the challenges and trade-offs related to the design and workings of an SPMS in a hotel multinational. The study shows, among other things, how LightStay, using an internationally approved methodology of data collection, calculation, metrics and benchmarking, compares a hotel’s predicted and actual environmental performance. It concludes by arguing that LightStay is a holistic platform that not only integrates precise measurement of the firm’s environmental effects with its business operations and strategic goals but also acts as a repository of sustainability... [more]

Electricity generation via renewable sources is emerging as a possible solution to meet the growing demand for electricity worldwide. Additionally, the need to produce clean energy, with little or no pollutants or greenhouse gas emission is paramount. Due to these factors, wind farms are noticeably increasing in number, especially in Brazil. However, the vast size of the country and the poor quality of its infrastructure are among several factors that make it difficult for effective decision-making to accelerate the growth of this segment in Brazil. With the purpose of assisting government agencies, regulatory agencies and other institutions in this area, the use of a multi-criteria selection method called the analytic hierarchy process is proposed here to assist in decision-making and to select priority regions for implementing wind farms. This work focuses on a case study of the state of Bahia, in which 27 territories were selected for an installation priority evaluation. Computation... [more]

A major energy transformation is required to prolong the rise in global temperature below 2 °C. The Indonesian government (GoI) has set a strategy to gradually remove fuel subsidies to meet its 2050 ambitious energy targets. Using a recursive dynamic computable general equilibrium (CGE) model, the present study aimed to determine whether or not the current energy subsidy reforms would meet the targets of both energy mix and energy intensity. It also incorporated the environmental aspect while developing a source of a detailed database in the energy sector. The energy subsidy reform policy (followed by an increase in infrastructure and renewable energy investments) could be the most appropriate alternative policy if the government aims to reduce energy intensity and emission, as well as improve energy diversification without pronounced reductions in the sectorial and overall economy. However, all simulations suggested that the removal of energy subsidy does not enough in attaining the t... [more]

In this article, a thermodynamic, exergy, and environmental impact assessment was carried out on a Brayton S-CO2 cycle coupled with an organic Rankine cycle (ORC) as a bottoming cycle to evaluate performance parameters and potential environmental impacts of the combined system. The performance variables studied were the net power, thermal and exergetic efficiency, and the brake-specific fuel consumption (BSFC) as a function of the variation in turbine inlet temperature (TIT) and high pressure (PHIGH), which are relevant operation parameters from the Brayton S-CO2 cycle. The results showed that the main turbine (T1) and secondary turbine (T2) of the Brayton S-CO2 cycle presented higher exergetic efficiencies (97%), and a better thermal and exergetic behavior compared to the other components of the System. Concerning exergy destruction, it was found that the heat exchangers of the system presented the highest exergy destruction as a consequence of the large mean temperature difference be... [more]

The Czech Republic is introducing new technological concepts for mitigation of greenhouse gases (GHG) in coal-based energy industries. One such technology, in power plants, is post combustion CO2 capture from flue gases by activated carbon adsorption. A life cycle assessment (LCA) was used as the assessment tool to determine the environmental impacts of the chosen technology. This article focuses on a comparative LCA case study on the technology of temperature-swing adsorption of CO2 from power plant flue gases, designed for the conditions of the Czech Republic. The LCA study compares the following two alternatives: (1) a reference power unit and (2) a reference power unit with CO2 adsorption. The most significant changes are observed in the categories of climate change potential, terrestrial acidification, and particulate matter formation. The adsorption process shows rather low environmental impacts, however, the extended LCA approach shows an increase in energy demands for the proce... [more]

We investigate with this study the effectiveness of mechanically activated serpentinite in capturing Cu (II) from the multi-constituent acidic wastewater of the pit lakes of the Agios Philippos mine (Greece), proposing specific areas with serpentinites suitable for such environmental applications. For this purpose ultramafic rock samples that are characterized by variable degrees of serpentinization from ophiolitic outcrops exposed in the regions of Veria-Naousa and Edessa have been examined regarding their capacity to remove the toxic load of Cu (II) from wastewater after having been mechanically activated through a Los Angeles (LA) machine (500, 1000 and 1500 revolutions). The more serpentinized and mechanically activated samples, as they have been characterized after a combination of various mineralogical, petrographic, geochemical analyses as well as after different stresses of abrasion and attrition, seem to be more effective in Cu removal than the less serpentinized ones. Selecti... [more]

Atmospheric stability has been studied for decades. There are several methodologies that evolved over the years. In this study, a special experimental meteorological mast that has been erected to a complex site has been used to calculate dimensionless Obukhov length ( ζ = z L ) , dimensionless momentum ( φ m ), and heat coefficients ( φ h ). The results are compared with the ones from average value approaches: Richardson number, flux-profile (F-P) relations, and wind shear exponent methods. The results show that the estimated ζ values, using the bulk Richardson number, get along well with the reference ζ within the neutral and stable regimes. F-P relations and wind shear exponent methods result in the best agreement for stable and neutral regimes. Nevertheless, average oriented methods are not reliable for the other regimes.

Urban heat island (UHI) effects significantly impact building energy. Traditional UHI investigation methods are often incapable of providing the high spatial density of observations required to distinguish small-scale temperature differences in the UHI. Crowdsourcing offers a solution. Building cooling/heating load in 2018 has been estimated in London, UK, using crowdsourced data from over 1300 Netatmo personal weather stations. The local climate zone (LCZ) scheme was used to classify the different urban environments of London (UK). Inter-LCZ temperature differences are found to be generally consistent with LCZ temperature definitions. Analysis of cooling degree hours in July shows LCZ 2 (the densest urban LCZ in London) had the highest cooling demand, with a total of 1550 cooling degree hours. The suburban related LCZs 5 and 6 and rural LCZs B and D all had about 80% of the demand of LCZ 2. In December, the rural LCZs A, B and D had the greatest heating demand, with all recording arou... [more]

In the last few years, several countries have accomplished their determined renewable energy targets to achieve their future energy requirements with the foremost aim to encourage sustainable growth with reduced emissions, mainly through the implementation of wind and solar energy. In the present study, we propose and compare five optimized robust regression machine learning methods, namely, random forest, gradient boosting machine (GBM), k-nearest neighbor (kNN), decision-tree, and extra tree regression, which are applied to improve the forecasting accuracy of short-term wind energy generation in the Turkish wind farms, situated in the west of Turkey, on the basis of a historic data of the wind speed and direction. Polar diagrams are plotted and the impacts of input variables such as the wind speed and direction on the wind energy generation are examined. Scatter curves depicting relationships between the wind speed and the produced turbine power are plotted for all of the methods and... [more]

This article reviews a method of hydrogen production based on partial non-catalytic oxidation of natural gas in an original synthesis gas generator. The working principles of the unit are similar to those of liquid-propellant rocket engines. This paper presents a description of the operation and technical characteristics of the synthesis gas generator. Its application in the creation of small-scaled plants with a capacity of up to 5−7 thousand m3/h of hydrogen is justified. Hydrogen production in the developed installation requires a two-stage method and includes a technological unit for producing a hydrogen-containing gas. Typical balance compositions of hydrogen-containing gas at the synthesis gas generator’s outlet are given. To increase the hydrogen concentration, it is proposed to carry out a two-stage steam catalytic conversion of carbon monoxide contained in the hydrogen-containing gas at the synthesis gas generator’s outlet using a single Cu−Zn−cement-containing composition. Ba... [more]

Smart cities are an extremely important, multi-faceted subject, both in terms of their practical aspects and in terms of research. This is expressed, among other things, in the multitude of approaches to this concept. These approaches differ based on the emphasis placed on individual aspects: some focus more on technology, and others put more weight on social issues, while still others value sustainable development issues. Currently, an important topic of discussion about the development of the smart city—the importance of which has become even greater in the context of the COVID-19 pandemic—is the digital transformation of the city. The use of robotic process automation (RPA) tools can be a part of such a transformation, as such tools, using advanced software, enable the automation of those tasks carried out thus far by humans. Although such an approach has, to date, been widespread in the case of enterprises (in particular, those operating in the financial and BPO/SSC sectors, but le... [more]

In this paper, the authors discuss the problem of the influence of the level of electrification in African countries on their sustainable development. The first aim of the article is to determine the relationship between changes in the electrification index and changes in the indicators showing individual components of sustainable development for African countries. The analyzed indicators of sustainable development include GDP per capita, Human Deveopment Index (HDI), and the CO2 emissions per capita indicator. The second goal of the article was to develop a synthetic indicator of sustainable development. This study uses the method of relationship research based on Gray Systems Theory—Gray Incidence Analysis. The main conclusion from the research carried out is that improving access to electricity is a necessary condition for the sustainable development of African countries. The lack of improvement in the availability of electricity is a basic barrier to development, especially in the... [more]