In recent years, the shipping industry has witnessed significant growth in its operations and is considered to be one of the fastest-growing sectors regarding energy consumption and carbon dioxide equivalent (CO2-e). Due to an increasing mandate for the reduction of carbon footprint, ports are developing policies to aid this initiative by upgrading outdated facilities, enhancing operational processes, and incorporating sustainable technologies. This study analyses the impact of the decarbonization strategies adopted in Ningbo-Zhoushan Port in an operation-based scenario and accounts for both the energy saved and for CO2 emissions. Incremental annual energy savings of 2.6, 3.0, and 3.7 (× 103 tce) in 2013, 2014, and 2015 respectively were achieved. From 2013, a 14% reduction in total CO2 emissions was achieved. However, considering annual energy consumption, an estimated reduction from 2.26 tonnes CO2-e/tce to 1.77 tonnes CO2-e/tce (approximately 22%) was obtained.

This review summarizes the recent advances in the development of electrocatalysts to facilitate the conversion of H 2 O, N 2 and CO 2 into essential global products, providing an in-depth understanding of the design of high-performance electrocatalysts.

Given that energy-efficiency policies focus on meso- or macro-scale interventions, it is imperative to establish a macro-scale evaluation approach for building retrofits to support policymaking in building energy conservation, management and sustainability. This study applies the generic idea of optimising the energy, economic and environmental outputs to propose a facile framework for evaluating the prospects of building retrofits on a macro-scale. Here, an extensive optimisation approach integrating life cycle cost evaluation and an environmental assessment is formulated, involving coordinated on-site survey, modelling and data analytics. The model framework is corroborated by a case study analysis focused on identifying the optimal retrofit solution for lowrise office buildings in Shanghai. Simulation results show that modifications in occupancy regime, improvements in natural ventilation, heating and cooling systems, cool roofs insulation and installation of renewable energy systems (such as geothermal and solar/photovoltaics) are the basic retrofit measures for a macro-scale intervention to attain maximum life-cycle benefits. Individually, an estimated investment cost for each retrofit project varied within RMB 1 - 5 million with a payback period < 13 years, depending on the building characteristics. Overall, an investment estimated at RMB 1.7 billion (with a payback period of 6 years) is required to achieve 80% energy reduction with a carbon dioxide savings of - 243 Gg-CO2/yr. In summary, this study provides a guidance framework for stakeholders to evaluate investments on retrofit projects, including existing and prospective ones.

Molybdenum disulfide (MoS2) monolayers with tertiary N atoms surrounding the single Mo-vacancy sites (MoS2_1VMo_3NS) sites have been found to exhibit outstanding adsorption activity and stability. While previous literature suggested the enhanced physical adsorption nature of CO2, N2 and H2O molecules on MoS2_1VMo_3NS sites due to promotional effects of tertiary nitrogen doping of 1 Mo-vacancy, this work highlights the adsorption and dissociation of CO2 and H2O on MoS2_1VMo_3NS sites, which are investigated using density functional theory (DFT). Compared with pure MoS2 (PMoS2), our DFT calculations reveal that the MoS2_1VMo_3NS are the most catalytically active sites. The interactions with CO2 and H2O are enhanced by the larger electron distribution with N dopants and neighboring S atoms. Climbing image nudged elastic band (Cl-NEB) and ab initio molecular dynamics (AIMD) analyses indicate that the interactions are exothermic and result in spontaneous molecular dissociation. Here, CO2 dissociates into CO* and O* on two N atoms with free energy barrier (Delta Ga) of -0.27 eV; while H2O dissociates via two mechanisms: (1) into adsorbed OH* and H* species (Delta Ga = 0.21 eV), and (2) into adsorbed O, H, H atoms (Delta Ga = 0.10 eV). The computed Delta Ga values are significantly lower than the threshold energy barrier for chemical reactions at room temperature (0.8 eV), which also indicates that CO2 and H2O dissociation is spontaneous at ambient temperature. This study shows the immense potential of MoS2_1VMo_3NS in the sustainable production of fuels and chemicals via the highly efficient dissociation of inert CO2 and H2O.

The challenge of Hg-0 emission control has necessitated the development of catalytic oxidation technology. Herein, a combination of experimental and computational approach to explore the potential over Mo-Mn catalysts was conducted. Series of catalysts were synthesized and characterized with varying Mn and Mo loading (1-10%). Among the various compositions, 1.25Mo2 Mn catalyst exhibited the best Hg-0 removal performance with Hg(0 )removal efficiency > 98% (oxidation ratio > 50%, and better stability over 10 h period at 250 degrees C). Most importantly, the synergistic interaction between MoO3 and defective delta-MnO2 nanosheet was promoted by the adjusted activation energy, bond strength, Bronsted acidic sites and defects, which facilitated the catalytic oxidation of Hg-0 to Hg2+. Furthermore, DFT calculations suggested that the role of Mo enabled the reduction in the energy barrier for the desorption step, which was defined as the rate-determining step for catalytic oxidation of Hg-0 on Mn-based catalyst.

A density functional theory study was conducted to analyze CO2 adsorption on defective and non-defective MoS2 surfaces with or without nitrogen doping. The MoS2_1V(S) and MoS2_1V mo _3N(S) were found exhibiting outstanding adsorption activity and stability, which is linked to an enhanced electron charge on the surface in the presence of vacancies and N species that alters strength and type of interactions with CO2 molecules. Results showed the dissociative chemisorption of CO2 on the MoS2_1V, and a significantly enhanced physisorption of CO2 on the MoS2_1V(Mo)_3N(S), which displays an adsorption energy of -1.818 eV compared with -0.139 eV of the pristine MoS2 surface. Meanwhile, the MoS2 _1V(S) exhibits an excellent selective adsorption of CO2 over N-2 and H2O, with the highest adsorption ratio of 5.1 and 3.5, respectively. Partial dissociation of CO2 to CO over the MoS2_1V(S) is also observed and attributed to increased covalent attractions at the vacant site, while the improved CO2 physisorption over the MoS2_1V(Mo)_3N(S) is attributed to the enhanced electrostatic interactions at the vacancy site due to N doping. These findings are confirmed by the computed vibrational frequencies of CO2 bound on these surfaces. The N-doping enabled defect engineering of MoS2 is proved effective and enhanced selective adsorption of CO2.

Hybrid Two-step synthesis method for preparation of MgAl LDHs materials for CO 2 adsorption has been employed because of the features of fast micromixing and enhanced mass transfer by using a ‘ T-mixer ’ reactor. MgAl LDHs with different morphologies were successfully obtained by three different synthesis routes: ultrasonication-intensified in ‘ T-mixer ’ (TU-LDHs), conventional co-precipitation (CC-LDHs) and ultrasonic-intensified in ‘ T-mixer ’ pretreatment followed by conventional co-precipitation (TUC-LDHs). The synthesized samples characterized by the XRD showed that LDHs formed a typical layered double hydroxide structure and no other impurities were identified in the compound. The SEM and TEM analyses also confirmed that the size distribution of TUC-LDHs was relatively uniform (with an average size of approximate 100 nm) and layered structure was clearly visible. The BET characterization indicated that such LDHs had a large surface area (235 m 2 g (cid:1) 1 ), which makes it a promising adsorbent material for CO 2 capture in practical application. It can be found that the CO 2 adsorption capacities of TU-LDHs, CC-LDHs and TUC-LDHs at 80°C were 0.30, 0.22 and 0.28 mmol g (cid:1) 1 , respectively. The CO 2 adsorption capacities of TU-LDHs, CC-LDHs and TUC-LDHs at 200°C were 0.33, 0.25 and 0.36 mmol g (cid:1) 1 , respectively. The order of CO 2 adsorption capacity to reach equilibrium at 80°C seen in Avrami model is: TU-LDHs > TUC-LDHs > CC-LDHs. The CO 2 adsorption/desorption cycling test reveals that TU-LDHs and TUC-LDHs have good adsorption stability than CC-LDHs.

The detrimental impact of urban airborne Hg-0 from fossil fuel utilization has necessitated the discovery and development of Hg-0 sensing materials for effective Hg-0 detection and mitigation of the pollutant. Earlier studies have hypothetically and experimentally supported 2-dimensional transition-metal dichalcogenides (2D TMDCs), particularly MoS2 to have excellent performance for Hg-0 removal. However, the potential of other TMDCs is yet to be investigated for Hg-0 sensor application. In this study, a total of 28 transition metals within periods 4-6 of the periodic table, excluding the lanthanides series, were examined. To ensure proper data management flow, a high-throughput data mining approach with integrated machine learning and cheminformatics simulation approaches is developed. The systemic approach integrates the Pymatgen, Factsage, Aflow and density functional theory simulation tools for accelerated discovery of suitable TMDCs from raw data via the chemical vapour reaction route. Predicted results showed that TiS2, NiS2, ZrS2, MoS2, PdS2 and WS2 exhibited TMDCs characteristics. Furthermore, first-principles calculation shows Hg-uptake capacity is in the order NiS2 > PdS2 > TiS2 > ZrS2 > WS2 > MoS2, while Hg sensing response is in the order PdS2 > MoS2 > WS2 > ZrS2 > NiS2 > TiS2. Accordingly, PdS2 depicted to be the most suitable TMDCs for airborne Hg-0 sensor application. The proposed systemic approach is an initial platform for materials discovery using integrated machine learning approaches and is well-suited for the screening and the discovery of new materials based on component-oriented structures.

Building retrofit measures provide a significant means of mitigating the effect of climate change on buildings by enhancing building energy performance at a beneficial cost-effectiveness. An insight into the applicable building retrofit measures within a climate zone will guide the optimisation framework to attaining sustainability in architecture and the built environment. This article presents a brief overview of recent studies on retrofit measures and its application on a variety of buildings in hot-summer–cold-winter climates, with emphasis on Shanghai. Findings show that the major retrofit measures include improvement in the building envelope, heating, ventilation and cooling (HVAC) and lighting, supported by photovoltaic (PV) systems, accordingly. Furthermore, the study identifies key elements and plausible challenges for the evaluation of building retrofit measures in this region. In this regard, financial barriers and lack of standards and regulatory support are the main challenges identified. These insights provide a systematic approach to guide building researchers, practitioners and decision-makers in the design and development of existing and new retrofit measures for the future of rapidly growing cities with a broad climate variation scope.

Attaining sustainability in high-rise office buildings necessitates determining the major elements and their associating impacts on the energy performance of this building typology. This study investigates the impact of architectural and engineering features on the energy performance of high-rise office buildings within a warm-summer-cold-winter climate. A rectangular building plan form with a 1:1.44 plan ratio, vertical split core position and central atrium presented the best building performance. The plan form, core position and atrium effect accounted for 59, 30 and 11%, respectively, of an estimated 20.6% building energy savings. Furthermore, exploiting passive strategies founded on the climate and building features as defined by `PassivHaus’ standards further reduced the building energy usage.

The space within the interlayer of 2-dimensional (2D) nanosheets provides new and intriguing confined environments for molecular interactions. However, atomic level understanding of the adsorption mechanism of CO2 confined within the interlayer of 2D nanosheets is still limited. Herein, we present a comparative study of the adsorption mechanisms of CO2 confined within graphene-molybdenum disulfide (MoS2) nanosheets using density functional theory (DFT). A comprehensive analysis of CO2 adsorption energies (EAE) at various interlayer spacings of different multilayer structures comprising graphene/graphene (GrapheneB) and MoS2/MoS2 (MoS2B) bilayers as well as graphene/MoS2 (GMoS2) and MoS2/graphene (MoS2G) hybrids is performed to obtain the most stable adsorption configurations. It was found that 7.5 Å and 8.5 Å interlayer spacings are the most stable conformations for CO2 adsorption on the bilayer and hybrid structures, respectively. Adsorption energies of the multilayer structures decreased in the following trend: MoS2B > GrapheneB > MoS2G > GMoS2. By incorporating van der Waals (vdW) interactions between the CO2 molecule and the surfaces, we find that CO2 binds more strongly on these multilayer structures. Furthermore, there is a slight discrepancy in the binding energies of CO2 adsorption on the heterostructures (GMoS2, MoS2G) due to the modality of the atom arrangement (C-Mo-S-O and Mo-S-O-C) in both structures, indicating that conformational anisotropy determines to a certain degree its CO2 adsorption energy. Meanwhile, Bader charge analysis shows that the interaction between CO2 and these surfaces causes charge transfer and redistributions. By contrast, the density of states (DOS) plots show that CO2 physisorption does not have a substantial effect on the electronic properties of graphene and MoS2. In summary, the results obtained in this study could serve as useful guidance in the preparation of graphene-MoS2 nanosheets for the improved adsorption efficiency of CO2.

The fluctuating energy requirement from time-varying demand changes require flexible power system to respond to the dynamic load balance. In certain scenarios, flexible power systems are necessary to provide high system efficiencies and increase the long-term economic benefits. Therefore, it is important to identify the relationship between energy requirement of a city and/or industrial zone with the dynamics of a flexible power system. In this paper, we evaluate the possible benefits of adopting the energy-cyber-physical-systems (e-CPSs) concept in realization of a flexible closed-loop control power system in case of coal-sewage sludge co-combustion. The case study performance analysis of flexibility, efficiency and economics (FEE) for a 356 MW coal-fired power plant was conducted by means of simulation in Aspen PLUS software. The analysis was based on a specific multifarious model of a dynamic power system with two energy sources and four energy products. The results confirmed that substantial advantages including a more flexible, efficient and economically viable system can be achieved by using e-CPSs based solution in different case scenarios. Moreover, following the analyzed data from the proposed case scenarios, a forecasting model for optimization of the power plant parameters based on the use of artificial neural network (ANN) was established. The results showed that ANN-based approach for predictive model is capable of modelling the complex process within an acceptable prediction accuracy. The study demonstrates that the proposed flexible closed-loop control power system based on e-CPSs concept is able to achieve higher efficiency and economic benefits compared to the traditional approaches.

Building retrofit is a critical measure for achieving sustainability in architecture and built environment. It adopts the use of a variety of retrofit technologies to enhance building energy performance at a beneficial cost-effectiveness. This may include certain approaches of building envelope improvement, mechanical systems improvement etc., while keeping the building indoor environment comfortable for human. Besides retrofitting of building envelope and the mechanical system, the improvement of operating and management practices should also be considered for whole general improvements. Therefore, this paper presents a brief overview of previous studies on retrofit measures, its application, performance evaluation and related challenges on a variety of buildings are provided. Furthermore, it defines an average mix of retrofit measures and ranks the related challenges for various building typologies. The objective of this study is to lay a foundation for building researchers, practitioners and decision-makers to effectively evaluate retrofit measures for achieving sustainable building performance globally.

Commercial buildings comprise of 25% office blocks, largest proportion in commercial sector with highest energy consumption in Shanghai. Nevertheless, the demand for office space is still rising, driven by state-owned enterprises. Unfortunately, these existing buildings are energy inefficient as they barely adapt to present varying climate conditions of the province. Owing to aggravated climate change and rising urbanization rate of Shanghai, attention should be directed towards upgrade of office buildings to meet set sustainable building standards. 3-dimensional spatial characterization using vector topographic mapping posits low-rise buildings account for more than 50% of total buildings in Shanghai. Hence, retrofitting existing low-rise office buildings will significantly contribute to building sustainability. Subsequently, a retrofit package guideline suitable for sporadic energy use mode in rapidly expanding cities like Shanghai should be established. This nascent study postulates an updated correlation between climate change and building energy consumption in Shanghai. Based on the postulation, it is recommended that the best energy conserving building retrofit package is that which can mitigate the impact of both societal factors (like urbanization rate) and climate change to building energy consumption. In general, this study defines a foundation framework for building researchers and decision-makers to effectively evaluate retrofit measures for existing buildings become sustainability in Shanghai.

The thermal characteristics of Cu-based catalysts for CO2 utilization towards the synthesis of methanol were analysed and discussed in this study. The preparation process were varied by adopting ultrasonic irradiation at various impulses for the co-precipitation route and also, by introducing ZnO promoters using the solid-state reaction route. Prepared catalysts were characterised using XRD, TPR, TPD, SEM, BET and TG-DTA-DSC. In addition, the CO2 conversion and CH3OH selectivity of these samples were assessed. Calcination of the catalysts facilitated the interaction of the Cu catalyst with the respective support bolstering the thermal stability of the catalysts. The characterisation analysis clearly reveals that the thermal performance of the catalysts was directly related to the sonication impulse and heating rate. Surface morphology and chemistry was enhanced with the aid of sonication and introduction of promoters. However, the impact of the promoter outweighs that of the sonication process. CO2 conversion and methanol selectivity showed a significant improvement with a 270% increase in methanol yield.

To improve CO2 adsorption, amine modified Layered double hydroxide (LDH) were prepared via a two stage process, SDS/APTS intercalation was supported by ultrasonic irradiation and then followed by MEA extraction. The prepared samples were characterised using Scanning electron microscope-Energy dispersive X-ray spectroscopy (SEM-EDX), X-ray Photoelectron Spectroscopy (XPS), X-ray diffraction (XRD), Temperature Programmed Desorption (TPD), Brunauer-Emmett-Teller (BET), and Thermogravimetric analysis (TGA), respectively. The characterisation results were compared with those obtained using the conventional preparation method with consideration to the effect of sonochemical functionalization on textural properties, adsorption capacity, regeneration and lifetime of the LDH adsorbent. It is found that LDHs prepared by sonochemical modification had improved pore structure and CO2 adsorption capacity, depending on sonic intensity. This is attributed to the enhanced deprotonation of activated amino functional groups via the sonochemical process. Subsequently, this improved the amine loading and effective amine efficiency by 60% of the conventional. In addition, the sonochemical process improved the thermal stability of the adsorbent and also, reduced the irreversible CO2 uptake, CUirrev, from 0.18mmol/g to 0.03mmol/g. Subsequently, improving the lifetime and ease of regenerating the adsorbent respectively. This is authenticated by subjecting the prepared adsorbents to series of thermal swing adsorption (TSA) cycles until its adsorption capacity goes below 60% of the original CO2 uptake. While the conventional adsorbent underwent a 10 TSA cycles before breaking down, the sonochemically functionalized LDH went further than 30 TSA cycles.

Amine functionalized layered double hydroxide (LDHs) adsorbents prepared using three different routes: co-precipitation, sono-chemical and ultrasonic-assisted high pressure hydrothermal. The prepared adsorbent samples were characterized using X-ray diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Scanning electron microscope-Energy dispersive X-ray spectroscopy (SEM-EDX), Temperature Programmed Desorption (TPD), Brunauer-Emmett-Teller (BET), and Thermogravimetric analysis (TGA), respectively. The performance of the prepared adsorbents was tested in a controlled thermal-swing adsorption process to measure its adsorption capacity, regeneration and cyclic efficiencies subsequently. The characterisation results were compared with those obtained using the conventional preparation routes but taking into account of the impact of sonochemical and hydrothermal pre-treatment on textural properties, adsorption capacity, regeneration and cyclic efficiencies. Textural results depicts a surge in surface area of the adsorbent synthesised by hydrothermal route (311 m(2)/g) from 25 to 171 m(2)/g for conventional and ultrasonic routes respectively. Additionally, it has been revealed from the present study that adsorbents prepared using ultrasonic-assisted hydrothermal route exhibit a better CO2 uptake capacity than that prepared using sonochemical and conventional routes. Thus, the ultrasonic-assisted hydrothermal treatment can effectively promote the adsorption capacity of the adsorbent. This is probably due to the decrease of moderate (M-O) and weak (OH- groups) basic sites with subsequent surge in the number of strong basic sites (O2-) resulting from the hydrothermal process. Moreover, the cyclic adsorption efficiency of the ultrasonic mediated process was found to be 76% compared with 60% for conventional and 53% for hydrothermal routes, respectively. According to the kinetic model analysis, adsorption mechanism is mostly dominated by physisorption before amine modification and by chemisorption after the modification process.