Low Pollutant Emissions Research Articles

Application and Development of Selective Catalytic Reduction Technology for Marine Low-Speed Diesel Engine: Trade-Off among High Sulfur Fuel, High Thermal Efficiency, and Low Pollution Emission

In recent years, the International Maritime Organization (IMO), Europe, and the United States and other countries have set up different emission control areas (ECA) for ship exhaust pollutants to enforce more stringent pollutant emission regulations. In order to meet the current IMO Tier III emission regulations, an after-treatment device must be installed in the exhaust system of the ship power plant to reduce the ship NOx emissions. At present, selective catalytic reduction technology (SCR) is one of the main technical routes to resolve excess NOx emissions of marine diesel engines, and is the only NOx emission reduction technology recognized by the IMO that can be used for various ship engines. Compared with the conventional low-pressure SCR system, the high-pressure SCR system can be applied to low-speed marine diesel engines that burn inferior fuels, but its working conditions are relatively harsh, and it can be susceptible to operational problems such as sulfuric acid corrosion, salt blockage, and switching delay during the actual ship tests and ship applications. Therefore, it is necessary to improve the design method and matching strategy of the high-pressure SCR system to achieve a more efficient and reliable operation. This article summarizes the technical characteristics and application problems of marine diesel engine SCR systems in detail, tracks the development trend of the catalytic reaction mechanism, engine tuning, and control strategy under high sulfur exhaust gas conditions. Results showed that low temperature is an important reason for the formation of ammonium nitrate, ammonium sulfate, and other deposits. Additionally, the formed deposits will directly affect the working performance of the SCR systems. The development of SCR technology for marine low-speed engines should be the compromise solution under the requirements of high sulfur fuel, high thermal efficiency, and low pollution emissions. Under the dual restrictions of high sulfur fuel and low exhaust temperature, the low-speed diesel engine SCR systems will inevitably sacrifice part of the engine economy to obtain higher denitrification efficiency and operational reliability.

Multi-dimensions analysis of solar hybrid CCHP systems with redundant design

The combination of photovoltaic cells and cooling, heating, and power (PV–CCHP) systems has the characteristics of high energy efficiency, low pollutant emissions, and good economic benefits. PV-CCHP systems contain multiple types of equipment, and every kind of equipment may malfunction during operation. Redundant design can effectively improve the reliability and availability of systems. This paper compares and analyzes the redundantly designed PV-CCHP (RPV-CCHP) system, the multi-device parallel operation without redundancy design PV-CCHP (MPV-CCHP) system, and the single device operation PV-CCHP (SPV–CCHP) system performance in economy, environment, and energy. A two-stage optimization strategy is proposed on the traditional operation mode, and an office building in Beijing takes as the case study. The result shows that the integrated performance of the RPV-CCHP system is the best, followed by the MPV-CCHP system and, finally, the SPV-CCHP system. The primary energy saving ratio, carbon dioxide emission reduction ratio, and annual total cost saving ratio of the RPV-CCHP system are significantly superior to the MPV-CCHP and SPV-CCHP. Furthermore, a sensitivity analysis of the three systems was carried out to show how the integrated performance will change when electricity and natural gas prices change.

Optimal combustion calibration for direct-injection compression-ignition engines using multiple injections

Multiple injections are widely used for direct-injection compression-ignition engines to mainly increase efficiency, lower pollutant emissions, and increase exhaust enthalpy. However, with each additional injection the degrees of freedom increase, which makes finding an optimal injection input by design of experiments a time-consuming task. In this paper, we present a model-based calibration method that determines the number of injections for a predefined set of requirements. First, we derive a zero-dimensional crank-angle-resolved cylinder process model based on first principles. The model includes a fuel injector and requires a low calibration effort. Second, we use this model in an optimal control problem that minimizes the fuel consumption subject to several constraints such as load, maximal pressure, maximal pressure gradient, engine-out temperature, and the limitations of the fuel injector. The optimal injector inputs are used as feedforward control signals on a real engine to validate the simulative results. In general, the experimental results are in good agreement with those obtained in simulations. Finally, we compare our approach to a state-of-the-art method known as pressure reference tracking which consists of two separate steps: the creation of an optimal pressure reference and the tracking by a discrete injector. We show that our method, which combines these two steps in a single optimization problem, results in an increase in indicated efficiency compared to the solution obtained by pressure reference tracking.

Reduction of operation temperature in SOFCs utilizing perovskites: Review

Fuel cells are electrochemical devices utilized for converting chemical energy to electrical energy. Solid Oxide Fuel Cells (SOFCs) have several advantages over other kinds. For instance, high energy efficiency expanded fuel flexibility, low environmental pollutant emission are the properties of SOFCs that make them superior to other fuel cell types. Due to these special characteristics, SOFCs are gained a great deal of attraction. These fuel cells consist of different main operating parts, a cathode, an anode, and electrolyte which each of them demands special materials to operate with the most efficiency. SOFCs mostly operate in high temperatures (800-1000 ᵒC). Reducing the operating temperature to lower than 600 ᵒC or intermediate temperatures 600-800 ᵒC is one of the methods that can make them more practical devices. Perovskite oxides can be used effectively as all main parts of SOFCs because of their excellent properties like electrical and ionic conductivities, oxygen ion vacancies, great catalytic properties, thermal durability, and chemical stability to decrease the operating temperature. In this review, numerous perovskite-based materials utilized in the anode and the cathode electrodes of SOFCs are investigated in the most recent, advanced, and novel works. The perovskite materials, their properties, and their influence on the fuel cell’s performance, and in some cases the sulfur tolerance of the materials when H2S co-exists in the fuel of the fuel cell are reviewed in this paper Adding different dopants in A-site and B-site of the perovskite oxides is the most effective way to modify the characteristics of the materials. This review can provide great data on the possible perovskite oxides with the capability of enhancing the efficiency of SOFCs by reducing the operating temperature, and their most decisive and significant characteristics, like composition, structure, electrical conductivity, electrochemical and mechanical properties for research groups working on solid oxide fuel cells.

Effects of Injection Overlap and EGR on Performance and Emissions of Natural Gas HPDI Marine Engine

ABSTRACT Due to the increasingly stringent emission regulations and the growing concern about energy hazard, natural gas (NG) has emerged as an alternative fuel with abundant reserves, low cost, high combustion performance and low pollutant emissions. In this study, a NG high pressure direct injection (HPDI) model is embedded in a Cummins ISX marine medium-speed four-stroke natural gas-diesel dual fuel (NGDDF) engine model. The strategies with different injection overlap of NG and pilot diesel oil (PDO) and different exhaust gas recirculation (EGR) were investigated, the following conclusions are drawn. At the same EGR rate, the injection start point of NG (SOING) has impact on the compression end pressure to some extent, while the injection end point of the pilot diesel oil (EOIPDO) makes little difference to the compression end pressure. With the increase of SOING, the maximum pressure (PMax) rises gradually. When the SOING remains unchanged, the longer the pilot diesel oil (PDO) injection lasts, the higher the PMax. The heat release rate (HRR) of HPDI engine has two peaks. The first one decreases as the EGR rate rises, while the other is inversely proportional only to the EGR rate. As the EGR rate increasing, the position of the second peak of HRR is increasingly delayed, irrespective of the injection strategy used. At the same EGR rate, the overlapping injection strategy has only a limited impact on the maximum in-cylinder temperature (about 42 K) and the soot emission (about 0.003 g/kwh). The first stage of nitrogen oxides (NOX) generation is closely related to the EGR rate. The higher the EGR rate, the longer the interval between the first and second stage of NOX generation. Though both reasonable injection overlap and delay of EOIPDO are conducive to reduce pollutant emissions, it remains necessary to delay the position of the overlap angle as much as possible, and the emission reduction effect of injection overlap will diminish as the EGR rate increasing. Either the injection overlap formed by delaying EOIPDO or advancing SOING has a positive impact on indicated mean effective pressure (IMEP). The introduction of EGR will increase indicated specific fuel consumption (ISFC) of the engine, while the injection overlap strategy can be used to reduce it by 5.35 g/kwh. In order to meet the Tier III standard, the combination of injection strategy B and 18% EGR can be considered as the most effective solution for soot, ISFC and IMEP factors.

Review and Development of Anode Electrocatalyst Carriers for Direct Methanol Fuel Cell

Direct methanol fuel cell (DMFC) can be used as a promising portable power device due to its excellent energy conversion efficiency and low pollutant emissions. The performance of DMFC largely depends on the anode electrocatalyst for methanol oxidation reaction (MOR). As an important part of the electrocatalyst, the carrier greatly affects the activity and stability of the electrocatalyst. Herein, the research progress of carbonaceous carriers (such as activated carbon, nanostructured carbon), noncarbonaceous carriers (metal compounds), and conducting polymers in DMFC is reviewed. Furthermore, an overview of the development of self‐supporting carriers for flexible DMFC electronics is presented. Its role as the most ideal DMFC carrier in the future provides new ideas for the challenges and development of the commercialization of flexible DMFC.

Improving Combustion Technology for Cooking Activities for Pollutant Emission Reduction and Carbon Neutrality

Inefficient residential solid fuel combustion contributes significantly to ambient and indoor air pollutants. It consumes large quantities of fuel and produces harmful effects on health. Improvements in residential biomass cooking stoves have great potential for energy savings and emission reduction. This study presents an advanced biomass gasifier cooking stove to overcome the disadvantages of high-pollutant emissions from widely used stoves in China. The most innovative features of the stove are (1) negative pressure produced by a jet fan located at the junction of the chimney, and (2) combustion and carbonization processes taking place in the same chamber. Compared with a traditional chimney stove, the advanced biomass gasifier cooking stove presented higher TE (thermal efficiency) and comprehensively lower pollutant emissions when raw crop straws, crop straw briquettes, and pellets were burned in it. Approximately 40% CO2 and 90% of PM2.5 (the aerodynamic diameter was less than or equal to 2.5 μm) EFs (emission factors) were eliminated, and TE drastically tripled. Furthermore, biomass briquette/pellet was identified as more suitable than raw biomass as a fuel to be burned in the new stove, especially because the raw biomass displayed an increase in the EFs of As, Se, and Pb when burned in the new stove. The advancement in biomass cooking stove technology is a practical approach to reducing the emissions of CO2, PM2.5, and other hazardous pollutants.

MID-IR laser absorption spectroscopy of 1- and 2-butanol in a shock tube facility

E-fuels are CO2-neutral fuels generated using renewable fuels such as wind and solar energy, where the carbon is taken out of the atmosphere or from biomass. One of the suitable e-fuel classes are alcohols with a low number of carbon atoms. Obtaining the low pollutant emissions on combusting liquid fuels such as fuel oil and kerosene, e-fuels with lean, premixed, pre-vaporized (LPP) concept plays a pivotal role. So, in this framework, the present work focuses on the combustion properties in the low pressure and high-temperature regime of 1- and 2-butanol isomers to evaluate their potential as future sustainable aviation fuels. The study investigates the fuel-lean conditions of 1- and 2-butanol in the fuel/oxygen equivalence ratios of 0.25, 0.5, and 0.9 relevant to the LPP (Yan et al. 2015) combustion concept for its applications in aviation. The flame chemistry of butanol isomers has been widely investigated; however, more investigations on ignition chemistry are needed. For this, tunable diode laser absorption spectroscopy is utilized to obtain the time-resolved CO formation history, ignition delay time (IDT), and progress in the butanol consumption by applying the central wavelength of 2059.91 cm−1 and 2948.27 cm−1, respectively. The measurements were performed in the temperature range of 1150–1500 K near 1.5 and 3 bar. The experimentally obtained IDT were validated with several recent reaction mechanisms available in the literature. The correlation between measured IDT, CO formation, and butanol consumption data was captured by the simulations satisfactorily. However, the CO formation from the simulation shows disagreement with the experimentally obtained signal. In addition, discrepancies in the absolute CO were observed between simulation and experiment. Moreover, a sharp drop was observed for the butanol consumption histories predominantly at ϕ= 0.9 in both 1-and 2-butanol, which could not be predicted from the available mechanisms. Furthermore, by updating the rate constants of several key reactions near the sharp fall region, a better prediction from the mechanism was seen. The time-resolved CO profile and butanol consumption history, along with the absorption cross-section data for 1- and 2-butanol isomers, are reported for the first time in this paper.

Boosting Mass Exchange between Pd/NC and MoC/NC Dual Junctions via Electron Exchange for Cascade CO2 Fixation.

Merging existing catalysts together as a cascade catalyst may achieve "one-pot" synthesis of complex but functional molecules by simplifying multistep reactions, which is the blueprint of sustainable chemistry with low pollutant emission and consumption of energy and materials only when the smooth mass exchange between different catalysts is ensured. Effective strategies to facilitate the mass exchange between different active centers, which may dominate the final activity of various cascade catalysts, have not been reached until now, even though charged interfaces due to work function driven electron exchange have been widely observed. Here, we successfully constructed mass (reactants and intermediates) exchange paths between Pd/N-doped carbon and MoC/N-doped carbon induced by interfacial electron exchange to trigger the mild and cascade methylation of amines using CO2 and H2. Theoretical and experimental results have demonstrated that the mass exchange between electron-rich MoC and electron-deficient Pd could prominently improve the production of N,N-dimethyl tertiary amine, which results in a remarkably high turnover frequency value under mild conditions, outperforming the state-of-the-art catalysts in the literature by a factor of 5.9.

Exergy and Exergoeconomic Analyses of Air Conditioning Applications Integrated with an Air Membrane Exchanger

The results obtained from the exergoeconomic and exergy analysis of a model of a generic air conditioning (A/C) system without and with an air membrane exchanger using three commercially available refrigerants: R410A, R407C, and R134a, are reported. The model used specialized software that was validated against recently published data and showed good agreement. A/C systems are energy intensive and consume a significant portion of global electricity. Improving their efficiency by even a small amount will produce considerable savings, reduce running costs, and lower pollution emissions. The efficiency of the same A/c system without and with a membrane was investigated for different ambient temperatures, relative humidities (RHs), and pressure ratios of the compressor. It was shown that the inclusion of a membrane improved the efficiency of the system for all three refrigerants tested, particularly at higher ambient temperature. Both the coefficient of performance and exergetic efficiency reduced with the increase in the pressure ratio due to increasing fuel exergy and losses. In all system components except one, it was found that the source of the cost is inefficiencies; hence, increasing the efficiency at the expense of the non-exergy cost will improve the cost effectiveness of the entire system.

Effect of negative valve overlap in a heavy-duty methanol-diesel dual-fuel engine: A pathway to improve efficiency

Methanol (MeOH) is a promising low-carbon liquid fuel to provide global energy security with a potential to achieve net-zero greenhouse gas emissions in transport sector. However, its utilization in diesel engines at high MeOH substitution ratios (MSR) suffers from misfire or high pressure rise rates owing to its distinct physio-chemical properties. This issue is addressed in the present study by adopting negative-valve overlap (NVO) and hot residual gases from the previous cycle. Experiments are performed in a single-cylinder heavy-duty CI engine for a constant MSR (90% energy based) and an engine speed of 1500 rpm. The aim of the study is to investigate the effects of 1) NVO period, 2) charge-air temperature (Tair), 3) MeOH lambda (λMeOH) on the MeOH-diesel dual-fuel (DF) combustion in NVO mode, and 4) to demonstrate the implications of NVO in yielding high net-indicated efficiency (ηind) together with low pollutant emissions at a wide range of engine operating loads (40–90%). The results show that the hot residual gases from the previous cycle enhance the reactivity of the fresh MeOH-air mixture by inducing slow oxidation processes before TDCf. The slow pre-flame oxidation processes are disruptive or oscillatory in nature, wherein NVO period, Tair and λMeOH can be used to control these processes and their induced reactivity enhancing capability. It is noticed that the pre-flame oxidation processes and the main combustion have a direct correlation between them. Based on the control strategy, the MeOH-diesel combustion in the NVO mode produced on average ηind of approx. 53% accompanied with very low NOx emission of 1.1 g/kWh at a wide range of engine operating loads (40–90%). Additionally, on average the combustion phasing (CA50) is maintained at ∼ 2 oCA aTDC, while the combustion stability remains high (COVIMEP ∼ 3.5%).

A novel and efficient cogeneration system of waste heat recovery integrated carbon capture and dehumidification for coal-fired power plants

Presently, coal-fired power plants are facing the situation of low energy utilization and high pollution emission, to achieve the goal of energy conservation and emission reduction, the implementation of waste heat recovery is imperative. Therefore, a novel and efficient cogeneration system of waste heat recovery integrated carbon capture and dehumidification, is developed in this investigation. The mathematical model of the system is first established and verified, and the performance comparison of high-temperature cycle, cooperativity discussion of cascade power generation system, sensitivity analysis of working parameters, and positive effect of dehumidification system, are then carried out. After mastering the change rule, the three-objective optimization is performed with the objectives of maximum power generation, minimum payback time, and maximum carbon capture capacity. Eventually, the benefit of the coal-fired power plant and cogeneration system is comprehensively evaluated. The numerical results display that the power generation and thermal efficiency of the coal-fired power plant are increased by 13.34% and 5.74%, under maximum working condition, with additional cooling capacity, moisture removal rate, and carbon capture capacity of 135.58 MW, 15.69 g/kg, and 130.99 kg/s, can recover capex within 5.36 years. It conforms to the concept of green and efficient development, complies with the requirements of carbon neutralization, and lays a theoretical foundation for the promotion of cogeneration system in coal-fired power plants.

Ethanol spray tubular flame established in a swirling air flow

This study proposes an efficient technique to burn ethanol spray in an intense swirling air flow and investigates the mechanism of flame lift-off. On the basis of typical tubular burners for gaseous fuels, ethanol spray was axially induced and mixed with the tangentially injected air under room temperature, yielding the ethanol spray tubular flames under various operating conditions. The results show that from an ultra-lean condition of global equivalence ratio of 0.1 to the rich condition, two typical flames, namely attached and lifted tubular flames, were established. Then, the structure of the ethanol spray tubular flame was specified by temperature measurements, OH-PLIF imaging, indicating its overwhelming aerodynamic and thermal stability with low pollutant emissions. Meanwhile, a flue gas analyzer was used to characterize the gas composition in the hot exhaust. It is found that the burner can achieve very low emissions of both CO and NOx, illustrating high combustion completeness under both attached and lifted flame conditions. To give a better understanding and make fully utilization of spray tubular flames, a parametric study was carried out to investigate the effects of the tangentially swirling air flow, the flow rate and oxygen concentration of atomizing gas, and the flow rate of liquid ethanol. Generally, an attached flame is lifted under a higher tangential velocity of air flow; increasing oxygen concentration of the atomizing gas flow leads to the height decrease of the flame lift-off, even the reattachment of the lifted flame; by raising the ethanol flow rate to exceed a critical value, the flame also lifts off. Furthermore, the evaporation time of droplets, residence time and chemical reaction time were calculated to quantify the flame lift-off behavior. The lifted flame can be established only when the evaporation time is larger than both the reaction time and the residence time.

Investigation of flame acoustic excitation of a gas burner

Combustion in ultrasonic field is a promising combustion technology as it provides high combustion efficiency and low pollutant emission. Imposing acoustic oscillations on flame front enhances the turbulent mixing, resulting in reduced NOx and CO emissions and reduced flame length. The acoustic field can be generated by using two types of devices: the piezoelectric devices and the sonic nozzle. In this paper, the combustion characteristics in ultrasonic field generated by a sonic nozzle attached to a gas burner have been experimentally and numerically studied. The acoustic intensity can be adjusted by modifying the pressure of feeding air or the nozzle size. The numerical model was validated against experimental data on CO concentration and temperature and was used to study the burner performance for different operation conditions (different air pressures and different nozzle sizes). For a given air pressure and nozzle size, the NOx emissions drop from 200 mg/Nm3 to 150 mg/Nm3, the CO emissions decrease from 125 mg/Nm3 to 100 mg/Nm3 and combustion efficiency increases from 94% to about 96%. The temperature field, with slightly lower temperatures, has more uniform distribution in the flame.

Evaluation of Series and Parallel Hybrid Propulsion Systems for UAVs Implementing Distributed Propulsion Architectures

Current environmental policies for the aviation sector motivate the use of cleaner propulsion alternatives in order to reduce their CO2 footprint and noise pollution in the coming years. In this context, hybrid propulsion systems have emerged as a potential solution, as they have demonstrated a good trade-off between performance and low pollutant emissions. The present work carries out a comparison between parallel and series hybrid propulsion systems using heterogeneous and homogeneous distributed propulsion architectures. In order to highlight the opportunities of distributed propulsion systems and validate the methodology developed, a single propulsion hybrid configuration is used as baseline case for this study. For the propulsion system sizing, this work uses a parametric modelling tool, which includes a constraint analysis coupled with a weight estimation module to determine suitable configurations for a environmental monitoring mission. The latter module includes semi-empirical correlations to size the electric and mechanical components for each propulsion setup. From the results, it has been found that for the representative case of monitoring in the Galapagos Islands, which requires an endurance of approximate 7 h, the parallel hybrid system using three distributed propulsors presents the best performance features in terms of fuel savings, showing a 34% reduction compared with the baseline case. To summarize, the main contribution of this study lies on the development of a methodology to set potential hybrid distributed propulsion configurations for UAVs aimed for determined monitoring missions.

CoFe2O4 NPs supported on graphitic carbon nitride as inexpensive electrocatalysts for methanol oxidation reaction

Electrochemical methanol oxidation (MOR) is considered an efficient route for generating clean energy with low pollutant emissions. In this study, we synthesized graphitic carbon nitride (GCN/g-C3N4) supported CoFe2O4 with different weights (100, 200, and 300 mg) of GCN by using the hydrothermal synthesis method; the synthesized cost-effective electrocatalysts have been denoted as g-CF1, g-CF2, and g-CF3 respectively. The electrochemical performance of the synthesized catalysts was studied using cyclic voltammetry (CV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS) techniques. In an alkaline medium, the g-CF2 electrocatalyst showed the best MOR activity, a larger electrochemically active surface area, and better stability compared to those of pure GCN, g-CF1, and g-CF3 electrocatalysts.

Evaluation of performance parameters on diesel engine with nano catalysts additives using dual fuel

In this study, an experim-ent is carried out to examine the engine performance of a blend of lemongrass and canola oil with neat diesel, as well as to compare the performance and emissions values of the biodiesel with diesel. TiO2 and AlO2 nano additives are combined with biodiesel to improve combustion through a catalytic effect and to shorten the ignition delay. It results in lower pollutant emissions, such as carbon monoxide and nitrogen oxides, as well as a significant increase in performance parameters such as BTE and SFC.

Designing of a Feasible Low Pollutant Grid Integrated System for Steel Plant

This paper presents system architecture with low pollutant emission for application in Bhilai Steel Plant (BSP) located in Bhilai, Chhattisgarh, India. Chhattisgarh is very rich in terms of renewable resources like solar, wind and biomass. The availability of solar radiation in this region is significantly rich for any kind of solar generation options. The government provides widespread support for the use of renewable energy, particularly solar and wind which provide power without additional pollutants. These natural energy sources can be harnessed for electricity generation which depends upon the cost and efficiency of technology that is constantly improving to reduce the costs per kWh on the source. Solar energy utilization becomes complex due to supply and demand logic. Also, a backup generating capacity is required due to its intermittent nature, escalating the cost of the system with an increasing proportion of variable renewable sources. Many countries including India, have policies to support renewable to confer priority in the grid system by subsidizing them. The analysis is carried out by investigating the potential of solar energy and collecting data from BSP. In this paper, the existing system is modeled with one option of solar grid integrated system so as to have a low pollutant emission system, together with cost-saving. The existing system is taking power from the power plant(PP) and grid NTPC-SAIL Power Corporation Limited (NSPCL) whereas a solar grid integrated system is also modeled as an option for future energy sources.

A dynamic interactive optimization model of CCHP system involving demand-side and supply-side impacts of climate change. Part I: Methodology development

Combined cooling, heating and power (CCHP) system, as a superior energy-provision form of public building, is capable of achieving flexible and stable energy provision with high energy-utilization efficiency and low pollutant emission. However, some difficulties exist in operating such a system, due to its intrinsic multi-period, multi-factor and multi-layer features. In addition, the fluctuation in weather elements under climate change exacerbates the inaccuracy of energy demand prediction and facilities’ power output calculation, leading to imbalanced energy supply and demand. To tackle this issue, a dynamic interactive model combining user-demand prediction, energy-provision calculation and operational collaborative optimization was developed. It attempts to combine the regional climate simulation (PRECIS), demand prediction (TRNSYS), equipment output calculation (mechanism modeling) and collaborative optimization (LINGO) into a general framework. The specific operation processes include: (i) utilize PRECIS model to identify the variations in temperature and radiation under climate change; (ii) exploit TRNSYS software to predict the users’ demand of targeted hospital in the future; (iii) establish a mechanism simulation model for gas turbine and estimate power output under extreme meteorological condition; (iv) incorporate the results generated by processes (ii) and (iii) into formulated operation optimization model of CCHP system; (v) generate optimal energy provision scheme adapted to climate change. This dynamic interactive model comprehensively considers the interactions at all aspects involved into operation management of CCHP system and improves the economy and adaptability of operation pattern. This study mainly addressed the problem background and model formulation. A detailed case study will be discussed in another follow-up work.

Antarctic Fish as a Global Pollution Sensor: Metals Biomonitoring in a Twelve-Year Period.

Antarctica represents a unique natural laboratory for ecotoxicological studies as it is characterized by low internal pollutants emissions but high external contamination levels. Indeed, warm temperatures promote pollutant evaporation (low latitudes), while cool temperatures (high latitudes) promote its deposition from the atmosphere on land/water. Metals are the most important pollutants in ecosystems and represent a serious and global threat to aquatic and terrestrial organisms. Since 2000, the risks posed by metals have led many States to ratify protocols aimed at reducing their emissions. Endemic Antarctic organisms represent excellent bioindicators in order to evaluate the efficacy of global measures adopted to mitigate pollutants release into the environment. In this study (supported by PNRA18-00133), we estimated the metals contamination levels and the metallothionein-1 expression in liver samples of two Antarctic fish species, the icefish Chionodraco hamatus and the red-blooded Trematomus bernacchii, collected in the same area during 2002 and 2014. The chosen area is located in the Ross Sea, a unique area as it is also isolated from the rest of the Southern Ocean. The analysis of contamination trends throughout this period showed, in both species, a significant increase over time of metals bioaccumulation and metallothionein-1 expression. In addition, our result clearly indicated that the detoxifying ability of the two organisms analyzed greatly differs, probably due to haemoglobin presence/absence. Our work represents an important early step to obtain valuable information in conservation strategies for both Antarctic and non-Antarctic ecosystems.