Emission Load Research Articles

Comparative analysis of various refrigerants used in transport refrigeration based on thermodynamics and environmental performances and cold chain management

In cooling systems, besides the refrigerant preferences, the probability of leakage due to dynamic conditions increases energy consumption and emissions directly or indirectly. In this study, thermodynamics and environmental performances of transport refrigeration systems using different and alternative refrigerants were examined. Leakage effects of refrigerants on the environment were investigated in terms of energy consumption and emission loads based on the coefficient of performance, exergy efficiency and improvement potentials. R152A stands out between the refrigerants taken as a reference with aspects of cooling capacity, environmental effects and refrigerant charge amount.

Occurrence and levels of micropollutants across environmental and engineered compartments in Austria

Occurrence and concentration of a broad spectrum of micropollutants are investigated in Austrian river catchments, namely polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs), organotin compounds, perfluoroalkyl acids (PFAAs) and metals. The parallel analysis across multiple environmental and engineered compartments sheds light on the ratio of dissolved and particulate transport and on differences in concentration levels between point and diffuse emission pathways. It is found that some PAHs and organotins are present in rivers, groundwater and bulk deposition at higher concentrations than in municipal wastewater effluents. Among PFAAs and metals, highest concentrations were recorded either in atmospheric deposition or in discharges from wastewater treatment plants. The relevance of the analysis across compartments is best shown by the case of perfluorooctanesulfonic acid (PFOS). Despite municipal wastewater effluents being the emission pathway with highest concentrations, this study reveals that not only rivers, but also atmospheric deposition and groundwater sometimes exceed the environmental quality standard for surface waters. Moreover, this work reveals partially counterintuitive patterns. In rivers with treated wastewater discharges, increasing levels of dissolved compounds were measured at rising flow conditions, whereas the opposite would be expected owing to the dilution effect. This might derive from the mobilisation from soil or suspended particulate matter or rather find its explanation in high concentrations in atmospheric deposition. These hypotheses require however being tested through targeted studies. Additional future research includes the analysis of how regional or catchment specific characteristics might alter the relative importance of different emission pathways, and the modelling of emission and river loads to assess their relative contribution to river pollution.

The influence of incorporating microbial fuel cells on greenhouse gas emissions from constructed wetlands

Microbial fuel cells (MFCs) were incorporated into constructed wetlands (CWs) in recent years aiming to enhance the wastewater treatment of CWs while simultaneously produce electricity. However, currently no information is available about the greenhouse gas (GHG) emissions from integrated CW–MFC systems during wastewater treatment. Therefore, this study investigated the influence of incorporating MFCs on GHG (especially CH4 and N2O) emissions from CWs under different external resistances, influent organic loadings and seasons. Results showed that incorporating the MFC significantly reduced the GHG emissions (by 5.9%–32.4% CO2 equivalents) from CWs by reducing 17.9%–36.9% CH4 and 7.2%–38.7% N2O emissions. The CH4 and N2O emissions from CW–MFCs significantly increased with increasing external resistance (above 500 Ω), while the CO2 emission showed the opposite trend. However, the CH4 and N2O emissions at external resistances below 500 Ω did not differ significantly. There was a significant positive correlation between the CO2 and CH4 emissions and influent organic loadings in CW–MFCs, but a significant negative correlation between the N2O emission and influent organic loadings. Influent chemical oxygen demand/total nitrogen (COD/TN) = 3 could result in a TN removal of ≥90% as well as the minimum CO2 equivalents emission in CW-MFCs. The GHG emissions from CW–MFCs showed significant seasonal variations.

A new method for assessing the efficacy of emission control strategies

Regional-scale air quality models and observations at routine air quality monitoring sites are used to determine attainment/non-attainment of the ozone air quality standard in the United States. In current regulatory applications, a regional-scale air quality model is applied for a base year and a future year with reduced emissions using the same meteorological conditions as those in the base year. Because of the stochastic nature of the atmosphere, the same meteorological conditions would not prevail in the future year. Therefore, we use multi-decadal observations to develop a new method for estimating the confidence bounds for the future ozone design value (based on the 4th highest value in the daily maximum 8-hr ozone concentration time series, DM8HR) for each emission loading scenario along with the probability of the design value exceeding a given ozone threshold concentration at all monitoring sites in the contiguous United States. To this end, we spectrally decompose the observed DM8HR ozone time series covering the period from 1981 to 2014 using the Kolmogorov-Zurbenko (KZ) filter and examine the variability in the relative strengths of the short-term variations (induced by synoptic-scale weather fluctuations; referred to as synoptic component, SY) and the long-term component (dictated by changes in emissions, seasonality and other slow-changing processes such as climate change; referred to as baseline component, BL). Results indicate that combining the projected change in the ozone baseline level with the adjusted synoptic forcing in historical ozone observations enables us to provide a probabilistic assessment of the efficacy of a selected emissions control strategy in complying with the ozone standard in future years. In addition, attainment demonstration is illustrated with a real-world application of the proposed methodology by using air quality model simulations, thereby helping build confidence in the use of regional-scale air quality models for supporting regulatory policies.

Bare Bones Teaching Learning-Based Optimization Technique for Economic Emission Load Dispatch Problem Considering Transmission Losses

Economic emission load dispatch plays a great role in power system cost analysis. The purpose of economic emission load dispatch is to minimize the fuel and emission cost satisfying load demand. Various iterative techniques had been used to solve economic emission load dispatch problem in previous years by different authors. In this article, the new teaching learning-based optimization (TLBO) technique using variant bare bones TLBO has been proposed for solving economic emission load dispatch problem with convex and non-convex constraints by considering transmission losses and valve point loading effects. Conventional TLBO has two phases like teacher phase and learner phase. In teacher phase, learners update their knowledge through sharing knowledge with teacher, and finally, learners improve their knowledge by interactions among learners. Bare bones TLBO employs an interactive learning strategy, which is the hybridization of the learning strategy in the conventional TLBO. The proposed algorithm has been applied on six-, ten- and forty-unit systems, and the results obtained are compared with existing techniques; hence, superiority of the proposed algorithm is proved.

Phthalic acid esters disturbed the genetic information processing and improved the carbon metabolism in black soils

Phthalic acid esters (PAEs), such as dimethyl phthalate (DMP) and dibutyl phthalate (DBP), are widely distributed as environmental pollutants. In this study, the effects of these chemicals were investigated in black soils using a metagenomics approach. The results clearly showed that DMP or DBP increased the abundance of genes involved in transcription, replication and repair in black soils. In addition, the abundances of genes associated with metabolic functions was improved following treatment with DMP or DBP, including those involved in lipid transport and metabolism, carbohydrate transport and metabolism, and energy production and conversion. There could be many reasons for these observed changes. First, the DMP or DBP treatments increased the abundances of genes associated with the LuxR family, the UvrABC repair system, DNA replication pathways, the RNA polymerase complex and base excision repair. Second, the abundances of genes associated with isocitrate lyase regulator (IclR) family transcriptional regulators, lipid metabolism and carbohydrate active enzymes (CAZys) were altered by the DMP or DBP treatments. Finally, the DMP or DBP treatments also increased the emission load of CO2 and altered the fluorescence intensity of humic acid. Therefore, the results of this study suggested that DMP and DBP contamination altered the abundances of genes associated with genetic information processing and improved the carbon metabolism in black soils.

Assessment of hurricane versus sine-cosine optimization algorithms for economic/ecological emissions load dispatch problem

Assessment of hurricane versus sine-cosine optimization algorithms for economic/ecological emissions load dispatch problem

Water Pollution Prevention and Control of Chemical Enterprises Based on Cooperative Game

Due to the particularity of its production technology and process, chemical enterprises are shouldering important missions in environmental protection and pollution control. For this, in this paper, based on the cooperative game, the pollution of chemical enterprises was analysed firstly; Then, in view of the interactive feature of pollution-emission behaviour and survival in Jilin Chemical Industry Park, the non-cooperative game model and cooperative game model of chemical enterprises were established by considering the factors such as tax revenue, governance cost and pollution loss etc. Finally, taking Jilin Chemical Industry Park as example, the models were verified, including the emission and profits respectively in the non-cooperative game state and cooperative game state. The results indicate that the cooperation situation is conducive to reducing pollution emissions, and the cooperative profit after distribution is greater than non-cooperative one, but more comprehensive countermeasures should be also taken to ensure the effective reduction of pollutant emission load in the park.

Shifting of air pollutants distribution during car free day event

According to Decree of Semarang Mayor No. 22/2011, car free day activities is addressed to give clean air for facilitating citizens activities. This car free day event is held every Sunday in the morning in the city center of Semarang i.e. located at Simpang Lima square. This research is aimed at identifying the shifting of pollutant during car fee day event by comparing ambient air pollutant concentration represented by carbon monoxide during car free day event and non-car free day event. About 14 streets had been measured its ambient CO concentration during Saturday (non-car free day event) and Sunday (car free day event). We also modeled (using Caline4) the CO dispersion at the certain area on those streets to know the spatial distribution of concentration during those two events. The ambient CO concentration, in general, during car free day event were somewhat increase for certain roads. The emission load of vehicles emission during CFD event was 1.37 times of non-CFD event. Nevertheless, based on spatial distribution of ambient CO concentration at the area of roads of interest, its concentrations were below the ambient CO concentration standard (PP.41/99).

Power Balance and Temperature in Optically Pumped Spasers and Nanolasers.

Spasers and nanolasers produce a significant amount of heat, which impedes their realizability. We numerically investigate the farfield emission and thermal load in optically pumped spasers with a coupled electromagnetic/thermal model, including additional temperature discontinuities due to interfacial Kapitza resistance. This approach allows to explore multiple combinations of constitutive materials suitable for robust manufacturable spasers. Three main channels of heat generation are quantified: metal absorption at pumping and spasing wavelengths and nonradiative relaxations in the gain material. Out-radiated power becomes comparable with absorption for spasers of realistic dimensions. Two optimized spaser configurations emitting light near 520 nm are compared in detail: a prolate metal-core/gain-shell and an oblate gain-core/metal-shell. The metal-shell design, which with the increasing size transforms into a metal-clad nanolaser, achieves an internal light-extraction efficiency of 22.4%, and stably operates up to several hundred picoseconds, an order of magnitude longer than the metal-core spaser.

Relaxed I-SHOT trust-region algorithm for solving multi-objective economic emission load dispatch problem

ABSTRACTIn this paper, a new algorithm for tackling nonlinear constrained multi-objective optimization problems is introduced. This algorithm, which we call relaxed the interactive sequential hybrid optimization technique (relaxed I-SHOT), is based on a hybrid method between the I-SHOT method and step method (STEM) to transform a multi-objective problem into a single-objective one. An active set strategy is used together with a suggested penalty method to transform a single-objective constrained optimization problem into unconstrained one. A trust-region globalization strategy is added to the algorithm to solve the obtained unconstrained problem to ensure global convergence. The suggested approach is utilized to solve the multi-objective economic emission load dispatch (EELD) problems to assert the effectiveness of the proposed algorithm. The proposed algorithm is tested on the standard IEEE 30-bus 6-generator test system. The results of the proposed approach are compared against those reported in the literature. The comparison asserts the potential of the proposed algorithm to solve the EELD problem.

A linear programming input–output model for mapping low-carbon scenarios for Vietnam in 2030

The intended nationally determined contribution (INDC) of Vietnam to the 2015 United Nations Climate Change Conference (COP21) is a 25% reduction in greenhouse gas (GHG) emissions relative to the business-as-usual (BAU) scenario by 2030. There are various measures proposed in the INDC, but studies to assess their potential effectiveness are still needed. An input–output based linear programming model is developed in this work to evaluate the maximum GHG emission reductions which can be achieved, given various climate change mitigation strategies. Six scenarios are considered to identify the highest GHG emission reduction that can be achieved by the year 2030. These scenarios include BAU, the consideration of two different levels of differentiated sector growth, the adoption of a low-carbon electricity mix, energy efficiency enhancement for final consumption, and energy efficiency enhancement in the agriculture, transport and waste sectors. Each scenario quantifies the sector final demand, sector gross output, sector GHG emission load and the impact on human health. Results show that the best strategy is to simultaneously implement all of the identified low-carbon measures, which achieves a 24.6% reduction in overall GHG emissions in comparison to BAU levels.

A Throttle Control Valve for Steam Turbines Operating with Large Volumetric Flowrates of Working Fluids

A new design of a throttle control valve for steam turbines with throttle steam admission and large volumetric steam flowrates is considered. The difficulty associated with using these valves is that increasing the seat dimensions of spools entails a drastic decrease in the relative valve chest free volume for steam passage. This, in turn, results not only in higher hydraulic losses in the steam admission system but also in a higher nonuniformity of steam flow in the flow paths of such valves. Both these factors facilitate generation of very high pulsations of pressure in the valve’s entire flow path, which gives rise to high levels of acoustic emission and dynamic loads acting on all components of the valve, thus degrading its vibration reliability. Along with the proposed valve design, the article considers the design version of standard balanced control valves installed in large-capacity Russian steam turbines. It is shown that the passage of large volumetric steam flowrates through standard valves entails a significant reduction in the free valve chest volume for passing steam. This results in a growth of local steam velocities inside the chest and in a more pronounced negative influence of the chest shape on the valve flowrate and vibration performance. This situation can be improved by using one of the following two ways: to make the chamber with a significantly larger structural volume (which entails a larger cost of making the chamber) or to radically change the valve design. The article considers the second approach to solving the problem. In the proposed design version, the entire valve balancing system is shifted to the valve chest upper part, and the guide bonnet is made with large lateral ports ensuring free passage of steam to the diffuser seat. To achieve a more uniform circumferential field of velocities in the valve flow path, its cup is made with two perforation belts, the holes of which are connected to a common damping chamber, and the chamber itself is connected via a hollow cylinder with the axial force relief system.

N2O and CH4 emissions from N-fertilized rice paddy soil can be mitigated by wood vinegar application at an appropriate rate

To understand the impacts of wood vinegar (WV), a by-product of biochar production, on N2O and CH4 emissions and their total global warming potential (GWPt) from N-fertilized rice paddy soil, a soil column experiment was conducted using three treatments: 240 kg urea-N ha−1 accompanied with 0, 5, and 10 t WV ha−1, respectively. Results showed that N2O and CH4 emission flux patterns were dominated by water regime of rice growth cycle, which was independent with WV application. The total N2O, CH4 emission loads and GWPt over rice season of three N received treatments were 6.41–8.85 kg ha−1, 127.7–405.0 kg ha−1, and 5.24–12.03 t CO2-e ha−1, respectively. Rice seasonal N2O and CH4 emissions were synchronously mitigated by 22.4% and 36.4%, respectively, when WV was applied at 5 t ha−1. Consequently, 5 t ha−1 WV treatment reduced 31.5% of GWPt compared with the urea treatment. In addition, 10 t ha−1 WV treatment exerted a more positive effect on suppressing N2O with 27.6% reduction. However, it increased GWPt by 57.2% because its CH4 emission load was increased by 101.8%. In conclusion, WV amendment applied at an appropriate rate (5 t ha−1) or combination with other CH4 control technologies were suggested to reduce both N2O and CH4 emissions and thereby the GWPt in N-fertilized rice paddy soil.

Estimation of Fine Particle (PM2.5) Emission Inventory from Cooking: Case Study for Shanghai

Cooking is one of important emission sources of fine particles (PM2.5). This study using the catering enterprises of Shanghai as an example, presents a method to estimate the PM2.5 emission inventory from cooking according to the number of stoves, cooking time, and number of customers. Based on in situ measurements, the concentrations of PM2.5 emissions ranged from 0.1 mg ·m-3 to 1.8 mg ·m-3, which exceeded the limit (1.0 mg ·m-3 for lampblack) in the national standard. Organic carbon dominated the PM2.5 emitted from cooking, accounting for more than 50%. Extremely high ratios of organic carbon to elemental carbon were observed, ranging from 58.8 to 752.3, which could be used as an indicator of cooking emissions. The emission factors of PM2.5 in the catering industry are closely related to the scale of the catering enterprises. The emission factors of large-and medium-sized enterprises are obviously higher than those of small and micro enterprises. The PM2.5 emissions of catering enterprises are mainly attributed to high emission loads of large enterprises and those for a large number of small and medium enterprises. The PM2.5 emission inventory of cooking in Shanghai was calculated according to the three emission factors above, and the results were very close. Therefore, the method for estimating the PM2.5 emission inventory for cooking presented in this study is helpful for other Chinese cities to calculate their PM2.5 emission inventory from cooking.

Combined Economic and Emission Load Dispatch Problem Solving by ITLBO Algorithm

Recent trends in economic and emission dispatch problem which turn has to promote the rise in the number of power generating stations and their capacity of generation. The Sulphur Dioxide (S02), Nitrogen Oxides (N2O) and Carbon Dioxide (CO2) are yields the CEED problem and they are created from generation of electricity from fossil fuel. Combined economic and emission load dispatch problem is a procedure to determine the generation of electrical power isdevoted generating units in a power system so that the both total generation costand total emission of the system is minimized, while fulfilling the load demand in directly. Improved teaching learning based optimization algorithm is used to solve combined economic emission load dispatch problem with constraints in generation of power system. This method was verified by thirteen generating bus and use with different load demand and compared with other existing techniques display the advantage of the proposed algorithm. The simulation has been done in MATLAB/Simulink with required formulation and the result is gotten in graph and numerical.

Urban tree leaves’ chlorophyll-a content as a proxy of urbanization

We tested the effect of urbanization on air pollution based on the chlorophyll-a content of Celtis occidentalis leaves along an urbanization gradient (urban, suburban and rural areas) in Debrecen, Hungary. Chlorophyll-a content of Celtis occidentalis, Acer campestre, and Corylus avellana were compared to test which species is the most useful to study the effects of urbanization. Furthermore, the effects of washing solutions (distilled water, tap water, and rainwater) on chlorophyll-a content of tree leaves were also tested during sample preparation. Chlorophyll-a was extracted from leaf samples with acetone, and it was measured using a spectrophotometer. Along the urbanization gradient, chlorophyll-a content of C. occidentalis leaves was the lowest in the urban area; thus, this species proved to be an effective indicator of anthropogenic emission load. Differences were not significant among species in the suburban and rural areas, where the level of air pollution was moderate. We found that effects of the washing solutions on chlorophyll-a content did not differ significantly from each other. Thus, tap water can be used safely to clean the leaf surface, without significant influence on chlorophyll-a. Our study demonstrated that the chlorophyll-a content of leaves was a useful indicator to assess the level of air pollution.

Recombinant adenovirus-delivered soluble CD163 and sialoadhesin receptors protected pigs from porcine reproductive and respiratory syndrome virus infection

Porcine reproductive and respiratory syndrome (PRRS) is one of the most important swine diseases affecting pig industry worldwide. Sialoadehesin (Sn) and CD163 are the two specific receptors for PRRSV infection of porcine alveolar macrophages. Our previous study showed that the soluble Sn receptor Sn4D-Fc and soluble CD163 receptor SRCR59-Fc expressed by the two recombinant adenoviral (rAd) vectors have an additive anti-PRRSV effect in vitro. In the present study, rAd-Sn4D-Fc and rAd-SRCR59-Fc were inoculated into pigs, and the efficient expression of Sn4D-Fc and SRCR59-Fc proteins was detected by ELISA. Then, PRRSV-naïve pigs were inoculated with rAd-Sn4D-Fc and/or rAd-SRCR59-Fc before contagious infection with different PRRSV strains. Among the three rAd inoculation groups, simultaneous inoculation with the two rAd vectors provided the best protection against highly pathogenic JXA1 strain PRRSV, followed by rAd-SRCR59-Fc inoculation and rAd-Sn4D-Fc inoculation. Clinical observation and quantitative RT-PCR analyses showed that all of the double rAd-inoculated pigs (n = 9) survived from the contagious infection with highly pathogenic JXA1, JS07 or SH1705 strain PRRSV with significantly alleviated clinical scores, viremia, fecal viral emission and tissue virus loads. These data suggest that rAd-Sn4D-Fc and rAd-SRCR59-Fc can be developed further as the universal therapeutic vaccine to facilitate PRRSV eradication.

Flicker emission, voltage fluctuations, and mechanical loads for small-scale stall- and yaw-controlled wind turbines

This study analyzes and compares flicker emission, voltage fluctuations, and mechanical loads for two small-scale wind turbines (WTs), considering different control strategies. The investigated strategies are active yaw and stall control strategies for above rated wind speed operation to limit the captured power. The yaw controller is designed to limit the output power and rotation speed in high wind speeds by rotating the turbine out of the wind direction. On the other hand, the optimal blades are designed for the stall-controlled WT to have appropriate performance in all wind speed regions, especially in the stall region. In this WT, the captured power is regulated by controlling the rotor speed in relation to wind speed via power electronic interface in all wind speed regions without requiring the aerodynamic active devices. The maximum power point tracking (MPPT) algorithms are also implemented in low and moderate wind speeds. A simulation platform is used that considers aerodynamic, mechanical, electrical, and control aspects of the WTs. The MPPT, yaw and stall control, and simulation results are presented and discussed. Results demonstrate that flicker emission level, voltage fluctuation and mechanical loads for the stall-controlled WT are less than those in the yaw-controlled turbine.

Measurement and interpretation of emission rate and loading rate of air pollutants from the non-point source of naturally ventilated dairy farm

Measurement and interpretation of emission rate and loading rate of air pollutants from the non-point source of naturally ventilated dairy farm