Combustion Plants Research Articles

A Multi-Criteria Decision Maker for Grid-Connected Hybrid Renewable Energy Systems Selection Using Multi-Objective Particle Swarm Optimization

Combating climate change issues resulting from excessive use of fossil fuels comes with huge initial costs, thereby posing difficult challenges for the least developed countries in Sub-Saharan Africa (SSA) to invest in renewable energy alternatives, especially with rapid industrialization. However, designing renewable energy systems usually hinges on different economic and environmental criteria. This paper used the Multi-Objective Particle Swarm Optimization (MOPSO) technique to optimally size ten grid-connected hybrid blocks selected amongst Photo-Voltaic (PV) panels, onshore wind turbines, biomass combustion plant using sugarcane bagasse, Battery Energy Storage System (BESS), and Diesel Generation (DG) system as backup power, to reduce the supply deficit in Sierra Leone. Resource assessment using well-known methods was done for PV, wind, and biomass for proposed plant sites in Kabala District in Northern and Kenema District in Southern Sierra Leone. Long term analysis was done for the ten hybrid blocks projected over 20 years whilst ensuring the following objectives: minimizing the Deficiency of Power Supply Probability (DPSP), Diesel Energy Fraction (DEF), Life Cycle Costs (LCC), and carbon dioxide (CO 2 ) emissions. Capacity factors of 27.41 % and 31.6 % obtained for PV and wind, respectively, indicate that Kabala district is the most feasible location for PV and wind farm installations. The optimum results obtained are compared across selected blocks for DPSP values of 0–50% to determine the most economical and environmentally friendly alternative that policy makers in Sierra Leone and the region could apply to similar cases.

An evaluation of effects of operational parameters on NOx emissions through detailed chemical kinetics simulations

Abstract NOx emissions from biomass and Municipal Solid Waste (MSW) combustion is a great concern. Technologies for reducing NOx emissions based on flue gas cleaning using e.g. Selective Non-Catalytic Reduction (SNCR) or Selective Catalytic Reduction (SCR) are well known. However, limiting NOx emissions by primary measures is an attractive opportunity, avoiding or limiting the use of costly secondary measures. Many factors influence the NOx emission level from biomass and MSW combustion plants, like fuel-N content and speciation, and operating parameters as air distribution and staging, flue gas recirculation, temperature and residence time. In this work a recent detailed chemical kinetics mechanism is used to investigate the NOx reduction potential by staged air combustion at different operational conditions, using two ideal plug flow reactors connected in series. This enables revealing a kinetics limited reduction potential, as a guideline for further detailed studies at targeted conditions using stochastic reactor networks or Computational Fluid Dynamics (CFD). The results show, for demolition wood as fuel, a large NOx reduction potential, as high as above 95% total fixed nitrogen reduction at theoretically optimum conditions. Through reaction path analyses the main reaction pathways and reactions are identified. Comparison with experimental results from grate combustion units is made. Finally, a comparison with earlier and less extensive detailed chemical kinetics mechanisms is made, to check for significant differences and assess the reasons for those. The final goal would be to arrive at computationally effective reduced chemical kinetics mechanisms that could be applied in CFD simulations of real biomass and MSW combustion plants, to arrive at improved operational conditions or improved design.

Ammonia as an environmentally benign energy carrier for the fast growth of China

In China, renewable energy is expected to account for a larger proportion of electric power systems although regional and intermittent characteristics have led to enormous unused wind and solar power stations in western and northern China. In the mean-while, there exists a large demand on energy in central and eastern areas. The energy storage capability of hydrogen makes it a significant medium for emerging energy storage systems. But the formidable challenge of hydrogen storage and long-distance transportation restricts its development. To address this issue, this paper proposes a scheme for an ammonia-based energy storage system in which ammonia, an environmentally benign hydrogen carrier, is expected to compromise the conflicts of renewable energy supply and consumption in China. By utilizing abandoned wind power and solar power, we get electrolyze water to generate hydrogen and get air to generate nitrogen. Compositing ammonia with hydrogen and nitrogen using Hubert’s method also need much electricity. And the power stored in ammonia can be released in form of thermal energy or electricity when needed. This paper then presents some typical applications of ammonia that can meet people’s needs of fuel, power, electricity, and zero-carbon fertilizer. The proposed scheme is particularly useful for storing discarded power in western and northern China in ammonia which can be transported and used in eastern regions without regional and seasonal restrictions. As an extra advantage, oxygen as a side product associated with the production of ammonia may play a significant role in oxygen-riched combustion plants.

A Study on the Improvement Measures of the Investigation of State Administration

우리 헌법 제35조는 환경권과 환경보호의무를 규정하고 있지만, 기후변화협약에 관한 국제조약을 이행하여야 할 의무에 관한 규정을 두고 있지 않다. 그렇지만 파리기후협약 등 국제조약이 헌법 제6조에 의하여 국내법과 동일한 효력을 가지게 되고, 이산화탄소 포집 및 저장(CCS : Carbon dioxide Capture & Storage) 등과 같은 다양한 수단을 통해 온실가스를 감축하도록 하고 있다. 그래서 우리나라보다 앞서서 온실가스를 감축하기 위한 정책을 입안하고 법률을 제정ㆍ개정한 영국을 비롯한 선진국들의 입법을 비교법적 관점에서 연구하고 참고하는 것이 필요하다. 특히 영국은 기후변화의 문제를 해결하고 석탄을 계속 에너지원으로 사용하기 위해 오래전부터 온실가스를 줄이기 위한 정책으로 CCS를 추진하였다. 이런 정책을 뒷받침하기 위해 단일법의 제정이 아닌 개별법의 개정을 통해 CCS에 관한 근거를 마련하고 정책과 사업을 진행하고 있다. CCS를 추진하기 위한 법률 중 「에너지법」에서는 신규 석탄화력발전소에 CCS 기술도입 의무화, 3년간 배출제한 유예, 보조금 지급을 통한 저탄소 전력발전의 유인책을 강구하였다. 그리고 「전기법」의 개정을 통해 300MW 이상의 모든 신규 연소 발전소는 CO2 포집대비(Capture Ready) 규정을 제도화하고 있다. 「작업등에서 건강과 안전법(Health & Safety at Work etc. Act)」은 2013년 4월부터 육상 및 해상 CCS 프로세스에 적용된다. 이 법에서 일반의무는 CCS 운영자가 모든 CCS 위험 관리에 비례적 접근을 취해야 한다. 이는 CO2 파이프라인의 설계, 시운전, 운전(유지 보수 및 검사 포함) 및 폐로에서 발생하는 위험 범위를 고려한 포괄적인 위험 평가를 통해 입증되어야 한다. 결국, 영국에서 추진해 왔던 기후변화정책과 이산화탄소 포집 및 저장 등에 관한 정책과 잘 정비된 법률의 검토를 통해 한국에서 추진하고 있는 CCS에 대한 시사점을 얻게 되었다. 한국도 영국 등의 선진적인 입법례를 참고로 하여 CCS를 통한 이산화탄소감축을 위한 구체적인 입법을 지속적으로 해 나가야 하며, 장기적으로는 헌법개정을 통하여 기후변화노력 등에 대한 규정을 두는 것이 필요하다.Article 35 of our Constitution provides environmental rights and environmental protection obligations but does not include the obligation to implement international treaties on climate change treaties. However, international treaties such as the Paris Climate Convention have the same effect as domestic law under Article 6 of the Constitution, and require our government to make effective measure including dioxide capture and storage (CCS) to embody greenhouse gas reduction efforts. Therefore, it is necessary to formulate law and policy to reduce greenhouse gas emissions ahead of Korea, and to study and refer to legislation from advanced countries including the UK, which enacted and amended laws, from a comparative legal point of view. UK has long pursued CCS as a policy to reduce greenhouse gases for climate change issues in the course of continuous using coal as an energy source. To support this policy, UK establishes the grounds for CO2 capture and storage and carries out policies and projects not by the enactment of a single law but by the method of the revision of the individual laws. The “Energy Law” established the emission standard (1 lb CO2/kWh) among the laws for promoting CCS. The Energy Law has contained the introduction of CCS technology to new coal-fired power plants, the three-year emission restriction, and subvention to encourage low-carbon power generation. Through the amendment of the Electricity Law, all new combustion plants of 300 MW above are institutionalizing the regulation of Capture Ready. “Health and Safety Law at Work etc.” will be applied to the land and marine CCS processes from April 2013. The general obligation in this Law is that CCS operators should take a proportional approach to all CCS risk management. This should be demonstrated through a comprehensive risk assessment that takes into account the range of hazards that occur in the design, commissioning, operation (including maintenance and inspection) of the CO2 pipeline and in the closed circuit. Therefore, We have gained successfully implications for CCS in Korea through the UK policies on climate change policy, carbon capture and storage, and the well-established UK laws.

Igniting Soaring Droplets of Promising Fuel Slurries

High rates of environmental pollution by boilers and thermal power plants burning coal of different grades are the main reason for active research in the world aimed at the development of alternative fuels. The solution to the formulated problem acceptable in terms of environmental, technical and economic criteria is the creation of composite slurry fuels with the use of fine coal or coal processing and enrichment waste, water of different quality, and oil sludge additive. This study considers modern technologies of burning slurry fuels as well as perspective research methods of the corresponding processes. A model combustion chamber is developed for the adequate study of ignition processes. The calculation of the basic geometric dimensions is presented. The necessity of manufacturing the combustion chamber in the form of an object of complex geometry is substantiated. With its use, several typical modes of slurry fuel ignition are determined. Principal differences of ignition conditions of a single droplet and group of fuel droplets are shown. Typical vortex structures at the fuel spray injection are shown. A comparison with the trajectories of fuel aerosol droplets in real combustion chambers used for the combustion of slurry fuels is undertaken.

Combustion of Miscanthus: Composition of the Ash by Particle Size

Miscanthus is an energy crop considered to show potential for a substantial contribution to sustainable energy production. In miscanthus combustion, 2.0% to 3.5% of the mass of the fuel remains as ash. This ash is less contaminated by heavy metals than ash from wood combustion. The concentrations are well below the typical limit concentrations for use as a soil conditioner on agricultural land and forests. The potassium concentration in the investigated miscanthus ash of 14.1% K2O was significantly higher than the typical concentration of potassium in ashes from wood combustion (3% to 7% K2O). However, in comparison to wood ashes, only very little enrichment of potassium in the fine size fractions of miscanthus ash was found. For most of the other elements, the enrichment in the fine size fractions was also low. Therefore, the production of a potassium-rich material by classification for the production of potassium fertilizer is not feasible. The absence of such an enrichment can be explained on the one hand by the significantly lower combustion temperature in the miscanthus combustion plant and, on the other hand, by the higher molar ratio of K to Cl and the low ratio of K to Si. Thus, the most sensible utilization of miscanthus ash is its direct recycling to the soil such as where the miscanthus plants are grown.

Establishing a Relationship between Coal Quality and the Enrichment of Radionuclides in Coal Combustion Residues

Coal-fired power plants (CFPP) provide approximately 40% of the world’s energy demand. Naturally occurring radioactive materials (NORM) contained in coal become enriched in coal combustion residues as a result of the elimination of carbon during combustion. The fly ash and bottom ash produced from CFPP may be significant sources of exposure to naturally occurring radionuclides for the population near the combustion plant or ash dumps. Despite this fact, very few studies have actually addressed the relationship of the NORM enrichment factors and the quality of coal used. This paper aims to relate the quality of coal to the enrichment factors for the radionuclides of interest (K40, Ra226, Th232 and Po210) in coal combustion residues from three South African CFPP. The data from other CFPP was also taken into account to establish this correlation. The feedstock coal used in these CFPP is typically low quality, with ash content in the range of 25 - 45 wt%. The radionuclides investigated were determined by gamma spectrometry with the exception of Po210, which was determined by alpha spectrometry. The enrichment factors for the radionuclides of K40, Ra226, Th232 and Po210 in the fly ash and bottom ash (except Po210) was found to be directly proportional to the quality of coal. That is when the ash percentage increased (coal quality decreased) the enrichment factor decreased. The Po210 radionuclide in the bottom ash had an enrichment factor less than one. The relationship between coal quality and enrichment factors for the radionuclides of K40, Ra226, Th232 and Po210 in both the fly ash and bottom ash (except Po210 in the bottom ash) was demonstrated by the following mathematical equation: . This equation may be used as a good indication in obtaining an estimate in determining the enrichment of the mentioned radionuclides in coal combustion products such as fly ash and bottom ash.

New chemical mechanism explaining the breakdown of protective oxides on high temperature steels in biomass combustion and gasification plants

Biomass is considered a replacement fuel over fossil fuels to mitigate climate change. The switch to biomass in the combustors changes the inorganic chemistry of the flue gases and leads to more severe corrosion of the construction materials of the combustors. The integrity of most high temperature steels relies on the formation of a protective Cr2O3 layer on the steel surface at a high temperature environment. The ash compound found on the heavily corroded steel in biomass combustion and gasification plants is KCl, but the mechanism, which triggers the breakdown of the protective Cr2O3 layer under the KCl salt is not known. We studied the chemical reactions involved with furnace exposure of KCl and KOH with Cr2O3 and identified the formed reaction products with XRD analysis. The amount of reaction products was analyzed from the leachates of the salt-oxide mixtures by UV/VIS spectroscopy. We also used thermodynamic Gibbs energy minimization calculations to evaluate the evolution of reactions as a function of temperature. The results suggests that the reaction of KCl with Cr2O3 involves a KOH reaction intermediate that forms before K2CrO4 is formed. The amount of reacted potassium as a function of temperature follows the trend of KCl decomposition to KOH and HCl(g) as predicted by thermodynamics calculations. Therefore, we argue that the suggested overall reaction of KCl with Cr2O3 as found in the corrosion literature: , starting with the initiation step: KCl + H2O(g) ⇒ KOH + HCl(g) and then the formed KOH reacts with Cr2O3 to form K2CrO4. This explains the initial breakdown of the protective Cr2O3 under KCl salt in water containing high temperature atmospheres. The result is essential for the development of new alloys for biomass fired combustors.

Experiments in use of bentonite for energy recovery of used oils

The paper proposes the development of advanced, integrated technologies for materials with properties of adsorbents (e.g. bentonite), and the use of these material in processes of used oil recovery with remediation effect and energy recovery. The main objective is to replace diesel fuel, which is an expensive fuel, with revitalized oils for energy production. For these, laboratory experiments are required in two important directions. The first tests are related to the determination the optimum concentration of bentonite for removal of metals from used oil. The revitalization of the used oil leads to the protection of the combustion plant, to the increase of its lifetime and polluting emissions reduction. The second set of experiments relates to the determination of energy characteristics of used oil and revitalized used oil for energy production. Elemental analysis, lower heating value, viscosity, density and ash analysis were determined. Experimental test of combustion process on a small scale boiler has been done and the results shows an improved combustion process of revitalized oil compares with used oil and the decrease of the pollutant emissions.

Reduce deposits on heat exchange surfaces when burning inferior coal

The phenomenon of soiling of heat exchange surfaces occurs in all types of combustion plants. The deposit of solids (combustion gases particles) worsens heat transfer by reducing combustion efficiency, increasing fuel consumption and pollution. Deposits are influenced by combustion temperature, gas flow rate, dimensions of solids drift by combustion gases as well as the composition of fuel mixtures used (eg inferior coal with flame retardant gas or tar fuel). In the present paper are presented techniques and methods adopted for the reduction of soiling of the heat exchange surfaces and the results obtained on high energy power plants (steam boilers).

The Health Costs of Coal-Fired Power Plants in India

This paper estimates the effect of coal-fired power plants on infant mortality in India. We find that a one GW increase in coal-fired capacity corresponds to a 14% increase in infant mortality rates in districts near versus far from the plant site. This effect is 2-3 times larger than estimates from the developed world. Our effects are larger for: (1) older plants, (2) plants located in areas with higher baseline levels of pollution, and (3) plants burning domestic rather than imported coal. The environmental benefits from policy aimed at the power sector are thus likely to be substantially higher if targeted at older plants located in more polluted areas tailored to burn domestic rather than imported coal.

RISK PREVENTION OF ATMOSPHERIC POLLUTION BY IMPLEMENTATION OF THE ENVIRONMENTAL MANAGEMENT SYSTEM AT THE HEAT ENERGY FACILITIES

Topicality. The problem of anthropogenic impact reducing on atmospheric air is especially relevant to date. Ukraine ranks one of the first places in the world of mortality rate from environmental pollution and one of the main sources of pollution is the operation of coal installations.Most of the equipment of the large power plants of Ukraine is in the pre-critical state, it is morally and physically obsolete. Unsatisfactory condition of environmental technologies and non-compliance with international requirements of the cleaning of atmospheric air emissions from the thermal power plants are the urgent issues of the current international economic and environmental policy of the country. Aim and tasks are to determine the prospects of introducing and improving the environmental management system at Large Combustion Plants in Ukraine in the context of the National Plan for Reducing Emissions to reduce the environmental risks posed by pollutant emissions from heat power plants and the entry of Ukraine into the international stage in the field of ecology and energy. Research results. The article examines the main environmental risks caused by the operation of heat energy facilities and international requirements that Ukraine must fulfill in the near future. Also reviewed are the possible risks faced by the objects of heat power in the path of environmentalization.Based on the research, implementation of the ecological management system at Large Combustion Plants of Ukraine in the context of the National Plan for Reducing Emissions is proposed in order to reduce the potential risks of environmentalization and rational use of the resource potential of heat power sector enterprises. The possible ways of introducing the ecological management system and the impact of such modernization of heat power engineering objects on the international status of Ukraine as a country that has joined the international initiatives are determined. An example of a successful introduction of the environmental management system at the heat energy project of Ukraine related to large combustion plants and its compliance with the requirements of the National Plan for Reducing Emissions is given.Conclusions. The introduction of the environmental management system will enable heat energy facilities to rapidly and rationally transition to new technologies, fulfill international requirements and, in turn, reduce to a minimum the risks associated with atmospheric air pollution.

An investigation of lime addition to fuel as a countermeasure to bed agglomeration for the combustion of non-woody biomass fuels in a 20kWth bubbling fluidised bed combustor

The unique fuel flexibility of fluidised bed system facilitates the combustion of low quality solid fuels such as agricultural residues, but may suffer from serious bed agglomeration problems especially when operating at the high end of the typical fluidised bed combustion temperature range (800–900 °C). In this study, a 1.5 wt% lime addition to biomass fuels was investigated as a countermeasure to agglomeration for the combustion of pelletised wheat straw and miscanthus in a 20 kW bubbling fluidised bed (BFB) combustor using quartz sand as the bed material. Comparing to the widely studied agglomeration countermeasures such as bed additives and alternatives, the lime addition to fuel can provide a continuous on-site agglomeration counter action. Without lime addition, defluidisation as a result of bed agglomeration occurred once the bed temperature reached 860 °C and 877 °C for miscanthus and wheat straw respectively. However, with the lime addition, stable combustion could be achieved at 900 °C for both fuels with a substantially prolonged operation time. The obtained agglomerates were characterised using CAMSIZER, XRD and SEM/EDX and the results showed that the presence of lime in the fuel could significantly reduce the agglomerates size by forming high melting point calcium silicates/phosphates which hinder the K-rich molten substance attachment and result in heterogeneous coating layers in the agglomerates. The results of this study clearly indicate that using lime as fuel additive can realise the combustion of the problematic non-woody biomass fuels by considerably reducing the bed agglomeration propensity in practical fluidised bed combustion plants.

Impacts of thermos-physical properties on plate-fin multi-stream heat exchanger design in cryogenic process for CO2 capture

Oxy-fuel combustion is one of the most promising technologies for CO2 capture for power plants. In oxy-fuel combustion plants, cryogenic process can be applied for CO2 purification because the main impurities in flue gas are non-condensable gases. The multi-stream plate-fin heat exchanger is one of the most important components in the CO2 cryogenic system. In-depth understanding of the impacts of property on the heat exchanger is of importance for appropriate design. In order to investigate the impacts of properties on sizing the heat exchanger and to further identify the key properties to be prioritized for the property model development, this paper presented the design procedure for the plate-fin multi-stream heat exchanger for the CO2 cryogenic process. Sensitivity study was conducted to analyze the impacts of thermos-physical properties including density, viscosity, heat capacity and thermal conductivity. The results show that thermal conductivity has the most significant impact and hence, developing a more accurate thermal conductivity model is more important for the heat exchanger design. In addition, even though viscosity has less significant impact compared to other properties, the larger deviation range of current viscosity models may lead to higher uncertainties in volume design and annual capital cost of heat exchanger.

Techno-economic analysis of a biomass gasification power plant dealing with forestry residues blends for electricity production in Portugal

In 2017, deadly wildfires flared across central and north of Portugal. Following these events, the Government released a set of forestry policies promoting the increase of the currently installed forest biomass combustion thermal power plant capacity. In this study, we conduct a techno-economic analysis of an 11 MW gasification power plant, as a cleaner alternative to traditional combustion plants, dealing with forest biomass blends in Portugal central region. The analysis is built based on existing literature review and evaluation reports concerning investment projects in biomass-to-energy power plants. A spreadsheet economic model combining net present value (NPV), internal rate of return (IRR) and payback period (PBP) is developed over the plant’s lifetime period of 25 years. Cost factors incurred in initial investment, amortizations, fixed assets and working capital investments, financial income, operation and maintenance costs, employees and structure costs. Revenues are generated from selling electricity to the grid. A Monte Carlo sensitivity analysis is employed to gauge the economic model performance and investment risk. Lastly, an assessment of the environmental impact, noxious emissions and future prospects to this biomass-based energy conversion process are addressed. Results predict the feasibility of the project, with an NPV of 2.367 M€, an IRR of 8.66% and PBP of 23.1 years. Sensitivity analysis foresees affordable risks for investors, and that the project’s NPV is highly sensitive to the electricity sales price and electricity production. Despite the viability of the project delivered by the economic model, the economic performance is strongly reliant on revenues from electricity sales regulated by uncertain tariffs and reimbursements. Thus, special concerns must be considered regarding the project attractiveness to potential investors.

The development of fly ash – red mud based geopolymer

Taking into account environmental considerations, such as decreasing CO2 emission and the ecological footprint, the utilisation of secondary raw materials is essential for sustainable development. Fly ash is the product of coal combustion plants that is collected by various air cleaning equipment from flue gas, and red mud is the by-product of the Bayer-process, through which alumina can be produced from bauxite. Geopolymerisation is a process that is suitable for the utilisation of such wastes to produce ceramics, cement, concrete etc. with many advantageous properties.
 The main objective of the article is to present data on the development and examination of geopolymer made out of deposited fly ash from Tatabánya and red mud from Almásfüzitő.
 During the experiments, red mud was added to previously optimised fly ash geopolymer in various quantities and compressive strength tests were carried out to determine the optimal fly ash and red mud ratio. However, as the cracking of the specimens could be observed, further tests were carried out on the durability of the geopolymers. The effect of the sealing conditions and RM calcination was investigated, both via visual inspection and with FT-IR analysis at the ages of 3, 7, 14, 28 and 90 days.
 Based on the results, it could be concluded that the sealing conditions have direct effect on the structural characteristics of fly ash – red mud based geopolymers, but further experiments should be carried out for the identification of the ongoing reactions.

Techno-Economic Evaluations of Copper-Based Chemical Looping Air Separation System for Oxy-Combustion and Gasification Power Plants with Carbon Capture

Energy and economic penalties for CO2 capture are the main challenges in front of the carbon capture technologies. Chemical Looping Air Separation (CLAS) represents a potential solution for energy and cost-efficient oxygen production in comparison to the cryogenic method. This work is assessing the key techno-economic performances of a CLAS system using copper oxide as oxygen carrier integrated in coal and lignite-based oxy-combustion and gasification power plants. For comparison, similar combustion and gasification power plants using cryogenic air separation with and without carbon capture were considered as benchmark cases. The assessments were focused on large scale power plants with 350–500 MW net electricity output and 90% CO2 capture rate. As the results show, the utilization of CLAS system in coal and lignite-based oxy-combustion and gasification power plants is improving the key techno-economic indicators e.g., increasing the energy efficiency by about 5–10%, reduction of specific capital investments by about 12–18%, lower cost of electricity by about 8–11% as well as lower CO2 avoidance cost by about 17–27%. The highest techno-economic improvements being noticed for oxy-combustion cases since these plants are using more oxygen than gasification plants.

Combining UK and German emissions monitoring proficiency testing data based on stack simulator facilities to determine whether increasingly stringent EU emission limits are enforceable

We report an examination of the capability of the existing measurement infrastructure in the industrial emissions sector for successfully enforcing emission limits across three generations of legislation: the Waste Incineration Directive and Large Combustion Plant Directive (WID and LCPD); the Industrial Emissions Directive (IED) which superseded the aforementioned directives in 2013; the Waste Incineration and Large Combustion Plant Best Available Technique Reference documents (BREFs) where the former is currently at the draft stage (WI BREF and LCP BREF). The significant volume of proficiency testing data based on semi-tech stack simulator facilities operated by the National Physical Laboratory in the UK and the Hessian Agency for Nature Conservation, Environment and Geology in Germany were combined into a unique database. The emission species considered and their associated standard reference methods (SRMs) were: CO EN 15058; NOx (NO + NO2) EN 14792; total organic carbon EN 12619; total dust EN 13284-1. Collectively analysing participant distributions from 2002 to 2015, it was found that emission limits: under the WID and LCPD could be enforced (the directives for which the SRMs were originally designed); under the IED could in principle be enforced; under the WI BREF and LCP BREF would struggle to be enforced. This evidenced the need for improvements in the existing measurement infrastructure, without which test laboratories would struggle to provide the data quality needed by process plant operators for reporting into national emission inventories, and for national regulators who are legally responsible for enforcing emission limits aimed at improving European health and environmental impact.

Variation tendency of pollution characterization, sources, and health risks of PM2.5-bound polycyclic aromatic hydrocarbons in an emerging megacity in China: Based on three-year data

In this study, a total of 180 PM2.5 samples were collected from December 3, 2013 to October 20, 2016 in an urban area in Zhengzhou, China, and 16 polycyclic aromatic hydrocarbons (PAHs) in PM2.5 were analyzed. Diagnostic ratio and positive matrix factorization (PMF) were used for annual PAH source identification, and health risks and source regions of PM2.5-bound PAHs were also investigated. Results showed high pollution levels of PM2.5, in which all annual average concentrations substantially exceeded the Chinese standard. Although the PAH concentrations exhibited an evident decreasing trend, PAH pollution remained serious, especially in winter. Combustion, particularly coal combustion and vehicle emission, which were relative sources of 4–5-ring PAHs, played important roles in PAH pollution associated with PM2.5 by diagnostic ratios. PMF results showed that coal combustion had the highest contribution to PM2.5-bound PAHs at 39.6%, 39.6%, and 42.6% and traffic at 29.3%, 25.4%, and 27.9% in 2014–2016, respectively. Biomass burning and coking plants were also important sources of PAHs in PM2.5, with an average contribution of 16.4% ± 1.3% and 15.4% ± 3.5%, respectively. The surrounding region in Henan Province was the key potential source area for PM2.5. However, the northwest and adjoining regions of Zhengzhou were the vital potential sources for PAHs during the entire study period. The concentration levels of benzo[a]pyrene (BaP), ∑16PAHsTEQ, and carcinogenic PAHs remained high, especially for BaP, which had an annual concentration (1.9–5.5 ng/m3) that was considerably higher than the Chinese standard. Carcinogenic risks existed in the order of ingestion > dermal absorption > inhalation and adults > children > seniors > adolescents (except for naphthalene). The risk for females was slightly high, and no remarkable non-carcinogenic risk from PAHs were found.

Ex ante assessment of social acceptance of small-scale agro-energy system: A case study in southern Italy

Social acceptance is a relevant determinant of the development of agro-energy systems because its absence can cause delays or even the abandonment of innovative projects. This paper aims at an ex ante assessment of the socio-political acceptance of small-scale agro-energy systems in rural areas located in southern Italy, according to the bioenergy village approach. Starting from a theoretical model, we investigated the key factors influencing the perception of the risks and benefits of the realization of a biomass combustion plant, by a statistical survey on a sample of 152 members of the local community living in eight municipalities located in a rural area. Through exploratory and confirmatory statistical analyses, we identified two key factors: (a) the economic, environmental, and social benefits for the community and (b) reassurance from the energy company management. This research shows that it is very important to consider these elements in order to facilitate dialogue and the debate within the local community. In this way, the involved actors will be enabled to express their expectations to decision makers and policymakers, thus contributing to the steering of the project. In other words, community involvement and the democracy of the energy policy processes are favoured.