CONVERSION OF LOW AND MEDIUM POWER BOILERS FOR COMBUSTION OF SOLID FUEL BIOMASS

The paper analyzes the existing fleet and the possibilities of replacing anthracite and natural gas boilers of low and medium capacity and substantiates that the reconstruction with conversion to biomass is appropriate for boilers with a thermal capacity of more than 5 MW. The main problem is the reduction of heat perception of furnace screens and increase of heat removal to the convective pass due to the increased specific yield of biomass combustion products. Based on the analysis of changes in the nature of combustion processes and redistribution of heat exchange in the boiler, it was determined the criteria for the possibility of converting boilers from fossil fuels to biomass with maximum use of available equipment and the most acceptable fuel for this - agricultural pellets and wood waste. Technical solutions for the reconstruction of a boiler with a dense bed with a steam capacity of 20 t/h on anthracite (24 t/h on natural gas) have been developed and calculated with transfer to burning of granules of biomass and/or gas coal without change of dimensions of a fire chamber and without loss of thermal power due to compensation of the lowered heat absorption of a fire chamber by increase of a surface of a water economizer with corresponding decrease in an air heater. Technical solutions were used during the reconstruction of 4 boilers "Babcock-Wilcox" of Khorostkiv Sugar Plant. Co-combustion of biofuel pellets with coal is implemented in the range of components share from 0 to 100%. When burning granules, underburning in the fly ash is almost absent, ash deposits on convective surfaces are self-cleaning for several hours of work on gas coal. The solutions developed allowed to solve the problem of renovation of old boilers with the expansion of their fuel base and improvement of environmental performance through the use of biomass. Bibl. 18, Fig. 3, Tab. 4.

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CFD Based Ash Deposition Prediction in a BFB Firing Mixtures of Peat and Forest Residue

17th International Conference on Fluidized Bed Combustion ◽

10.1115/fbc2003-102 ◽

2003 ◽

Cited By ~ 2

Author(s):

Christian Mueller ◽

Dan Lundmark ◽

Bengt-Johan Skrifvars ◽

Rainer Backman ◽

Maria Zevenhoven ◽

...

Keyword(s):

Combustion Chamber ◽

Computational Fluid Dynamic ◽

Power Plants ◽

Fossil Fuels ◽

Fluid Dynamic ◽

Thermal Power ◽

Biomass Combustion ◽

Mineral Matter ◽

Forest Residue ◽

Bubbling Fluidized Bed

Fuels currently used for energy production in thermal power plants are characterized by their huge variety ranging from fossil fuels to biomass and waste. This multitude of fuels offers opportunities to the energy industry and nowadays many power plants do not fire either of these fuels but mixtures of them are burnt. While this procedure may lead to overall economic and environmental advantages it is very demanding for the boiler operators to still meet expectations concerning boiler performance, boiler availability and emission regulations. In the course of this latest trend in boiler operation, ash related operational problems such as slagging, fouling and corrosion are ranking very high on the list of reasons leading to significant reduction of boiler availability. Ash related problems strongly dependent on fuel specific aspects, such as the mineral matter distribution in the fuel, aspects specific to the used combustion technique as well as design aspects unique for the combustion chamber of any operating power plant. The overall goal in combustion related research is therefore the prediction of potential operational problems originating from fuel streams entering the combustion chamber as well as those originating from the design of individual furnaces. In our earlier work we have strongly focused on developing an advanced ash behavior prediction tool for biomass combustion combining computational fluid dynamic calculations (CFD) and advanced fuel analysis. In this paper the tool is applied to analyze the slagging and fouling tendency in a 295 MW bubbling fluidized bed boiler fired with mixtures of peat and forest residue. In addition to the overall deposition prediction this work focuses on details of the models used in the computational fluid dynamic calculations. These include a study on the importance of the accurate description of the fuel feeding system and related to this aspect the advanced description of the bubbling bed with regard to release of primary gas and ash particles from its surface to the freeboard. Evaluation of the predictions comparing simulation results with deposits on the furnace walls show good agreement.

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Analysis of the Correlation between Combustion Products in Biomass Thermal Power Plant Using Association Rule Mining

Energies ◽

10.3390/en13215532 ◽

2020 ◽

Vol 13 (21) ◽

pp. 5532

Author(s):

Saša Igić ◽

Dragana Bošković ◽

Barbara Vujkov ◽

Nemanja Igić ◽

Todor Janić ◽

...

Keyword(s):

Power Plant ◽

Association Rule ◽

Association Rule Mining ◽

Thermal Power ◽

Combustion Process ◽

Combustion Products ◽

Biomass Combustion ◽

Rule Mining ◽

Operation Process ◽

Biomass Plant

The biomass combustion process is inevitably accompanied by the emission of pollutant gasses. This paper gives a comprehensive analysis of the external variables and combustion products of the biomass plant. The analyzed data were collected from 18 MWt boiler in combined heat and power plant Sremska Mitrovica over a period of four months. The correlations between the recorded data were determined using a unique methodology, which is based on association rule mining. The results of the study can be further used for the reduction of the harmful combustion products, as well as for the optimization of the operation process.

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Current Status and Future Applications of Supercritical Pressures in Power Engineering

Volume 5: Fusion Engineering; Student Paper Competition; Design Basis and Beyond Design Basis Events; Simple and Combined Cycles ◽

10.1115/icone20-power2012-54558 ◽

2012 ◽

Cited By ~ 1

Author(s):

Anastasiia Zvorykina ◽

Sahil Gupta ◽

Wargha Peiman ◽

Igor Pioro ◽

Natalia Fialko

Keyword(s):

Carbon Dioxide ◽

Natural Gas ◽

Thermal Efficiency ◽

Nuclear Power ◽

Power Plants ◽

Fossil Fuels ◽

Thermal Power ◽

Combustion Process ◽

Electrical Energy ◽

Electrical Generation

It is well known that the electrical-power generation is the key factor for advances in any other industries, agriculture and level of living. In general, electrical energy can be produced by: 1) non-renewable sources such as coal, natural gas, oil, and nuclear; and 2) renewable sources such as hydro, wind, solar, biomass, geothermal and marine. However, the main sources for electrical-energy production are: 1) thermal - primary coal and secondary natural gas; 2) nuclear and 3) hydro. The rest of the sources might have visible impact just in some countries. Therefore, thermal and nuclear electrical-energy production as the major source is considered in the paper. From thermodynamics it is well known that higher thermal efficiencies correspond to higher temperatures and pressures. Therefore, modern SuperCritical (SC)-pressure coal-fired power plants have thermal efficiencies within 43–50% and even slightly above. Steam-generator outlet temperatures or steam-turbine inlet temperatures have reached a level of about 625°C (and even higher) at pressures of 25–30 (35–38) MPa. This is the largest application of SC pressures in industry. In spite of advances in coal-fired power-plants they are still considered as not environmental friendly due to producing a lot of carbon-dioxide emissions as a result of combustion process plus ash, slag and even acid rains. The most efficient modern thermal-power plants with thermal efficiencies within a range of 50–60%, are so-called, combined-cycle power plants, which use natural gas as a fuel. Natural gas is considered as a clean fossil fuel compared to coal and oil, but still due to combustion process emits a lot of carbon dioxide when it used for electrical generation. Therefore, a new reliable and environmental friendly source for the electrical-energy generation should be considered. Nuclear power is also a non-renewable source as the fossil fuels, but nuclear resources can be used for significantly longer time than some fossil fuels plus nuclear power does not emit carbon dioxide into atmosphere. Currently, this source of energy is considered as the most viable one for electrical generation for the next 50–100 years. Current, i.e., Generation II and III, Nuclear Power Plants (NPPs) consist of water-cooled reactors NPPs with the thermal efficiency of 30–35% (vast majority of reactors); subcritical carbon-dioxide-cooled reactors NPPs with the thermal efficiency up to 42% and liquid-sodium-cooled reactor NPP with the thermal efficiency of 40%. Therefore, the current fleet of NPPs, especially, water-cooled NPPs, are not very competitive compared to modern thermal power plants. Therefore, next generation or Generation-IV reactors with new parameters (NPPs with the thermal efficiency of 43–50% and even higher for all types of reactors) are currently under development worldwide. Generation-IV nuclear-reactor concept such as SuperCritical Water-cooled Reactor (SCWR) is intended to operate with direct or in-direct SC-“steam” Rankine cycle. Lead-cooled Fast Reactor (LFR) can be connected to SC-“steam” Rankine cycle or SC CO2 Brayton cycle through heat exchangers. In general, other Generation IV reactor concepts can be connected to either one or another cycle through heat exchangers. Therefore, this paper discusses various aspects of application of SC fluids in power engineering.

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Expediency of using the method of thermochemical regeneration at the reconstruction of a gas thermal power plant

The Problems of General Energy ◽

10.15407/pge2020.03.053 ◽

2020 ◽

Vol 2020 (3) ◽

pp. 53-57

Author(s):

I.V. Antonets ◽

Keyword(s):

Power Plant ◽

Natural Gas ◽

Gas Turbine ◽

Thermal Power Plant ◽

Thermal Power ◽

Calorific Value ◽

Combustion Products ◽

Steam Superheater ◽

Working Fluid ◽

Gas Power Plant

The article is devoted to finding ways for the improvement of technical, economic and environmental characteristics of an existing gas thermal power plant (TPP). One of such ways is the use of thermochemical regeneration (TCR) technology. Thermochemical regeneration is the technology of utilization of the waste-gas heat, which lies in the conversion of fuel due to this heat, as a result of which a new fuel with a significantly higher calorific value is formed. In addition, this fuel contains a significant amount of hydrogen, the combustion of which is accompanied by lower NOx emissions as compared with, for example, natural gas. Thus, TCR enables one to solve simultaneously environmental problems (at least in part). When using this technology, there is a problem of finding a heat source to implement the conversion process. It is shown that the replacement of intermediate steam superheater by thermochemical reactor reduces the efficiency of power plant as a whole. Therefore, we analyze the variant of gas-turbine superstructure over the TPP. Two schemes of the realization of TCR with steam-gas power plant (SGP) are considered: a scheme with the use of air excess for decreasing the temperature of working body before the gas turbine (α > 1) and a scheme with ballast in the form of combustion products. Calculations show that the presence of oxygen in the reagent of conversion significantly reduces its degree, which makes such schemes inefficient, and the use of combustion products as ballast to reduce the temperature of working fluid before the gas turbine gives an increase in efficiency of 3.6% (rel.) as compared with conventional SGP. It is established that the introduction of scheme with ballast in the form of combustion products will save 2790 nm3 / h of natural gas. Keywords: thermal power industry, thermochemical regeneration, steam-gas power plant

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Evaluasi Prediksi Higher Heating Value (HHV) Biomassa Berdasarkan Analisis Proksimat

Risalah Fisika ◽

10.35895/rf.v4i1.166 ◽

2020 ◽

Vol 4 (1) ◽

pp. 1-7

Author(s):

Made Dirgantara ◽

Karelius Karelius ◽

Marselin Devi Ariyanti, Sry Ayu K. Tamba

Keyword(s):

Renewable Energy ◽

Natural Gas ◽

Key Words ◽

Critical Analysis ◽

Fossil Fuels ◽

Calorific Value ◽

Proximate Analysis ◽

Heating Value ◽

Bomb Calorimeter ◽

Hhv Prediction

Abstrak – Biomassa merupakan salah satu energi terbarukan yang sangat mudah ditemui, ramah lingkungan dan cukup ekonomis. Keberadaan biomassa dapat dimaanfaatkan sebagai pengganti bahan bakar fosil, baik itu minyak bumi, gas alam maupun batu bara. Analisi diperlukan sebagai dasar biomassa sebagai energi seperti proksimat dan kalor. Analisis terpenting untuk menilai biomassa sebagai bahan bakar adalah nilai kalori atau higher heating value (HHV). HHV secara eksperimen diukur menggunakan bomb calorimeter, namun pengukuran ini kurang efektif, karena memerlukan waktu serta biaya yang tinggi. Penelitian mengenai prediksi HHV berdasarkan analisis proksimat telah dilakukan sehingga dapat mempermudah dan menghemat biaya yang diperlukan peneliti. Dalam makalah ini dibahas evaluasi persamaan untuk memprediksi HHV berdasarkan analisis proksimat pada biomassa berdasarkan data dari penelitian sebelumnya. Prediksi nilai HHV menggunakan lima persamaan yang dievaluasi dengan 25 data proksimat biomassa dari penelitian sebelumnya, kemudian dibandingkan berdasarkan nilai error untuk mendapatkan prediksi terbaik. Hasil analisis menunjukan, persamaan A terbaik di 7 biomassa, B di 6 biomassa, C di 6 biomassa, D di 5 biomassa dan E di 1 biomassa.Kata kunci: bahan bakar, biomassa, higher heating value, nilai error, proksimat Abstract – Biomass is a renewable energy that is very easy to find, environmentally friendly, and quite economical. The existence of biomass can be used as a substitute for fossil fuels, both oil, natural gas, and coal. Analyzes are needed as a basis for biomass as energy such as proximate and heat. The most critical analysis to assess biomass as fuel is the calorific value or higher heating value (HHV). HHV is experimentally measured using a bomb calorimeter, but this measurement is less effective because it requires time and high costs. Research on the prediction of HHV based on proximate analysis has been carried out so that it can simplify and save costs needed by researchers. In this paper, the evaluation of equations is discussed to predict HHV based on proximate analysis on biomass-based on data from previous studies. HHV prediction values using five equations were evaluated with 25 proximate biomass data from previous studies, then compared based on error value to get the best predictions. The analysis shows that Equation A predicts best in 7 biomass, B in 6 biomass, C in 6 biomass, D in 5 biomass, and E in 1 biomass. Key words: fuel, biomass, higher heating value, error value, proximate

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Determination of Traces Heavy Metals from Solid Residues Formed by Combustion of Lignite in Relation to Degree of Accessibility in Soil and Plants

Revista de Chimie ◽

10.37358/rc.17.10.5886 ◽

2017 ◽

Vol 68 (10) ◽

pp. 2363-2366

Author(s):

Delia Nica Badea

Keyword(s):

Heavy Metals ◽

Power Plant ◽

Thermal Power ◽

Reference Value ◽

Combustion Products ◽

Toxic Heavy Metals ◽

Area Of Influence ◽

Risk Potential

The paper evaluates the presence and content of traces of heavy metals Hg, Pb, Ni, Cd (total forms) from coal and solid combustion products, the degree of transfer and accessibility in the area of influence of a lignite power plant. The content of toxic heavy metals in residues are characterized by RE Meiji [ 1 (Pb and Hg) and REMeij �1 (Ni and Cd) for the filter ash. Pb and Ni content in the soil exceeds normal values, and Pb exceeds and alert value for sensitive soils around the residue deposit (70.20 mg.Kg-1). The degree of accessibility of the metals in plants (TF), reported at the Khan reference value (0.5), indicates a significant bioaccumulation level for the metals: Cd (1.9) and Hg (0.6) inside the deposit; Cd (0.39) at the base of the deposit, Hg (0.8) in the area of the thermal power plant. The trace levels of heavy metals analyzed by GFAAS and CVAAS (Hg), indicates a moderate risk potential for food safety and quality of life in the studied area.

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Emissions Effects of Energy Storage for Frequency Regulation: Comparing Battery and Flywheel Storage to Natural Gas

Energies ◽

10.3390/en14030549 ◽

2021 ◽

Vol 14 (3) ◽

pp. 549

Author(s):

Eric Pareis ◽

Eric Hittinger

Keyword(s):

Energy Storage ◽

Natural Gas ◽

Fossil Fuels ◽

Storage Systems ◽

Storage System ◽

The United States ◽

Frequency Regulation ◽

So2 Emissions ◽

Gas Generation ◽

Electrical Generation

With an increase in renewable energy generation in the United States, there is a growing need for more frequency regulation to ensure the stability of the electric grid. Fast ramping natural gas plants are often used for frequency regulation, but this creates emissions associated with the burning of fossil fuels. Energy storage systems (ESSs), such as batteries and flywheels, provide an alternative frequency regulation service. However, the efficiency losses of charging and discharging a storage system cause additional electrical generation requirements and associated emissions. There is not a good understanding of these indirect emissions from charging and discharging ESSs in the literature, with most sources stating that ESSs for frequency regulation have lower emissions, without quantification of these emissions. We created a model to estimate three types of emissions (CO2, NOX, and SO2) from ESSs providing frequency regulation, and compare them to emissions from a natural gas plant providing the same service. When the natural gas plant is credited for the generated electricity, storage systems have 33% to 68% lower CO2 emissions than the gas turbine, depending on the US eGRID subregion, but higher NOX and SO2 emissions. However, different plausible assumptions about the framing of the analysis can make ESSs a worse choice so the true difference depends on the nature of the substitution between storage and natural gas generation.

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Accelerating oil and gas investment and reserves by design

The APPEA Journal ◽

10.1071/aj17116 ◽

2018 ◽

Vol 58 (2) ◽

pp. 557

Author(s):

Barry A. Goldstein

Keyword(s):

Natural Gas ◽

Fossil Fuels ◽

Oil And Gas ◽

South Australia ◽

Land Access ◽

Oil And Gas Exploration ◽

Oil And Gas Producers ◽

Crude Oil Prices ◽

Exploration And Production ◽

Oil And Gas Operations

Facts are stubborn things; and whatever may be our wishes, our inclinations, or the dictates of our passion, they cannot alter the state of facts and evidence (Adams 1770). Some people unfamiliar with upstream petroleum operations, some enterprises keen to sustain uncontested land use, and some people against the use of fossil fuels have and will voice opposition to land access for oil and gas exploration and production. Social and economic concerns have also arisen with Australian domestic gas prices tending towards parity with netbacks from liquefied natural gas (LNG) exports. No doubt, natural gas, LNG and crude-oil prices will vary with local-to-international supply-side and demand-side competition. Hence, well run Australian oil and gas producers deploy stress-tested exploration, delineation and development budgets. With these challenges in mind, successive governments in South Australia have implemented leading-practice legislation, regulation, policies and programs to simultaneously gain and sustain trust with the public and investors with regard to land access for trustworthy oil and gas operations. South Australia’s most recent initiatives to foster reserve growth through welcomed investment in responsible oil and gas operations include the following: a Roundtable for Oil and Gas; evergreen answers to frequently asked questions, grouped retention licences that accelerate investment in the best of play trends; the Plan for ACcelerating Exploration (PACE) Gas Program; and the Oil and Gas Royalty Return Program. Intended and actual outcomes from these initiatives are addressed in this extended abstract.

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