scholarly journals Aspects of using biomass as energy source for power generation

2017 ◽  
Vol 11 (1) ◽  
pp. 181-190
Author(s):  
Raluca-Nicoleta Tîrtea ◽  
Cosmin Mărculescu
Keyword(s):  
Carbon Dioxide ◽  
Flue Gas ◽  
Power Plants ◽  
Fossil Fuels ◽  
Development Stage ◽  
Green Energy ◽  
Sulphur Content ◽  
Heating Value ◽  
Biomass Plant ◽  
Biomass Power Plants

AbstractBiomass represents an important source of renewable energy in Romania with about 64% of the whole available green energy. Being a priority for the energy sector worldwide, in our country the development stage is poor compared to solar and wind energy. Biomass power plants offer great horizontal economy development, local and regional economic growth with benefic effects on life standard. The paper presents an analysis on biomass to power conversion solutions compared to fossil fuels using two main processes: combustion and gasification. Beside the heating value, which can be considerably higher for fossil fuels compared to biomass, a big difference between fossil fuels and biomass can be observed in the sulphur content. While the biomass sulphur content is between 0 and approximately 1%, the sulphur content of coal can reach 4%. Using coal in power plants requires important investments in installations of flue gas desulfurization. If limestone is used to reduce SO2emissions, then additional carbon dioxide moles will be released during the production of CaO from CaCO3. Therefore, fossil fuels not only release a high amount of carbon dioxide through burning, but also through the caption of sulphur dioxide, while biomass is considered CO2neutral. Biomass is in most of the cases represented by residues, so it is a free fuel compared to fossil fuels. The same power plant can be used even if biomass or fossil fuels is used as a feedstock with small differences. The biomass plant could need a drying system due to high moisture content of the biomass, while the coal plant will need a desulfurization installation of flue gas and additional money will be spent with fuel purchasing.

scholarly journals Towards monitoring localized CO<sub>2</sub> emissions from space: co-located regional CO<sub>2</sub> and NO<sub>2</sub> enhancements observed by the OCO-2 and S5P satellites

2019 ◽  
Author(s):  
Maximilian Reuter ◽  
Michael Buchwitz ◽  
Oliver Schneising ◽  
Sven Krautwurst ◽  
Christopher W. O'Dell ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Power Plants ◽  
Fossil Fuels ◽  
Open Data ◽  
Point Sources ◽  
Background Concentration ◽  
Multiple Sources ◽  
Cross Sectional ◽  
Fire Emissions ◽  
Dry Air

Abstract. Despite its key role for climate change, large uncertainties persist in our knowledge of the anthropogenic emissions of carbon dioxide (CO2) and no global observing system exists allowing to monitor emissions from localized CO2 sources with sufficient accuracy. The Orbiting Carbon Observatory-2 (OCO-2) satellite can retrieve the column-average dry-air mole fractions of CO2 (XCO2). However, regional column-average enhancements of individual point sources are usually small compared to the background concentration and its natural variability. This makes the unambiguous identification and quantification of anthropogenic emission plume signals challenging. NO2 is co-emitted with CO2 when fossil fuels are combusted at high temperatures. It has a short lifetime of the order of hours so that NO2 columns often exceed background levels by orders of magnitude near sources making it a suitable tracer of recently emitted CO2. Based on six case studies (Moscow, Russia; Lipetsk, Russia; Baghdad, Iraq; Medupi and Matimba power plants, South Africa; Australian wildfires; and Nanjing, China), we demonstrate the usefulness of simultaneous satellite observations of NO2 and the column-average dry-air mole fraction of CO2 (XCO2). For this purpose, we analyze co-located regional enhancements of XCO2 observed by OCO-2 and NO2 observed by the Sentinel-5 Precursor (S5P) satellite and estimate the CO2 plume's cross-sectional fluxes. We take advantage of the nearly simultaneous NO2 measurements with S5P's wide swath by identifying the source of the observed XCO2 enhancements, excluding interference with remote upwind sources, allowing to adjust the wind direction, and by constraining the shape of the CO2 plumes. We compare the inferred cross-sectional fluxes with the Emissions Database for Global Atmospheric Research (EDGAR), the Open-Data Inventory for Anthropogenic Carbon dioxide (ODIAC), and, in the case of the Australian wildfires, with the Global Fire Emissions Database (GFED). The inferred cross-sectional fluxes range from 32 Mt CO2/a to 158 Mt CO2/a with uncertainties (1σ) between 23 % and 72 %. For the majority of analyzed emission sources, the estimated cross-sectional fluxes agree within their uncertainty with either EDGAR or ODIAC or lie in between them. We assess the contribution of multiple sources of uncertainty and find that the dominating contributions are related to the computation of the effective wind speed normal to the plume's cross-section. The planned European Copernicus anthropogenic CO2 monitoring mission (CO2M) will not only provide precise measurements with high spatial resolution but also imaging capabilities with a wider swath of simultaneous XCO2 and NO2 observations. Such a mission, in particular as a constellation of satellites, will deliver CO2 emission estimates from localized sources at an unprecedented frequency and level of accuracy.

Concepts and Experiences for Higher Plant Efficiency With Modern Advanced Boiler and Incineration Technology

2010 ◽  
Author(s):  
Armin Main ◽  
Thomas Maghon
Keyword(s):  
Flue Gas ◽  
Power Plants ◽  
Fossil Fuels ◽  
Live Steam ◽  
Gas Temperature ◽  
Higher Plant ◽  
Advantages And Disadvantages ◽  
Boiler Tubes ◽  
Steam Parameters ◽  
Plant Efficiency

The efforts for reducing CO2 Emissions into atmosphere and increasing costs for fossil fuels concepts are the drivers for Energy from Waste (EfW) facilities with higher plant efficiency. In the past steam parameters for EfW were requested mainly at 40 bars and 400 °C (580 psi and 752 F). In case of coal fired power plants at the same location as the EfW facilities higher steam parameters at 90 bar, 520 °C (1305 psi, 968 F) have been used for the design of stoker and boiler. This long-term experience with higher steam parameters is the platform for the todays and future demand in higher plant efficiency. Increase in EfW plant efficiency is achievable by increasing temperature and pressure of live steam going along with optimized combustion conditions when using well proven grate technology for waste incineration. On the other hand higher steam parameters result in higher corrosion rates on the boiler tubes and the optimization of the combustion conditions are limited by the burn out quality requirements of slag and flue gas. Advantages and disadvantages have therefore to be balanced carefully. This paper will present different measures for optimized boiler and combustion conditions compared to an EfW plant with live steam at 40 bars and 400 °C (580 psi and 752 F) and 60% excess of combustion air. Plants operated at these conditions have very low maintenance costs created by corrosion of boiler tubes and show performance with very high availability. The following parameters and experiences will be evaluated: - reduction of excess air; - flue gas temperature at boiler outlet; - higher steam parameters (pressure and temperature); - heating surfaces for steam superheating in the radiation boiler section; - steam reheating; - external superheaters using auxiliary fuels. The comparison of the different methods for increasing the efficiency together with resulting technology challenges incorporates the experiences from modern EfW reference facilities built in Naples/Italy, Ruedersdorf (Berlin)/Germany and Heringen/Germany.

scholarly journals Development of Multimode Gas Fired Combined Cycle Chemical-Looping Combustion Based Power Plant Lay-Outs

2021 ◽  
Author(s):  
Basavaraja Revappa Jayadevappa
Keyword(s):  
Carbon Dioxide ◽  
Power Plant ◽  
Natural Gas ◽  
Flue Gas ◽  
Power Plants ◽  
Carbon Dioxide Capture ◽  
Combined Cycle ◽  
Chemical Looping Combustion ◽  
Chemical Looping ◽  
Operating Pressure

Abstract Operation of power plants in carbon dioxide capture and non-capture modes and energy penalty or energy utilization in such operations are of great significance. This work reports on two gas fired pressurized chemical-looping combustion power plant lay-outs with two inbuilt modes of flue gas exit namely, with carbon dioxide capture mode and second mode is letting flue gas (consists carbon dioxide and water) without capturing carbon dioxide. In the non-CCS mode, higher thermal efficiencies of 54.06% and 52.63% efficiencies are obtained with natural gas and syngas. In carbon capture mode, a net thermal efficiency of 52.13% is obtained with natural gas and 48.78% with syngas. The operating pressure of air reactor is taken to be 13 bar for realistic operational considerations and that of fuel reactor is 11.5 bar. Two power plant lay-outs developed based combined cycle CLC mode for natural gas and syngas fuels. A single lay-out is developed for two fuels with possible retrofit for dual fuel operation. The CLC Power plants can be operated with two modes of flue gas exit options and these operational options makes them higher thermal efficient power plants.

scholarly journals Towards monitoring localized CO<sub>2</sub> emissions from space: co-located regional CO<sub>2</sub> and NO<sub>2</sub> enhancements observed by the OCO-2 and S5P satellites

2019 ◽  
Vol 19 (14) ◽  
pp. 9371-9383 ◽  
Author(s):  
Maximilian Reuter ◽  
Michael Buchwitz ◽  
Oliver Schneising ◽  
Sven Krautwurst ◽  
Christopher W. O'Dell ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Power Plants ◽  
Fossil Fuels ◽  
Open Data ◽  
Point Sources ◽  
Measurement Noise ◽  
Background Concentration ◽  
Multiple Sources ◽  
Cross Sectional ◽  
Fire Emissions

Abstract. Despite its key role in climate change, large uncertainties persist in our knowledge of the anthropogenic emissions of carbon dioxide (CO2) and no global observing system exists that allows us to monitor emissions from localized CO2 sources with sufficient accuracy. The Orbiting Carbon Observatory-2 (OCO-2) satellite allows retrievals of the column-average dry-air mole fractions of CO2 (XCO2). However, regional column-average enhancements of individual point sources are usually small, compared to the background concentration and its natural variability, and often not much larger than the satellite's measurement noise. This makes the unambiguous identification and quantification of anthropogenic emission plume signals challenging. NO2 is co-emitted with CO2 when fossil fuels are combusted at high temperatures. It has a short lifetime on the order of hours so that NO2 columns often greatly exceed background and noise levels of modern satellite sensors near sources, which makes it a suitable tracer of recently emitted CO2. Based on six case studies (Moscow, Russia; Lipetsk, Russia; Baghdad, Iraq; Medupi and Matimba power plants, South Africa; Australian wildfires; and Nanjing, China), we demonstrate the usefulness of simultaneous satellite observations of NO2 and XCO2. For this purpose, we analyze co-located regional enhancements of XCO2 observed by OCO-2 and NO2 from the Sentinel-5 Precursor (S5P) satellite and estimate the CO2 plume's cross-sectional fluxes. We take advantage of the nearly simultaneous NO2 measurements with S5P's wide swath and small measurement noise by identifying the source of the observed XCO2 enhancements, excluding interference with remote upwind sources, allowing us to adjust the wind direction, and by constraining the shape of the CO2 plumes. We compare the inferred cross-sectional fluxes with the Emissions Database for Global Atmospheric Research (EDGAR), the Open-Data Inventory for Anthropogenic Carbon dioxide (ODIAC), and, in the case of the Australian wildfires, with the Global Fire Emissions Database (GFED). The inferred cross-sectional fluxes range from 31 MtCO2 a−1 to 153 MtCO2 a−1 with uncertainties (1σ) between 23 % and 72 %. For the majority of analyzed emission sources, the estimated cross-sectional fluxes agree, within their uncertainty, with either EDGAR or ODIAC or lie somewhere between them. We assess the contribution of multiple sources of uncertainty and find that the dominating contributions are related to the computation of the effective wind speed normal to the plume's cross section. The flux uncertainties are expected to be reduced by the planned European Copernicus anthropogenic CO2 monitoring mission (CO2M), which will provide not only precise measurements with high spatial resolution but also imaging capabilities with a wider swath of simultaneous XCO2 and NO2 observations. Such a mission, particularly if performed by a constellation of satellites, will deliver CO2 emission estimates from localized sources at an unprecedented frequency and level of accuracy.

Ultrasonic Pelleting and Synchronized Torrefaction of Cellulosic Biomass for Bioenergy Production

2017 ◽  
Author(s):  
Yang Yang ◽  
Nicholas Eisenbarth ◽  
Xiaoxu Song ◽  
Meng Zhang ◽  
Donghai Wang
Keyword(s):  
Power Plants ◽  
Fossil Fuels ◽  
Single Step ◽  
Cellulosic Biomass ◽  
Heating Value ◽  
Step Process ◽  
High Heating Value ◽  
Torrefied Biomass ◽  
High Heating ◽  
The U.S

The U.S. is sustainably producing of over 1 billion dry tons of biomass annually. This amount of biomass is sufficient to produce bioenergy that can replace about 30 percent of the nation’s current annual consumption of conventional fossil fuels. This then gives us the opportunity to turn waste into bioenergy that can assist in meeting the U.S. Renewable Fuel Standard (RFS). Besides being converted into bioethanol through the biochemical platform, biomass can also be utilized solid fuels to generate bioenergy through the thermochemical platform. Co-firing power plants use torrefied biomass pellets combined with coal for electricity generation. A two-step process, torrefaction followed by pelleting, is the prevailing technique that the industry is currently using to produce torrefied biomass pellets. Torrefaction converts biomass into biochar with high heating value, and pelleting densifies torrefied biochar into pellets with high durability and density. For the same purpose, we developed the ultrasonic pelleting and synchronized torrefaction of cellulosic biomass process, which is a single-step process to generate high quality solid fuel pellets with high heating value together with good durability and density. This study reports the first experimental investigation to demonstrate the feasibility of the novel process. Key process parameters have been identified, and their effects on the feasibility of generating quality torrefied biomass pellets are reported. Pellets are evaluated from the aspects of feasibility, durability, heating value, and thermal stability.

CO2 Emission Abatement in CC-IGCC Power Plants: Energy and Economic Comparisons

2008 ◽  
Author(s):  
Marco Gambini ◽  
Michela Vellini
Keyword(s):  
Carbon Dioxide ◽  
Natural Gas ◽  
Co2 Emissions ◽  
Power Plants ◽  
Fossil Fuels ◽  
Combined Cycle ◽  
Exhaust Gas ◽  
Gas Treatment ◽  
Low Co2 ◽  
Global Efficiency

In this paper two methodologies, able to avoid CO2 dispersion in atmosphere, have been analyzed: • treating exhaust gases in order to remove, liquefy and store the produced carbon dioxide; • de-carbonizing fossil fuels before using them in the combustion in order to inhibit completely carbon dioxide production. These methodologies have been implemented in advanced power plants based on gas turbine: a combined cycle power plant (CC), fed by natural gas, and an integrated gasification combined cycle (IGCC), fed by coal. The exhaust gas treatment is based on a chemical process of absorption, while the fossil fuel decarbonization is based on partial oxidation of methane, steam methane reforming and coal gasification. These systems require material and energetic integrations with the power sections and so the best interconnections must be investigated in order to obtain good overall performance. With reference to thermodynamic and economic performance, significant comparisons have been made between the above mentioned reference plants. An efficiency decrease and an increase in the cost of electricity have been obtained when power plants are equipped with systems able to reduce CO2 emissions. However, in order to obtain low CO2 emissions when coal is used, the coal decarbonization must be implemented: in this case it is possible to attain a global efficiency of about 38%, a specific emission of 0.1117 kg/kWh and an increase of kWh cost of about 32%. Vice versa, in order to obtain low CO2 emissions when natural gas is used, the exhaust gas treatment must be implemented: in this case it is possible to attain a global efficiency of about 50.7%, a specific emission of 0.0391 kg/kWh and an increase of kWh cost of about 15%. The clean use of coal seems to have good potential because it allows low energy penalizations (about 7.5 percentage points) and economic increases of about 32%. Because of the great availability, the homogeneous distribution and the low cost of this fuel, these results seem to be very interesting especially in the viewpoint of a transition towards the “hydrogen economy”, based, at least in the medium term, on fossil fuels.

Recent advances in low-temperature electrochemical conversion of carbon dioxide

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Farihahusnah Hussin ◽  
Mohamed Kheireddine Aroua
Keyword(s):  
Carbon Dioxide ◽  
Fossil Fuels ◽  
Industrial Revolution ◽  
Low Cost ◽  
Value Added ◽  
Primary Source ◽  
Green Energy ◽  
Computational Method ◽  
Electrochemical Conversion ◽  
Electrochemical Approach

AbstractSince the onset of the industrial revolution, fossil fuels have been the primary source of energy generation, and the continued exploitation of fossil fuels has led to an increase in the amount of atmospheric carbon dioxide. A lot of research currently focuses much on decreasing dependence on fossil fuels by replacing them with green energy. However, this technique poses a number of challenges, such as the need for improved infrastructure and technology and the high market penetration of renewable energy technologies. Capturing and converting carbon dioxide using electrochemical approaches can help to stabilize atmospheric greenhouse gas levels and create a positive future for the transformation of carbon dioxide into a number of value-added products. The conversion of carbon dioxide via electrochemical approach is a major challenge, and consideration must be given to the development and production of low-cost, stable, and highly efficient electrocatalysts. Hence, this review presents an overview of the current developments in the electrochemical conversion of carbon dioxide. In addition, this study discusses the current progress of electrocatalysts, in particular, the homogeneous and heterogeneous catalyst, which has a high level of activity and selectivity of low overpotential preferred products. The overview of the mechanisms and kinetics of the carbon dioxide reduction using the computational method are also addressed.

CO2capture by amines in aqueous media and its subsequent conversion to formate with reusable ruthenium and iron catalysts

2016 ◽  
Vol 18 (21) ◽  
pp. 5831-5838 ◽  
Author(s):  
Jotheeswari Kothandaraman ◽  
Alain Goeppert ◽  
Miklos Czaun ◽  
George A. Olah ◽  
G. K. Surya Prakash
Keyword(s):  
Carbon Dioxide ◽  
Flue Gas ◽  
Power Plants ◽  
Aqueous Media ◽  
Ambient Air ◽  
Iron Catalysts ◽  
Subsequent Conversion ◽  
Industrial Sources

Conversion of carbon dioxide (CO2) captured from industrial sources (e.g.flue gas of power plants) or even from ambient air to formate through CO2capture and utilization (CCU) as a possible strategy to mitigate anthropogenic CO2emissions to the atmosphere is proposed.

Pre-Combustion Removal of Carbon Dioxide From Natural Gas Power Plants and the Transition to Hydrogen Energy Systems

1992 ◽  
Vol 114 (3) ◽  
pp. 221-226 ◽  
Author(s):  
Y. Mori ◽  
S. M. Masutani ◽  
G. C. Nihous ◽  
L. A. Vega ◽  
C. M. Kinoshita
Keyword(s):  
Carbon Dioxide ◽  
Carbon Dioxide Emissions ◽  
Power Plants ◽  
Fossil Fuels ◽  
Energy Systems ◽  
Deep Ocean ◽  
Hydrocarbon Fuel ◽  
Hydrogen Energy ◽  
Power Cost ◽  
Gas Treatment

A system to reduce carbon dioxide emissions from combustion power plants is described. Unlike earlier proposals based on flue gas treatment, the problem is addressed prior to combustion by reforming the hydrocarbon fuel into H2 and CO2. Following separation, H2 is burned in place of the original fuel and the captured CO2 is liquefied and injected into the deep ocean at a depth sufficient to ensure effective containment, and to minimize damage to the marine environment. Calculations indicate moderate plant thermal efficiency and power cost penalties. In addition, the H2 production potential of this system may be exploited as a means to facilitate the transition from fossil fuels to future hydrogen energy systems.

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