scholarly journals Applications of oxygen for NOx control and CO2 capture in coal-fired power plants

2006 ◽  
Vol 10 (3) ◽  
pp. 119-142 ◽  
Author(s):  
Fabienne Châtel-Pélage ◽  
Rajani Varagani ◽  
Pavol Pranda ◽  
Nicolas Perrin ◽  
Hamid Farzan ◽  
...  
Keyword(s):  
Co2 Capture ◽  
Power Plants ◽  
Nox Reduction ◽  
Cost Effective ◽  
Pilot Scale ◽  
Capital Requirements ◽  
Pure Oxygen ◽  
Gas Treatment ◽  
Nox Control ◽  
The Cost

Two promising combustion modification approaches applicable to pulverized coal fired boilers are presented: "Oxygen-Enriched Combustion" (OEC) for NOx control and "Oxy-Combustion" (PC-OC) for CO2 capture. Oxygen-enriched air rather than air is used as an oxidizer in the OEC technology. Unlike flue gas treatment technologies, OEC directly impacts the NOx formation process by significantly reducing the conversion of coal bound nitrogen to NOx. Pilot-scale and full-scale tests have shown 20 to 30% NOx reduction from an optimized staged-air baseline. In addition to the overall cost competitiveness and the reduced capital requirements, other significant advantages of the O2-enriched technology vs. existing low NOx technologies are presented. The PC-OC technology is shown as a cost-effective technology for CO2 capture from existing or new coal-fired power plants. Pure oxygen diluted in recycled flue gases is used as an oxidizer. The process has been successfully demonstrated and extensively characterized at pilot-scale level (1.5 MWt). The tests have shown substantial benefits of the PC-OC technology, in terms of NOx reduction (60-70% from air-baseline), overall plant efficiency, etc. The cost effectiveness of this capture technology compared to competitive amine scrubbing technology was investigated. The cost of CO2 avoided was around $36/ton for the new PC-OC cases, about $48/ton on a retrofit PC-OC case, which is about 25 to 40% cheaper than the amine scrubbing system. Those numbers were calculated for sub-critical units and include the cost of CO2 compression up to 80 bar. .

Solar Concentrating Systems Using Small Mirror Arrays

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
Joachim Göttsche ◽  
Bernhard Hoffschmidt ◽  
Stefan Schmitz ◽  
Markus Sauerborn ◽  
Reiner Buck ◽  
...  
Keyword(s):  
Power Plants ◽  
Raw Materials ◽  
Large Fraction ◽  
Steel Structure ◽  
Steel Structures ◽  
Cost Effective ◽  
Wind Loads ◽  
Drive Systems ◽  
Mirror Area ◽  
The Cost

The cost of solar tower power plants is dominated by the heliostat field making up roughly 50% of investment costs. Classical heliostat design is dominated by mirrors brought into position by steel structures and drives that guarantee high accuracies under wind loads and thermal stress situations. A large fraction of costs is caused by the stiffness requirements of the steel structure, typically resulting in ∼20 kg/m2 steel per mirror area. The typical cost figure of heliostats (figure mentioned by Solucar at Solar Paces Conference, Seville, 2006) is currently in the area of 150 €/m2 caused by the increasing price of the necessary raw materials. An interesting option to reduce costs lies in a heliostat design where all moving parts are protected from wind loads. In this way, drives and mechanical layout may be kept less robust, thereby reducing material input and costs. In order to keep the heliostat at an appropriate size, small mirrors (around 10×10 cm2) have to be used, which are placed in a box with a transparent cover. Innovative drive systems are developed in order to obtain a cost-effective design. A 0.5×0.5 m2 demonstration unit will be constructed. Tests of the unit are carried out with a high-precision artificial sun unit that imitates the sun’s path with an accuracy of less than 0.5 mrad and creates a beam of parallel light with a divergence of less than 4 mrad.

Exhaust Gas Recirculation Performance in Dry Low Emissions Combustors

2011 ◽  
Author(s):  
A. M. Elkady ◽  
A. R. Brand ◽  
C. L. Vandervort ◽  
A. T. Evulet
Keyword(s):  
Gas Turbine ◽  
Co2 Capture ◽  
Carbon Capture ◽  
Power Plants ◽  
Nox Reduction ◽  
Co2 Concentration ◽  
Exhaust Gas Recirculation ◽  
Exhaust Gas ◽  
Low Oxygen ◽  
Gas Recirculation

In a carbon constrained world there is a need for capturing and sequestering CO2. Post-combustion carbon capture via Exhaust Gas Recirculation (EGR) is considered a feasible means of reducing emission of CO2 from power plants. Exhaust Gas Recirculation is an enabling technology for increasing the CO2 concentration within the gas turbine cycle and allow the decrease of the size of the separation plant, which in turn will enable a significant reduction in CO2 capture cost. This paper describes the experimental work performed to better understand the risks of utilizing EGR in combustors employing dry low emissions (DLE) technologies. A rig was built for exploring the capability of premixers to operate in low O2 environment, and a series of experiments in a visually accessible test rig was performed at representative aeroderivative gas turbine pressures and temperatures. Experimental results include the effect of applying EGR on operability, efficiency and emissions performance under conditions of up to 40% EGR. Findings confirm the viability of EGR for enhanced CO2 capture; In addition, we confirm benefits of NOx reduction while complying with CO emissions in DLE combustors under low oxygen content oxidizer.

NOx Reduction of a 165 MW Wall-Fired Boiler Utilizing Air and Fuel Flow Measurement and Control

2002 ◽  
Author(s):  
Marion Cherry ◽  
Dave Earley ◽  
David Silzle
Keyword(s):  
Measurement System ◽  
Flow Measurement ◽  
Power Plants ◽  
Nox Reduction ◽  
Capital Requirements ◽  
Unburned Carbon ◽  
Front Wall ◽  
Future System ◽  
Reduction Strategies ◽  
Coal Flow

As a result of increasingly stringent emissions limitations being imposed on coal-fired power plants today, electric utilities are faced with having to make major compliance related modifications to their existing power plants. While many utilities have elected to implement expensive post-combustion NOx reduction programs on their largest generating units, infurnace NOx reduction offers a less expensive alternative suitable to any size boiler, to reduce NOx while also improving overall combustion. In-furnace NOx reduction strategies have proven that, when used with other less expensive approaches (Overfire air, fuel switching, and/or SNCR), levels less than 0.15 lb./MMBtu can be economically achieved. Furthermore, when implemented in conjunction with an expensive post-combustion SCR program, initial capital requirements and ongoing operating costs can be cut to save utilities millions of dollars. For the purpose of developing a system-wide NOx reduction strategy, Santee Cooper, a southeastern U.S. utility applied pulverized coal flow and individual burner airflow measurement systems to Unit 3 at its Jefferies Station, a 165MW, 16-burner front wall-fired boiler. The airflow measurement system, in service for many years, applied a well-proven averaging Pitot tube technology to measure individual burner secondary airflow. The coal flow measurement system utilized low energy microwaves to accurately measure coal density and coal velocity in individual coal pipes. The combination of these two systems provided the accurate measurements necessary for controlled manipulation of individual burner stoichiometries, giving the plant the ability to improve burner combustion, yielding a reduction in NOx levels approaching 20%. Optimized burner combustion also resulted in a leveling of the excess O2 profile, which will enable the plant to pursue further reductions in excess air as well as staged combustion, thus allowing for further NOx reductions in the future. How this program produced a significant NOx reduction will be presented in detail in this paper. The paper will also discuss the effects on excess O2, opacity, and unburned carbon. In addition, this program will allow for future system-wide planning with regard to possible SCR implementation.

scholarly journals MARKET AND DEVELOPMENT TRENDS IN COGENERATION AND COMBINED HEAT AND POWER PLANTS

2018 ◽  
Vol 20 ◽  
pp. 86-97
Author(s):  
Jan Slad ◽  
Andreas Pickard ◽  
Frank Strobelt
Keyword(s):  
Power Generation ◽  
Energy Efficiency ◽  
Power Plants ◽  
Economic Value ◽  
Cost Effective ◽  
Combined Heat And Power ◽  
Development Trends ◽  
Eu Countries ◽  
Increase Energy Efficiency ◽  
The Cost

The transition of energy mix in Europe is placing greater focus on energy efficiency. Lawmakers in some of EU countries have already recognized that combined heat and power generation (cogeneration, CHP) can help increase energy efficiency. Targeted promotion and subsidization have raised the cost-effective profitability of cogeneration plants significantly. But how can the economic value of this investment be maximized?

scholarly journals Microalgae Cultivation in Pilot Scale for Biomass Production Using Exhaust Gas from Thermal Power Plants

Energies ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3497 ◽  
Author(s):  
Sanghyun Park ◽  
Yongtae Ahn ◽  
Kalimuthu Pandi ◽  
Min-Kyu Ji ◽  
Hyun-Shik Yun ◽  
...  
Keyword(s):  
Continuous Culture ◽  
Power Plants ◽  
Mine Drainage ◽  
Thermal Power ◽  
Cost Effective ◽  
Pilot Scale ◽  
Biofuel Production ◽  
Thermal Power Plants ◽  
Acutodesmus Obliquus ◽  
Carbon Dioxide Co2

Exhaust gases from thermal power plants have the highest amount of carbon dioxide (CO2), presenting an environmental problem related to a severe impact on ecosystems. Extensively, the reduction of CO2 from thermal power plants has been considered with the aid of microalgae as a cost-effective, sustainable solution, and efficient biological means for recycling of CO2. Microalgae can efficiently uptake CO2 and nutrients resulting in high generation of biomass and which can be processed into different valuable products. In this study, we have taken Nephroselmis sp. KGE8, Acutodesmus obliquus KGE 17 and Acutodesmus obliquus KGE32 microalgae, which are isolated from acid mine drainage and cultivated in a photobiological incubator on a batch scale, and also confirmed that continuous culture was possible on pilot scale for biofuel production. We also evaluated the continuous culture productivity of each cultivate-harvest cycle in the pilot scale. The biomass of the cultivated microalgae was also evaluated for its availability.

scholarly journals Pilot testing of CO2 capture from a coal-fired power plant—Part 2: Results from 1-MWe pilot tests

Clean Energy ◽  
2020 ◽  
Vol 4 (1) ◽  
pp. 12-25 ◽  
Author(s):  
Sharon Sjostrom ◽  
Constance Senior
Keyword(s):  
Power Plant ◽  
Fluidized Bed ◽  
Co2 Capture ◽  
Pilot Plant ◽  
Power Plants ◽  
Ion Exchange Resin ◽  
Pilot Scale ◽  
Solid Sorbent ◽  
Pilot Testing ◽  
Handling Characteristics

Abstract Using a 1-MWe slipstream pilot plant, solid-sorbent-based post-combustion CO2 capture was tested at a coal-fired power plant. Results from pilot testing were used to develop a preliminary full-scale commercial design. The sorbent selected for pilot-scale evaluation during this project consisted of an ion-exchange resin that incorporated amines covalently bonded to the substrate. A unique temperature-swing-absorption (TSA) process was developed that incorporated a three-stage fluidized-bed adsorber integrated with a single-stage fluidized-bed regenerator. Overall, following start-up and commissioning challenges that are often associated with first-of-a-kind pilots, the pilot plant operated as designed and expected, with a few key exceptions. The two primary exceptions were associated with: (i) handling characteristics of the sorbent, which were sufficiently different at operating temperature than at ambient temperature when design specifications were established with lab-scale testing; and (ii) CO2 adsorption in the transport line between the regenerator and adsorber that preloaded the sorbent with CO2 prior to entering the adsorber. Results from the pilot programme demonstrate that solid-sorbent-based post-combustion capture can be utilized to achieve 90% CO2 capture from coal-fired power plants.

Process Analysis of Selective Exhaust Gas Recirculation for CO2 Capture in Natural Gas Combined Cycle Power Plants Using Amines

2017 ◽  
Author(s):  
Maria Elena Diego ◽  
Jean-Michel Bellas ◽  
Mohamed Pourkashanian
Keyword(s):  
Natural Gas ◽  
Co2 Capture ◽  
Flue Gas ◽  
Power Plants ◽  
Exhaust Gas Recirculation ◽  
Combined Cycle ◽  
Exhaust Gas ◽  
Natural Gas Combined Cycle ◽  
The Cost ◽  
Gas Recirculation

Post-combustion CO2 capture from natural gas combined cycle (NGCC) power plants is challenging due to the large flow of flue gas with low CO2 content (∼3–4%vol.) that needs to be processed in the capture stage. A number of alternatives have been proposed to solve this issue and reduce the costs of the associated CO2 capture plant. This work focuses on the selective exhaust gas recirculation (S-EGR) configuration, which uses a membrane to selectively recirculate CO2 back to the inlet of the compressor of the turbine, thereby greatly increasing the CO2 content of the flue gas sent to the capture system. For this purpose, a parallel S-EGR NGCC system (53% S-EGR ratio) coupled to an amine capture plant using MEA 30%wt. was simulated using gCCS (gPROMS). It was benchmarked against an unabated NGCC system, a conventional NGCC coupled with an amine capture plant (NGCC+CCS), and an EGR NGCC power plant (39% EGR ratio) using amine scrubbing as the downstream capture technology. The results obtained indicate that the net power efficiency of the parallel S-EGR system can be up to 49.3% depending on the specific consumption of the auxiliary S-EGR systems, compared to the 49.0% and 49.8% values obtained for the NGCC+CCS and EGR systems, respectively. A preliminary economic study was also carried out to quantify the potential of the parallel S-EGR configuration. This high-level analysis shows that the cost of electricity for the parallel S-EGR system varies from 82.1–90.0 $/MWhe for the scenarios considered, with the cost of CO2 avoided being in the range of 79.7–105.1 $/tonne CO2. The results obtained indicate that there are potential advantages of the parallel S-EGR system in comparison to the NGCC+CCS configuration in some scenarios. However, further benefits with respect to the EGR configuration will depend on future advancements and cost reductions achieved on membrane-based systems.

Opportunities for CO2 Capture and Storage in Iranian Electricity Generation

2010 ◽  
Author(s):  
Farshid Zabihian ◽  
Alan S. Fung
Keyword(s):  
Natural Gas ◽  
Co2 Capture ◽  
Co2 Emission ◽  
Electricity Generation ◽  
Power Plants ◽  
Fossil Fuel ◽  
Combined Cycle ◽  
Pure Oxygen ◽  
Co2 Capture And Storage ◽  
And Storage

CO2 capture and storage (CCS) systems are technologies that can be used to reduce CO2 emissions by different industries where combustion is part of the process. A major problem of CCS system utilization in electricity generation industry is their high efficiency penalty in power plants. For different types of power plants fueled by oil, natural gas and coal, there are three main techniques that can be applied: • CO2 capture after combustion (post-combustion); • CO2 capture after concentration of flue gas by using pure oxygen in boilers and furnaces (oxy-fuel power plant); • CO2 capture before combustion (pre-combustion). More than 90% of electricity generation in Iran is based on fossil fuel power plants. Worldwide, electricity generation is responsible for 54% of GHG emissions. Thus, it is vital to reduce CO2 emission in fossil fuel-fired power plants. In this paper, it is shown that, by applying CO2 capture systems in power generation industry, very low CO2 emission intensity is possible but the energy and economic penalties are substantial. The analyses showed that for different technologies efficiency penalty could be as high as 25% and cost of electricity might increase by more than 65%. Two scenarios for Iranian electricity generation sector were investigated in this paper: installing CCS in the existing power plants with current technologies and replacing existing power plants by natural gas combined cycle plants equipped with CO2 capture system. The results revealed that the GHG intensity can be reduced from 610 to 79 gCO2eq/kWh in the first scenario and to 54 gCO2eq/kWh in the second scenario.

Fuel Oil Reburning Application for NOx Control to Firetube Package Boilers

1987 ◽  
Vol 109 (2) ◽  
pp. 207-214 ◽  
Author(s):  
J. A. Mulholland ◽  
R. E. Hall
Keyword(s):  
Natural Gas ◽  
Nitrogen Content ◽  
Nox Reduction ◽  
Pilot Scale ◽  
Fuel Oil ◽  
Limiting Factor ◽  
Boiler Load ◽  
Residual Fuel Oil ◽  
Nox Control ◽  
Percent Nitrogen

Two pilot-scale (0.73 MW or 2.5 × 106 Btu/hr) firetube package boilers were retrofitted for fuel oil reburning application for NOx emission control. When firing distillate fuel oil (0.01 percent nitrogen content), an overall NOx reduction of 46 percent from an uncontrolled emission of 125 ppm (dry, at zero percent O2) was realized by diverting 20 percent of the total boiler load to a second stage burner; a 51 percent NOx reduction from 265 ppm was achieved in a distillate/residual fuel oil mixture (0.14 percent nitrogen content) reburning application. Nitrogen-free fuel oil reburning was found to be slightly more effective at reducing NOx than was natural gas reburning, although longer fuel-rich zone residence times were required to allow for evaporation and mixing of the fuel oil droplets. Key parameters investigated which impact the reburning process were: primary flame NOx, reburn zone stoichiometry, and reburn zone residence time. Reburning applied to firetube package boilers requires minimal facility modification. Reburning can be coupled with other NOx control techniques (e.g., distributed air low NOx burners) to achieve NOx emissions of less than 100 ppm. However, for very low primary flame NOx conditions (i.e., less than 200 ppm), reburning fuel nitrogen content is a limiting factor, and reburning with a low-nitrogen-content fuel, such as natural gas or nitrogen-free distillate oil, may be necessary to achieve 50 percent NOx reduction.

Sign in / Sign up

Export Citation Format

Share Document