Filtration Assessment and Thermal Effects on Aerodynamic Regeneration in Silicon Carbide and Cordierite Particulate Filters

Larsen, Christopher A.; Levendis, Yiannis A.; Shimato, Koji

doi:10.4271/1999-01-0466

Cited by 17 publications

(15 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…SiC Ibiden filters capture the PM 2.5 particulates with an efficiency of 99%. 35 Micromembrane-coated Corning/Ceramem filters also have efficiencies of 99%. Moreover, there is an advantage in capturing particulates at a high temperature and retaining them therein for a certain residence time: high carbon and hydrocarbon burnout can be achieved, eventually producing ash with greater potential for subsequent utilization value.…”

Section: Resultsmentioning

confidence: 99%

“…Extrapolations were based on our lengthy experience of using ceramic monoliths to filter the exhaust of diesel engines as well as the experiences gathered at Penn State University on a pilot-scale, coal-fired furnace [30][31][32][33] where ceramic filters were installed in the effluent duct at a gas temperature of 478 K. Over the last ten years, studies have been conducted in this laboratoty on the filtration of particulates from diesel engines using ceramic honeycomb monoliths in conjunction with aerodynamic regeneration. [34][35][36] It was extrapolated that at the same temperature of 478 K, the airflow rate of 215,700 scfm of the Elmer Smith boiler may be handled with a number of 3400 cylindrical filters (±100) of a size of 16 cm diameter × 30 cm height (6.5 × 12 in.) and maintain an acceptable pressure drop (back pressure) not exceeding 25 mbars, as suggested in the Penn State tests.…”

Section: Economic Analysismentioning

confidence: 99%

See 1 more Smart Citation

Economics of an Integrated Approach to Control SO₂, NO_x, HCl, and Particulate Emissions from Power Plants

Shemwell

Ergut

Levendis

2002

Journal of the Air & Waste Management Association

Self Cite

View full text Add to dashboard Cite

An integrated approach for the simultaneous reduction of major combustion-generated pollutants from power plants is presented along with a simplified economic analysis. With this technology, the synergistic effects of high-temperature sorbent/coal or sorbent/natural gas injection and high-temperature flue gas filtration are exploited. Calcium-based (or Na-based, etc.) sorbents are sprayed in the post-flame zone of a furnace, where they react with S-and Cl-containing gases to form stable salts of Ca (or Na, etc.). The partially reacted sorbent is then collected in a high-temperature ceramic filter, which is placed downstream of the sorbent injection point, where it further reacts for a prolonged period of time. With this technique, both the likelihood of contact and the length of time of contact between the solid sorbent particles and the gaseous pollutants increase, because reaction takes place both in the furnace upstream of the filter and inside the filter itself. Hence, the sorbent utilization increases significantly.Several pollutants, such as SO 2 , H 2 S, HCl, and particulate (soot, ash, and tar), may be partially removed from the effluent. The organic content of the sorbents (or blends) also pyrolyzes and reduces NO x . Unburned carbon in the ash may be completely oxidized in the filter. The filter is cleaned periodically with aerodynamic regeneration (back pulsing) without interrupting furnace operation. The effectiveness of this technique has been shown in laboratory-scale experiments using either rather costly carboxylic salts of Ca or low-to moderate-cost blends of limestone, lime, or sodium bicarbonate with coal fines.Injection occurred in the furnace at 1150 ºC, while the filter was maintained at 600 ºC. Results showed that 65 or 40% SO 2 removal was obtained with calcium formate or a limestone/coal blend, respectively, at an entering calciumto-sulfur molar ratio of 2. A sodium bicarbonate/coal blend resulted in 78% SO 2 removal at a sodium-to-sulfur molar ratio of 2. HCl removal efficiencies have been shown to be higher than those for SO 2 . NO x reductions of 40% have been observed with a fuel (coal)-to-air equivalence ratio, φ, around 2. The filter has been shown to be 97-99% efficient in removing PM 2.5 particulates. Calculations herein show that this integrated sorbent/filter method is costeffective, in comparison with current technologies, on both capital cost ($/kW) and levelized cost ($/ton pollutant removed) bases, if a limestone/coal mixture is used as the sorbent for fossil fuel plants.Capital costs for the filter/sorbent combination are estimated to be in the range of $61-$105/kW for a new plant. Because current technologies are designed for removing one pollutant at a time, both their cost and space requirements are higher than those of this integrated technique. At the minimum projected removal efficiencies for HCl/SO 2 /NO x of about 40%, the levelized costs are projected to be $203-$261/ton of combined pollutant SO 2 /HCl/NO x and particulates removed from coalfired power pla...

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Economic Analysismentioning

confidence: 99%

Economics of an Integrated Approach to Control SO₂, NO_x, HCl, and Particulate Emissions from Power Plants

Shemwell

Ergut

Levendis

2002

Journal of the Air & Waste Management Association

Self Cite

View full text Add to dashboard Cite

show abstract

“…The filter was located inside the primary furnace, prior to its exit, and it was continuously regenerated at the high temperatures therein. Its filtration efficiency was previously measured to be 99% for highly respirable submicron particles (14), which are considered to have significant health hazardous effects.…”

Section: Introductionmentioning

confidence: 99%

Polynuclear Aromatic Hydrocarbon and Particulate Emissions from Two-Stage Combustion of Polystyrene: The Effects of the Secondary Furnace (Afterburner) Temperature and Soot Filtration

Wang

Richter

Howard

et al. 2002

Environ. Sci. Technol.

Self Cite

View full text Add to dashboard Cite

Laboratory experiments were conducted in a two-stage horizontal muffle furnace in order to monitor emissions from batch combustion of polystyrene (PS) and identify conditions that minimize them. PS is a dominant component of municipal and hospital waste streams. Bench-scale combustion of small samples (0.5 g) of shredded styrofoam cups was conducted in air, using an electrically heated horizontal muffle furnace, kept at Tgas = 1000 degrees C. Upon devolatilization, combustion of the polymer took place in a diffusion flame over the sample. The gaseous combustion products were mixed with additional air in a venturi and were channeled to a secondary muffle furnace (afterburner) kept at Tgas = 900-1100 degrees C; residence time therein varied between 0.6 and 0.8 s. At the exits of the primary and the secondary furnace the emissions of CO, CO2, O2, NOx, particulates as well as volatile and semivolatile hydrocarbons, such as polycyclic aromatic hydrocarbons (PAH), were monitored. Online analyzers, gravimetric techniques, and gas chromatography coupled to mass spectrometry (GC-MS) were used. Experiments were also conducted with a high-temperature barrier filter, placed just before the exit of the primary furnace to prevent the particulates from entering into the secondary furnace. Results demonstrated the beneficial effect of the afterburner in reducing PAH concentrations, including those of mutagenic species such as benzo[a]pyrene. Concentrations of individual PAH exhibited a pronounced after burner temperature dependence, typically ranging from a small decrease at 900 degrees C to a larger degree of consumption at 1100 degrees C. Consumption of PAH was observed to be the dominant feature at 900 degrees C, while significant quantities of benzene and some of its derivatives, captured by means of carbosieve/Carbotrap adsorbents, were formed in the afterburner at a temperature of 1000 degrees C. In the primary furnace, about 30% of the mass of the initial polystyrene was converted into soot, while the total mass of PAH represented about 3% of the initial mass of combustible. The afterburner reduced the particulate (soot) emissions by only 20-30%, which indicates that once soot is formed its destruction is rather difficult because its oxidation kinetics are slow undertypical furnace conditions. Moreover, increasing the afterburnertemperature resulted in an increasing trend of soot emissions therefrom, which might indicate competition between soot oxidation and formation, with some additional formation occurring at the higher temperatures. Contrary to the limited effect of the afterburner, high-temperature filtration of the combustion effluent prior to the exit of the primary furnace allowed for effective soot oxidation inside of the ceramic filter. Filtration drastically reduced soot emissions, by more than 90%. Limited soot formation in the afterburner was again observed with increasing temperatures. The yields of both CO and CO2 were largely unaffected by the temperature of the afterburner but increased at the presence o...

show abstract

“…In order to prevent any combustion-generated particulate matter (as the premixed flames were transient in nature in these batch combustion experiments) from entering the synthesis chamber and contaminate the catalyst, a barrier filter was placed in the division of the two sections of the apparatus. This filter consists of a honeycomb structure made out of silicon carbide (SiC), and performs with a high filtration efficiency resulting in 97% retention for submicron particles 15 . The method for the nanomaterials synthesis used in this work was the catalytic chemical vapor deposition (CCVD).…”

Section: Samples Preparationmentioning

confidence: 99%

Microstructural analysis of carbon nanomaterials produced from pyrolysis/combustion of Styrene-Butadiene-Rubber (SBR)

et al. 2011

View full text Add to dashboard Cite

Styrene-Butadiene-Rubber (SBR) is a synthetic rubber copolymer used to fabricate several products. This study aims to demonstrate the use of SBR as feedstock for carbon nanomaterials (nanofibers and nanotubes) growth, and therefore to establish a novel process for destination of waste products containing SBR. A three stage electrically heated flow reactor was used. Small pellets of rubber were pyrolyzed at a temperature of 1000 °C. The pyrolyzates were mixed with oxygen-containing gases and were burned. The products of combustion were used to synthesize the carbon nanomaterials (CNMs) at the presence of a catalyst. CNMs have a wide range of potential applications due to their extraordinary mechanical, thermal and electrical properties. Produced materials were characterized by SEM and TEM, whereas combustion products were assessed using GC. Results showed that CNMs with outer diameters of 30-100 nm and lengths of about 30 µm were formed. Therefore, it was demonstrated that waste products containing SBR can be used to generate CNMs which are value-added products of intense technological interest.

show abstract

Filtration Assessment and Thermal Effects on Aerodynamic Regeneration in Silicon Carbide and Cordierite Particulate Filters

Cited by 17 publications

References 10 publications

Economics of an Integrated Approach to Control SO₂, NO_x, HCl, and Particulate Emissions from Power Plants

Economics of an Integrated Approach to Control SO₂, NO_x, HCl, and Particulate Emissions from Power Plants

Polynuclear Aromatic Hydrocarbon and Particulate Emissions from Two-Stage Combustion of Polystyrene: The Effects of the Secondary Furnace (Afterburner) Temperature and Soot Filtration

Microstructural analysis of carbon nanomaterials produced from pyrolysis/combustion of Styrene-Butadiene-Rubber (SBR)

Contact Info

Product

Resources

About

Filtration Assessment and Thermal Effects on Aerodynamic Regeneration in Silicon Carbide and Cordierite Particulate Filters

Cited by 17 publications

References 10 publications

Economics of an Integrated Approach to Control SO2, NOx, HCl, and Particulate Emissions from Power Plants

Economics of an Integrated Approach to Control SO2, NOx, HCl, and Particulate Emissions from Power Plants

Polynuclear Aromatic Hydrocarbon and Particulate Emissions from Two-Stage Combustion of Polystyrene: The Effects of the Secondary Furnace (Afterburner) Temperature and Soot Filtration

Microstructural analysis of carbon nanomaterials produced from pyrolysis/combustion of Styrene-Butadiene-Rubber (SBR)

Contact Info

Product

Resources

About

Economics of an Integrated Approach to Control SO₂, NO_x, HCl, and Particulate Emissions from Power Plants

Economics of an Integrated Approach to Control SO₂, NO_x, HCl, and Particulate Emissions from Power Plants