Reactive Carbon from Life Support Wastes for Incinerator Flue Gas Cleanup

Fisher, John W.; Pisharody, Suresh; Moran, Mark; Wignarajah, Kanapathipillai; Shi, Yao; Chang, Shuenn‐Yih

doi:10.4271/2000-01-2283

Cited by 10 publications

(4 citation statements)

References 18 publications

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“…Observably, MG-AC-10 and TG-AC-10 show distinct S 2p XPS spectra. As shown in Figure c, the S 2p spectrum of MG-AC-10 can be fitted into two peaks at ∼164.5 and 165.8 which can be assigned to S 2p 3/2 and S 2p 1/2 spectra, respectively. − Therein, the relatively high-ratio S 2p 3/2 spectrum mainly represents the S = S species, clearly suggesting the formation of elemental S, which should be ascribed to the following reactions: 3 n C + 2 n H 2 SO 4 → 3 n CO 2 + S n + 2 n H 2 O; n C + n SO 2 → S n + n CO 2 . − By contrast, there is only the sulfate (∼171.5 eV) signal existing in the S 2p XPS spectrum in Figure d. We also supplemented XPS tests of the saturated desulfurization activated coke before MG-AC-10 and TG-AC-10.…”

Section: Resultsmentioning

confidence: 94%

Microwave Irradiation Induced High-Efficiency Regeneration for Desulfurized Activated Coke: A Comparative Study with Conventional Thermal Regeneration

Sun

Gao

et al. 2017

Energy Fuels

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Low desorption efficiency and inferior adsorbate recovery rate during conductive-heating regeneration have always been the key issues facing activated carbon-based SO 2 removal technology, which commonly leads to a short cycling life of an adsorbent. Herein, microwave heating was employed to regenerate desulfurized activated coke, which demonstrates great improvements in regeneration efficiency and cycling desulfurization performances. Compared with the long-time conductiveheating process (30 min), microwave heating shows a more rapid heating rate with just 4 min to achieve complete regeneration. After 10 desulfurization−regeneration cycles, microwave regenerated activated coke (MG-AC) can still maintain a high SO 2 removal capacity of 94 mg g −1 , more than double than that of thermal regenerated AC (TG-AC). Physicochemical structures analyses confirm that microwave heating selectively activates the adsorbate H 2 SO 4 molecules and thus promotes the porosity development and selective removal of oxygen-containing functional groups. Additionally, surface sulfur species analysis provides a new insight into the adsorbate desorption mechanism that microwave irradiation could create instantaneous high temperature within activated coke and induce deep reduction of H 2 SO 4 to elemental sulfur. This finding is of great significance for the development of high-value sulfur recovery technology. This work also suggests that microwave heating is an attractive method for the high-efficiency regeneration of desulfurized activated coke.

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Section: Resultsmentioning

confidence: 94%

Microwave Irradiation Induced High-Efficiency Regeneration for Desulfurized Activated Coke: A Comparative Study with Conventional Thermal Regeneration

Sun

Gao

et al. 2017

Energy Fuels

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“…Thus, the activated carbon produced from wheat straw is sufficient to control NO x emission. In fact, NO x adsorption was shown to improve after regeneration …”

Section: Resultsmentioning

confidence: 99%

Method for the Control of NO_x Emissions in Long-Range Space Travel

Shi

Liu³

et al. 2003

Energy Fuels

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The wheat straw, an inedible biomass that can be continuously produced in a space vehicle has been used to produce activated carbon for effective control of NOx emissions from the incineration of wastes. The optimal carbonization temperature of wheat straw was found to be around 600 degrees C when a burnoff of 67% was observed. The BET surface area of the activated carbon produced from the wheat straw reached as high as 300 m2/g. The presence of oxygen in flue gas is essential for effective adsorption of NO by activated carbon. On the contrary, water vapor inhibits the adsorption efficiency of NO. Consequently, water vapor in flue gas should be removed by drying agents before adsorption to ensure high NO adsorption efficiency. All of the NO in the flue gas was removed for more than 2 h by the activated carbons when 10% oxygen was present and the ratio of carbon weight to the flue gas flow rate (W/F) was 30 g min/L, with a contact time of 10.2 s. All of NO was reduced to N2 by the activated carbon at 450 degrees C with a W/F ratio of 15 g min/L and a contact time of 5.1 s. Reduction of the adsorbed NO also regenerated the activated carbon, and the regenerated activated carbon exhibited an improved NO adsorption efficiency. However, the reduction of the adsorbed NO resulted in a loss of carbon which was determined to be about 0.99% of the activated carbon per cycle of regeneration. The sufficiency of the amount of wheat straw in providing the activated carbon based on a six-person crew, such as the mission planned for Mars, has been determined. This novel approach for the control of NOx emissions is sustainable in a closed system such as the case in space travel. It is simple to operate and is functional under microgravity environment.

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“…Thus, the activated carbon produced from rice hulls is enough to control NO x emission. In fact, NO x adsorption was shown to improve after regeneration . Also, rice straw can be used in addition to rice hulls for the production of more activated carbon.…”

Section: Resultsmentioning

confidence: 99%

“…In fact, NO x adsorption was shown to improve after regeneration. 23 Also, rice straw can be used in addition to rice hulls for the production of more activated carbon.…”

Section: Resultsmentioning

confidence: 99%

The Use of Rice Hulls for Sustainable Control of NO_x Emissions in Deep Space Missions

Xu¹,

Shi²,

Kwak³

et al. 2003

Ind. Eng. Chem. Res.

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The use of the activated carbon produced from rice hulls to control NOx emissions for the future deep space missions has been demonstrated. The optimal carbonization temperature range was found to be between 600°C and 750°C. The burnoff of 61.8% was found at 700°C in pyrolysis and 750°C in activation. The BET surface area of the activated carbon from rice hulls was determined to be 172 m 2 /g when prepared at 700°C. The presence of oxygen in flue gas is essential for effective adsorption of NO by the activated carbon. On the contrary, water vapor inhibits the adsorption efficiency of NO. Consequently, water vapor in flue gas should be removed by drying agents before adsorption to ensure high NO adsorption efficiency. All of NO in the flue gas was removed for more than one and a half hours when 10% oxygen was present and using a ratio of the carbon weight to the flue gas flow rate (W/F) of 15.4 g-min/L. The reduction of the adsorbed NO to form N 2 can be effectively accomplished under anaerobic conditions at 550°C. For NO saturated activated carbon, the loss of carbon mass was determined to be about 0.16% of the activated carbon per cycle of regeneration. The reduction of the adsorbed NO also regenerates the activated carbon. The regenerated activated carbon exhibits improved NO adsorption efficiency.

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Reactive Carbon from Life Support Wastes for Incinerator Flue Gas Cleanup

Cited by 10 publications

References 18 publications

Microwave Irradiation Induced High-Efficiency Regeneration for Desulfurized Activated Coke: A Comparative Study with Conventional Thermal Regeneration

Microwave Irradiation Induced High-Efficiency Regeneration for Desulfurized Activated Coke: A Comparative Study with Conventional Thermal Regeneration

Method for the Control of NO_x Emissions in Long-Range Space Travel

The Use of Rice Hulls for Sustainable Control of NO_x Emissions in Deep Space Missions

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Reactive Carbon from Life Support Wastes for Incinerator Flue Gas Cleanup

Cited by 10 publications

References 18 publications

Microwave Irradiation Induced High-Efficiency Regeneration for Desulfurized Activated Coke: A Comparative Study with Conventional Thermal Regeneration

Microwave Irradiation Induced High-Efficiency Regeneration for Desulfurized Activated Coke: A Comparative Study with Conventional Thermal Regeneration

Method for the Control of NOx Emissions in Long-Range Space Travel

The Use of Rice Hulls for Sustainable Control of NOx Emissions in Deep Space Missions

Contact Info

Product

Resources

About

Method for the Control of NO_x Emissions in Long-Range Space Travel

The Use of Rice Hulls for Sustainable Control of NO_x Emissions in Deep Space Missions