scholarly journals Comparison of various chemical compounds for the removal of SO2 and NOx with wet scrubbing for marine diesel engines

2021 ◽  
Author(s):  
Terence Chin ◽  
Ivan CK Tam ◽  
Chun-Yang Yin
Keyword(s):  
Aqueous Phase ◽  
Consumption Rate ◽  
Chemical Compounds ◽  
Ionic Concentration ◽  
Oxidation Potential ◽  
Wet Scrubbing ◽  
Marine Diesel ◽  
Wet Scrubber ◽  
Oxidation Of No ◽  
Removal Of So2

AbstractSeawater, NaOH, NaClO, NaClO2, H2O2, and KMnO4 were used as scrubbing liquids to react with SOx and NOx separately in a customized wet scrubber. The absorption of SO2 in the aqueous phase was influenced by three factors: pH, ionic concentration, and oxidation potential. For NOx removal, the effectiveness of various chemical compounds can be ranked from least to most effective as follows: seawater, NaOH, H2O2 < NaClO < KMnO4 < NaClO2. This effectiveness was influenced by the chemical compound’s ability to oxidize NO to NO2, absorb the NO2 that was formed, and retaining the nitrogen in the aqueous phase. High oxidation potential promoted the oxidation of NO to NO2 but hindered the absorption of NO2. NaClO2 was superior compared to NaClO in all three categories of oxidizing, absorption and retention. NaClO could not retain a significant amount of NO2 which it absorbed in the aqueous phase. The pH around 8 provided a good balance between oxidation versus absorption/retention and reactant utilization for the chlorine-based oxidants. KMnO4 had the lowest reactant consumption rate; only half a mole was consumed for every mole of NO removed, compared to around 2–3 mol of chlorite or 3–5 mol of hypochlorite.

scholarly journals Comparison of various chemical compounds for the removal of SO2 and NOx with wet scrubbing for marine diesel engines.

2021 ◽  
Author(s):  
Terence Chin ◽  
Ivan Tam ◽  
Chun-Yang Yin
Keyword(s):  
Aqueous Phase ◽  
Consumption Rate ◽  
Chemical Compounds ◽  
Ionic Concentration ◽  
Oxidation Potential ◽  
Wet Scrubbing ◽  
Marine Diesel ◽  
Wet Scrubber ◽  
Oxidation Of No ◽  
Removal Of So2

Abstract Seawater, NaOH, NaClO, NaClO2, H2O2 and KMnO4 were used as scrubbing liquids to react with SOx and NOx separately in a customized wet scrubber. The absorption of SO2 in the aqueous phase was influenced by three factors: pH, ionic concentration and oxidation potential. For NOx removal, the effectiveness of various chemical compounds can be ranked from least to most effective as follows: Seawater, NaOH, H2O2 < NaClO < KMnO4 < NaClO2. This effectiveness was influenced by the chemical compound’s ability to oxidize NO to NO2, absorb the NO2 that was formed and retaining the nitrogen in the aqueous phase. High oxidation potential promoted the oxidation of NO to NO2 but hindered the absorption of NO2. NaClO2 was superior compared to NaClO in all three categories of oxidizing, absorption and retention. NaClO could not retain a significant amount of NO2 which it absorbed in the aqueous phase. The pH around 8 provided a good balance between oxidation versus absorption/retention and reactant utilization for the chlorine-based oxidants. KMnO4 had the lowest reactant consumption rate; only half a mole was consumed for every mole of NO removed, compared to around 2–3 moles of chlorite or 3–5 moles of hypochlorite.

A novel wet-scrubbing process using Fe(vi) for simultaneous removal of SO2 and NO

2011 ◽  
Vol 13 (4) ◽  
pp. 864 ◽  
Author(s):  
Dehua Xia ◽  
Chun He ◽  
Linfei Zhu ◽  
Yanling Huang ◽  
Hanying Dong ◽  
...  
Keyword(s):  
Simultaneous Removal ◽  
Wet Scrubbing ◽  
Removal Of So2

scholarly journals SIFAT ANTI RAYAP DARI EKSTRAK IJUK AREN (Arenga pinnata Merr.)

PERENNIAL ◽  
2007 ◽  
Vol 3 (1) ◽  
pp. 15 ◽  
Author(s):  
Astuti Arif ◽  
M. Natsir Usman ◽  
Fatmawaty Samma
Keyword(s):  
Key Words ◽  
Consumption Rate ◽  
Construction Materials ◽  
Chemical Compounds ◽  
Tree Age ◽  
Subterranean Termites ◽  
Palm Tree ◽  
Ground Contact ◽  
Bioactive Components ◽  
Wood Construction

The fiber of sugar-palm tree Arenga pinnata Merr., locally known as ijuk, is frequently harvested after the tree age of 5 years and traditionally used as covering to protect ground-contact wood construction materials against organism attack, particularly subterranean termites. The effectiveness of sufar-palm tree fiber extract of marketed formation using acetone and and hexane againts subterannean termites (Coptotermes sp.) has been observed. The results showed that mortality of termite after 2 weeks is 100% on samples given the sugar-palm tree fiber extract, compared with the mortality of controls (without sugar-palm tree fiber extract) is 7,07% after 3 weeks. The consumption rate of termites opposited with the mortality value, due to the existence of bioactive components or chemical compounds having inhibitor or toxic against termites activities. Key words: Sugar-Palm Tree Fiber, Arenga pinnata, Antitermiticidal activities, Coptotermes sp.

scholarly journals Plasma technology to remove NOx from off-gases

Nukleonika ◽  
2021 ◽  
Vol 66 (4) ◽  
pp. 227-231
Author(s):  
Andrzej Pawelec ◽  
Andrzej G. Chmielewski ◽  
Yongxia Sun ◽  
Sylwester Bułka ◽  
Toms Torims ◽  
...  
Keyword(s):  
Electron Beam ◽  
Flue Gas ◽  
Laboratory Tests ◽  
High Efficiency ◽  
Gas Treatment ◽  
First Case ◽  
Harmful Emissions ◽  
Wet Scrubbing ◽  
Marine Diesel ◽  
Ship Emission

Abstract Operation of marine diesel engines causes significant emission of sulphur and nitrogen oxides. It was noticed worldwide and the regulations concerning harmful emissions were introduced. There were several solutions elaborated; however, emission control for both SOx and NOx requires two distinctive processes realized in separated devices, which is problematic due to limited space on ship board and high overall costs. Therefore, the electron beam flue gas treatment (EBFGT) process was adopted to ensure the abatement of the problem of marine diesel off-gases. This novel solution combines two main processes: first the flue gas is irradiated with electron beam where NO and SO2 are oxidized; the second stage is wet scrubbing to remove both pollutants with high efficiency. Laboratory tests showed that this process could be effectively applied to remove SO2 and NOx from diesel engine off-gases. Different compositions of absorbing solution with three different oxidants (NaClO, NaClO2 and NaClO3) were tested. The highest NOx removal efficiency (>96%) was obtained when seawater-NaClO2-NaOH was used as scrubber solution at 10.9 kGy dose. The process was further tested in real maritime conditions at Riga shipyard, Latvia. More than 45% NOx was removed at a 5.5 kGy dose, corresponding to 4800 Nm3/h off-gases arising from ship emission. The operation of the plant was the first case of examination of the hybrid electron beam technology in real conditions. Taking into account the experiment conditions, good agreement was obtained with laboratory tests. The results obtained in Riga shipyard provided valuable information for the application of this technology for control of large cargo ship emission.

scholarly journals Optical properties and oxidative potential of aqueous-phase products from OH and <sup>3</sup>C<sup>*</sup>-initiated photolysis of eugenol

2021 ◽  
Author(s):  
Xudong Li ◽  
Ye Tao ◽  
Longwei Zhu ◽  
Shuaishuai Ma ◽  
Shipeng Luo ◽  
...  
Keyword(s):  
Aqueous Phase ◽  
Dominant Role ◽  
Ambient Air ◽  
Oxidation Potential ◽  
Direct Photolysis ◽  
Oxidative Potential ◽  
Adverse Health Effects ◽  
Degradation Rates ◽  
Phase Oxidation ◽  
Harmful Species

Abstract. In ambient air, aqueous-phase oxidation may turn precursors into more light-absorbing and toxic products, leading to air quality deterioration and adverse health effects. In this study, we investigated eugenol degradation in aqueous phase under direct photolysis, and triplet excited organic (3C*) and hydroxyl radical (OH) as oxidants. Results showed degradation rates of eugenol followed the order of 3C* > OH > direct photolysis. Relative contributions of reactive oxygen species (ROS) and 3C* were evaluated via quenching and O2-free experiments. 3C* played a dominant role in eugenol degradation for 3C*-initiated oxidation, while both O2 and O2•-generated were important for eugenol degradation for OH-initiated oxidation. Rate constants under O2, air and N2 followed the order of ko2＞kAir＞kN2 under both direct photolysis and OH oxidation, and it changed to kAir＞kN2＞ko2 in 3C*-initiated oxidation. Light absorption spectra showed absorbance at 300–400 nm increased as photolysis progressed, and there were new broad fluorescent spectra at excitation/emission (Ex/Em) = 250/(400–500) nm, suggesting the formation of new chromophores and fluorophores, such as humic-like substances (HULIS). Additionally, distinct fluorescence peaks appeared at Ex/Em=(300–350)/300 nm at different stages. Concentration of generated HULIS increased gradually over time, then leveled off. Dithiothreitol (DTT) assay was applied to assess the oxidation potential of products, which was greater than pure eugenol, suggesting more harmful species were produced during oxidation. Detailed reaction pathways were elucidated via analyses of chemical characteristics of the products.

scholarly journals Characterization of a High Efficiency Pilot Plant Wet Scrubber with Internals for Fly Ash Removal

2008 ◽  
Vol 2 (1) ◽  
pp. 100-105 ◽  
Author(s):  
A. Biswas ◽  
B. Rajmohan ◽  
C.R. Mohanty ◽  
B.C. Meikap
Keyword(s):  
Fly Ash ◽  
Pilot Plant ◽  
High Efficiency ◽  
Maximum Efficiency ◽  
Size Analysis ◽  
Present System ◽  
Wet Scrubbing ◽  
Wet Scrubbers ◽  
Wet Scrubber ◽  
Ash Removal

Removal of fly ash using wet scrubbers is widely used in the small and medium scale industries. Among the wet scrubbing methods, spray column falls into the simplest type category for its simple construction and various advantages. A novel pilot plant wet scrubber has been conceived, designed and fabricated. This paper distinctly focuses on the detailed design and fabrication of the ejector, which has been used to prepare fly ash-air mixture in the laboratory. A detail experimental investigation has been carried out to characterize the system. Studies indicate very encouraging result. The size analysis of the fly ash sample along with efficiency of fly ash removal in the wet scrubber has critically been examined. It has been found that the present system yielded mentionable high efficiency for the scrubbing of fly ash. In most of the cases, the efficiency lies between 70.% and 90.%. The maximum efficiency obtained is above 90 %.

scholarly journals Organic pollutant removal from marine diesel engine off-gases under electron beam and hybrid electron beam and wet scrubbing process

Nukleonika ◽  
2021 ◽  
Vol 66 (4) ◽  
pp. 193-199
Author(s):  
Yongxia Sun ◽  
Andrzej G. Chmielewski ◽  
Andrzej Pawelec ◽  
Gösta Mattausch ◽  
Toms Torims
Keyword(s):  
Electron Beam ◽  
Organic Compounds ◽  
Organic Pollutants ◽  
Organic Pollutant ◽  
Nitro Compounds ◽  
Pollutant Removal ◽  
Aliphatic Hydrocarbons ◽  
Gas Chromatography Mass Spectrometry ◽  
Wet Scrubbing ◽  
Wet Scrubber

Abstract The removal of organic pollutants from ship emission was studied using two processes namely electron beam (EB) and hybrid EB with wet scrubbing process. A mobile accelerator unit was used to treat 4915 Nm3/h of flue gas emitted from a tugboat in Riga Shipyard. A volume of 3 m3 seawater containing 36.8 mM of NaClO2 oxidant was used as a wet scrubber solution. Organic pollutants, mainly volatile organic pollutants (VOCs), were collected at three different sampling points, before and after irradiation vessels, and after wet-scrubber unit, respectively. They were collected with glass sampling bottles, tedlar bags, Coconut Shell Charcoal (CSC) sorbents and XAD-2 sorbents. CH3OH and CH3OH/CH2Cl2 (1:1) were used to extract VOCs from CSC and XAD-2 sorbents, respectively. Syringe filters were used to obtain the solid-free extraction solutions. They were concentrated using a micro-extractor under continuously blowing high-purity Ar. A gas chromatography–mass spectrometry (GC-MS) was used for analysis. The identified organic compounds were: aliphatic hydrocarbons (dodecane C12H26 to eicosane C20H42), aromatic hydrocarbon (toluene), esters (C3H7COOCH3, (C4H9OCO)2C6H4), nitro compounds (C3H5NO3, C4H7NO2) and acid (C7H15COOH). After 4.2 kGy EB irradiation, around 50–100% aliphatic hydrocarbons, 83% toluene and 7.5% (C4H9OCO)2C6H4 were removed from the off-gases, and after EB hybrid wet-scrubber process, most organic compounds including nitro compounds were removed. Only trace amount of toluene, hexadecane, octadecane and dibutyl phthalate were found to be present in the gas phase.

Simultaneous removal of SO2, NO and Hg0 by wet scrubbing using urea+KMnO4 solution

2013 ◽  
Vol 106 ◽  
pp. 645-653 ◽  
Author(s):  
Ping Fang ◽  
Chao-ping Cen ◽  
Xin-ming Wang ◽  
Zi-jun Tang ◽  
Zhi-xiong Tang ◽  
...  
Keyword(s):  
Simultaneous Removal ◽  
Wet Scrubbing ◽  
Removal Of So2

Oxidative Potential and Chemical Characteristics of Ambient PM2.5 in Guangzhou, China

2020 ◽  
Author(s):  
Peng Cheng ◽  
Manman Zhang ◽  
Yongjie Li
Keyword(s):  
Consumption Rate ◽  
Dominant Role ◽  
Chemical Species ◽  
Oxidation Potential ◽  
Water Soluble ◽  
Atmospheric Particulate Matter ◽  
Oxidative Potential ◽  
Soluble Ions ◽  
Water Soluble Ions

&lt;p&gt;The dithiothreitol (DTT) assay is widely used to characterize the Oxidation Potential (OP) of atmospheric particulate matter (PM), which can cause adverse effects on human health. However, it&amp;#8217;s under debate which chemical species determines the consumption rate of DTT. During January and April 2018, we measured the improved DTT assay of daily PM&lt;sub&gt;2.5&lt;/sub&gt; samples collected in Guangzhou, China with complimentary measurements of water-soluble ions, organic/elemental carbon (OC/EC) and metal elements. The average sampled air volume normalized consumption rate of DTT (DTT&lt;sub&gt;v&lt;/sub&gt;) was 4.67 &amp;#177;1.06 and 4.45 &amp;#177; 1.02 nmol min&lt;sup&gt;-1&lt;/sup&gt; m&lt;sup&gt;-3&lt;/sup&gt;, in January and April, respectively while the average PM&lt;sub&gt;2.5&lt;/sub&gt; mass normalized consumption rate of DTT (DTT&lt;sub&gt;m&lt;/sub&gt;) was 13.47 &amp;#177; 3.86 and 14.66 &amp;#177; 4.49 pmol min&lt;sup&gt;-1&lt;/sup&gt; &amp;#956;g&lt;sup&gt;-1&lt;/sup&gt;. Good correlations were found between DTT&lt;sub&gt;v&lt;/sub&gt; and concentration of PM&lt;sub&gt;2.5&lt;/sub&gt;, OC, and EC while no correlation was found between DTT&lt;sub&gt;m&lt;/sub&gt; and concentrations of water-soluble ions, OC, EC or metal element, which is consistent with most early observations. We also evaluated the contribution of soluble metals to DTT assay by addition of EDTA, a strong metal chelator. We found that nearly 90% of DTT&lt;sub&gt;v&lt;/sub&gt; and DTT&lt;sub&gt;m&lt;/sub&gt; were reduced by EDTA, suggesting a dominant role of soluble metals in determining the response of DTT to ambient PM&lt;sub&gt;2.5&lt;/sub&gt;. Based on responses of DTT to soluble metals in literature, we found that Cu(II) and Mn(II) are the major contributors to OP of PM&lt;sub&gt;2.5&lt;/sub&gt; in Guangzhou. The correlation coefficient between DTT&lt;sub&gt;m &lt;/sub&gt;and OC shows a clear increase after addition of EDTA, implying that the response of DTT to quinones is not strongly suppressed by EDTA.&lt;/p&gt;

scholarly journals Simultaneous Removal of SO2 and NOX by Wet Scrubbing Using NaOH Solutions

2014 ◽  
Vol 26 (Supp.) ◽  
pp. S27-S30
Author(s):  
Jin-Xi Zhou ◽  
Song Zhou ◽  
Dian-Tao Liu
Keyword(s):  
Simultaneous Removal ◽  
Wet Scrubbing ◽  
Removal Of So2
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