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<oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
  <dc:contributor>Joseph A. DeBarr</dc:contributor>
  <dc:creator>Anthony A. Lizzio</dc:creator>
  <dc:date>1997</dc:date>
  <dc:description>&lt;p class="p1"&gt;&lt;span class="s1"&gt;The reaction of SO&lt;/span&gt;&lt;span class="s2"&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;/span&gt;&lt;span class="s1"&gt; with carbon (C) in the presence of O&lt;/span&gt;&lt;span class="s2"&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;/span&gt;&lt;span class="s1"&gt; and H&lt;/span&gt;&lt;span class="s2"&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;/span&gt;&lt;span class="s1"&gt;O involves a series of reactions that leads to the formation of sulfuric acid as the final product. The rate-determining step in the overall process is the oxidation of SO&lt;/span&gt;&lt;span class="s2"&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;/span&gt;&lt;span class="s1"&gt; to SO&lt;/span&gt;&lt;span class="s2"&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;/span&gt;&lt;span class="s1"&gt;. Three SO&lt;/span&gt;&lt;span class="s2"&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;/span&gt;&lt;span class="s1"&gt; oxidation reactions are possible. Adsorbed SO&lt;/span&gt;&lt;span class="s2"&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;/span&gt;&lt;span class="s1"&gt; (C−SO&lt;/span&gt;&lt;span class="s2"&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;/span&gt;&lt;span class="s1"&gt;) can react either with gas phase O&lt;/span&gt;&lt;span class="s2"&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;/span&gt;&lt;span class="s1"&gt; or with adsorbed oxygen (C−O complex) to form sulfur trioxide (SO&lt;/span&gt;&lt;span class="s2"&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;/span&gt;&lt;span class="s1"&gt;), or gas phase SO&lt;/span&gt;&lt;span class="s2"&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;/span&gt;&lt;span class="s1"&gt; can react directly with the C−O complex. In optimizing the SO&lt;/span&gt;&lt;span class="s2"&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;/span&gt;&lt;span class="s1"&gt; removal capabilities of carbon, most studies only assume a given mechanism for SO&lt;/span&gt;&lt;span class="s2"&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;/span&gt;&lt;span class="s1"&gt; adsorption and conversion to H&lt;/span&gt;&lt;span class="s2"&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;/span&gt;&lt;span class="s1"&gt;SO&lt;/span&gt;&lt;span class="s2"&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;/span&gt;&lt;span class="s1"&gt; to be operable. The appropriate SO&lt;/span&gt;&lt;span class="s2"&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;/span&gt;&lt;span class="s1"&gt; oxidation step and role of the C−O complex in this mechanism remain to be determined. The ultimate goal of this study was to prepare activated char from Illinois coal with optimal properties for low-temperature (80−150°C) removal of sulfur dioxide from coal combustion flue gas. The SO&lt;/span&gt;&lt;span class="s2"&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;/span&gt;&lt;span class="s1"&gt; adsorption capacity of activated char was found to be inversely proportional to the amount of oxygen adsorbed on its surface. A temperature-programmed desorption technique was developed to titrate those sites responsible for adsorption of SO&lt;/span&gt;&lt;span class="s2"&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;/span&gt;&lt;span class="s1"&gt; and conversion to H&lt;/span&gt;&lt;span class="s2"&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;/span&gt;&lt;span class="s1"&gt;SO&lt;/span&gt;&lt;span class="s2"&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;/span&gt;&lt;span class="s1"&gt;. On the basis of these results, a mechanism for SO&lt;/span&gt;&lt;span class="s2"&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;/span&gt;&lt;span class="s1"&gt; removal by carbon was proposed. The derived rate expression showed SO&lt;/span&gt;&lt;span class="s2"&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;/span&gt;&lt;span class="s1"&gt; adsorption to be dependent only on the fundamental rate constant and concentration of carbon atoms designated as free sites. Recent studies indicate a similar relationship exists between the rate of carbon gasification (in CO&lt;/span&gt;&lt;span class="s2"&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;/span&gt;&lt;span class="s1"&gt; or H&lt;/span&gt;&lt;span class="s2"&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;/span&gt;&lt;span class="s1"&gt;O) and the number of reactive sites as determined by transient kinetics experiments. Utilizing the concept of active or free sites, it was possible to produce a char from Illinois coal having an SO&lt;/span&gt;&lt;span class="s2"&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;/span&gt;&lt;span class="s1"&gt; adsorption capacity surpassing that of a commercial catalytic activated carbon.&lt;/span&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1021/ef960197+</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>American Chemical Society</dc:publisher>
  <dc:title>Mechanism of SO2 removal by carbon</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>