The Hydroxyl Radical Reaction Rate Constant and Atmospheric Transformation Products of 2-Butanol and 2-Pentanol
Author | : |
Publisher | : |
Total Pages | : 12 |
Release | : 1998 |
ISBN-10 | : OCLC:946626928 |
ISBN-13 | : |
Rating | : 4/5 (28 Downloads) |
Book excerpt: The relative rate technique has been used to measure the hydroxyl radical (OH) reaction rate constant to +2-butanol (2BU, CH3CH2CHOHch3 and 2-pentanol (2PE, CH3CH2CH2CHOHch3. 2BU and 2PE react with OH yielding bimolecular rate constants of (8.1 +/- 2.0) x 10(exp -12 cm3/molecule/s and (11.9 +/- 3.0) x 10(exp-12) cm3/molecule/s, respectively, at 297 +/- 3 K and 1 atmosphere total pressure. Both 2BU and 2PE OH rate constants reported here are in agreement with previously reported values. In order to more clearly define these alcohols' atmospheric reaction mechanisms, an investigation into the OH + alcohol reaction products was also conducted. The OH + 2BU reaction products and yields observed were: methyl ethyl ketone (MEK, 60 +/- 2%, CH3CH2C(=O)CH3 and acetaldehyde (29 +/- 4%, HC(=O)CH3. The OH + 2PE reaction products and yields observed were: 2-pentanone (2PO, 4 +/- 4%, CH3C(=O)CH2CH2CH3, propionaldehyde (14 +/- 2%, HC(=O)CH2CH3, and acetaldehyde 40 +/- 4%, HC(=O)CH3. The alcohols' reaction mechanisms are discussed in light of current understanding of oxygenated hydrocarbon atmospheric chemistry. Labeled (O-18) 2BU/OH reactions were conducted to investigate 2BUs atmospheric transformation mechanism details. The findings reported here can be related to other structurally similar alcohols and may impact regulatory tools such as ground level ozone-forming potential calculations (incremental reactivity).