![]() ![]() One of the most used methods to extract plant water is the cryogenic vacuum distillation (CVD), which tends to extract total plant water. Recent tracer-based studies using stable isotopes of hydrogen and oxygen showed that different methods for extracting water from plant tissues can return different isotopic compositions due to the presence of organic compounds and because they extract different plant water domains. This entry was posted in Week 04 and tagged Week 4 by Michael Henry Bufalini. ![]() In comparison to aromatics, such as benzene, which are stabilized molecules and require higher temperatures to dissociate the molecules bonds. Higher K factors are at lower temperatures (paraffins), which makes sense because paraffins are easily cracked. In most cases, the refineries will operate below the lower end temperature to avoid as much accumulation of carbonaceous material as possible. Watson K factor and a band is used for plotting this range on the graph. The Watson Characterization Factor gives refineries an idea of the range of temperatures for vacuum distillation to help avoid coking. Cracking the molecules would lead to coking on the metal surface of the distillation column and interfere with fractionation in distillation. This is desired because high temperatures will cause vibrations and allow for thermal cracking or destruction of bonds within a given molecule carbon chain. Creating a vacuum chamber will greatly lower the pressure and uses Ideal Gas Law, one can use the correlation with a pressure drop then the required temperature will drop as well. ![]() The heavy distillates require a vacuum because of how temperature and pressure affect molecules. Atmospheric Distillation is used for separation of light and heavy crudes. Vacuum Distillation Units process the fuel’s heavy distillates after settling on the bottom of the Atmospheric Distillation Unit and not vaporizing like the lighter fractions. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |