Commodity Protection and Quality Site Logo
ARS Home About Us Helptop nav spacerContact Us En Espanoltop nav spacer
Printable VersionPrintable Version E-mail this pageE-mail this page
Agricultural Research Service United States Department of Agriculture
Search
  Advanced Search
 
Programs and Projects
Subjects of Investigation
 

Research Project: Retaining export and food security of U.S. Specialty Crops: Low-emission methyl bromide fumigations for quarantine and pre-shipment uses

Location: Commodity Protection and Quality

2012 Annual Report


1a.Objectives (from AD-416):
Develop novel sorbents, destructive catalysts, and combustion techniques to eliminate the atmospheric input of the most widely used quarantine and pre-shipment (QPS) fumigant, MB.


1b.Approach (from AD-416):
Utilizing a cooperative effort between USDA-ARS, industry, Yale University, Conneticut Agricultural Experiment Station, and U California at Berkeley, research in the context of retaining specialty crops exports that have quarantine and pre-shipment (QPS) fumigation requirements. The team will develop a commercially viable, cost efficient and effective process to contain, destroy, or recapture/reuse methyl bromide and its alternatives following postharvest fumigations.


3.Progress Report:

This Assistance Type Cooperative Agreement was established to support objective 1 of the in-house project and is related to finding postharvest methyl bromide alternatives and techniques for improving methyl bromide fumigations. A Yale University collaborator synthesized and tested catalysts that destroy methyl bromide in a continuous fixed-bed quartz reactor. A constant flow of 64 mg/L methyl bromide, a level that might be encountered at the end of a chamber fumigation event, was conveyed through stainless steel coil tubing to the reactor. The bed depth was ~1.5 mm corresponding to a residence time of the air stream over the catalyst of ~0.014 seconds. The potential for the catalysts to oxidize methyl bromide followed the order CeO2 > CeO2-Al2O3 mixtures > Al2O3 > TiO2. In addition, chloropicrin was used as a surrogate molecule to study the potential for sulfur-containing nucleophiles to destroy methyl bromide. The rate constant for thiosulfate destruction of chloropicrin in aqueous solution was measured and reaction products were characterized. The results indicate that chloropicrin degraded much faster than previously thought, as it was detectable at only trace levels after 2 h.


   

 
Project Team
Walse, Spencer
 
Project Annual Reports
  FY 2012
 
Related National Programs
  Methyl Bromide Alternatives (308)
 
 
Last Modified: 05/18/2013
ARS Home | USDA.gov | Site Map | Policies and Links 
FOIA | Accessibility Statement | Privacy Policy | Nondiscrimination Statement | Information Quality | USA.gov | White House