USDA Phase I SBIR Final Report
Award No. 2005-33610-15474
Proposal No. 2005-00212
Project Title: Prevention of Ozone Layer Depletion by Methyl Bromide Used for Soil Fumigation
Period of Performance 05/01/2005 through 12/31/2005
CRIS Number 0202962
Agency Name
Management Branch
Cooperative State Research, Education, and
Extension Service / USDA
Washington, DC 20250-2271
Awardee Organization
Value Recovery, Inc.
510 Heron Drive, Suite 301
Bridgeport, NJ 08014
Tel/ Fax 856-467-6316 / 856-467-6317
Project Director
Peter J. Joyce
Value Recovery, Inc.
510 Heron Drive, Suite 301
Bridgeport, NJ 08014
Tel/ Fax 856-467-6316 / 856-467-6317
Phase I Final Report
Executive Summary
A laboratory modeling study and economic analysis has been performed showing the economic and technical feasibility of recoveringmethyl bromide from farmland after it has undergone a broadcast soil fumigation with methyl bromide. A large cylinder filled with California sandy loam soil (1.3 m tall by 0.3 m diameter) from Watsonville, CA meant to mimic actual de-sorption was set up and charged with methyl bromide. An air sweep was imposed on the headspace to de-sorb the methyl bromide and convey it to a scrubber. Value Recovery has already shown an 85% destruction of methyl bromide in scrubbing equipment that would be the same size in demonstration trials done at the Port of Wilmington and in Westfield, Indiana (and handle the same concentrations) as that proposed to be used for methyl bromide emissions coming from 20 acres of farmland.
The math model representing the soil de-sorption phenomena showed an excellent fit to experimental data. The model proved that a small, consistent flow of air in the gap between the soil and the plastic film (VIF or Virtually Impermeable Film) can be modeled as an unsteady state differential equation that yields information on the equilibrium concentration of methyl bromide under the covering and the mass transfer coefficients that govern the rate of de-sorption of methyl bromide from the soil. All of these were needed to size the equipment needed for commercial applications.
Experiments were also performed on a small strip of farmland in New Jersey that demonstrated the concept of collecting gas from underneath a VIF film. Concentration profiles of a methyl bromide substitute (propane) were obtained that are in the expected range for a commercial application of methyl bromide de-sorption thus supporting our approach.
An economic analysis was done that shows that the total incremental cost is $208/acre and is made up of an operating cost of $189/acre and a capital cost of $20/acre at a capital recovery of 10 years at a 10% interest rate. Over 80% of the operating cost is for the scrubber solution and includes the cost of waste disposal. Since the cost of broadcast fumigation in California is estimated at between $2,000 and $2,500/acre, the additional cost is under the 10% incremental cost target and thus is "economical". There is a potential to directly discharge the scrubber solution. If direct discharge of scrubber solution is acceptable, and strong evidence exists that this is feasible, the total cost will go down by $45/acre to a total of $163/acre.
