Location: Application Technology Research
Project Number: 5082-21000-001-103-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 1, 2024
End Date: Aug 31, 2026
Objective:
This project aims to develop experimental testbeds for membrane technology and a simulation environment to evaluate how the technology can reduce costs for greenhouse growers. Specific objectives include the development of:
1. Models of membrane performance for evaluating energy requirements
2. Experimental membrane dehumidification system for evaluating membrane materials, desiccants, and operating conditions
3. Software for growers to evaluate the impact of membrane technology on greenhouse operation
Approach:
Membrane contactors have been used for various mass transfer applications. The dehumidification application involves contacting the greenhouse air with a liquid desiccant to remove water selectively. Existing contactor performance models can be adapted for the dehumidification application Contactor performance depends on several factors including, the gas and liquid stream flows, the membrane module, the membrane properties including porosity and thickness, and water and desiccant diffusion coefficients in the liquid phase. There are also a variety of ways that are used to regenerate saturated desiccant. A lab-scale experimental system will be developed to evaluate these options in a closed-loop process. The system will use flat sheet membrane samples in holders that can be connected to create a continuous process for dehumidification and desiccant regeneration. The long-term stability of the process will be determined by running for extended periods. The key material properties of the system (e.g., water osmotic pressure and desiccant viscosity) will be determined and correlated with performance. The results will be used to identify potential new desiccants or combinations of materials to improve performance. The lab-scale experimental results will be used to design a pilot-scale system for use in cooperator test greenhouse. Specifications will be developed for the membrane components and required ancillary equipment. A process flow diagram with complete mass and energy balances will be created. Equipment vendors will be identified, and quotes will be obtained for equipment.
