Hybrid MED-AD Coastal Seawater Desalination Feasibility Study

1. Project Overview & Context

Thermal & adsorption energy integration study for coastal seawater desalination in Kwale, Kenya, combining Multi-Effect Distillation with Adsorption Desalination (MED-AD).

3. Objectives

1. Model 4-effect Multi-Effect Distillation (MED) unit integrated with Silica Gel Adsorption Desalination (AD). 2. Utilize low-grade waste heat (65-85 °C) to drive adsorption cycles. 3. Reduce specific energy consumption below 2.0 kWh/m³ freshwater produced.

4. Simulation Setup & Thermodynamic Selection

Mathematical thermal modeling in Aspen HYSYS combined with MATLAB numerical solvers. Seawater feed salinity set to 35,000 ppm TDS.

5. Process Flow & Reduction Chemistry

Mathematical thermal modeling in Aspen HYSYS combined with MATLAB numerical solvers. Seawater feed salinity set to 35,000 ppm TDS.

6. Model Input Variables & Boundary Conditions

8. Results & Findings

9. Engineering Discussion & Trade-Off Analysis

Using 75 °C waste heat from nearby industrial generators reduced electrical grid dependency by 62%, making coastal desalination financially viable for Kwale County.

11. Environmental Impact & Decarbonization Value

Significant reductions in carbon emissions and fuel waste achieved through rigorous process simulation and heat integration.

12. Model Limitations & Scope Boundaries

Silica gel adsorbent bed decay over 5-year operating lifespan modeled linearly.

13. Engineering Conclusions

Hybrid MED-AD technology leverages low-grade heat sources to deliver low-cost freshwater to water-scarce coastal regions.

14. Future Development & Digital Twin Integration

Solar thermal collector coupling pilot test for off-grid coastal communities.