Page 516 - Industrial Wastewater Treatment, Recycling and Reuse

486 Industrial Wastewater Treatment, Recycling, and Reuse

• Reduction in cooling water
• Improving integration of co-gen plants with process.
Simultaneous water and heat integration could achieve up to 20% reduction
in soda loss and 20% reduction in energy consumption per ton alumina.

12.4 CONCLUSION

In conclusion, we find that there is immense potential in various industries to
achieve direct bottom-line benefits through the use of these mathematical
models. These will in the coming years become best practice for running
water networks inside these process plants. A logical approach to gain the
maximum benefits in this area will require:
• Benefit assessment through a comprehensive study of the current setup
• Using core knowledge of water networks and purification technology to
assess the specific area of improvement
• Application of software and systems in each of these areas to analyze, design,
and operate in the most optimum way
• Continuous improvement initiatives through the use of domain knowledge
to keep the system performing at the highest levels of optimized
operation.
In addition to the above steps, which have been successfully applied by many
companies in various industry sectors, some additional modern initiatives
that are at an early stage of evaluation include:
• Retrofits of existing plants, where water reuse may be limited by geo-
graphical, process, or design constraints
• Uncertainty and flexibility of contaminant loads
• Multiple species/contaminants/properties, because the feasibility of
water reuse changes when secondary species, or properties (e.g., conduc-
tivity) are brought into the picture and therefore requires a different
approach
• Simultaneous heat and water integration, because the issues are related,
for example, the tradeoff between wash-water utilization and
evaporation
• Simultaneous application of heat integration, exergy analysis, and opti-
mization techniques to look at energy recovery opportunities, that is, the
potential for improvement relative to an ideal, taking into account the
quality of energy
• Methods for analysis and synthesis.
As we become more globally conscious in our usage of precious resources
such as fresh water, it is without a doubt that companies will adopt more