Energy optimization of Multiple Stage Evaporator system using Water Cycle Algorithm

Area of Science:

• Chemical Engineering
• Energy Engineering
• Biomass Valorization

Background:

• Black liquor, a byproduct of paper production, is a significant biomass energy resource.
• Concentrating black liquor via Multiple Stage Evaporators is highly energy-intensive.
• Improving the energy efficiency of these evaporators is crucial for sustainability.

Purpose of the Study:

• To develop a non-linear model for a Heptads' stage Multiple Stage Evaporator.
• To optimize evaporator performance using energy-saving strategies.
• To enhance the energy efficiency of black liquor concentration.

Main Methods:

• Non-linear modeling and simulation of a backward feed Multiple Stage Evaporator.
• Application of the Water Cycle Algorithm (WCA) for optimization.
• Integration of energy-saving strategies: steam-split, feed-split, and feed-preheating.

Main Results:

• The Water Cycle Algorithm effectively identified optimal operating parameters.
• A hybrid model combining all energy-saving strategies achieved the best performance.
• Optimized Steam Economy: 7.092; Optimized Steam Consumption: 1.919 kg/s.

Conclusions:

• The hybrid energy-saving strategy significantly enhances evaporator performance.
• The optimized model shows a 52.84% improvement in Steam Economy and a 28.13% reduction in Steam Consumption compared to real plant data.
• This approach offers substantial energy savings and improved sustainability in the pulp and paper industry.