Environmental Protection in Design

Study Notes

Individuals and companies have a duty of care towards their neighbors and the environment.
Countries implement strict laws to regulate the quality of air, water, and land.
Design and operation of process plants must ensure compliance with legal environmental standards.
Key considerations include:
- Emissions to land, air, and water
- Waste management practices
- Odor control
- Noise pollution mitigation
- Visual impact assessment
- Other potential nuisances
- Environmental friendliness of products

Engineers must evaluate multiple factors to design an effective pollution control system.
Key steps include:
- Investigating pollution sources and properties of emissions.
- Designing collection and transfer systems for pollutants.
- Selecting appropriate control devices.
- Ensuring dispersion of exhaust meets regulatory standards.
The size of equipment correlates to the volume of pollutants treated; reducing exhaust volume can lower costs.
Treatment stages are determined by the quantity of pollutants needing removal.
Process changes or material substitutions can significantly reduce pollution sources.

Waste originates from by-products, unused reactants, and misoperation-related products.
Additional waste arises from leaks, spills, and emergency discharges.
Emphasis should be on minimizing waste at the source before considering treatment options.
Hierarchical waste management approaches prioritize:
- Source reduction (best practice)
- Recycling waste streams
- Treatment to lessen environmental impact
- Legal disposal of waste

Purification of Feeds:
- Reducing impurities leads to fewer side reactions and less waste.
- Select purification approaches that don't generate additional waste.
Protecting Catalysts and Adsorbents:
- Prevent deactivation of catalysts by filtering out contaminants using guard beds.
Eliminating Extraneous Materials:
- Avoid unnecessary solvents and separation agents that degrade and create waste.
Increasing Recovery from Separations:
- Higher recovery rates reduce waste but may increase capital and operational costs.
Improving Fuel Quality:
- Switching to cleaner fuels like natural gas decreases emissions; costs should be considered.

A five-step review process for waste minimization includes:
- Identifying waste components for regulatory impacts.
- Assessing waste streams for size and economic effects.
- Uncovering root causes of waste production.
- Evaluating modifications to tackle root causes.
- Prioritizing and implementing effective solutions.
Effluent summary worksheets are often used to track regulated pollutants and summarize their quantities.