Difference between revisions of "Environmental concerns"
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All industrial processes produce waste in some form that must be carefully handled and disposed of according to regulations set down by governments at varying levels. The key areas for consideration are
All industrial processes produce waste in some form that must be carefully handled and disposed of according to regulations set down by governments at varying levels. The key areas for consideration are to the land, air, watermanagement, pollution considerations are both a moral and legal obligation for any engineer or industry .
Revision as of 16:22, 21 February 2014
Authors: Sean Cabaniss, David Park, Maxim Slivinsky and Julianne Wagoner (ChE 352 in Winter 2014)
Steward: David Chen, Fengqi You
Date Presented: Feb. 23, 2014
All industrial processes produce waste in some form that must be carefully handled and disposed of according to regulations set down by governments at varying levels. The key areas for consideration are emissions to the land, air, and water, waste management, smells, noise, and visual impact. It is important to remember that pollution considerations are both a moral and legal obligation for any engineer or industry .
The human costs of pollution and contamination of the environment are the most
Causes & Pollutants
Causes & Pollutants
Causes & Pollutants
Chemical engineers need to keep several environmental considerations in mind when designing processes. During the design of the process, the toxicities of all the products, byproducts, and wastes produced by the system must be considered. Then, the reaction pathway that minimizes toxic components should be chosen whenever possible. A good design will seek to minimize, recycle, and make use of segregated waste streams in order to satisfy the demands of the waste market . Optimization is a powerful tool for waste minimization because it cuts down on toxic materials as well as improving the overall system. Optimization can be used to account for environmental impact, such as the effects of carbon monoxide or other greenhouse gases.
Example Environmental Design Problem
Volatile Organic Compound Abatement 
The 1990 Clean Air Act mandates a reduction in emissions of volatile organic compounds (VOC). Any VOC emission sources exceeding 10tons/year must retrofit abatement processes with the best available control technology (BACT).
A paint spraying plant emits VOCs from vents in the paint spray booths. The stream contains primarily toluene, methyl ethyl ketone (MEK), and xylene, with small impurities of silicone and phosphorus. The concentration of VOCs in the dryer effluent varies between a minimum of 0.3 wt% VOC and a maximum of 1.2 wt% VOC with an approximate composition of 50% toluene, 25% MEK, and 25% xylene.
The painting company has commissioned you to evaluate three different technologies for a reduction in VOCs: thermal incineration, catalytic incineration, and carbon absorbtion and destrcution of the VOCs. The low quality steam can be used by a nearby bottle washing plant.
Design an emission control plant for 50,000 scfm of vent gas at 100F and 25% relative humidity for 99% removal. The plant is located in Dearborn, Michigan, and the paint spray booths operate on a single 12-hour shift per day. Include the necessary start-up controls. The available fuel is natural gas or oil. Calculate the capital and operating cost and the $/lb or ton of VOC removed. Compare the three processes and recommend which is most suitable for this application.
- Towler, G.P. and Sinnot, R. (2012). Chemical Engineering Design: Principles, Practice and Economics of Plant and Process Design. Elsevier.
- Towler, G.P. (2012). Chemical Engineering Design, PowerPoint presentation.
- Seider, W.D. (2004). Process Design Principles: Synthesis, Analysis, and Evaluation, Wiley: New York.
- E. Robert Becker, "Volatile Organic Compound Abatement", Environex, January 1994