Certificates

We are aware of an issue with certificate availability and are working diligently with the vendor to resolve. The vendor has indicated that, while users are unable to directly access their certificates, results are still being stored. Certificates will be available once the issue is resolved. Thank you for your patience.

(67d) Technology Opportunities for Reduction of Emissions from Sulfuric Acid Manufacturing Plants

Authors: 
Nagaraj, A., Texas A&M University-Kingsville
Mills, P. L., Texas A&M University-Kingsville

Heterogeneous catalysis is a very important
technology for manufacture of various commercial and end-user products due to
its significant economic and environmental impact. In 2012, the commercial
value of annual catalyst production was estimated to be approximately 14 MMM US
dollars with more than 85% of all chemical commodities are manufactured using
catalysis1.

      H2SO4
catalysis has intrigued researchers and scientists for centuries due to the process
economics, various complexities and environmental impact. H2SO4
is a very important chemical commodity since a nation's acid production has
been used as a reasonably good indicator of its industrial strength for the
last century or so2,3.  Nearly 350 MM tons of H2SO4
were produced in 20144.  Rising
demand for commercial and sustainable process technologies for H2SO4
production is the primary driving force for industrial R&D to provide
state-of-art technologies.  Both sulfur
and H2SO4 as raw materials have been the subject of
various annual and biannual conferences5,6,but limited open literature exists on the economics and technical
advancements of H2SO4 manufacture with most data kept as
company proprietary.

      From an environmental
perspective, SO2 is identified as one of the ?criteria air pollutants?
by Environmental Protection Agency (US EPA). 
These pollutants can cause harm to human health, environment and also
cause property damage. Therefore, the EPA regulates these pollutants by
development of human-based and/or environmentally-based criteria to set permissible
levels. The catalytic oxidation of SO2 to SO3, which is
heart of the H2SO4 production process, is always
incomplete due to equilibrium limitation. Hence, unconverted SO2 emissions
have to be controlled to meet environmental regulations before released into
the atmosphere.

      Figure 1 is the schematic
representation of the three main facets of H2SO4
catalysis for sulfuric acid manufacturing plants. These technological areas are
(1) catalysts used for SO2 oxidation7,8;
(2) process technologies used for different aspects of H2SO4
manufacturing such as preheating feed gases, dry gas SO2 oxidation,
wet gas process, SO3 mist control and optimal heat recovery systems9,10,11;
(3) End-of-pipe control technologies, such as scrubbing of unconverted SO2
in stack gases and recycling weak H2SO4 for better waste
management12.

Figure 1.
The three faces of H2SO4 catalysis for H2SO4
plants13,14.

The primary objective of this presentation is to provide an overview of current
processes for sulfuric acid process production and the current status of
next-generation clean technologies for reduced emissions of SO2 from
H2SO4 acid manufacturing plants to meet future more stringent
environmental regulations.  Emphasis will
be placed on opportunities for development of new particulate and monolith
catalyst technology having improved performance.  An example of modeling of transport-kinetic
interactions in 3-D multi-lobe catalysts using the Dusty Gas model is shown in
Figure 2 where the concentration and temperature profiles are compared for two
different catalyst shapes.


 

Figure 2. Concentration and
Temperature profiles for Rounded step and Light bulb

                  shapes
using Dusty Gas diffusion model

References

1.      Heveling, J. (2012). "Heterogeneous Catalytic
Chemistry by Example of Industrial Applications." Journal of Chemical
Education 89(12): 1530-1536.

2.     
Muller, T. L.
(2000). Sulfuric Acid and Sulfur Trioxide. Kirk-Othmer Encyclopedia of
Chemical Technology, John Wiley & Sons, Inc.

3.     
ChemSystems
(2009). PERP program sulfuric acid report abstract.

4.      IHS (2014). Sulfuric Acid. Chemical
Economics Handbook.

5.     
CRU, G. (2013).
Sulphur, sulphur acid, sulphur dioxide.

6.     
Sulphuric-acid.com.
(2015). "Industry Conferences."  
Retrieved May 2015, 2015, from

http://www.sulphuric-acid.com/sulphuric-acid-on-the-web/conferences.htm.

7.     
Haldor-Topsoe.
(2015). "Sulfuric Acid."  
Retrieved May 2015, 2015, from http://www.topsoe.com/processes/sulfuric-acid.

8.     
MECS. (2015).
"MECS® Sulfuric Acid Catalyst Products." from http://www.dupont.com/products-and-services/consulting-services-process-technologies/brands/sustainable-solutions/sub-brands/clean-technologies/uses-and-applications/mecs-catalyst.html.

9.     
Laursen, J. K.
(2007). "The Process Principles, Detailed Advances in Sulfur Recovery by
the WSA Process." Hydrocarbon Engineering 12: 47-51.

10.  MECS. (2015). "MECS® SULFOX? Wet Gas Sulfuric
Acid Process."   Retrieved May 2015,
2015, from http://www.dupont.com/products-and-services/consulting-services-process-technologies/brands/sustainable-solutions/sub-brands/clean-technologies/products/mecs-sulfuric-acid-environmental-technologies/sub-products/mecs-sulfox.html.

11.  MECS. (2015). "MECS® Brink® Fiber Bed Mist
Eliminators."   Retrieved May 2015,
2015, from http://www.dupont.com/products-and-services/consulting-services-process-technologies/brands/sustainable-solutions/sub-brands/clean-technologies/products/mecs-sulfuric-acid-environmental-technologies/sub-products/bed-mist-eliminator-products.html.

12.  MECS. (2015). "MECS® DynaWave® Wet Gas
Scrubber."   Retrieved May 2015,
2015, from http://www.dupont.com/products-and-services/consulting-services-process-technologies/brands/sustainable-solutions/sub-brands/clean-technologies/products/mecs-sulfuric-acid-environmental-technologies/sub-products/dynawave.html.

13.  MECS (2015). ?How DynaWave
works.? Retrieved May 2015, from

http://www.mecsglobal.com/howthe-dynawave-wet-gas-scrubber-works.aspx

14.  Kiss, A. A., C. S. Bildea, et al. (2010).
"Dynamic modeling and process optimization of an industrial sulfuric acid
plant." Chemical Engineering Journal 158(2): 241-249.