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Reducing SO2 emissions from industrial/petrochemical complexes

  • 1.  Reducing SO2 emissions from industrial/petrochemical complexes

    SENIOR MEMBER
    Posted 12-11-2019 03:52
    SO2 emissions constitute almost 80% of the total emissions coming out of industrial/petrochemical processes. These are extremely toxic not only to living things but also do considerable harm to the environment.

    We need to develop novel materials which can reduce almost 99% of SO2 emissions. The present technique can only manage to absorb 90% of the SO2 out-gas.

    Any discussions/recent development trends are welcome. If we are able to recover SO2, same could be utilized for sulfuric acid manufacture, which an important industrial chemical.

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    Rohit Korde MSc,CEng
    Program Manager
    Worley
    Thane (W)
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  • 2.  RE: Reducing SO2 emissions from industrial/petrochemical complexes

    SENIOR MEMBER
    Posted 12-12-2019 01:34
      |   view attached
    I should point out that the technology for converting  "waste" SO2 is very well established. For example, the CS2 emissions from viscose plants are combusted to generate SO2. This SO2 is converted into H2SO4 by "wet process" technology. Haldor-Topsoe have a catalyst suitable for such "wet process" conversion. Many companies are using this indirect CS2 recovery route for 2 reasons (1) recovering CS2 would have been ideal but problematic due to its hazardous properties although (i) adsorbents (ii) liquid phase processes and (iii) membranes have been known for recovering CS2 and (2) H2SO4 is anyway required in the viscose process and converting CS2 to H2SO4 is more efficient than recovering CS2 itself. However, the capital cost for the "wet process" technology may be higher. Please refer the following:
    1) McIntosh, Michael J. Removal and Recovery of Carbon Disulfide Emitted by the Viscose Process. Hazardous Waste Research and Information Center, 1992 (https://scholar.google.co.in/scholar?hl=en&as_sdt=0%2C5&q=Removal+and+Recovery+of+Carbon+Disulfide+Emitted+by+the+Viscose+Process&btnG=#d=gs_cit&u=%2Fscholar%3Fq%3Dinfo%3ARI_hxymzFh4J%3Ascholar.google.com%2F%26output%3Dcite%26scirp%3D0%26hl%3Den).
    2) You-xin, L., & De-zhen, Q. (1985) Cost-benefit analysis of the recovery of carbon disulfide in the manufacturing of viscose rayon. Scandinavian journal of work, environment & health, 60-63.
    3) Enneking, J. C. (2002) Control of carbon disulfide emissions from viscose processes. Environmental progress, 21(3), 169-174.
    Besides the above referred "wet process" & other technologies there are other processes which I had covered in my paper "Pangarkar, V.G.-1972-Liquid phase processes for the removal of sulfur compounds from natural-refinery & stack gases": Chem Industry Developments incorporating Chem. Processing & Engg., Sept, 1972: pp 17-28. This vintage paper covers almost all processes which were and are used industrially. There are no major developments especially for recovery of SO2 as H2SO4. I am attaching this paper of mine to this post since it may not be readily available to members of AICHE.
    If there are any queries, I should be glad to help.

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    Vishwas Pangarkar PhD
    Retired Professor of Chemical Engineering, University of Mumbai, India.
    Currently: Independent Chemical Engineering Academic/Professional.
    Nasik-422013, India.
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  • 3.  RE: Reducing SO2 emissions from industrial/petrochemical complexes

    SENIOR MEMBER
    Posted 12-12-2019 04:57
    You may explore installation of wet scrubbing system, running with caustic addition and maintaining pH between 8 to 8.5.

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    KOTTI KUMAR
    HEAD PLANT OPERATIONS
    INDO GERMAN PETROCHEMICALS LIMITED
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  • 4.  RE: Reducing SO2 emissions from industrial/petrochemical complexes

    SENIOR MEMBER
    Posted 12-12-2019 06:02
    Using NaOH to knock out SO2 is not a sustainable solution. It uses a precious alkali to generate a dilute solution of sodium sulphite which cannot be released into the aquatic environment due to regulations. The cheapest alternative is lime that is practiced in removal of small quantities of SO2  that are not economically amenable to conversion to acid. Use of lime  generates calcium sulphite which has a far lower solubility and hence can be filtered. The problem again is to dispose the solid waste unless there is a cement plant which can utilize CaSO3/CaSO4
    In most metallurgical plants (Cu/Zn smelters) the SO2 coming from the roaster is converted to H2SO4. The latter plant is an inevitable addition to the main metal roasting plant. There was a post relating to this issue from Mr Kombe of Zambia in Dec. last year. You can check out that discussion.

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    Vishwas Pangarkar PhD
    Retired Professor of Chemical Engineering, University of Mumbai, India.
    Currently: Independent Chemical Engineering Academic/Professional.
    Nasik-422013, India.
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  • 5.  RE: Reducing SO2 emissions from industrial/petrochemical complexes

    SENIOR MEMBER
    Posted 12-20-2019 22:53
    Hi guys. I agree with Mr. Vishwas.

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    Han Li
    project manager
    Hualu
    Xi'an
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  • 6.  RE: Reducing SO2 emissions from industrial/petrochemical complexes

    Posted 12-21-2019 06:32
    Sir,
    I would wish to direct your attention recent post by Solvay on LinkedIn.
    https://www.solvay.com/en/article/sustainable-solution-to-reduce-industrial-pollution?utm_medium=social&utm_source=linkedin&utm_campaign=Stories+or+Medium&utm_content=100000989994651&linkId=100000008486298
     Here, they have used Sodium bicarbonate to wash of SOx, NOx, HCl from the flue gas. According to my understanding, this creates sodium chemicals like NaCl, Na2SO4, NaNO3, etc. Though the problem of polluted gas is solved, how could these chemicals be recycled? This is a complex nature of solution. Would the separation not get complicated here.

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    Jayendran Iyer
    Bandra
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  • 7.  RE: Reducing SO2 emissions from industrial/petrochemical complexes

    SENIOR MEMBER
    Posted 12-22-2019 00:43
    Re: Comments by
    Jayendra Iyer: I have seen the link provided by Jayendra Iyer: My reading is : Yes, they can recycle NaHCO3 & NaCl to the Solvay-Ammonia-Soda process but I am not sure what happens to the nitrates/nitrites. Both are monovalent like NaHCO3 & NaCl.
    William Polk: The Haldor-Topsoe wet process for H2SO4 works well and with proper design it can meet the pollution norms~ 1 kg SO2/T H2SO4, mist ~ 30-50 mg/Nm3, etc. However, what happens when excess water ingress occurs ? particularly during start-up when the catalyst bed needs to be heated up by for example burning natural gas.

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    Vishwas Pangarkar PhD
    Retired Professor of Chemical Engineering, University of Mumbai, India.
    Currently: Independent Chemical Engineering Academic/Professional.
    Nasik-422013, India.
    ------------------------------



  • 8.  RE: Reducing SO2 emissions from industrial/petrochemical complexes

    SENIOR MEMBER
    Posted 12-30-2019 11:24
    Dr. Pangarkar,
    Haldor Topsoe makes catalysts for our wet sulfuric acid process as well as conventional "dry gas" sulfuric acid plants.  The procedures for preheating the catalyst for both types of plants are the same.  The catalyst is preheated to approximately 150C either by "dry blows" or in the smelting industries using their gas pre-heater.  The "dry blow" involves heating the furnace to approximately 1000C and venting the combustion gases before the catalyst.  Once the furnace is up to 1000C, the natural gas is shut off and dry air is blown through the furnace and into the catalyst beds to preheat the catalyst.  Once the catalyst is up to 150C the "dry blows" can be stopped and natural gas feed can be reintroduced and the combustion gases allowed to flow through the entire plant.


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    William Polk
    Sales Manager
    Haldor Topsoe, Inc
    Dickinson TX
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  • 9.  RE: Reducing SO2 emissions from industrial/petrochemical complexes

    SENIOR MEMBER
    Posted 12-31-2019 00:23
    Dr Polk,
    I am familiar with Haldor-Topsoe catalysts. The start-up procedure you describe is definitely the right one & should be followed both for "dry" /"wet" processes. The problem that can arise is thru' the H2O vapor generated in natural gas combustion. If the bed temperature accidentally drops below the dew point then water condensation can damage the catalyst. The ideal/fail-safe way would be to avoid water laden combustion gases but that would entail an additional air heater. I am sure plant personnel take all the required precautions to protect the catalyst.

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    Vishwas Pangarkar PhD
    Retired Professor of Chemical Engineering, University of Mumbai, India.
    Currently: Independent Chemical Engineering Academic/Professional.
    Nasik-422013, India.
    ------------------------------



  • 10.  RE: Reducing SO2 emissions from industrial/petrochemical complexes

    SENIOR MEMBER
    Posted 12-23-2019 16:03
    Hello Jayendran:  

    Yes, DSI (dry sorbent injection) control of SOx using sodium bicarbonate creates unwanted solid byproducts which must be disposed.  However, they are quite benign compared to SOx which can be fatal (IDLH - Immediately Dangerous to Life and Health) at 100 ppm.  

    It's always a tradeoff in the pollution control business.  

    One other unwanted byproduct of this reaction is CO2.

    Bill Stuble
    Design20FIRST LLC, PE







  • 11.  RE: Reducing SO2 emissions from industrial/petrochemical complexes

    SENIOR MEMBER
    Posted 12-12-2019 07:26
    What years does this data cover?  And, what countries or parts of the world?  In the US in recent years, the shut down of numerous coal-burning power plants has reduced sulfur dioxide emissions significantly.  These plants were likely the largest source of the emissions in the US.  Inexpensive natural gas has allowed this to occur.  As the US exports more gas and as natural gas becomes more available worldwide, the same phenomena should occur on a broader global scale.

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    Marise Textor PE
    Manager Regulatory Affairs
    Marathon Petroleum Company
    El Paso TX
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  • 12.  RE: Reducing SO2 emissions from industrial/petrochemical complexes

    SENIOR MEMBER
    Posted 12-12-2019 08:00
    I would like to point out that SO2 from coal burning plants is a much more benign issue than Hg, As,Pb, etc in the emissions. The low boiling Hg for example goes into the chimney & does travel far more than a few 100 miles. The higher melting toxic species get concentrated in the fly ash and can readily leach out into the water table. They are far more difficult to tackle that the poor innocuous SO2 !
    We are all glad to know that the US is shutting down some coal fired utilities. The most sustainable solution is solar energy because it is boundless in quantity and time. Recent data show that solar generation is being added wherever possible including the US but it is still not sufficient to make a dent in CO2 reduction (Pl see a very recent paper:Rojas, Enrique Garralaga, Hamed Sadri, and Wiebke Krueger (October 2019) "Case study of MW‐sized power generation at St. Eustatius island combining photovoltaics, battery storage, and gensets." Progress in Photovoltaics: Research and Applications).

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    Vishwas Pangarkar PhD
    Retired Professor of Chemical Engineering, University of Mumbai, India.
    Currently: Independent Chemical Engineering Academic/Professional.
    Nasik-422013, India.
    ------------------------------



  • 13.  RE: Reducing SO2 emissions from industrial/petrochemical complexes

    SENIOR MEMBER
    Posted 12-12-2019 15:10
    Rohit is correct.  Only 90% of SO2 emissions are captured using current technology, and that is the most optimal.  An example is provided in this study of dry sorbent injection (DSI) of trona (sodium sesquicarbonate), a relatively inexpensive naturally occurring mineral that is sourced mainly from Green River, Wyoming.  


    Interestingly, the maritime industry will be coming under new fuel sulfur content regulations starting next month.  They have been getting away with minimal regulation of their high sulfur "bunker oil"  fuel.  The new regulution calls for a 77% reduction in fuel sulfur to 0.50%.


    That is assuming two things:  1.  the low sulfur fuel is available;   2. the industry doesn't appeal the decision.  

    Thanks, Rohit, for starting this discussion.





  • 14.  RE: Reducing SO2 emissions from industrial/petrochemical complexes

    SENIOR MEMBER
    Posted 12-16-2019 12:28
    Dear Rohit,

    I work for Haldor Topsoe and we have advanced catalysts that can oxidize and remove 99.9+% of the SO2 in sulfuric acid plants.  We also have a "wet gas sulfuric acid process" that can be utilized to remove 99+% of all SO2 from essentially any sulfur containing compound that can be combusted or thermally decomposed to SO2.

    In refineries we are working with Worley with a new "Top Claus" process that utilizes our "wet gas process" on the tail end of a Claus plant.  Any SO2 leaving the Claus plant is then converted to sulfuric acid.  The sulfuric acid can then be used internally, sold or fed back into the front end of the Claus plant to recover as sulfur.

    The technology and catalysts are available to remove 99+% SO2 from most processes and turn the SO2 into industrial grade sulfuric acid.  Companies just need to commit to doing it.  Most companies see SO2 removal as an environmental issue and only do the minimal SO2 removal that is required by the appropriate governmental agencies.

    For more information go to our website www.topsoe.com

    Regards,

    Patrick Polk
    Sales Manager, Sulfuric Acid Catalysts
    Haldor Topsoe, Inc
    Houston, TX

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    William Polk
    Sales Manager
    Haldor Topsoe, Inc
    Dickinson TX
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  • 15.  RE: Reducing SO2 emissions from industrial/petrochemical complexes

    SENIOR MEMBER
    Posted 01-04-2020 03:02

    All conventional fossil fuels contain various sulphur bound organic and inorganic compounds and their sulphur content present as follows: • Wood and cellulose rich biomass (0.1%),Natural gas (0-15 percent), Crude oil (0.3 to several percent), Coal (0.5 to >3.0 percent)

    Approaches and Strategies for SO2 Emission Control

    1. Use of clean fuel
    2. Removal of sulphur from the fuel
    3. Preventing production and release of SO2 during combustion
    4. Flue gas desulphurization

     



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    [Prem ] [Baboo] [DGM]
    [Mr.]
    [Dangote Fertilizer Projects]
    [Lekki] [Lagos]
    [Nigeria]
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