Limiting the Formation of Carbon Monoxide in the Formox-Process
(2024) KETM05 20241Chemical Engineering (M.Sc.Eng.)
- Abstract
- In the Formox-process, methanol is converted to formaldehyde via partial oxidation on a heterogeneous iron-molybdate catalyst. To an extent, the formed formaldehyde (FA) is over-oxidized into carbon monoxide (CO) which cannot be recycled into FA. As CO affects the environment negatively and decreases the process economy, internal attempts have previously been made to decrease the CO formation of the process. This project has been conducted with the intent to decrease the CO formation of the process by at least 0.5 percentage points from today’s roughly 4.5%.
In this project, CO reduction of the Formox-process has been attempted by investigating two different pathways; with the first being addition of a readily combustible material... (More) - In the Formox-process, methanol is converted to formaldehyde via partial oxidation on a heterogeneous iron-molybdate catalyst. To an extent, the formed formaldehyde (FA) is over-oxidized into carbon monoxide (CO) which cannot be recycled into FA. As CO affects the environment negatively and decreases the process economy, internal attempts have previously been made to decrease the CO formation of the process. This project has been conducted with the intent to decrease the CO formation of the process by at least 0.5 percentage points from today’s roughly 4.5%.
In this project, CO reduction of the Formox-process has been attempted by investigating two different pathways; with the first being addition of a readily combustible material known as a Pore Former in various amounts to increase the porosity of the catalyst, as well as doping the catalyst with a metal oxide to act as a hardener. Changes to the mixing method of these ingredients has also been investigated. Analysis of the produced catalyst pellets showed that after these changes, the catalyst is either too fragile to be tested at a pilot scale, or exhibit too low porosity to be deemed promising for further study.
The other method that was tested involved replicating a washing step of the catalyst that is currently done in large-scale production. A washing liquid with a lower number of ions compared to the one being currently used was tested and compared to commercial references. Three samples with different washing liquids were produced and tested at a pilot scale, and the sample washed with process water showed an increased FA yield and a decreased byproduct yield compared to the commercial reference. However, the samples also exhibited an increased CO yield. These results potentially indicate a shift in the nature of the active sites of the catalyst from acidic to basic, but further testing must be done to determine the exact nature of the changes that have been made. Overall, the results provide a good basis for further study. (Less) - Popular Abstract (Swedish)
- De flesta associerar förmodligen ordet katalysator med bilkatalysatorer där smutsiga avgaser från fordon renas genom att gasen får reagera med syre och därmed bilda mindre skadliga produkter. Så kallade heterogena katalysatorer är ofta metalloxider och de används i många industrier för att möjliggöra kemiska reaktioner. Ett sådant exempel är Formox-processen, där en katalysator bestående av järnmolybdat används för att förena syre och metanol under bildningen av formaldehyd. Reaktionen sker inne i porer i denna ihåliga, pelletsformade, katalysator, och skulle dessa porer vara för små kan den bildade formaldehyden fångas i porerna och enkelt reagera med mer syre under bildning av kolmonoxid och koldioxid. Då dessa ämnen är välkända... (More)
- De flesta associerar förmodligen ordet katalysator med bilkatalysatorer där smutsiga avgaser från fordon renas genom att gasen får reagera med syre och därmed bilda mindre skadliga produkter. Så kallade heterogena katalysatorer är ofta metalloxider och de används i många industrier för att möjliggöra kemiska reaktioner. Ett sådant exempel är Formox-processen, där en katalysator bestående av järnmolybdat används för att förena syre och metanol under bildningen av formaldehyd. Reaktionen sker inne i porer i denna ihåliga, pelletsformade, katalysator, och skulle dessa porer vara för små kan den bildade formaldehyden fångas i porerna och enkelt reagera med mer syre under bildning av kolmonoxid och koldioxid. Då dessa ämnen är välkända växthusgaser, och ämnena inte kan återcirkuleras och reagera till formaldehyd igen, finns det en stor drivkraft att försöka öka storleken på porerna i katalysatorn, vilket har varit syftet med denna studie. Projektet gjordes i samarbete med Johnson Mattheys R&D-avdelning i Perstorp under första hälften av 2024.
Två olika metoder har testats; dels har ett ämne tillsats katalysatorn som lätt kan brännas bort under hög temperatur i en ugn. Tanken var att när ämnet bränns bort kommer den efterlämna hål i strukturen och därmed ge större porer. Analyser av dessa katalysatorer visade emellertid att strukturen nu blir väldigt bräcklig, vilket skulle leda till problem vid förvaring och transport av katalysatorn. Därmed genomgick inte dessa prover ytterligare tester.
Utöver detta testades det även att tvätta katalysatorerna med avjoniserat vatten i stället för vatten med högre koncentration av joner, vilket motsvarar den nuvarande tvättningen i produktionen. Här var tanken att tvättning med det avjoniserade vattnet skulle leda till en mindre mängd joner som sätter sig i porerna och utgör ett fysiskt hinder för formaldehyden på dess väg ut ur porerna. Pilotförsök av de tvättade katalysatorpartiklarna visade emellertid att mängden CO som bildades ökade för samtliga prover, samtidigt som bildningen av andra biprodukter minskade. Detta kan möjligen hänföras till ett skifte i karaktären hos de aktiva sätena i katalysatorn, från sura till basiska, men vidare studier behöver bedrivas för att säkerställa detta. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9166203
- author
- Okutan, Rezan LU
- supervisor
- organization
- course
- KETM05 20241
- year
- 2024
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- Heterogeneous Catalysis, Chemical Engineering, Formaldehyde
- language
- English
- id
- 9166203
- date added to LUP
- 2024-06-20 14:01:18
- date last changed
- 2024-06-25 03:42:52
@misc{9166203,
abstract = {{In the Formox-process, methanol is converted to formaldehyde via partial oxidation on a heterogeneous iron-molybdate catalyst. To an extent, the formed formaldehyde (FA) is over-oxidized into carbon monoxide (CO) which cannot be recycled into FA. As CO affects the environment negatively and decreases the process economy, internal attempts have previously been made to decrease the CO formation of the process. This project has been conducted with the intent to decrease the CO formation of the process by at least 0.5 percentage points from today’s roughly 4.5%.
In this project, CO reduction of the Formox-process has been attempted by investigating two different pathways; with the first being addition of a readily combustible material known as a Pore Former in various amounts to increase the porosity of the catalyst, as well as doping the catalyst with a metal oxide to act as a hardener. Changes to the mixing method of these ingredients has also been investigated. Analysis of the produced catalyst pellets showed that after these changes, the catalyst is either too fragile to be tested at a pilot scale, or exhibit too low porosity to be deemed promising for further study.
The other method that was tested involved replicating a washing step of the catalyst that is currently done in large-scale production. A washing liquid with a lower number of ions compared to the one being currently used was tested and compared to commercial references. Three samples with different washing liquids were produced and tested at a pilot scale, and the sample washed with process water showed an increased FA yield and a decreased byproduct yield compared to the commercial reference. However, the samples also exhibited an increased CO yield. These results potentially indicate a shift in the nature of the active sites of the catalyst from acidic to basic, but further testing must be done to determine the exact nature of the changes that have been made. Overall, the results provide a good basis for further study.}},
author = {{Okutan, Rezan}},
language = {{eng}},
note = {{Student Paper}},
title = {{Limiting the Formation of Carbon Monoxide in the Formox-Process}},
year = {{2024}},
}