Critical review and exergy analysis of formaldehyde production processes

Bahmanpour, Ali M.; Hoadley, Andrew; Tanksale, Akshat

doi:10.1515/revce-2014-0022

Cited by 80 publications

(78 citation statements)

References 65 publications

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“…Forward relaxation of TS3 leads to intermediate structure I5, which consists of a formate anion adsorbed at a Ce 40 O 77 (OH) 3 slab. The newly formed hydroxyl group is tilted toward another surface oxygen atom and forms a weak hydrogen bond (223 pm).…”

Section: Resultsmentioning

confidence: 99%

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Activity versus Selectivity of the Methanol Oxidation at Ceria Surfaces: A Comparative First-Principles Study

Kropp

Paier

2015

J. Phys. Chem. C

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Ceria nanoparticles may expose (100) and (111) facets depending on the preparation method. Motivated by that, we study the reactions of methanol with the CeO 2 (100) surface using dispersion-corrected PBE+U subject to periodic boundary conditions and compare with results for the CeO 2 (111) surface. At (100) facets, the oxidative dehydrogenation of methanol to formaldehyde occurs with an intrinsic barrier of only 0.94 eV (91 kJ/mol), which is significantly lower than the corresponding barrier of 1.23 eV (119 kJ/mol) at the (111) surface. The lower barrier maps to lower formaldehyde desorption temperatures as observed in temperature-programmed desorption spectroscopy. The higher activity is in accordance with predicted lower oxygen defect formation energy in the (100) surface. Thus, defect formation energies are valid reactivity descriptors for oxidation reactions following a Mars-van Krevelen mechanism. At both surfaces, formaldehyde either desorbs or forms a bridging dioxymethylene intermediate, which can be further oxidized into carbon oxides. However, formaldehyde desorption from the (100) surface is significantly more endothermic. Thus, methanol oxidation at the (100) surface is predicted to yield both formaldehyde and carbon oxides, whereas at the (111) surface, formaldehyde can easily desorb. Therefore, the desorption step appears to be the key to the selectivity of methanol oxidation to formaldehyde.

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Section: Resultsmentioning

confidence: 99%

“…2 By virtue of heterogeneous catalysis, metal oxides are used to convert methanol via oxidative dehydrogenation (ODH) to formaldehyde, 3 which is the parent compound for many fine chemicals and pharmaceuticals.…”

Section: Introductionmentioning

confidence: 99%

Activity versus Selectivity of the Methanol Oxidation at Ceria Surfaces: A Comparative First-Principles Study

Kropp

Paier

2015

J. Phys. Chem. C

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“…However, despite the high conversion of CH 3 OH and high selectivity toward HCHO, the industrial methods of HCHO production suffer from CO 2 generation as a byproduct 1 and a high energy consumption rate which leads to low exergy efficiency (43.2%). 11 A novel HCHO production method through direct CO hydrogenation in the aqueous phase using Ru−Ni/Al 2 O 3 was recently introduced, which could potentially increase the exergy efficiency with no CO 2 production, 12 as a result of bypassing the production of methanol and also the much lower reaction temperatures. However, it was not clear how the reaction proceeds in the aqueous phase.…”

Section: ■ Introductionmentioning

confidence: 99%

Hydrogenation of Carbon Monoxide into Formaldehyde in Liquid Media

Bahmanpour

Hoadley

Mushrif

et al. 2016

ACS Sustainable Chem. Eng.

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Formaldehyde is a bulk chemical which is produced in excess of 30 million tons per annum and is growing in demand. However, the current production process requires methanol production, which is oxidized in air to produce formaldehyde, which must then be absorbed into water. Our recent work introduced a novel method to produce formaldehyde through CO hydrogenation in the aqueous phase. However, the aqueous phase has certain limitations which must be overcome to make it commercially viable. By applying a deuterium labeling technique and investigating the potential intermediates, the reaction mechanism was established which showed that solvents play a vital role in determining the yield. Various solvents were used for formaldehyde production, and the highest formaldehyde yield was achieved by using pure methanol followed by methanol−water mixtures. Formaldehyde reacts with methanol and water to produce hemiacetal and methylene glycol, respectively, thereby shifting the equilibrium of CO hydrogenation toward formaldehyde production. Methanol and water stabilize the hemiacetal and methylene glycol molecules, respectively, via hydrogen bonding. The highest yield of formaldehyde in methanol solvent was found to be 15.58 mmol L −1 g cat −1 at 363 K and 100 bar, which is four times higher than our previous report. The liquid phase method shown here has the potential to be greener and more sustainable than the commercial processes because it operates at low temperatures and results in 100% selectivity toward formaldehyde with no CO 2 generation. ■ INTRODUCTIONDue to the increasing global energy demand, many researchers have focused on reduction of energy consumption in the chemical industry. It is essential to search for more efficient, energy saving processes for the production of valuable chemicals. Many aspects can be considered and evaluated during process optimization. Increasing the conversion of reactants and product yield are often considered; however, process alternatives to save energy and capital costs are sometimes overlooked by researchers. Formaldehyde (HCHO) industrial production through methanol (CH 3 OH) partial oxidation dates back to 1882. 1 Since then, other methods of production such as methane (CH 4 ) partial oxidation 2−8 or CO 2 hydrogenation 9,10 were considered, but none were able to compete with the high conversion achieved by the methanol oxidation process. However, despite the high conversion of CH 3 OH and high selectivity toward HCHO, the industrial methods of HCHO production suffer from CO 2 generation as a byproduct 1 and a high energy consumption rate which leads to low exergy efficiency (43.2%). 11 A novel HCHO production method through direct CO hydrogenation in the aqueous phase using Ru−Ni/Al 2 O 3 was recently introduced, which could potentially increase the exergy efficiency with no CO 2 production, 12 as a result of bypassing the production of methanol and also the much lower reaction temperatures. However, it was not clear how the reaction proceeds in the aqueous phase. Although th...

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“…2Simplified scheme of the FA production process based on the silver catalyst. The side product methyl formate (MF) and traces of not converted MeOH are quantified at the top of the absorption tower, indicated with a red arrow [31, 32] …”

Section: Production Of Formaldehydementioning

confidence: 99%

“…The side product methyl formate (MF) and traces of not converted MeOH are quantified at the top of the absorption tower, indicated with a red arrow [31, 32]…”

Section: Production Of Formaldehydementioning

confidence: 99%

On-line monitoring of methanol and methyl formate in the exhaust gas of an industrial formaldehyde production plant by a mid-IR gas sensor based on tunable Fabry-Pérot filter technology

et al. 2016

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On-line monitoring of key chemicals in an industrial production plant ensures economic operation, guarantees the desired product quality, and provides additional in-depth information on the involved chemical processes. For that purpose, rapid, rugged, and flexible measurement systems at reasonable cost are required. Here, we present the application of a flexible mid-IR filtometer for industrial gas sensing. The developed prototype consists of a modulated thermal infrared source, a temperature-controlled gas cell for absorption measurement and an integrated device consisting of a Fabry-Pérot interferometer and a pyroelectric mid-IR detector. The prototype was calibrated in the research laboratory at TU Wien for measuring methanol and methyl formate in the concentration ranges from 660 to 4390 and 747 to 4610 ppmV. Subsequently, the prototype was transferred and installed at the project partner Metadynea Austria GmbH and linked to their Process Control System via a dedicated micro-controller and used for on-line monitoring of the process off-gas. Up to five process streams were sequentially monitored in a fully automated manner. The obtained readings for methanol and methyl formate concentrations provided useful information on the efficiency and correct functioning of the process plant. Of special interest for industry is the now added capability to monitor the start-up phase and process irregularities with high time resolution (5 s).

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Critical review and exergy analysis of formaldehyde production processes

Cited by 80 publications

References 65 publications

Activity versus Selectivity of the Methanol Oxidation at Ceria Surfaces: A Comparative First-Principles Study

Activity versus Selectivity of the Methanol Oxidation at Ceria Surfaces: A Comparative First-Principles Study

Hydrogenation of Carbon Monoxide into Formaldehyde in Liquid Media

On-line monitoring of methanol and methyl formate in the exhaust gas of an industrial formaldehyde production plant by a mid-IR gas sensor based on tunable Fabry-Pérot filter technology

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