scholarly journals Autothermal Reforming of Acetic Acid to Hydrogen and Syngas on Ni and Rh Catalysts

Catalysts ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1504
Author(s):  
Lifita N. Tande ◽  
Erik Resendiz-Mora ◽  
Valerie Dupont ◽  
Martyn V. Twigg
Keyword(s):  
Acetic Acid ◽  
Coke Formation ◽  
Sustainable Use ◽  
Packed Bed ◽  
Significant Loss ◽  
Autothermal Reforming ◽  
Flow Strength ◽  
Equilibrium Limit ◽  
Al2o3 Support ◽  
H2 Yield

The autothermal reforming (ATR) of acetic acid (HAc) as a model bio-oil compound is examined via bench scale experiments and equilibrium modelling to produce hydrogen and syngas. This study compares the performance of nickel (Ni-Al, Ni-CaAl) vs. rhodium (Rh-Al) for particulate packed bed (PPB), and of Rh-Al in PPB vs. Rh with and without Ceria for honeycomb monolith (‘M’) catalysts (R-M and RC-M). All PPB and M catalysts used Al2O3 as main support or washcoat, and when not pre-reduced, exhibited good performance with more than 90% of the HAc converted to C1-gases. The maximum H2 yield (6.5 wt.% of feed HAc) was obtained with both the Rh-Al and Ni-CaAl catalysts used in PPB, compared to the equilibrium limit of 7.2 wt.%, although carbon deposition from Ni-CaAl at 13.9 mg gcat−1 h−1 was significantly larger than Rh-Al’s (5.5 mg gcat−1 h−1); close to maximum H2 yields of 6.2 and 6.3 wt.% were obtained for R-M and RC-M respectively. The overall better performance of the Ni-CaAl catalyst over that of the Ni-Al was attributed to the added CaO reducing the acidity of the Al2O3 support, which provided a superior resistance to persistent coke formation. Unlike Rh-Al, the R-M and RC-M exhibited low steam conversions to H2 and CH4, evidencing little activity in water gas shift and methanation. However, the monolith catalysts showed no significant loss of activity, unlike Ni-Al. Both catalytic PPB (small reactor volumes) and monolith structures (ease of flow, strength, and stability) offer different advantages, thus Rh and Ni catalysts with new supports and structures combining these advantages for their suitability to the scale of local biomass resources could help the future sustainable use of biomasses and their bio-oils as storage friendly and energy dense sources of green hydrogen.

Hydrogen Production via Catalytic Autothermal Reforming of Desulfurized Jet-A Fuel

2016 ◽  
Author(s):  
Shuyang Zhang ◽  
Xiaoxin Wang ◽  
Peiwen Li
Keyword(s):  
Energy Efficiency ◽  
Hydrogen Production ◽  
Hydrogen Storage ◽  
Coke Formation ◽  
Autothermal Reforming ◽  
Operating Conditions ◽  
Hydrogen Yield ◽  
Fuel Conversion ◽  
Optimal Operating ◽  
Reaction Equilibrium

On-board hydrogen production via catalytic autothermal reforming is beneficial to vehicles using fuel cells because it eliminates the challenges of hydrogen storage. As the primary fuel for both civilian and military air flight application, Jet-A fuel (after desulfurization) was reformed for making hydrogen-rich fuels in this study using an in-house-made Rh/NiO/K-La-Ce-Al-OX ATR catalyst under various operating conditions. Based on the preliminary thermodynamic analysis of reaction equilibrium, important parameters such as ratios of H2O/C and O2/C were selected, in the range of 1.1–2.5 and 0.5–1.0, respectively. The optimal operating conditions were experimentally obtained at the reactor’s temperature of 696.2 °C, which gave H2O/C = 2.5 and O2/C = 0.5, and the obtained fuel conversion percentage, hydrogen yield (can be large than 1 from definition), and energy efficiency were 88.66%, 143.84%, and 64.74%, respectively. In addition, a discussion of the concentration variation of CO and CO2 at different H2O/C, as well as the analysis of fuel conversion profile, leads to the finding of effective approaches for suppression of coke formation.

Comparison of steam and autothermal reforming of methanol using a packed-bed low-cost copper catalyst

2009 ◽  
Vol 34 (18) ◽  
pp. 7656-7665 ◽  
Author(s):  
Hong-Yue Tang ◽  
Paul Erickson ◽  
Hyung Chul Yoon ◽  
Chang-Hsien Liao
Keyword(s):  
Copper Catalyst ◽  
Low Cost ◽  
Packed Bed ◽  
Autothermal Reforming

scholarly journals Coke formation in the oxidative dehydrogenation of ethylbenzene to styrene by TEOM

2014 ◽  
Vol 4 (11) ◽  
pp. 3879-3890 ◽  
Author(s):  
C. Nederlof ◽  
P. Vijfhuizen ◽  
V. Zarubina ◽  
I. Melián-Cabrera ◽  
F. Kapteijn ◽  
...  
Keyword(s):  
Oxidative Dehydrogenation ◽  
Coke Formation ◽  
Packed Bed ◽  
Dehydrogenation Of Ethylbenzene ◽  
Oxidative Dehydrogenation Of Ethylbenzene

A packed bed microbalance reactor setup (TEOM-GC) is used to investigate the formation of coke as a function of time-on-stream on γ-Al2O3 and 3P/SiO2 catalyst samples under different conditions for the ODH reaction of ethylbenzene to styrene.

scholarly journals Surveying Denitrification Efficacy in Up-Flow Packed Bed Bioreactor Operated under Heterotrophic Condition Using Autotrophic Bacteria

2019 ◽  
Author(s):  
Ali Asghar Neshat ◽  
Abdomajid Gholizadeh ◽  
Babak Jahed ◽  
Pouria Nikvand
Keyword(s):  
Acetic Acid ◽  
Carbon Source ◽  
High Efficiency ◽  
Nitrate Removal ◽  
Packed Bed ◽  
Critical Issue ◽  
Pilot Scale ◽  
Aqueous Environment ◽  
Packed Bed Bioreactor ◽  
Autotrophic Bacteria

Introduction: The biological denitrification process is an interesting cost-effective technique to remove nitrate from water supplies. Acetic acid can be used as a carbon source in this process, but its consumption rate is a critical issue and, in some cases, it is quite different from stoichiometric constants. The current study aimed to investigate the nitrate removal in an up-flow packed bed bioreactor. Furthermore, various parameters affecting this process were investigated and optimized. In this study, the autotrophic bacteria were used for the heterotrophic process. Materials and Methods: Initially, the autotrophic bacteria were cultured and used for the following heterotrophic conditions in distinct reactors. A pilot-scale anoxic up flow bioreactor packed was constructed using the polyethylene media and applied to remove nitrate from the aqueous environment. Consequently, the effects of hydraulic retention times (HRT) and different acetic acid concentrations as carbon source were evaluated. During the study, the amounts of alkalinity, pH, temperature, and nitrate were checked. Results: The designed bioreactor removed an average of over 88% of nitrate, while the acetic acid consumption was 2 mg/mg NO3-N, which was lower than the stoichiometric constant for heterotrophic process. Moreover, in the three studied HRTs (1.5, 3, and 5 h), the Alkalinity increased from 14.2 to 19.8 %. Conclusion: The results of this study showed high efficiency in nitrate removal via heterotrophic denitrification using acetic acid as carbon source for autotrophic bacteria.

Steam Reforming of Acetic Acid for Hydrogen Production: Thermodynamic Calculations

2012 ◽  
Vol 534 ◽  
pp. 141-145 ◽  
Author(s):  
Long Guo ◽  
Xin Bao Li ◽  
Qi Wang ◽  
Shu Rong Wang
Keyword(s):  
Acetic Acid ◽  
Hydrogen Production ◽  
Steam Reforming ◽  
Thermodynamic Calculation ◽  
Model Compound ◽  
Thermodynamic Calculations ◽  
Product Gas ◽  
Bio Oil ◽  
Effects Of Temperature ◽  
H2 Yield

In our work, acetic acid was used as a bio-oil model compound. Thermodynamic calculation of hydrogen production via steam reforming of acetic acid was attempted to investigate the effects of temperature (200-1100 °C), pressure（1-19 atm ）and steam to carbon ratio (1.5-10.5) on the concentration of equilibrium product gas and H2 yield. The results show that temperature has a profound effect on the steam reforming of acetic acid. Lower pressure and higher steam to carbon ratio are in favor of higher hydrogen production.

scholarly journals Plasma-Catalytic Ammonia Synthesis Beyond the Equilibrium Limit

2020 ◽  
Author(s):  
Prateek Mehta ◽  
Patrick M. Barboun ◽  
Yannick Engelmann ◽  
David B. Go ◽  
Annemie Bogaerts ◽  
...  
Keyword(s):  
Elevated Temperatures ◽  
Ammonia Synthesis ◽  
Packed Bed ◽  
Reaction Rates ◽  
Thermal Reaction ◽  
Equilibrium Limit ◽  
Plasma Activation ◽  
Catalytic Material ◽  
Material Choice ◽  
Catalytic Ammonia Synthesis

We explore the consequences of non-thermal plasma activation on product yields in catalytic ammonia synthesis, a reaction that is equilibrium-limited at elevated temperatures. We employ a minimal microkinetic model that incorporates the influence of plasma activation on N<sub>2</sub> dissociation rates to predict NH<sub>3</sub> yields into and across the equilibrium-limited regime. NH<sub>3</sub> yields are predicted to exceed bulk thermodynamic equilibrium limits on materials that are thermal-rate-limited by N<sub>2</sub> dissociation. In all cases, yields revert to bulk equilibrium at temperatures at which thermal reaction rates exceed plasma-activated ones. Beyond-equilibrium NH<sub>3</sub> yields are observed in a packed bed dielectric-barrier-discharge reactor and exhibit sensitivity to catalytic material choice in a way consistent with model predictions. The approach and results highlight the opportunity to exploit synergies between non-thermal plasmas and catalysts to affect transformations at conditions inaccessible through thermal routes.

scholarly journals Plasma-Catalytic Ammonia Synthesis Beyond the Equilibrium Limit

2020 ◽  
Author(s):  
Prateek Mehta ◽  
Patrick M. Barboun ◽  
Yannick Engelmann ◽  
David B. Go ◽  
Annemie Bogaerts ◽  
...  
Keyword(s):  
Elevated Temperatures ◽  
Ammonia Synthesis ◽  
Packed Bed ◽  
Reaction Rates ◽  
Thermal Reaction ◽  
Equilibrium Limit ◽  
Plasma Activation ◽  
Catalytic Material ◽  
Material Choice ◽  
Catalytic Ammonia Synthesis

We explore the consequences of non-thermal plasma activation on product yields in catalytic ammonia synthesis, a reaction that is equilibrium-limited at elevated temperatures. We employ a minimal microkinetic model that incorporates the influence of plasma activation on N<sub>2</sub> dissociation rates to predict NH<sub>3</sub> yields into and across the equilibrium-limited regime. NH<sub>3</sub> yields are predicted to exceed bulk thermodynamic equilibrium limits on materials that are thermal-rate-limited by N<sub>2</sub> dissociation. In all cases, yields revert to bulk equilibrium at temperatures at which thermal reaction rates exceed plasma-activated ones. Beyond-equilibrium NH<sub>3</sub> yields are observed in a packed bed dielectric-barrier-discharge reactor and exhibit sensitivity to catalytic material choice in a way consistent with model predictions. The approach and results highlight the opportunity to exploit synergies between non-thermal plasmas and catalysts to affect transformations at conditions inaccessible through thermal routes.

scholarly journals Does acetone react with HO<sub>2</sub> in the upper-troposphere?

2010 ◽  
Vol 10 (7) ◽  
pp. 16747-16773 ◽  
Author(s):  
T. J. Dillon ◽  
A. Pozzer ◽  
J. N. Crowley ◽  
J. Lelieveld
Keyword(s):  
Acetic Acid ◽  
Rate Coefficient ◽  
Theoretical Calculations ◽  
Thermal Dissociation ◽  
Peroxy Radical ◽  
Significant Loss ◽  
Radical Product ◽  
Upper Troposphere ◽  
Tropopause Region ◽  
First Time

Abstract. Recent theoretical calculations showed that reaction of HO2 with acetone (CH3C(O)CH3) could be a potentially important sink for acetone and source for acetic acid in cold parts of the atmosphere (e.g. the tropopause region). The reaction HO2+CH3C(O)CH3⇌(CH3)2C(OH)OO (R1, R-1) was therefore studied experimentally at low-temperatures for the first time. HO2 was generated by pulsed laser photolysis, and converted by reaction with NO to OH for detection by laser induced fluorescence. Reduced yields of OH at T<220 K provided evidence for stabilisation of (CH3)2C(OH)OO at such temperatures. In contrast, no evidence for (R1) was observed at T>230 K, probably due to rapid thermal dissociation of the peroxy radical product back to reactants (R-1). The experimental data indicate that the rate coefficient for the forward reaction, k1(207 K), is larger than 1.6×10-12 cm3 molecule−1 s−1, in line with recent quantum mechanical calculations. In contrast, an upper limit for the equilibrium constant K1(T)=k1(T)/k-1(T) of 7.8×1028exp(50.6 kJ mol-1/RT) was obtained, considerably smaller than calculated from theory. Incorporation of these results into a global 3-D chemical model demonstrated that (R1) is neither a significant loss process for CH3C(O)CH3 nor a significant source of acetic acid in the atmosphere.

scholarly journals The characterization of NiO-CoO/MgO catalyst for autothermal reforming of methane

2018 ◽  
Vol 4 (2) ◽  
pp. 191
Author(s):  
Tutuk Djoko Kusworo ◽  
A R Songip ◽  
N A. Saidina Amin
Keyword(s):  
Steam Reforming ◽  
Coke Formation ◽  
Autothermal Reforming ◽  
Impregnation Method ◽  
Carbon Formation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Programmed ◽  
Tga Analysis

The characterization of NiO-CoO/MgO catalyst for autothermal reforming of methaneThe drawback of conventional reforming of methane such as partial oxidation and steam reforming was carbon formation. The research was developed a suitable catalyst for combination of partial and steam reforming of methane and called autothermal reforming to reduce the coke formation. The NiO-CoO/MgO catalysts were prepared by an impregnation method and characterized by Temperature Programmed Reduction (TPR), X-ray Diffraction (XRD) and Thermal Gravitymetry Analysis (TGA). The TPR and XRD results reveal that the catalyst characteristic is strongly influenced by the Co/Ni ratio. From TPR and TGA analysis, the sintering phenomena did not occur in the autothermal reforming of methane. The results reveal that Co/Ni ratios have a small effect in the catalytic activity for autothermal reforming. Nevertheless, the catalyst showed an optimum performance in this process when its Co/Ni ratio was 0.75. Keywords: Autothermal ReformingAbstrakMasalah yang terjadi pada proses konvensional reformasi metana seperti oksidasi parsial metana dan reformasi kukus adalah pembentukan karbon. Penelitian yang dilakukan adalah mengembangkan katalis yang sesuai untuk gabungan proses oksidasi parsial dan reformasi kukus atau yang disebut reformasi metana secara autothermal. Katalis NiO-CoO/MgO yang digunakan dibuat dengan metode impregnasi dan dilakukan pengujian dengan TPR, XRD dan TGA untuk mengetahui sifat-sifat dari katalis tersebut. Hasil TPR dan XRD menunjukkan bahwa karakteristik dari katalis sangat dipengaruhi oleh perbandingan CoiN i. Hasil pengamatan TPR dan TGA menunjukan bahwa sintering tidak terjadi di dalam proses reformasi metana secara autothermal. Hasil eksperimen juga menunjukan bahwa perbandingan Co/Ni hanya kecil pengaruhnya pada unjuk kerja katalis. Namun demikian katalis menunjukan unjuk kerja yang optimum pada perbandingan CoiN i = 0.75. Kata Kunci: Reformasi Autothermal

scholarly journals Prevention and control of dimethylamine vapors emission: Herbicide production plant

2008 ◽  
Vol 14 (4) ◽  
pp. 239-243
Author(s):  
Zorana Arsenijevic ◽  
Bosko Grbic ◽  
Zeljko Grbavcic ◽  
Sasa Miletic ◽  
Gordan Savcic ◽  
...  
Keyword(s):  
Air Pollution ◽  
Acetic Acid ◽  
Manufacturing Industry ◽  
Pollution Prevention ◽  
Packed Bed ◽  
Production Plant ◽  
Air Pollution Control ◽  
Vapor Pressures ◽  
Pilot Plant Scale ◽  
Dichlorophenoxy Acetic Acid

The widely used herbicide, dimethylamine salt of 2,4-dichlorophenoxy acetic acid (2,4-D-DMA), is usually prepared by mixing a dimethylamine (DMA) aqueous solution with a solid 2,4-dichlorophenoxy acetic acid (2,4-D). The vapors of the both, reactants and products, are potentially hazardous for the environment. The contribution of DMA vapors in overall pollution from this process is most significant, concerning vapor pressures data of these pollutants. Therefore, the control of the air pollution in the manufacture and handling of methylamines is very important. Within this paper, the optimal air pollution control system in preparation of 2,4-D-DMA was developed for the pesticides manufacturing industry. This study employed the simple pollution prevention concept to reduce the emission of DMA vapors at the source. The investigations were performed on the pilot plant scale. To reduce the emission of DMA vapors, the effluent gases from the herbicide preparation zone were passed through the packed bed scrubber (water scrubbing medium), and the catalytic reactor in sequence. The end result is a substantially improved air quality in the working area, as well as in the urbanized areas located near the chemical plant.

Sign in / Sign up

Export Citation Format

Share Document