Ethylene production via ethanol dehydration over desilicated ZSM-5 catalyst

2021 ◽  
Vol 10 (4) ◽  
pp. 75-79
Author(s):  
Loc Bui Tan ◽  
Tu Le Nguyen Quang ◽  
Long Nguyen Quang
Keyword(s):  
Ethylene Production ◽  
Fossil Fuels ◽  
Opposite Effect ◽  
External Surface ◽  
Space Velocity ◽  
Ethanol Conversion ◽  
Ethanol Dehydration ◽  
Modified Zeolite ◽  
Potential Alternative ◽  
Lower Temperature

The catalytic dehydration of ethanol is a potential alternative route to synthesize ethylene apart from the traditional method which depends on fossil fuels. This report successfully prepared modified ZSM-5 with mesopores using desilication methods to enhance ethanol catalytic dehydration performance and ethylene production at lower temperature. The modified zeolite have the external surface area increased by 3.5 times and a higher dehydration efficiency compared with the original sample especially at temperatures below 220°C. Increasing reaction temperatures and gas houly space velocity (GHSV) increased the dehydration efficiency while increasing the inlet ethanol concentration had opposite effect. Significantly, the ethanol conversion over modified zeolite remained above 90 % when the GHSV increased to 36000 h‑1 after the time-on-stream of 24 h.

scholarly journals Conversion of biomass to biofuels and life cycle assessment: a review

2021 ◽  
Author(s):  
Ahmed I. Osman ◽  
Neha Mehta ◽  
Ahmed M. Elgarahy ◽  
Amer Al-Hinai ◽  
Ala’a H. Al-Muhtaseb ◽  
...  
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Energy Demand ◽  
Fossil Fuels ◽  
Biomass Conversion ◽  
Biofuel Production ◽  
Process Efficiency ◽  
Liquid Fuels ◽  
Thermochemical Processes ◽  
Lower Temperature

AbstractThe global energy demand is projected to rise by almost 28% by 2040 compared to current levels. Biomass is a promising energy source for producing either solid or liquid fuels. Biofuels are alternatives to fossil fuels to reduce anthropogenic greenhouse gas emissions. Nonetheless, policy decisions for biofuels should be based on evidence that biofuels are produced in a sustainable manner. To this end, life cycle assessment (LCA) provides information on environmental impacts associated with biofuel production chains. Here, we review advances in biomass conversion to biofuels and their environmental impact by life cycle assessment. Processes are gasification, combustion, pyrolysis, enzymatic hydrolysis routes and fermentation. Thermochemical processes are classified into low temperature, below 300 °C, and high temperature, higher than 300 °C, i.e. gasification, combustion and pyrolysis. Pyrolysis is promising because it operates at a relatively lower temperature of up to 500 °C, compared to gasification, which operates at 800–1300 °C. We focus on 1) the drawbacks and advantages of the thermochemical and biochemical conversion routes of biomass into various fuels and the possibility of integrating these routes for better process efficiency; 2) methodological approaches and key findings from 40 LCA studies on biomass to biofuel conversion pathways published from 2019 to 2021; and 3) bibliometric trends and knowledge gaps in biomass conversion into biofuels using thermochemical and biochemical routes. The integration of hydrothermal and biochemical routes is promising for the circular economy.

Adsorptive removal of trace oxytetracycline from water by acid-modified zeolite: influencing factors

2013 ◽  
Vol 68 (11) ◽  
pp. 2473-2478 ◽  
Author(s):  
Wenhao An ◽  
Hua Xiao ◽  
Man Yu ◽  
Xiaoyang Chen ◽  
Yuxin Xu ◽  
...  
Keyword(s):  
Humic Acid ◽  
Removal Efficiency ◽  
Natural Zeolite ◽  
Opposite Effect ◽  
Swine Wastewater ◽  
Adsorption Efficiency ◽  
Tetracycline Antibiotics ◽  
Modified Zeolite ◽  
Alkaline Conditions ◽  
Acidic Conditions

Because of the wide use of antibiotics in the livestock industry, trace tetracycline antibiotics are frequently detected in swine wastewater and water bodies near pig farms. Based on natural zeolite, modified zeolite was synthesized by treatment with nitric acid. As one kind of typical tetracyclines, oxytetracycline (OTC) was chosen as the target adsorbate. Removal of trace OTC by modified zeolite and the effects of several main water matrices on OTC adsorption were studied in detail. OTC removal efficiency by acid-modified zeolite was about 90%, compared to less than 20% by natural zeolite. In general, in acidic conditions the removal efficiency of OTC by modified zeolite was about 90%, which was much higher than 20–35% in alkaline conditions. An increase in ionic strength from 0.01 to 1.0 M led to a decrease in adsorption efficiency from 90 to 27%. The presence of 10.0 mg L−1 dissolved humic acid accelerated sorption of OTC on modified zeolite, while 100.0 mg L−1 humic acid resulted in the opposite effect. An increase in temperature contributed to enhancing the adsorption efficiency.

Ethylene production via catalytic ethanol dehydration by 12-tungstophosphoric acid@ceria-zirconia

Fuel ◽  
2019 ◽  
Vol 239 ◽  
pp. 491-501 ◽  
Author(s):  
Maria Clara H. Clemente ◽  
Gesley Alex V. Martins ◽  
Elon F. de Freitas ◽  
José A. Dias ◽  
Sílvia C.L. Dias
Keyword(s):  
Ethylene Production ◽  
Tungstophosphoric Acid ◽  
Ethanol Dehydration

scholarly journals Tolerance of Cherimoya (Annona cherimola Mill.) to Cold Storage

1994 ◽  
Vol 119 (3) ◽  
pp. 524-528 ◽  
Author(s):  
Rafael Alique ◽  
José P. Zamorano ◽  
Ma Luisa Calvo ◽  
Carmen Merodio ◽  
José L. De la Plaza
Keyword(s):  
Cold Storage ◽  
Ethylene Production ◽  
Soluble Sugar ◽  
Chilling Injury ◽  
Ethylene Synthesis ◽  
Ripe Fruit ◽  
Acid Accumulation ◽  
Ripe Stage ◽  
Lower Temperature ◽  
Stimulation Of

`Fino de Jete' cherimoya fruit were stored at 20, 10, 8, or 6C, 80% relative humidity. Two rises of CO2 production and an ethylene rise following the first peak of respiration were obtained in fruit held at 20C. The ripe stage coincided with the onset of the second respiratory rise. Soluble sugar and organic acid concentration were maximal, and flesh firmness was 18 N in ripe fruit. Lower temperature reduced respiration rate and ethylene production; however, some stimulation of ethylene synthesis was observed at 10C. Cherimoyas ripened to edible condition during 6 days at 10C, but fruit maintained at 8C for up to 12 days required transfer to 20C to ripen properly. Our results suggest that high increases in CO2 are not sufficient to complete cherimoya fruit ripening without the concurrent rise in ethylene production. Citric acid accumulation, inhibition of ethylene synthesis, and reduced accumulation of sucrose were observed during storage at 6C. Removal to 20C after 12 days at 6C resulted in no ripening, almost complete inhibition of ethylene synthesis, and severe skin browning. Thus, 8C is the lowest tolerable temperature for prolonged cold storage of cherimoya `Fino de Jete'. Fruit can be held at 8C for up to 12 days without damage from chilling injury.

scholarly journals Ethanol Dehydration over WO3/TiO2Catalysts Using Titania Derived from Sol-Gel and Solvothermal Methods

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Anchale Tresatayawed ◽  
Peangpit Glinrun ◽  
Bunjerd Jongsomjit
Keyword(s):  
Physicochemical Properties ◽  
Pore Volume ◽  
Catalytic Properties ◽  
Sol Gel ◽  
Acid Sites ◽  
Ethanol Conversion ◽  
Ethanol Dehydration ◽  
Preparation Methods ◽  
Solvothermal Methods ◽  
Different Characteristics

The present study aims to investigate the catalytic ethanol dehydration to higher value products including ethylene, diethyl ether (DEE), and acetaldehyde. The catalysts used for this reaction were WO3/TiO2catalysts having W loading of 13.5 wt.%. For a comparative study, the TiO2supports employed were varied by two different preparation methods including the sol-gel and solvothermal-derived TiO2supports, denoted as TiO2-SG and TiO2-SV, respectively. It is obvious that the different preparation methods essentially altered the physicochemical properties of TiO2supports. It was found that the TiO2-SV exhibited higher surface area and pore volume and larger amounts of acid sites than those of TiO2-SG. As a consequence, different characteristics of support apparently affected the catalytic properties of WO3/TiO2catalysts. As expected, both catalysts WO3/TiO2-SG and WO3/TiO2-SV exhibited increased ethanol conversion with increasing temperatures from 200 to 400°C. It appeared that the highest ethanol conversion (ca. 88%) at 400°C was achieved by the WO3/TiO2-SV catalysts due to its high acidity. It is worth noting that the presence of WO3onto TiO2-SV yielded a remarkable increase in DEE selectivity (ca. 68%) at 250°C. In summary, WO3/TiO2-SV catalyst is promising to convert ethanol into ethylene and DEE, having the highest ethylene yield of ca. 77% at 400°C and highest DEE yield of ca. 26% at 250°C. These can be attributed to proper pore structure, acidity, and distribution of WO3.

scholarly journals Exploring Simplified Methods for Insect Chitin Extraction and Application as a Potential Alternative Bioethanol Resource

Insects ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 788 ◽  
Author(s):  
Mahmoud Kamal ◽  
Eslam Adly ◽  
Sulaiman Ali Alharbi ◽  
Amany Soliman Khaled ◽  
Magda Hassan Rady ◽  
...  
Keyword(s):  
Submerged Fermentation ◽  
Fossil Fuels ◽  
Periplaneta Americana ◽  
Mucor Circinelloides ◽  
American Cockroach ◽  
Bioethanol Production ◽  
Chitin Extraction ◽  
Potential Alternative ◽  
Immense Potential ◽  
Insect Biomass

Chitin, the second most plentiful biopolymer in nature, is a major component of insect cuticle. In searching for alternative resources for fossil fuels, some fungal strains of Mucor circinelloides from an insect-source were found to produce bioethanol directly using insect chitin as a substrate. Herein, simplified methods for insect chitin extraction and application as a substrate in submerged fermentation for bioethanol production were explored. Chitin of the American cockroach (Periplaneta americana (L.)) was isolated by refluxing the cockroaches dried exoskeletons with 4% NaOH. The purity of the extracted chitin was assessed to be high when the physicochemical properties of the extracted chitin matched these of commercially available crab and shrimp samples. The extracted chitin was employed as a substrate in submerged fermentation using two strains of M. circinelloides. One of these, strains M. circinelloides 6017 showed immense potential for bioethanol production directly. It could to bio-transform 15 g/L of colloidal chitin directly to 11.22 ± 0.312 g/L of bioethanol (74% of the initial chitin mass) after 6 days of incubation. These results confirm the possibility of using insect biomass as a potential alternative resource for bioethanol production in a simple manner thus contributing to the creation of an alternate energy source.

scholarly journals First-Principles-Based Simulation of an Industrial Ethanol Dehydration Reactor

Catalysts ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 921
Author(s):  
Van der Borght ◽  
Alexopoulos ◽  
Toch ◽  
Thybaut ◽  
Marin ◽  
...  
Keyword(s):  
Temperature Drop ◽  
Multiscale Model ◽  
Ethanol Conversion ◽  
Ethanol Dehydration ◽  
Reactor Model ◽  
Design And Optimization ◽  
Industrial Reactor ◽  
Intrinsic Kinetics ◽  
Kinetics Of ◽  
High Ethanol

The achievement of new economically viable chemical processes often involves the translation of observed lab-scale phenomena into performance in an industrial reactor. In this work, the in silico design and optimization of an industrial ethanol dehydration reactor were performed, employing a multiscale model ranging from nano-, over micro-, to macroscale. The intrinsic kinetics of the elementary steps was quantified through ab initio obtained rate and equilibrium coefficients. Heat and mass transfer limitations for the industrial design case were assessed via literature correlations. The industrial reactor model developed indicated that it is not beneficial to utilize feeds with high ethanol content, as they result in lower ethanol conversion and ethene yield. Furthermore, a more pronounced temperature drop over the reactor was simulated. It is preferred to use a more H2O-diluted feed for the operation of an industrial ethanol dehydration reactor.

Hydrogen Production by Bio-Fuel Steam Reforming at Low Reaction Temperature

2011 ◽  
Author(s):  
Tsuyoshi Maeda ◽  
Toshio Shinoki ◽  
Jiro Funaki ◽  
Katsuya Hirata
Keyword(s):  
Reaction Temperature ◽  
Steam Reforming ◽  
High Performance ◽  
Space Velocity ◽  
Ethanol Conversion ◽  
Ethanol Steam Reforming ◽  
High Hydrogen ◽  
Low Reaction Temperature ◽  
Al2o3 Catalyst ◽  
Ethanol Steam

The authors reveal the dominant chemical reactions and the optimum conditions, supposing the design of ethanol steam-reforming reactors. Specifically speaking, experiments are conducted for Cu/ZnO/Al2O3 catalyst, together with those for Ru/Al2O3 catalyst for reference. Using a household-use-scale reactor with well-controlled temperature distributions, the authors compare experimental results with chemical-equilibrium theories. It has revealed by Shinoki et al. (2011) that the Cu/ZnO/Al2O3 catalyst shows rather high performance with high hydrogen concentration CH2 at low values of reaction temperature TR. Because, the Cu/ZnO/Al2O3 catalyst promotes the ethanol-steam-reforming and water-gas-shift reactions, but does not promote the methanation reaction. So, in the present study, the authors reveal that the Ru/Al2O3 catalyst needs high TR > 770 K for better performance than the Cu/ZnO/Al2O3 catalyst, and that the Ru/Al2O3 catalyst shows lower performance at TR < 770 K. Then, the Ru/Al2O3 catalyst is considered to activate all the three reactions even at low TR. Furthermore, concerning the Cu/ZnO/Al2O3 catalyst, the authors reveal the influences of liquid-hourly space velocity LHSV upon concentrations such as CH2, CCO2, CCO and CCH4 and the influence of LHSV upon the ethanol conversion XC2H5OH, in a range of LHSV from 0.05 h−1 to 0.8 h−1, at S/C = 3.0 and TR = 520 K. And, the authors reveal the influences of the thermal profile upon CH2, CCO2, CCO, CCH4 and XC2H5OH, for several LHSV’s. To conclude, with well-controlled temperatures, the reformed gas can be close to the theory. In addition, the authors investigate the influences of S/C.

Sign in / Sign up

Export Citation Format

Share Document