Production of hydrogen and medium BTU gas via pyrolysis of a Kraft lignin in a fixed-bed reactor

2000 ◽  
Author(s):  
D. Ferdous ◽  
A. Dalai ◽  
S. Bej ◽  
R. Thring
Keyword(s):  
Fixed Bed ◽  
Kraft Lignin ◽  
Fixed Bed Reactor ◽  
Production Of Hydrogen

SER Process Variable Evaluation for the Production of Hydrogen using Calcined Dolomite

2011 ◽  
Vol 14 (2) ◽  
pp. 121-126
Author(s):  
A. Lopez-Ortiz ◽  
V. Collins-Martinez ◽  
D. P. Harrison
Keyword(s):  
Fixed Bed ◽  
Catalyst Particle ◽  
Process Variable ◽  
Fixed Bed Reactor ◽  
Particle Sizes ◽  
Gas Composition ◽  
Co2 Diffusion ◽  
Production Of Hydrogen ◽  
Kinetic Effects ◽  
Co2 Absorbent

Reaction performance of the sorption enhanced reforming (SER) process for the production of hydrogen was studied using commercial dolomite as inexpensive solid CO2 absorbent. The combined reforming, shift, and CO2 separation reactions were studied using a laboratory-scale fixed-bed reactor as a function of temperature, feed gas composition, dolomite type, and dolomite and catalyst particle sizes. Reactor was loaded with a mixture of calcined dolomite (≈ 23g) and a commercial reforming catalyst (NiO/Al2O3, ≈ 10g). Temperature was varied from 550 to 650°C at 15 atm. Feed gas composition was varied from 6 to 20% CH4/balance N2 and steam, with a feed H2O/CH4 ratio = 4. Two sources of dolomite were used; Rockwell and Stonelite. Particle sizes of dolomite and catalyst were 75>dp>150 μm and 300>dp>425 μm, respectively and were inversely varied. Results show that at 550°C Ca(OH)2 formation is possible, thus reducing the available CaO for carbonation, negatively affecting the performance of the SER system, while 650°C reached the SER thermodynamic equilibrium (TE). The use of dolomite approached the TE of the feed gas compositions studied, disregarding of its source. Kinetic effects observed in the tests suggest that small dolomite and large catalyst particles favor the decrease of CO2 diffusion effects.

scholarly journals Solar-Driven Thermochemical Water-Splitting by Cerium Oxide: Determination of Operational Conditions in a Directly Irradiated Fixed Bed Reactor

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2451 ◽  
Author(s):  
Lucía Arribas ◽  
José González-Aguilar ◽  
Manuel Romero
Keyword(s):  
Water Splitting ◽  
Cerium Oxide ◽  
Radiation Power ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Solar Simulator ◽  
Operational Conditions ◽  
Concentrated Solar Energy ◽  
Production Of Hydrogen ◽  
Temperature Levels

Concentrated solar energy can be transformed into electricity, heat or even solar fuels, such as hydrogen, via thermochemical routes with high exergetic efficiency. In this work, a specific methodology and experimental setup are described, developed to assess the production of hydrogen by water splitting making use of commercial cerium oxide, ceria (CeO2), in a solarized reactor. A fixed bed reactor, directly irradiated by a 7 kWe high flux solar simulator (HFSS) was used. Released H2 and sample temperature levels were continuously monitored. Three tests were carried out consisting of three consecutive redox cycles each, with irradiances in the range of 1017–2034 kWm−2. It was necessary to achieve a compromise between sample temperatures (higher temperatures lead to higher reduction rates) and sample stability, since absorbed radiation can degrade a sample at lower temperature (1280–1480 °C) than in a conventional infrared oven (T > 2000 °C). Irradiating the surface of the sample with an irradiance of 2034 kWm−2 (270 W of total radiation power) during 9.5 min eventually degraded the sample, resulting in a conversion into stoichiometrically reduced oxide (Ce2O3) of 11%. A similar conversion was achieved (9.7%) after 2 min of irradiation at 270 W (100% of radiation), but without irreversibly damaging the sample.

Production of Hydrogen and Syngas via Steam Gasification of Glycerol in a Fixed-Bed Reactor

2008 ◽  
Vol 49 (1-2) ◽  
pp. 59-67 ◽  
Author(s):  
T. Valliyappan ◽  
D. Ferdous ◽  
N. N. Bakhshi ◽  
A. K. Dalai
Keyword(s):  
Fixed Bed ◽  
Steam Gasification ◽  
Fixed Bed Reactor ◽  
Production Of Hydrogen

Steam Gasification of Biochar Derived from Fast Pyrolysis for Hydrogen-Rich Gas Production

2013 ◽  
Vol 830 ◽  
pp. 477-480 ◽  
Author(s):  
Wei Qing Zeng ◽  
Ling Jun Zhu ◽  
Qi Wang
Keyword(s):  
Carbon Number ◽  
Fast Pyrolysis ◽  
Fixed Bed ◽  
Gas Production ◽  
Steam Gasification ◽  
Fixed Bed Reactor ◽  
Hydrogen Yield ◽  
Low Carbon ◽  
Production Of Hydrogen ◽  
Pyrolysis Of Biomass

Steam gasification of biochar from fast pyrolysis of biomass was conducted in a fixed bed reactor. The experiments were carried out at temperature of 700, 750, 800 °C with steam flow rate of 0.1 g/min and reaction time of 3 h. The gas products mainly included H2, CO, CO2and some hydrocarbons with low carbon number. The results showed that the conversion of biochar at 700, 750, 800 °C was 68, 78, 96 wt%, respectively, and high gasification temperature favored the production of hydrogen-rich gases. The hydrogen yield increased with temperature rising and reached the maximum of 35.70 mol/kg with a hydrogen concentration of 74 V% at 800 °C.

Production of Hydrogen from Ethanol Using Pt/Hydrotalcite Catalysts Stabilized with Tungsten Oxides

2012 ◽  
Vol 15 (3) ◽  
pp. 215-223 ◽  
Author(s):  
J.L. Contreras ◽  
M.A. Ortiz ◽  
R. Luna ◽  
G.A. Fuentes ◽  
M. Autié ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Steam Reforming ◽  
Fixed Bed ◽  
Thermal Stabilization ◽  
Fixed Bed Reactor ◽  
Ethanol Steam Reforming ◽  
Vis Spectroscopy ◽  
Production Of Hydrogen ◽  
Stabilization Effect ◽  
Ethanol Steam

An stabilization effect of WOx over the Pt/hydrotalcite catalysts to produce H2 by ethanol steam reforming at low concentration was studied. The catalysts were characterized by N2 physisorption, X-ray diffraction, Infrared (IR), and UV-vis spectroscopy. The catalytic tests were made in a fixed bed reactor. The catalysts showed porous with the shape of parallel layers with a monomodal mesoporous distribution. By IR spectroscopy it was found superficial chemical such as: -OH, H2O, Al-OH, Mg-OH, and CO32-. The reaction products were; H2, CO2, CH3CHO, CH4 and C2H4. These catalysts did not produce CO and showed low selectivity to C2H4. By XRD we found that catalysts having Pt and the lowest W concentration showed the highest crystallinity and the highest stability during the reaction of ethanol steam reforming. A possible thermal stabilization effect of W in the hydrotalcite crystal structure leading to prevent the Pt sintering is proposed. By IR the hydrotalcite hydroxil groups coordinated with Mg and Al decreased by the presence of WOx. We found that catalysts with low W concentration and Pt having high crystallinity showed the highest stability after ethanol steam reforming. It could be a possible thermal stabilization effect of W in the hydrotalcite crystal structure leading to prevent the Pt sintering.

scholarly journals Hydrogen production from cassava processing wastewater in an anaerobic fixed bed reactor with bamboo as a support material

2015 ◽  
Vol 35 (3) ◽  
pp. 578-587 ◽  
Author(s):  
Cristiane L. Andreani ◽  
Douglas G. B. Torres ◽  
Leonardo Schultz ◽  
Karina Q. de Carvalho ◽  
Simone D. Gomes
Keyword(s):  
Hydrogen Production ◽  
Waste Treatment ◽  
Sugar Content ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Organic Load ◽  
Organic Loading Rate ◽  
Total Sugar Content ◽  
Working Volume ◽  
Production Of Hydrogen

Attempting to associate waste treatment to the production of clean and renewable energy, this research sought to evaluate the biological production of hydrogen using wastewater from the cassava starch treatment industry, generated during the processes of extraction and purification of starch. This experiment was carried out in a continuous anaerobic reactor with a working volume of 3L, with bamboo stems as the support medium. The system was operated at a temperature of 36°C, an initial pH of 6.0 and under variations of organic load. The highest rate of hydrogen production, of 1.1 L.d-1.L-1, was obtained with application of an organic loading rate of 35 g.L-1.d-1, in terms of total sugar content and hydraulic retention time of 3h, with a prevalence of butyric and acetic acids as final products of the fermentation process. Low C/N ratios contributed to the excessive growth of the biomass, causing a reduction of up to 35% in hydrogen production, low percentages of H2 and high concentrations of CO2in the biogas.

scholarly journals Production of Hydrogen-Rich Gas by Oxidative Steam Reforming of Dimethoxymethane over CuO-CeO2/γ-Al2O3 Catalyst

Energies ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3684
Author(s):  
Sukhe Badmaev ◽  
Vladimir Sobyanin
Keyword(s):  
Fuel Cell ◽  
Partial Oxidation ◽  
Steam Reforming ◽  
Comparative Studies ◽  
Catalytic Properties ◽  
Fixed Bed ◽  
Space Velocity ◽  
Fixed Bed Reactor ◽  
Production Of Hydrogen ◽  
Al2o3 Catalyst

The catalytic properties of CuO-CeO2 supported on alumina for the oxidative steam reforming (OSR) of dimethoxymethane (DMM) to hydrogen-rich gas in a tubular fixed bed reactor were studied. The CuO-CeO2/γ-Al2O3 catalyst provided complete DMM conversion and hydrogen productivity > 10 L h−1 gcat−1 at 280 °C, GHSV (gas hourly space velocity) = 15,000 h−1 and DMM:O2:H2O:N2 = 10:2.5:40:47.5 vol.%. Comparative studies showed that DMM OSR exceeded DMM steam reforming (SR) and DMM partial oxidation (PO) in terms of hydrogen productivity. Thus, the outcomes of lab-scale catalytic experiments show high promise of DMM oxidative steam reforming to produce hydrogen-rich gas for fuel cell feeding.

scholarly journals Produção de hidrogênio a partir da manipueira em reator anaeróbio de leito fixo

2016 ◽  
Vol 2 (3) ◽  
pp. 54-63
Author(s):  
Andressa Nóe Nunes ◽  
Antonio Pedro de Oliveira Netto
Keyword(s):  
Loading Rate ◽  
Maximum Yield ◽  
Fixed Bed ◽  
Caproic Acid ◽  
Progressive Increase ◽  
Fixed Bed Reactor ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
Heat Treated ◽  
Production Of Hydrogen

The use of agro-industrial waste for the production of hydrogen has shown a very promising trend, because its improper disposal creates environmental problems. Thus, the objective of the research was to evaluate the production of hydrogen from cassava processing residue in anaerobic fixed bed reactor operated under progressively increasing organic loading rate (OLR) of 12 kg.m-3.d-1 a 96 kg.m-3.d-1. The support material for the adhesion of biomass was expanded clay with a diameter between 2.80 - 3.35 mm, and the reactor was inoculated with anaerobic sludge pre heat-treated. The reactor was operated for 250 days and the progressive increase of ORL was carried out keeping the COD affluent around 4000 mg. L-1, throughout the operation of the reactor and varying the hydraulic retention time (HRT) of 8 hours to 1 hour. The maximum yield of hydrogen was obtained in HRT of 2h (1.66 mol H2 / mol glucose). The soluble metabolites present during operation of the reactor were acetic acid (30.72% to 84.9%), butyric acid (2.89% to 29.13%), propionic acid (3.98 to 13.09%), caproic acid (0.55% and 22.79%) and ethanol (3.64% to 10.46%). Methane production was observed along with hydrogen in all operating phases.

Steam Gasification of Catalytic Pyrolysis Char for Hydrogen-Rich Gas Production

2013 ◽  
Vol 316-317 ◽  
pp. 105-108
Author(s):  
Wu Xing Sun ◽  
Yan Zhou ◽  
Qi Wang ◽  
Shu Rong Wang
Keyword(s):  
Atmospheric Pressure ◽  
Catalytic Pyrolysis ◽  
Fixed Bed ◽  
Gas Production ◽  
Steam Gasification ◽  
Fixed Bed Reactor ◽  
Bed Temperature ◽  
Production Of Hydrogen ◽  
Pyrolysis Of Biomass ◽  
Gasification Temperature

Steam gasification of biochar from catalytic pyrolysis of biomass was studied in a fixed bed reactor at atmospheric pressure. The experiments were carried out at bed temperature of 700, 750, 800 °C at steam flow rate of 0.1 g/min with reaction time of 3h. The gases produced included mainly H2, CO, CO2 and some small molecular hydrocarbons. The results showed that high gasification temperature was favorable for the production of hydrogen-rich gases. The maximum concentration of hydrogen exceeded 85% at 800 °C and the total gas yield increased with temperature rising. Meanwhile, the conversion efficiency of biochar at 700, 750, 800 °C was 48%, 60%, 72% respectively.

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