Thermodynamic Analysis of Glycerol Steam Reforming to Ethylene

2014 ◽  
Vol 67 (3) ◽  
Author(s):  
Zaki Yamani Zakaria ◽  
Juha Linekoski ◽  
Nor Aishah Saidina Amin
Keyword(s):  
Steam Reforming ◽  
Energy Minimization ◽  
Operating Temperature ◽  
Product Distribution ◽  
Equilibrium Analysis ◽  
Minimization Method ◽  
Glycerol Water ◽  
Process Operation ◽  
Gibbs Free Energy Minimization ◽  
Water Ratio

Thermodynamic equilibrium analysis of glycerol steam reforming to ethylene has been investigated based on the total Gibbs free energy minimization method. Equilibrium product compositions for glycerol steam reforming were determined for temperatures ranging from 573–1273 K and GWR (glycerol/water ratio) 1:12 to 2:1 at 1 bar pressure. The objectives of this study are to identify the thermodynamic range of the process operation and study the variation of product distribution. It was found that the formation of ethylene was difficult to accomplish and the amount of ethylene produced is very small. The formation of coke, which will poison the catalyst, could be suppressed at higher operating temperature. The thermoneutral temperature of the process was found to increase with GWR. Other means to encourage the formation of more ethylene is required.  

scholarly journals Energy Analysis in Combined Reforming of Propane

2013 ◽  
Vol 2013 ◽  
pp. 1-10
Author(s):  
K. Moon ◽  
Ganesh R. Kale
Keyword(s):  
Steam Reforming ◽  
Energy Requirement ◽  
Minimum Energy ◽  
Dry Reforming ◽  
Optimum Process ◽  
Methane Formation ◽  
Equilibrium Data ◽  
Process Operation ◽  
Gibbs Free Energy Minimization ◽  
Pure Steam

Combined (steam and CO2) reforming is one of the methods to produce syngas for different applications. An energy requirement analysis of steam reforming to dry reforming with intermediate steps of steam reduction and equivalent CO2addition to the feed fuel for syngas generation has been done to identify condition for optimum process operation. Thermodynamic equilibrium data for combined reforming was generated for temperature range of 400–1000°C at 1 bar pressure and combined oxidant (CO2+ H2O) stream to propane (fuel) ratio of 3, 6, and 9 by employing the Gibbs free energy minimization algorithm of HSC Chemistry software 5.1. Total energy requirement including preheating and reaction enthalpy calculations were done using the equilibrium product composition. Carbon and methane formation was significantly reduced in combined reforming than pure dry reforming, while the energy requirements were lower than pure steam reforming. Temperatures of minimum energy requirement were found in the data analysis of combined reforming which were optimum for the process.

Thermodynamic Investigation of Acetic Acid Steam Reforming for Hydrogen Production

2012 ◽  
Vol 550-553 ◽  
pp. 2801-2804
Author(s):  
Peng Fu ◽  
Sen Meng An ◽  
Wei Ming Yi ◽  
Xue Yuan Bai
Keyword(s):  
Carbon Monoxide ◽  
Acetic Acid ◽  
Hydrogen Production ◽  
Steam Reforming ◽  
Operating Conditions ◽  
Negative Effects ◽  
Minimization Method ◽  
Gibbs Free Energy Minimization ◽  
Methane Selectivity ◽  
Increasing Temperature

The thermodynamics of acetic acid steam reforming (AASR) for hydrogen production were simulated using a Gibbs free energy minimization method to study the influences of pressure, temperature and water to acetic acid molar feed ratios (WAFR) on the AASR. On the basis of the equilibrium calculations, the optimal operating conditions obtained were 700-800 oC, 1bar and WAFR = 6-10. At these conditions, the yield and selectivity of hydrogen were maximized and the formation of methane and coke was almost inhibited. Higher pressures had negative effects on the yields and selectivities of hydrogen and carbon monoxide. With increasing temperature from 300 to 1000 oC, the selectivity for hydrogen and carbon monoxide increased significantly along with a reduction in methane selectivity. Increase in the WAFR led to the increase in hydrogen selectivity and the decrease in carbon monoxide selectivity.

Plasma-Augmented Fluidized Bed Gasification of Sub-bituminous Coal in CO2–O2 Atmospheres

2016 ◽  
Vol 35 (1) ◽  
pp. 89-101
Author(s):  
C. Lelievre ◽  
C. A. Pickles ◽  
S. Hultgren
Keyword(s):  
Fluidized Bed ◽  
Energy Minimization ◽  
Bituminous Coal ◽  
Minimization Method ◽  
Gasification Process ◽  
Coal Gasifier ◽  
Bed Temperature ◽  
Gibbs Free Energy Minimization ◽  
Fluidized Bed Gasifier ◽  
Hsc Chemistry

AbstractThe gasification of a sub-bituminous coal using CO2–O2 gas mixtures was studied in a plasma-augmented fluidized bed gasifier. Firstly, the coal was chemically characterized and the gasification process was examined using Thermogravimetric and Differential Thermal Analysis (TGA/DTA) in CO2, O2 and at a CO2 to O2 ratio of 3 to 1. Secondly, the equilibrium gas compositions were obtained using the Gibbs free energy minimization method (HSC Chemistry®7). Thirdly, gasification tests were performed in a plasma-augmented fluidized bed and the off-gas temperatures and compositions were determined. Finally, for comparison purposes, control tests were conducted using a conventional fluidized bed coal gasifier and these results were compared to those achieved in the plasma-augmented fluidized bed gasifier. The effects of bed temperature and CO2 to O2 ratio were studied. For both gasifiers, at a given bed temperature, the off-gas compositions were in general agreement with the equilibrium values. Also, for both gasifiers, an experimental CO2 to O2 ratio of about 3 to 1 resulted in the highest syngas grade (%CO + %H2). Both higher off-gas temperatures and syngas grades could be achieved in the plasma-augmented gasifier, in comparison to the conventional gasifier. These differences were attributed to the higher bed temperatures in the plasma-augmented fluidized bed gasifier.

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