Carbon dioxide membrane reactor

First of all, the space time defined in Eq. (11-5) or (11-6) depends on the volume of the reactor and the total volumetric feed rate. Thus, for a given reactor volume, space time is inversely proportional to the total feed rate. Itoh et al. [1993] studied the use of a dense yttria-stabilized zirconia membrane reactor for thermal decomposition of carbon dioxide. The reactor temperature was not kept constant everywhere in the reactor but varying with the reactor length instead. The resulting temperature profile is parabolic with the maximum temperature at the midpoint of the reactor length. This nonisothermal... 

Rui, Z., Ji, H., and Lin, Y.S. (2011) Modeling and analysis of ceramic-carbonate dualphase membrane reactor for carbon dioxide reforming with methane. Int J. Hydrogen... 

Damle, A.S., Separation of Hydrogen and Carbon Dioxide in Advanced Fossil Energy Conversion Processes using a Membrane Reactor, 2002 Pittsburgh Coal Conference, Pittsburgh, PA, September 2002. 

Pex, P.P.A.C. and Y.C. van Delft, Silica membranes for hydrogen fuel production by membrane water gas shift reaction and development of a mathematical model for a membrane reactor, in Carbon Dioxide Capture for Storage in Deep Geologic Formations—Results from the C02 Capture Project Capture and Separation of Carbon Dioxide from Combustion Sources, eds., D. Thomas, and B. Sally, Vol. 1, Chapter 17, 2005. 

After preformation, the substrates and carbon dioxide were supplied continuously. The membrane reactor was pressurized at the feed side up to 20 MPa with the reaction mixture. A trans-membrane pressure was created by opening a needle valve on the permeate side after which the continuous process started. 

The present study investigates a different approach. The membrane is used to allow the desired intermediate product to escape from the reaction zone before it is consumed by further reaction. This use of a membrane reactor was first suggested by Michaels [15]. The partial oxidation of methane, which is a challenging reaction of the type propos for this application of membrane reactors, has been analyzed herein. There is no thermodynamic limitation for the production of carbon dioxide and water, actually these products are favored. It is desired to remove any partial oxidation product, for example formaldehyde, before it has a chance to be further oxidized. 

There are maty other examples of cofactor regeneration reactions and/or of reactions which may be performed in an enzyme membrane reactor. An important example is the regeneration of NADH by formate dehydrogenase (FDH), starting with formate (Wichmaim et al, 1981). The advantage of this reaction is that it is irreversible because carbon dioxide is hberated, while formate is a relatively cheap electron donor. 

Lozano, P., G. Villora, D. Gomez, A.B. Gayo, J.A. Sanchez-Conesa, M. Rubio and J.L. Iborra, Membrane Reactor with Immobilized Candida Antarctica Lipase B for Ester Synthesis in Supercritical Carbon Dioxide, Journal of Supercritical Fluids, 29, 121-128 (2004). 

The book explores various examples of these important materials, including perovskites, zeolites, mesoporous molecular sieves, silica, alumina, active carbons, carbon nanotubes, titanium dioxide, magnesium oxide, clays, pillared clays, hydrotalcites, alkali metal titanates, titanium silicates, polymers, and coordination polymers. It shows how the materials are used in adsorption, ion conduction, ion exchange, gas separation, membrane reactors, catalysts, catalysts supports, sensors, pollution abatement, detergency, animal nourishment, agriculture, and sustainable energy applications. 

Some dense inorganic membranes made of metals and metal oxides are oxygen specific. Notable ones include silver, zirconia stabilized by yttria or calcia, lead oxide, perovskite-type oxides and some mixed oxides such as yttria stabilized titania-zirconia. Their usage as a membrane reactor is profiled in Table 8.4 for a number of reactions decomposition of carbon dioxide to form carbon monoxide and oxygen, oxidation of ammonia to nitrogen and nitrous oxide, oxidation of methane to syngas and oxidative coupling of methane to form C2 hydrocarbons, and oxidation of other hydrocarbons such as ethylene, methanol, ethanol, propylene and butene. 

Similar to the case of dehydrogenation or other hydrogen-generating reactions, the use of a dense membrane reactor to remove oxygen from an oxygen-generating reaction such as decomposition of carbon dioxide displaces the reaction equilibrium and increases the conversion from 1.2% (limited by the equilibrium) to 22% [Nigara and Cales, 1986]. This has been confumed by Itoh et al. [1993]. 

Figure 9.3 Conversion of thermal decomposition of carbon dioxide in a dense yttria-stabilized zirconia membrane reactor as a function of membrane thickness when a sweep gas is used (top) and when vacuum is applied (bottom) [Itoh et al., 1993]...

Goetheer ELV, Verkerk AW, van den Broeke UP, de Wolf E, Deelman B-J, van Koten G, and Keurentjes JTF. Membrane reactor for homogeneous catalysis in supercritical carbon dioxide. J. Catal. 2003 219 126-133. 

Lozano P, Villora G, Gomez D, Gayo AB, Sanchez-Conesa JA, Rubio M, and Iborra JL. Membrane reactor with immobilized Candida antarctica lipase B for ester synthesis in supercritical carbon dioxide. J. Supercrit. Fluids 2004 29(1-2) 121-128. 

The Kolbe electrolysis of acetate to ethane and carbon dioxide was modeled for a parallel-plate reactor. Three zones were considered in the model a turbulent bulk region, and a thin diffusion layer at each electrode [184b]. The same authors describe the electrolysis of gaseous acetic acid in a polymer electrolyte membrane (PEM) reactor. Platinized... 

Reduction of carbon dioxide to graphite carbon via methane by catalytic fixation with membrane reactor... 

Through membrane reactor model calculations it has been shown that membranes can enhance the conversion of a WGS membrane reactor and concurrently separate hydrogen from carbon dioxide. This system can be used to control the release of CO2 to the atmosphere from a IGCC power plant. Through process... 

It has been shovm that membranes can enhance the conversion of a water-gas shift membrane reactor and concurrently separate hydrogen from carbon dioxide. The efficiency of CO2 control using the membrane reactor with a H2/CO2 selectivity of 15 is significantly higher compared to a conventioncd technique (i.e. wet washing with a sorbent). It is not necessary to exceed a selectivity of approximately 40 for H2/CO2 for the process under consideration, because further increase in reactor performance seems marginal. Enlargement of the permeation is an important aspect on the other hand, so that the total surface area necessary for the full-scale application can be reduced. 

Hernandez FJ, de los Rios AP, Gomez D, Rubio M, ViUora G. A new recirculating enzymatic membrane reactor for ester synthesis in ionic liquid/supercritical carbon dioxide biphasic systems. Appl Catal B 2006 67 121-126. 

Fig. 8.1 Experimental set-up of the recirculating enzymatic membrane reactor used for the synthesis of butyl propionate from vinyl propionate and 1-butanol catalysed by Candida antarctica lipase B in supercritical carbon dioxide and supercritical carbon dioxide/ionic liquid biphasic system [17]...

Hemdndez FJ, de los Rfos AP, Gomez D et al (2007) Understanding the chemical reaction and mass-transfer phenomena in a recirculating enzymatic membrane reactor for green ester synthesis in ionic Uquid/supercritical carbon dioxide biphasic systems. J Supercrit Flitids 43 303-309... 

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