Modeling of sorption enhanced steam methane reforming in an adiabatic fixed bed reactor

Abstract

Sorption enhanced methane reforming (SER), employing a CaO-based solid as a high temperature CO 2 sorbent, is generally considered to be a promising route for H 2 production. In this paper we present a dynamic pseudo-homogeneous model to describe the operation of a packed bed reactor in which the SER reaction is carried out under adiabatic conditions. This reactor can be implemented according to several process schemes, including a novel Ca/Cu looping process for hydrogen generation with inherent CO 2 capture. The proposed SER model is based on the well-established principles of gas-solid contact and heat transfer in fixed-bed reactors and on the kinetic expressions published in the literature that describe the main reactions involved in the process. The resulting model describes the transient performance of the SER reaction and confirms the theoretical viability of this critical reaction stage in a large scale H 2 production facility. It is demonstrated that the SER process can yield a CH 4 conversion 2 and H 2 purity of up to 85% and 95%, respectively, under operating conditions of 923 K, 3.5 MPa, a steam/carbon ratio of 5 and a space velocity of 3.5 kg/m 2 s.

Modelling of H2 production in a packed bed reactor via sorption enhanced steam methane reforming process

“…In this paper, one dimensional heterogeneous mathematical model of SE-SMR process is developed and implemented in gPROMS model builder 4.1.0 ® . The predictions of reactor model are validated against the modelling data published by Fernández et al [13]. The model predictions are also compared with the equilibrium data generated on an independent equilibrium based software (Chemical equilibrium and application software).…”

“…Then this reaction proceeds towards Ca(OH)2 carbonation reaction (R2). Fernández et al [13] developed a mathematical model of SE-SMR process in a fixed bed reactor using Ca/Cu looping process and CaO as the sorbent and studied the effect of operating variables, such as catalyst to sorbent ratio, space velocity, S/C, pressure and temperature, on the composition of product gases. They used the experimental work of Lee et al [14] for their model validation.…”

Chemical looping combustion process in fixed-bed reactors using ilmenite as oxygen carrier: Conceptual design and operation strategy

“…Moreover, an ideal plug flow pattern and negligible axial gas dispersion are assumed to approximately represent the cyclic operation of the CLC system. These assumptions, that are typical of many fixed-bed catalytic systems [53][54][55], have also been adopted in recent works to describe the performance of dynamically operated fixed-bed systems in CLC [26,27,36,56] and sorption enhanced reforming applications [35,[56][57][58]. Heat exchange fronts are also formed when the process is not thermally neutral and/or when the temperatures of the gases and solids in contact are different.…”

Modeling the process of producing hydrogen from methane

“…The steam reforming process is considered for the ratio H 2 O : CH 4 = 2 : 1, in contrast to [3,4], where the given pro cess is considered at a ratio H 2 O : CH 4 = 1 : 1.…”

“…Carbon monoxide that is formed by reaction (1) At the boundary condition Steam is spent at a rate in reaction (1) with CH 4 , and H 2 O is spent at a rate in reaction (2) with CO. Steam is formed by reaction (3) from CO 2 and H 2 at a rate Let us derive the mass balance equations for reac tions (2) and (3), which take place in the second reac tor on an iron/chromium catalyst.…”