Pressure swing adsorption for coproduction of power and ultrapure H2 in an IGCC plant with CO2 capture

Abstract

The coproduction of power and ultrapure H2 within an integrated gasification combined cycle (IGCC) plant implementing CO2 capture offers advantages in terms of flexible operation while retaining good efficiency. The common design includes an absorption unit for removing CO2 from a high pressure syngas followed by a pressure swing adsorption (PSA) unit for purifying a part of the resulting H2-rich gas stream. A drawback of this design consists in the necessity for compression of the PSA tail gas in order to recover the energy available in the residual H2 content. This paper presents two novel configurations for power and H2 coproduction with CO2 capture, entirely based on PSA technology. The first relies on two PSA trains in series (Two-train PSA), while the other is able to carry out CO2 separation and H2 purification within a single PSA train (One-train PSA). The two systems were defined and simulated through a composite model of the whole plant. The process simulation results showed that both the configurations proposed are able to shift between the two energy products without compromising the performance of the plant. The load of the plant could be decreased by increasing the ultrapure H2 throughput, while maintaining a constant feed of coal to the gasifier. The Two-train PSA configuration achieved higher performance in terms of energy efficiency and H2 purity. The One-train PSA configuration returned slightly lower but still good performance, while its design includes a single separation stage instead of two. Additionally, both configurations enable the avoidance of PSA tail gas compression giving an advantage against the absorption-based design. A comparative analysis with results taken from the literature seems to confirm this assertion.

Adsorption for efficient low carbon hydrogen production: part 1—adsorption equilibrium and breakthrough studies for H2/CO2/CH4 on zeolite 13X

“…Extended isotherms are convenient to use in process modeling and optimization, as they provide an explicit equation for multi-component adsorption based on single component isotherm data only. For the Sips isotherm, the extended isotherm for N components is given as [32] Another well known approach for describing multi-component-adsorption is the adsorbed solution theory introduced by Mofarahi and Bakhtyari [25], which treats adsorption equilibria as phase equilibria between adsorbed phase as solution in equilibrium with the gas phase:…”

“…In addition, we assume that the interaction energy between CO 2 and CH 4 is the mean of the interaction between the individual species, as suggested in the literature [32]:…”

“…A variety of options like cryogenic separation, absorption, membranes or adsorption, are discussed and even tested at pilot scale for coupling fossil-or biofuel based hydrogen production with CCS, but they typically require the addition of a dedicated CO 2 separation stage [11,17,18,47]. CO 2 can be captured from the reformer flue gas; after reformer and water-gas shift reactor, but before entering the H 2 purification through pressure swing adsorption (PSA) [32]; or from the H 2 -PSA tail-gas. As an alternative, we target the integration of H 2 purification and carbon capture into a single, adsorption based unit thus reducing the number of required separation stages from two (H 2 -PSA and CO 2 capture) to one, thereby likely also reducing capital cost and process complexity.…”

Screening Deep Eutectic Solvents for CO2 Capture With COSMO-RS

“…There are several technologies for CO 2 capture, for example, physical, or chemical solvent scrubbing (Abdeen et al, 2016) and pressure swing adsorption (Riboldi and Bolland, 2016). Because of the complexity of the gas components, most technologies still suffer from high energy demand, high cost, and serious secondary pollutions.…”

CFD Modeling of Syngas Combustion and Emissions for Marine Gas Turbine Applications

“…In addition, it is the transition fuel from the carbon based economy to hydrogen based economy in the transportation sector [15,16]. Moreover, syngas fuel can be produced from coal using Integrated Gasification Combined Cycle (IGCC) [17]. Therefore, syngas is a competitive option for power generation, compared to direct fired pulverized coal plants and natural gas fired combined cycle plants [18,19].…”