GAS COOLING EXPANDER APPLICATION IN HIGH PRESSURE GASIFICATION
Publication Date: 2012-Dec-31
The IP.com Prior Art Database
This publication relates to integrating syngas expansion with high-pressure gasification. Integration of syngas expansion with high-pressure gasification can be done in numerous ways. This publication introduces a simple and a pragmatic process by which syngas, from the application of high-pressure gasification, can be heated and expanded to generate power prior to end use in lower pressure applications such as combustion in boilers, gas turbines, or chemical synthesis. This increases the overall efficiency of the integrated gasification plant by reducing net power consumption via power production, and utility loads.
This publication relates to high-pressure gasification, which is an efficient means of converting low value-residuals into higher value products including power, steam, and industrial gases. It is a process that produces mixtures of hydrogen and carbon monoxide (synthesis gas or syngas) from carbon-based feed stocks such as coal, petroleum coke, and heavy oils.
The operating pressure for a gasifier is generally established by the downstream (end user) process requirements. Increasing the gasifier pressure has shown to increase gasification reaction rates. However, this effect is less pronounced or negligible at higher pressures.
Tighter regulations on sulfur emissions/specifications coupled with diminishing availability of low-sulfur hydrocarbon feed stocks have resulted in a drive to use gasification with acid gas removal (AGR). Adsorption with liquid solvent with subsequent desorption step is the main process utilized for acid gas removal from gasification. At lower temperatures and high pressures, acid gases in the syngas adsorb more readily in physical solvents. Consequently, higher pressures and colder temperatures reduce solvent circulation rates.
There are numerous ways to integrate syngas expansion with high-pressure gasification. However, not all are practical or feasible. In related art, U.S. Patent No. 7,004,985 relates to an integrated gasification and hydroprocessing plant wherein compressed hydrogen-poor syngas is expanded to drive a compressor. In other related art, U.S. Patent Application Ser. No. 2008/0028765A1 relates to generating and deriving energy from high pressure syngas in a gas turbine combined cycle and. U.S. Patent Application Ser. No. 2002/0121093 discloses a method of utilizing COS hydrolysis system in high pressure gasification. This publication discloses a simple and pragmatic process configuration for integrating syngas expansion with high-pressure gasification.
BRIEF DESCRIPTION OF DRAWINGS-
A process for integrating syngas expansion with high-pressure gasification is disclosed in which:
Figure 1 shows the process of integrated gasification and expansion of syngas.
A flow diagram of the process of heat integration and syngas expansion is shown in Fig. 1. The figure describes a process by which syngas, from the application of high-pressure gasification, can be heated and expanded to generate power prior to end use in lower pressure applications such as combustion in boilers, gas turbines, or chemical synthesis (i.e. Fischer-Tropsch).
This new method of syngas gasification and expansion comprises the following steps:
Ø Raw syngas from gas cooling  is used to heat clean syngas from the AGR  in the Clean Syngas Reheater 1.
Ø Power is generated when the heated clean syngas...