Browse Prior Art Database

POST-GASIFICATION NITROGEN SEPARATION FROM AIR-BLOWN GASIFIERS

IP.com Disclosure Number: IPCOM000226824D
Publication Date: 2013-Apr-22
Document File: 3 page(s) / 124K

Publishing Venue

The IP.com Prior Art Database

Abstract

The invention relates to coal gasifiers and improving efficiency thereof. Air-blown gasification systems have a large volume of nitrogen embedded in the product syngas, which is a high volume inert constituent. To improve efficiency, nitrogen separation is an option. The invention proposes a non-cryogenic separation system for nitrogen in the syngas stream. Raw syngas is subjected to a separation step to remove nitrogen after cooling and before further downstream processing such as scrubbing. Nitrogen separation can be effected using either a) adsorption swing system (pressure or vacuum swing adsorption) or b) membrane separation to separate the nitrogen from the raw syngas at the exit of the gasifier. The nitrogen-depleted syngas with a lower volume and higher calorific value is sent to subsequent processing or use. The new process disclosed will significantly reduce the volume of inert constituent in the syngas and therefore reduce handling requirements of downstream equipment, and associated capital expenditure.

This text was extracted from a Microsoft Word document.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 52% of the total text.

POST-GASIFICATION NITROGEN SEPARATION FROM AIR-BLOWN GASIFIERS

BACKGROUND

This invention relates to coal gasifiers and improving efficiency thereof. Air blown gasification systems have a large volume of nitrogen embedded in the product syngas, which is a high volume inert constituent. To improve efficiency, nitrogen separation is an option. The present process uses a cryogenic air separation unit to remove the nitrogen prior to gasification, which is energy intensive. Nitrogen separation from gas streams has been done using membranes, such as disclosed in EP2025390A1, or JP2001096124A2, or by cryogenic separation as disclosed in EP0983218A1. However, thus far, this problem has not been attempted to be solved in the gasification process. This invention discloses non-cryogenic methods to remove nitrogen from syngas streams.

BRIEF DESCRIPTION OF DRAWINGS

Post-gasification nitrogen separation from air-blown gasifiers is described further with reference to the following drawing.

Figure 1 shows air-blown post-gasification N2 removal.

DETAILED DESCRIPTION

The invention proposes a non-cryogenic separation system for nitrogen in the syngas stream, as shown in Fig. 1. As shown in the figure, raw syngas is subjected to a separation step to remove nitrogen after cooling and before further downstream processing such as scrubbing. Nitrogen separation can be effected using either a) adsorption swing system (pressure or vacuum swing adsorption) or b) membrane separation to separate the nitrogen from the raw syngas at the exit of the gasifier. The nitrogen-depleted syngas with a lower volume and higher calorific value is sent to subsequent processing or use. As indica...