Process for capturing CO2 from a gas stream

A process for capturing carbon dioxide from a gas stream, the process comprising the steps of:

• (a) contacting the gas stream with solid adsorbent particles in an adsorption zone, wherein the adsorption zone has at least two beds of fluidized solid adsorbent particles, and
• wherein the solid adsorbent particles are flowing downwards from bed to bed, and
• wherein the gas stream is flowing upwards, and
• wherein the adsorption zone has at least one internal cooling means in each of the beds of fluidized solid absorbent particles, and
• wherein the solid adsorbent particles comprise 15 to 75 weight % of organic amine compounds, based on the total weight of the adsorbent particles, and
• wherein the gas stream entering the adsorption zone, at the pressure at which it enters the adsorption zone, has a dew point which is at least 5° C., below the forward flow temperature of the cooling medium in the internal cooling means having the lowest forward flow temperature in the adsorption zone;
• (b) passing carbon dioxide enriched solid adsorbent particles obtained in step (a) to a riser zone (I) with a riser gas (I);
• (c) heating at least a part of the carbon dioxide enriched solid adsorbent particles in the riser zone (I), optionally by means of direct or indirect heat exchange with carbon dioxide depleted solid adsorbent particles in the riser zone (II) of step (f);
• (d) separating the heated carbon dioxide enriched solid adsorbent particles from the riser gas (I) at the end of the riser zone (I) in a separating device;
• (e) regenerating at least a part of the carbon dioxide enriched solid absorbent particles obtained in step (d) in a desorption zone,
• wherein the desorption zone has at least two beds of fluidized solid adsorbent particles, and
• wherein the solid adsorbent particles are flowing downwards from bed to bed and a stripping gas is flowing upwards, and
• wherein the stripping gas comprises at least 50 volume % steam;
• wherein the desorption zone has at least one internal heating means in each of the beds of fluidized solid absorbent particles;
• (f) passing carbon dioxide depleted solid adsorbent particles obtained in step (e) to a riser zone (II) with a riser gas (II);
• (g) cooling at least a part of the carbon dioxide depleted solid absorbent particles in riser zone (II), optionally by means of direct or indirect heat exchange with carbon dioxide enriched solid adsorbent particles in the riser zone (I) of step (b);
• (h) separating the carbon dioxide depleted solid adsorbent particles from the riser gas (II) at the end of the riser zone (II) in a separating device;
• and
• (i) recycling at least 50% of the carbon dioxide depleted solid adsorbent particles obtained in step (h) to the adsorption zone.