| 摘要 |
<p>Semicontinuous production of crystalline calcium carbonate comprises: reacting calcium hydroxide with carbon dioxide (CO 2), where the calcium hydroxide is provided as lime milk; arising biogas used as a carbon dioxide source; nucleating the calcium carbonate nucleus and simultaneously separating a crystal growth from the nucleation step; operating the nucleation of reactors in a single stage or multistage process and with optional variable filling level of lime milk in each reactor; and operating the crystal growth and crystal stabilization with the reactors in a bath process. Semicontinuous production of crystalline calcium carbonate comprises: reacting calcium hydroxide with carbon dioxide (CO 2), where the calcium hydroxide is provided as lime milk; arising biogas used as a carbon dioxide source, which is purified into biomethane by depletion of the CO 2; nucleating the calcium carbonate nucleus and simultaneously separating a crystal growth from the nucleation step; operating the nucleation of one or more reactors in a single stage or multistage process and with optional variable filling level of lime milk in each reactor; and operating the crystal growth and crystal stabilization with one or more reactors in a bath process and with a constant filling level part of unreacted lime milk in each reactor, where the entry of biogas and air circulation in the reactors takes place by an aeration device, preferably an aeration turbine, present in the each reactor, and the desired crystalline form of calcium carbonate crystals is controlled by an adjustment of calcium hydroxide concentration of the lime milk, average hydraulic residence time of the registered lime milk and a degree of saturation of the lime milk with CO 2and a degree of conversion of calcium hydroxide with CO 2. An independent claim is included for a plant for the semicontinuous production of crystalline calcium carbonate, comprising one or more reactors continuously operated in series, in which the nucleation of calcium carbonate germs is operated and connected with the intermediate container by forward and reverse lines, where: the intermediate container is provided with the agitator and the device for aerating the biogas; the reactor allows to work with the variable filling level; the intermediate container is connected with one or more reactors discontinuously operated in series, in which the crystal growth and the crystal stabilization take place; and all reactors comprise the aeration device, preferably the aeration turbine with optionally turned off fan, which is useful for aerating the biogas and mixing reactor contents.</p> |
