Treatment method for recycling gasification ash water

Abstract

The invention provides a treatment method for recycling gasification ash water. A treatment process is performed in a sedimentation tank; and the sedimentation tank comprises a first water tank, a second water tank and a third water tank which are connected with one another in sequence. The method comprises the following steps: (1) mixing the ash water and lime water at an inlet of the first water tank, entering the first water tank to perform softening reaction, standing and settling, and overflowing supernatant to the second water tank, wherein the weight of the lime water is 2.5-5 percent of the weight of the ash water; and (2) introducing pure aqueous alkali with mass percentage concentration of 5-10 percent into the second water tank, mixing the pure aqueous alkali and the supernatant which is obtained in the step 1 and reacting, standing and settling, and overflowing the supernatant to the third water tank for further sedimentation, wherein the obtained supernatant is recycled as industrial circulating water, and the weight of the pure aqueous alkali is 1-2 percent of the weight of the ash water. The treatment method is convenient to operate and has a good softening effect; and the scaling tendency of a heat exchanger and the like is greatly reduced through the ash water which is subjected to the softening treatment.

Description

technical field [0001] The invention relates to a treatment method for ash water reuse in a coal gasification process, in particular to a treatment method for ash water reuse in a Texaco gasification process, and belongs to the technical field of water treatment. Background technique [0002] At present, for coal gasification technology, there are mainly the following problems that need to be solved in the gray water system: 1. Scaling of the gray water system; 2. Pollution of external drainage; 3. Waste of water resources. Following the national environmental protection and water-saving requirements, some manufacturers have adopted measures to reuse naturally clarified gray water. Although adding a certain proportion of scale inhibitors to temporarily relieve gray water scaling at severe scaling points, there are still problems. Severe scaling tendency. Severe scaling of the gray water system will affect the continuous operation of the device, shorten the operating cycle, a...

AI Technical Summary

Problems solved by technology

[0002] At present, for coal gasification technology, the gray water system mainly has the following problems to be solved: 1. Scaling of the gray water system; 2. Pollution of external drainage; 3. Waste of water resources

In order to ensure stable water quality, an effective method is to maintain a certain amount of external drainage. However, maintaining the external drainage increases the amount of wastewater discharged by the enterprise, which cannot meet the requirements of energy saving and emission reduction, and is not conducive to environmental protection.

Images