1. Technical field 

This project mainly studies the integration and engineering application of ethylene waste alkali wet flue gas desulfurization process and control. It belongs to the field of energy and environmental technology and involves the intersection of environmental protection, equipment, process and control and other disciplinary fields.

2. Main research contents

1. Composition analysis and desulfurization mechanism analysis of waste ethylene alkali liquor.

2. Development of wet flue gas desulfurization process based on ethylene waste alkali liquor.

3. Analysis of the corrosion mechanism of the desulfurization device and the selection, processing and manufacturing of anti-corrosion materials for the straight-row chimney.

4. Integrated design and development of wet flue gas desulfurization process and control based on ethylene waste alkali liquor.

5. Coordinated and optimized control of desulfurization system based on multivariate control theory.

3. Main innovations

1. Aiming at many problems of traditional desulfurization methods, combined with the characteristics of ethylene waste alkali liquor in petrochemical enterprises, a complete wet flue gas desulfurization process and control system based on ethylene waste alkali liquor have been developed, realizing the concept of waste treatment based on waste. Comprehensive reuse of environmental resources.

2. Aiming at the common corrosion problems in desulfurization units, a new processing and manufacturing process of carbon steel lined pure titanium plates suitable for flue gas desulfurization chimneys is proposed to reduce anti-corrosion costs and achieve a full maintenance-free life (30 years) of the chimney.

3. Adopt multivariate control technology to establish manipulated variables, controlled variables and interference variables such as desulfurization efficiency, flue gas (flow rate, composition), desulfurization agent (flow rate, composition), pH value of absorption liquid/absorption completion liquid, and desulfurization circulation liquid flow rate. Mathematical model of variables achieves overall coordination and optimization control of the desulfurization system.

4. Adopt an integrated optimization design method of process technology and control to comprehensively consider the control performance and design margin of the desulfurization system, so that the process design not only has certain operating flexibility, but also reduces equipment investment and operating costs.

4. Promotion situation

The ethylene waste alkali flue gas desulfurization process was successfully applied in a self-owned power plant of Petroleum China. After horizontal search, it was determined that the desulfurization process system involved in this project was at the domestic leading and international advanced level, and no relevant foreign applications were found. The results of this project use waste ethylene alkali liquor as a desulfurizer to not only remove SO2 from boiler flue gas, but also condense the waste alkali liquor through the desulfurization system and discharge it to the sewage treatment plant, which greatly reduces the sewage treatment capacity, and also reduces the sewage COD through the desulfurization device oxidation system. Taking a set of 3×410t/h boiler flue gas desulfurization device as an example, SO2 emissions are reduced by more than 3800 tons per year, and ethylene waste alkali liquor is consumed by 80,000 tons every year. Moreover, using waste alkali liquor as a desulfurizer not only the cost of the desulfurizer is almost zero, but also saves more than 5600 tons of concentrated sulfuric acid for neutralizing waste alkali liquor every year, achieving the goal of treating waste with waste, achieving multiple goals at one stroke, and achieving the strategic goal of sustainable development of the enterprise. Compared with the traditional limestone/lime-gypsum wet desulfurization technology, the annual operating cost is saved by 21.737 million yuan. It has been in operation for 2 years and 3 months, and the cumulative cost is saved by 53.2217 million yuan. The economic, social and environmental benefits are significant. The smooth commissioning and operation of the project will make an important contribution to PetroChina's emission reduction. This achievement will be further promoted and applied in the flue gas desulfurization transformation project of another three 410t/h boilers of the power plant in 2014, and will also be further promoted in petrochemical enterprises across the country. Promote within the scope of enterprises.