System and method for improving comprehensive utilization rate of yellow phosphorus tail gas

Abstract

The invention discloses a system and method for improving the comprehensive utilization rate of yellow phosphorus tail gas, and relates to the field of yellow phosphorus tail gas recovery and utilization. The system includes a tail gas purification device, a tail gas combustion device, a steam utilization device and a waste liquid recovery device. The device is connected with the tail gas combustion device, and the tail gas combustion device is connected with the steam utilization device and the waste liquid recovery device; the tail gas purification device includes a dust removal device and an acid removal device, and the tail gas combustion device includes a burner, a boiler, a waste heat recovery device, an induced draft fan and a chimney; Dust removal device, acid removal device, burner, boiler, waste heat recovery device, induced draft fan and chimney are connected in sequence; there is a steam outlet valve on the outside of the boiler. The steam outlet valve includes the main steam outlet and branch steam outlet. A number of heat storage bricks made of rare earth are arranged, and the heat storage bricks are arranged in a honeycomb shape; the invention is more environmentally friendly, can increase the economic value of the yellow phosphorus tail gas, and improve the utilization rate of the yellow phosphorus tail gas.

Description

technical field [0001] The invention relates to the field of recovery and utilization of yellow phosphorus tail gas, in particular to a system and method for improving the comprehensive utilization rate of yellow phosphorus tail gas. Background technique [0002] The existing yellow phosphorus production method is usually the electric furnace method, and every ton of yellow phosphorus produced will produce 2500-2800Nm 3 Phosphorus exhaust. The main component of yellow phosphorus tail gas is CO with a volume fraction of 87-92%, and it also contains inorganic sulfur (S, H 2 S, SO 2 ), organic sulfur (CH 4 SH, COS), SiF 4 、PH 3 ,P 4 , HF, CH 4 , CO 2 , O 2 , N 2 , cyanide and dust and other impurities. In the existing yellow phosphorus tail gas, the sulfur content is 0.8% to 8.0% g / m 3 , the phosphorus content is 0.5% ~ 1.5% g / m 3 , the combustion value of yellow phosphorus tail gas is 10.5~11MJ / m 3 . [0003] At this stage, enterprises usually ignite the yellow ...

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Problems solved by technology

[0005] (1) After the yellow phosphorus tail gas is burned, a large amount of NO will be produced 2 , SO 2 and SO 3 After the acid gas enters the atmosphere and soil, it is easy to pollute the environment

[0006] (2) Use yellow phosphorus tail gas as fuel to dry ore, as a heat source for the polymerization kiln in the phosphate production system, or as fuel to heat water, hot water can be used for yellow phosphorus heat preservation, due to yellow phosphorus heat preservation, drying ore and Polymerization kiln heat source consumes less energy, accounting for only 15% of the total heat production of yellow phosphorus tail gas, so most of the yellow phosphorus tail gas can only be burned and discharged, and the utilization rate of yellow phosphorus tail gas is low

[0007] (3) Purified yellow phosphorus tail gas is used as raw material gas for carbon-one chemical industry, such as sodium formate, formic acid, etc., due to the high purification cost of yellow phosphorus tail gas and technical limitations, currently domestically developed carbon-one The added value of chemical products is low. Therefore, the economic value of using yellow phosphorus tail gas as a synthetic raw material is low. The production capacity of carbon-one chemical products is seriously overcapacitated, the product is discontinued or intermittently produced, and the utilization rate of yellow phosphorus tail gas is low.

[0008] (4) When yellow phosphorus tail gas is used as boiler fuel to produce low-pressure saturated steam for chemical production or power generation, if all the yellow phosphorus tail gas produced per unit of yellow phosphorus is used to produce saturated steam, the amount of saturated steam required for yellow phosphorus production itself , accounting for only 20% of the total steam production; when saturated steam is used for power generation, the power generation efficiency is low, and saturated steam is easy to cause cavitation of turbine blades. Due to the complex composition of yellow phosphorus tail gas, the acidic substances in the gas after combustion More, more corrosive, easy to corrode the boiler, therefore, the cost of using yellow phosphorus tail gas to generate electricity is relatively high

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