Unlock instant, AI-driven research and patent intelligence for your innovation.

A kind of dilute nitric acid recovery method and its special equipment

A recovery method, the technology of dilute nitric acid, applied in the field of recovery of dilute nitric acid, can solve the problems of poor utilization of nitric acid energy, energy waste, waste of nitric acid and lye, etc., so as to avoid large consumption, reduce production cost, and reduce consumption Effect

Active Publication Date: 2016-03-30
宁夏润夏能源化工有限公司
View PDF9 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] In the production of nitric acid, there will be some nitric acid with a concentration of 3-8%. In the prior art, this part of dilute nitric acid is directly discharged to the neutralization tank, and then discharged after being neutralized with lye, so that both nitric acid and lye are treated. Huge waste, but also caused a waste of energy, wherein the nitric acid, water and energy can not be well utilized

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • A kind of dilute nitric acid recovery method and its special equipment

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0012] A kind of dilute nitric acid recovery method, comprises the steps:

[0013] Dilute nitric acid with a concentration of 3-8% produced during production enters the middle of the rectification tower, and the water vapor steamed from the top of the rectification tower is sent to the heat exchanger to exchange heat with the tail gas at 20°C from the absorption tower. After the tail gas is heated with high-temperature NOx again, it enters the tail gas expander to recover energy; water vapor forms condensate during heat exchange, part of which is sent to the top of the rectification tower as reflux liquid, and part of it is used as water for the nitric acid absorption tower; the rectification tower The solution at the bottom enters the reboiler, returns to the rectifying tower after part of the water is vaporized, and the solution is concentrated to form nitric acid with a concentration of more than 35%, which is sent back to the straight nitric system for processing concentrat...

Embodiment 2

[0016] A dilute nitric acid recovery device, such as figure 1 As shown, it includes a rectifying tower 1, wherein a dilute nitric acid feed port is provided in the middle, and a water vapor outlet connected to the inlet end of the heat exchanger 2 is arranged on the top, and the outlet end of the heat exchanger 2 is connected to the rectifying tower respectively. Tower 1 is connected with absorption tower; The bottom of described rectifying tower 1 is provided with nitric acid solution outlet, is connected with the inlet end of reboiler 3, and described reboiler 3 has two outlets of side and bottom, and the outlet of described side The outlet is connected with the rectifying tower 1, and the outlet at the bottom is connected with the straight nitrification system.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention relates to a recycling method of dilute nitric acid. The recycling method comprises the following steps of: feeding the dilute nitric acid with the concentration of 3-8% into the middle part of a rectifying tower; feeding the steam evaporated from the top of the rectifying tower into a heat exchanger to exchange heat with the 20 DEG C tail gas from an absorption tower, heating the tail gas (which is subjected to heat exchange) by using high-temperature NOx, and recycling the energy in a tail gas expanding machine; sending a part of liquid condensate, which is formed when steam is subjected to heat exchange, to the top of the rectifying tower to serve as a reflux, and using the other part of liquid condensate as the water for a nitric acid absorption tower; and sending the nitric acid, which is formed at the bottom of the rectifying tower and has concentration of over 35%, back to a direct nitrating system so that the nitric acid is processed into concentrated nitric acid. By adopting the method provided by the invention, nitric acid is recycled, the high consumption of alkali liquor is avoided, the consumptions of the medium pressure steam and the recycling water are reduced, and the energy consumption is low.

Description

technical field [0001] The invention relates to a chemical process, in particular to a method for recovering dilute nitric acid in the nitric acid preparation process and special equipment thereof. Background technique [0002] In the production of nitric acid, there will be some nitric acid with a concentration of 3-8%. In the prior art, this part of dilute nitric acid is directly discharged to the neutralization tank, and then discharged after being neutralized with lye, so that both nitric acid and lye are treated. Huge waste, also caused the waste of energy simultaneously, wherein nitric acid, water and energy all can not be well utilized. In today's energy-scarce society, reducing energy consumption and waste has become the top priority in production, and the level of cost also holds the lifeline of enterprise development. Therefore, there is an urgent need for a dilute nitric acid recovery technology that can reduce enterprise costs, save energy and protect the environ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): C01B21/44
CPCY02P20/10
Inventor 王莉莉宋磊柴锋
Owner 宁夏润夏能源化工有限公司