Method for recovering and utilizing nitrogen containing substance

Abstract

The present invention discloses method of recovering and utilizing nitrogen containing substance generated during coal pyrolysis and coking, and belongs to the field of environment protecting and clean coal converting technology. During coal pyrolysis and coking, nitrogen containing substance is made to release from solid coal or semi-coke to minimize nitrogen content in coke, and the gaseous nitrogen containing substance exists in ammonia and HCN capable of synthesizing cyanide, ammonia water, nitrogen fertilizer, etc. The regulating gas of mixed gas comprising water steam, methane and oxygen in certain proportion and in 10-15 vol% is mixed with inert gas Ar or N2 to form the gas mixture as the environment atmosphere for pyrolyzing coal to produce coke. The present invention can utilize coal nitrogen at most while maintaining the coke yield.

Description

1. Technical field: [0001] A method for recycling nitrogen-containing substances of the present invention mainly involves coal nitrogen in the process of coal pyrolysis and coking to maximize NH 3 It can be released in the form of HCN or HCN, which can be used as resource recycling while reducing environmental pollution, and belongs to the technical field of environmental protection and coal clean conversion and utilization research. 2. Background technology: [0002] The coal-based energy structure will not change for a long period of time in the future. The need to establish energy security and improve environmental pollution has made clean and effective coal conversion technology more and more important. In the consumption of coal, the pyrolysis coking of coal is second only to direct combustion. my country has become the world's largest coke producer since 1991. In 2003, the coke production was as high as 178 million tons, and in 2004 it is estimated to exceed 200 milli...

AI Technical Summary

Problems solved by technology

[0003] Coal pyrolysis is the most basic and necessary step in other coal conversion processes. In the process of pyrolysis and coking, part of the nitrogen-containing substances in coke oven gas are the precursors of nitrogen oxides HCN, NH 3 and N 2 Exist in other forms, the gas must be purified and removed before the use of harmful substances, HCN, NH 3 After separation and concentration, the nitrogen in the gas can be produced at the same time as cyanide, ammonia water or ammonium fertilizer, etc., but as raw materials for synthetic products, HCN and NH in coke oven gas 3 The concentration is too low, using the current production technology, there are serious side-benefit problems in the economy; in addition to a part of the nitrogen released in the gas phase in the form of small molecules, there is also a considerable part of nitrogen retained in the coke, and coke nitrogen is its further Utilizing the main source of nitrogen oxides in the process, the denitrification technology of nitrogen oxide gas formed by further conversion of pyronitrogen mainly adopts selective catalytic reduction (SCR) and selective non-catalytic reduction (SNCR) technologies, but they still exist Low efficiency, re-pollution and other shortcomings, effective and reasonable NO x Removal technology is still very lacking