Design And Implementation Of Low-temperature Waste Heat Recovery From Sulphuric Acid Production Process

Sulfur in the combustion process produces a large amount of waste heat,there is a great use value.But due to the recycling technology and equipment safety factors such as limit,its heat most wasted,especially in the low temperature waste heat.With the progress of science and technology,low temperature waste heat recovery unit in sulfuric acid industry booming,xiangyang ze east chemical industry group co.,LTD.Sulphuric acid at low temperature waste heat recovery unit is one of them.Xiangyang ze east chemical group co.,LTD.,built in 2010 320000 tons/year sulphuric acid plant,waste heat boiler of the devices and economizer,recovery burning sulfur transformation of high,medium heat,435?,3.82 MPa medium-pressure superheated steam to generate electricity.Found that in the operation of the dry absorption section of low-temperature waste heat by circulating cooling water into the environment,caused great waste.This phenomenon has caused the great attention of the company,in 2012 began the research and development of low temperature waste heat recovery technology.This technique to use SO3 absorption process of reaction heat to generate steam,so we must raise the temperature of circulating acid at about 200?.As a result of the sulfuric acid corrosion generally increased with the increase of the temperature to strengthen,therefore high-temperature concentrated sulfuric acid corrosion of materials selection is a key in the project.In order to adapt to the operating environment of low temperature recovery,acid in the acid circulation system must be strict control in 99%or more,so as to ensure the corrosion resistance and long term stable operation of system,but also to ensure that in high temperature absorption tower in 99%sulfuric acid concentration,in order to ensure efficiency of SO3 absorption,heat recovery efficiency of low temperature heat recovery system.General technology reform scheme is proposed in this paper,combined with the actual operation parameters,on the low temperature waste heat recovery system heat balance analysis,the key equipment in the accounting,the arrangement of the equipment.Benefits after the innovation was analyzed,and the dry absorption section of sulphuric acid and low temperature waste heat recycling,an annual output of 165 tons of 0.7 Mpa,165? low-pressure steam,used to dry products,greatly reduce outsourcing steam,at the same time reduce consumption of circulating water and supplement water and electricity consumption,reduce the waste emissions,is conducive to environmental protection.Realize the energy-saving benefit RMB 12.54 million per year,with remarkable energy conservation and emissions reduction and economic and social benefits.Now with sulphuric acid at low temperature waste heat recovery technology,does not affect the output of the existing production system,every tons of acid of 0.457 t of recycling waste heat to produce steam festival energy 14000 tce,illustrate the sulphuric acid at low temperature waste heat recovery technology with high level,project transformation was a success.Suggestions to further improve the summer low temperature vapor recovery system to produce the amount.