Under the energy shortage situation, the low-temperature sulfuric acid that was not taken seriously before began to highlight the recovery value. However, due to the lack of mature technologies and equipment in the country, the introduction of technology and high prices have led to the implementation of this energy-saving measure. The stalemate is now about to be broken. The sulfuric acid low-temperature heat recovery system independently researched and developed by the Nanjing Institute of Design of Sinopec has successfully completed industrial tests and is expected to be widely applied.
In the sulfuric acid production process, sulfur dioxide is generated from the combustion of sulfur-containing raw materials, sulfur trioxide is converted into sulfur trioxide, and sulfur trioxide is absorbed. Each step of sulfuric acid formation is an exothermic reaction. The domestic sulfuric acid enterprises basically recovered the heat released from the combustion and conversion reactions, but for the low-temperature thermal energy that accounts for 30% to 40% of the total heat energy released, the recycling was almost blank, and the investment in foreign investment in complete sets of technologies and equipment caused the company to fail. Use this energy-saving measure.
To this end, Sinopec Nanjing Design Institute has successfully developed low-temperature heat recovery technology and achieved localization of materials and equipment thanks to its technical strength and engineering experience accumulated in sulfuric acid design for many years. The institute built a test facility at Nanhua Group in October last year. The operation conditions are good. All technical parameters have met the design requirements and the industrialization test has been successfully completed. The successful development of the sulfuric acid low-temperature heat recovery package technology has enabled China's overall technology for sulfuric acid production to reach the international advanced level. The Institute has begun to promote the application of the technology, and is exploring the optimization of materials to further reduce the cost of the device.
The technology adopts advanced detection and control technologies, and the operation of the device is fully automated during normal operation. It adopts two towers absorption, high and low temperature absorption and separation, can be flexibly operated according to the actual situation of the production enterprise, and at the same time is conducive to ensure the absorption efficiency and control of acid mist indicators, to ensure the safe operation of the entire sulfuric acid plant. For the transformation of old factories, only high-temperature absorption tower systems can be built, and the original suction tower circulation system can be used as a low-temperature absorption tower system. For new installations, high and low temperature absorption can be performed in segments within the same tower.
It is understood that this low-temperature heat recovery system includes a high-temperature absorption tower, a high-temperature circulating acid pump, a steam generator, a mixer, and a feed water heater. With this technology, 0.4 to 0.5 tons of low-pressure steam can be produced as a by-product of the production of 1 ton of sulfuric acid.
In view of the fact that this technology is not only energy-saving, but also an investment province, its investment prospects are widely viewed by the industry.