Thread Content
Xintian Coal Chemical: Emission gases meet standards \"here\" Author/Source: Zhejiang Energy Xintian Coal Chemical Date: 2021-01-21 Clicks: 8 The regenerative thermal oxidation unit is an important environmental protection device at Xintian Coal Chemical; it is capable of processing 720,000 cubic meters per hour of exhaust gases from the low-temperature methanol washing unit as well as carbon dioxide-containing gases. Since there are no mature processes available in China that can be used as a reference for this type of unit, since its installation, Xintian Coal Chemical has formed several task forces to ensure that the emission gases meet the required standards at this outlet. A regenerative thermal oxidation unit, abbreviated as RTO unit (hereafter referred to as RTO), is a new type of device; currently, there are limited mature processes available for reference. Since its operation began, Xintian Coal Chemical has continuously pursued research and exploration, addressing problems as they arose. In the initial stage, the high flow rate and speed of the exhaust gases caused excessive noise at the site as well as significant vibration in the pipelines. The company’s purification workshop promptly carried out technical modifications to address these issues, using methods such as installing more silencers and adding additional supports. During the same period, the methanol content in the carbon dioxide product gas resulting from low-temperature methanol washing was high, which led to overheating of the RTO furnace and incomplete treatment of the waste gases. To identify the cause of this issue, the company’s responsible personnel held several meetings, starting with the raw materials at the point of production as well as each process upstream, and continuously conducted experiments to improve the manufacturing process. Eventually, it was decided that the carbon dioxide product gas after low-temperature methanol washing should be washed with water in the wastewater scrubber associated with that unit before being fed into the RTO device. The carbon dioxide product gas exiting the low-temperature methanol washing unit has its methanol content reduced after water washing; this not only solves the problem of excessive furnace temperature when all the product gas enters the furnace but also reduces the methanol consumption in the low-temperature methanol washing unit. This solution achieves two goals at once. The RTO unit features a high degree of automation, with few valves that require manual operation; this means that the valves in this unit are not easy to control. Lift valves are a representative example of such valves – they are not only numerous but also operate at a high frequency, opening and closing every 40 seconds, resulting in thousands of operations per day. Therefore, during inspections it is important to pay close attention to the operation of these lift valves. However, it is also necessary to monitor the operating status of the pumps, as well as the liquid levels in the troughs, water tanks, and dosing units. Winters in Xinjiang exemplify the extreme cold, with night temperatures in the Ili River Valley dropping below minus 20 degrees Celsius. Under such harsh low-temperature conditions, abnormal liquid accumulation occurs within the equipment; this persistent presence of liquid leads to icing, thereby affecting the proper operation of the equipment. To ensure the safe and stable operation of the equipment, the staff braved the severe cold to deal with the ice accumulation, making every effort to guarantee its safe and steady functioning. Since its inception, Xintian Coal Chemical has placed particular emphasis on harmonious coexistence between the enterprise and the environment. It has invested considerable human, material, and financial resources in establishing and improving environmental protection facilities, strictly adhering to relevant standards in order to meet environmental requirements. By taking practical actions, it fulfills its responsibilities as a state-owned enterprise, ensures that emissions remain within acceptable levels, and works together with local residents to preserve the clean waters and blue skies of the Ili River Valley.