Titanium heat exchangers, condensers and related auxiliary equipment have been successfully used in petrochemical manufacturers for more than 20 years.
The most commonly used industrial titanium in titanium (the most widely used is gr2)
Ti-6Al-4V (when a certain strength is required) and Ti-0.8Ni-0.3Mo (when a gap exists or in a non-oxidizing medium). When hydrogen absorption and hydrogen embrittlement may occur, especially in the case of weld zone corrosion and hydrogen absorption, the use of low iron is required
(1) In the refining of crude oil with high sulfur and salt content, titanium equipment is relatively ambitious. Many foreign countries have successfully selected titanium equipment for many years in atmospheric distillation equipment, sewage treatment equipment, condensers for desulfurization and separation towers, and radiators for stripping towers. China has also selected cast titanium seawater pumps, titanium condensers for catalytic cracking fractionation, cryogenically separate titanium condensers, and porous titanium plates in this system, all of which have been in normal operation for more than ten years.
(2) Chlorinated hydrocarbons are one of the largest types of petrochemicals. Because of the chlorination response, stainless steel equipment has been difficult to serve. Foreign countries have used titanium materials to make rectification towers, triple heat exchangers, condensation towers and fractionation towers, condensation towers, perchloroethylene heat exchangers and polychloride coil heaters. In the production of vinyl chloride in China, Ti-0. 2Pd fabric has been used for the tray support, receiving and flange sealing surfaces of the cooling tower, waste water stripping tower and waste water storage tank, and has not been used for nearly ten years. Titanium pipes, joints and gas diffusers have been selected for many years.
(3) It is an important material for petrochemical industry. It is a new process to obtain the sum from isopropyl and isopropyl peroxide by using the sum of oil and gas in refining. The world chose titanium equipment more than ten years ago, and this process is still under development in China. The old process was produced with sulfonated alkali solution. In China, titanium neutralization reaction kettles, titanium coil coolers and stirrer shaft sleeves of ionized titanium nitride have been used in our country, which work well.
(4) In the equipment for oxidizing ethylene, oxidizing acetic acid, and oxidizing materials, in addition to materials and products that must be corrosive, the primary corrosion medium is the catalyst. Stainless steel corrodes quickly during this time. Only titanium has outstanding corrosion resistance. As early as 1963, the United States succeeded in using titanium in the production of ethylene oxidation.
(5) Oxidation to acetic acid is a common process in China. Titanium has been selected as a high-boiler reboiler, first-grade acetic acid column reboiler and condensation cooler. Titanium equipment has been used abroad in rectification towers, fractionation towers and distillation towers. Especially in the oxidation of primary alkane to acetic acid, there are many by-products, the content is up to 8%, and the corrosion is very strong. At this moment, the use of titanium to replace stainless steel is very ambitious.
(6) For the second one, it is made of polyester, which is industrially produced by oxidation. Whether high temperature oxidation or low temperature oxidation, there is high temperature corrosion of acetic acid and compounds. In a medium with a temperature higher than 135 ° C, 316L stainless steel pits after tens of hours. Therefore, the planning code stipulates that it is necessary to use titanium material above 135 ° C. Beijing Petrochemical Plant introduced a complete set of titanium equipment, including 16 oxidation reaction kettles, solvent dehydration towers, heaters, condensers, reboilers and so on. Nanjing Yangzi Petrochemical Company has introduced an annual output of 450,000 tons of dual-equipment, 56 titanium equipment and many titanium pipeline valves. The oxidation reaction kettle introduced by Shanghai Petrochemical Plant is 32m high, 4m upper diameter, 5.3m lower diameter, volume is 505m, and the equipment has a weight of 175t. The use of titanium works well and promotes the use of bright prospects.
(7) Urea is a high-quality chemical fertilizer and a petrochemical material. Since the first titanium-lined urea composition tower was put into production in 1963, nearly 10,000 equipments have been running around the world, and practice has shown that the titanium-lined composition tower has no significant corrosion. The reduced corrosion rate of 316L stainless steel is 4.1-4.5mm / a. Therefore, titanium has better economic benefits than stainless steel. In addition to titanium-lined urea composition towers, since the 1970s, C02 stripping towers, heat exchangers, mixers and pump valves have been used in China.