Development of Fluorinated Alcohols in China   

By Luo Yamin, Research Institute of Industrial Economics of CNCIC

Fluorinated alcohols are formed by using fluorine atoms to replace hydrogen atoms on the carbon chains of alcohols. Because of their excellent solubility, they are widely used as solvents in recordable CDs, electronics, polymer and other industries.
    As a type of important intermediates, they are also used in the synthesis of fluorine-containing pesticides, pharmaceuticals and dyes. In China, fluorinated alcohols with large-scale production mainly include: 2,2,2-trifluoroethanol (TFEA), 2,2,3,3-tetrafluoropropanol (TFP), 1,1,1,3,3,3-hexafluoro-2-isopropanol (HFIP), 2,2,3,4,4,4-hexafluorobutanol (HFB) and 2,2,3,3,4,4,5,5-octafluoro-1-pentanol (OFP).

1. TFEA

2,2,2-trifluoroethanol (TFEA) can be miscible with water and most organic solvents and is an excellent solvent. It is also an intermediate for pharmaceuticals and pesticides, mainly used in the synthesis of narcotics such as desflurane, isoflurane alkyl, flecainide, silodosin and lansoprazole, as well as pesticides such as trifloxysulfuron and triflusulfuron-methyl. It can also be used for the synthesis of poly(trifluoroethyl methacrylate), fluorinated phosphazene rubber and fluorine-containing polyurethane polymer. It is also used in optical fiber, paints, rubber products and contact lenses and used as a solvent in the synthesis of organics and polymers as well as chemical analysis.
   Major global TFEA producers are Japan's Tosoh Fluorine Technology Company, Belgium's Solvay, France's Rhodia and the United States' Halocarbon Products Inc. Japan's Daikin Industries Inc also has a small-scale TFEA plant. In 2002, China began to produce TFEA at a large scale. In the country, major TFEA producers are Weihai Xinyuan Chemical Co Ltd, Jiangsu Kangtai Fluorine Chemical Co Ltd (Jiangsu Kangtai), Zhejiang Lantian Environmental Protection Fluorine Materials Co Ltd (Lantian EP), Nantong Xinhai Green Refrigerant Co Ltd (Nantong Xinhai), and Sinochem Taicang Environmental Protection Chemical Co Ltd. These producers have a total TFEA production capacity of more than 5 000 t/a. While gradually meeting the domestic demand, they also export part of their products to overseas markets.
   The main production process of TFEA is as follows: use trichloroethanol (TCE) as the initial material to synthesize intermediate 1,1,1-trifluoro-2-chloroethane (HCFC-133a), and then hydrolyze HCFC-133a into TFEA. HCFC-133a is also an intermediate of refrigerant HFC-134a. Jiangsu Kangtai, Nantong Xinhai and Lantian EP are large producers of HFC-134a. With the rapid growth of China's HFC-134a production capacity, the production capacity of TFEA, which is closely related to HFC-134a, also increases fast.
   China's annual consumption of TFEA is about 2 000 - 3 000 tons, of which 40-50% is used for the production of pharmaceuticals and pesticides, 30% is used for the synthesis of  polymer materials, and the rest is used as refrigerants, solvents and reagents, etc. In 2010, China exported about 1 000 tons of TFEA, mainly to the United States, Britain, France, Russia and India, mostly for the synthesis of pharmaceuticals. After 2008, China's import volume of TFEA is very small, about tens of tons annually.
   It is expected that the demand for TFEA will grow 4% to 5% annually in the world and 7% in China, and the main driver for such growth will come from pharmaceutical, polymer and related industries.

2. TFP

2,2,3,3-tetrafluoropropanol (TFP) is a new fluorine-containing solvent and used as a paint solvent and release agent in recordable CDs, a cleaning agent in microelectronics and optoelectronics and a processing aid for intermediates, fluorine resin and fluorine rubber. It is also widely used in photographic color makeup agents and textile finishing agents. TFP can be used to produce a variety of halogenated aromatic alkyl ethers, polyfluoroalkoxy propionitrile, fluorinated olefins, fluorinated diols and vulcanized rubber. It has no damage to the atmosphere and is a superior alternative to Freon cleaning agents. In the world, more than 70% of TFP is used for the production of recordable CDs, 20% is used in a variety of cleaning agents and surfactants, and 10% is used for the synthesis of sodium tetrafluoropropionate (a pesticide) and other products.
   The main synthesis method of TFP is as follows: difluorochloromethane (HCFC-22) is cracked into tetrafluoroethylene, which is turned into TFP through the telomerization reaction with methanol. Major global TFP manufacturers are Japan's Daikin Industries and Asahi Glass. Some Western and Russian companies also produce TFP. Since 2004, China has become the world's largest producer of TFP. In 2010, the country had a total TFP capacity of 8 000 t/a, an output of 5 000 tons and an export volume of more than 3 000 tons. China Fluoro Technology Co Ltd is China's largest TFP producer. Other major TFP producers in China are China Haohua Chenguang Research Institute of Chemical Industry, Zhejiang Sanhuan Chemical Co Ltd and Zhejiang Juhua Group.
   TFP is a raw material of recordable CDs, serving the Chinese (including Taiwan), India and Japan markets. The capacity expansion of TFP in the Chinese mainland in recent years has made TFP prices fall by nearly one half.
   During 2011 - 2015, the demand for TFP in China's recordable CD industry is expected to grow 6% - 7% annually, and the demand for TFP from other areas, such as surfactants, cleaning agents and sodium tetrafluoropropionate, will grow 3% to 4% annually.

3. HFIP

1,1,1,3,3,3-hexafluoro-2- propanol (hexafluoro isopropanol, HFIP) is a highly polar solvent and can be easily miscible with water and many organic solvents and has good thermal stability, so it is an ideal polymerization solvent. Because it can dissolve a variety of polymers, such as polyamide, polyacrylonitrile, polyester and polyacetal, it is often used as a polymer regeneration agent. HFIP is also used as an electronics cleaning agent and a pharmaceutical intermediate. Its best known application is to synthesize sevoflurane, which is an inhalation anesthetic. Sevoflurane and the above-mentioned isoflurane and desflurane are considered to be the most promising inhaled general anesthetics.
   China's total HFIP production capacity is about 900 t/a. Sanming Hexfluor Chemical Co Ltd is the largest HFIP producer in China, and the second one is Lianyungang Taizhuo New Materials Co Ltd.
   HFIP is usually made through the hydrogenation of hexafluoroacetone, which is prepared from hexafluoro propylene oxide. This is its most economical production method. Industrially, hexafluoroacetone trihydrate reacts with hydrogen to synthesize HFIP. Like HFIP and hexafluoroacetone, hexafluoro propylene oxide can also derive a large number of products like new-type surfactants. China's total production capacity of hexafluoro propylene oxide is about 2 000 t/a, half of which is prepared by the oxidation of hexafluoropropylene.
   China's demand for HFIP will grow about 5% annually over the next five years from 2011 to 2015, driven by the sevoflurane market.

4. HFB

Like TFP, 2,2,3,4,4,4-hexafluorobutanol (HFB) is also an excellent solvent and can be used to produce recordable CDs. It is also an excellent solvent for a variety of polymers and is used in the regeneration process of the polymers. As an intermediate, HFB is also often used to prepare various fluorine-containing surfactants, such as fluorine-containing hydroxy alkyl ether sulfate. It can also be used as an antistatic agent and lubricant for synthetic resin. HFB is also used to make hexafluoro butyl bromo-undecanate, which can r