According to reports, the total global formic acid production capacity has reached 620,000 t/a, mainly distributed in Europe. It is predicted that formic acid will have a broad application prospect in Asia in the next few years.
Present situation and progress of production technology
There are four main technological routes for industrial formic acid production: sodium formate method, formamide method, butane (or light oil) liquid phase oxidation method and methyl formate hydrolysis method.
Sodium formate method is a traditional method of formic acid production, but the working conditions are poor and the pollution is serious. Many industrialized countries have eliminated this method, but most formic acid production enterprises in China still adopt this method. The formamide process developed by BASF in Germany was also eliminated because of its high production cost. Liquid phase oxidation of butane (or light oil) is a method to produce acetic acid and formic acid at the same time. 0.05~0.25t formic acid per production of 1t acetic acid was the main method to produce formic acid abroad in 1970s. Later, with the industrialization of low-pressure carbonylation of methanol to acetic acid, this method has no development prospect. At present, most butane (or light oil) liquid phase oxidation units have been discontinued. At present, methyl formate hydrolysis process is mainly used in formic acid production abroad, accounting for more than 80% of the total formic acid production capacity.
The hydrolysis process of methyl formate is as follows: (1) carbonylation of methanol and carbon monoxide to synthesize methyl formate; (2) Methyl formate is hydrolyzed to produce formic acid and methanol, and the methanol is recycled. According to the different characteristics of the process, this method can be divided into Camilla-Leonard method, Baesler Chem-Steyr method, BASF method and Soviet method.
Kemira-Leonard process is characterized by the use of unique alkoxide catalysts and additives, which reduces the reaction pressure by half. In the process of hydrolysis, a large amount of methyl formate is distilled out in the flash evaporator by premixing and flash evaporation technology. The formic acid separation tower is operated at low reflux ratio, low reaction temperature and short contact time, and the re-esterification rate of formic acid is less than 0.65438 0%. The process was industrialized in a 20,000 t/a plant in Kemira, Finland on 1982, and was improved by Kemira Company, and was applied in plants in Korea, India and Indonesia respectively.
The Bethlechem Stell process is characterized by the fact that the hydrolysis reaction is carried out in homogeneous liquid phase, the reaction conditions are mild, the process is simple, the equipment reliability is strong, and high-purity formic acid can be produced. Generally, the ratio of hydrolysis product is water: methyl formate =3: 1~ 1:3, and the by-product methanol is 10%. This technology was jointly developed by SD Company and Bethlechem Stell Company in 1980s.
The operating conditions of carbonylation process in BASF process are similar to those in Kemira-Leonard process. Its main feature is that special solvent is used as extractant when methyl formate is hydrolyzed, so the conversion rate of methyl formate is high, and the steam consumption can be reduced by 30% when the formic acid separation tower is operated at atmospheric pressure, but the process operation is difficult. The method is industrialized in a 10000 t/a plant in ludwigshafen.
The USSR process is characterized by two-stage reaction and continuous hydrolysis, and strong acid ion exchange resin is used as acid catalyst. However, the process operation is difficult and the investment is high. The reaction temperature was 55 ~ 62℃, the molar ratio of water to methyl formate was 14: 1, the conversion of methyl formate was 87%, and the purity of formic acid product was 86.5%. The method was industrialized in a 40,000-ton/year factory in saratov, Ukraine on 1989.
It is said that these four hydrolysis processes have their own advantages, and the Camilla-Leonard process has the least investment and the most economical and reasonable process.
Because the existing methyl formate hydrolysis method needs a lot of process water in the production process, the production cost of product separation is high. Therefore, manufacturers are developing more effective separation technology of formic acid. For example, Kemira Company proposed to use solid ion exchange substances with catalytic hydrolysis and adsorption to separate methanol from formic acid while methyl formate was hydrolyzed. BASF Company proposed to hydrolyze methyl formate under mild conditions, then separate formic acid and methyl formate, and then extract and separate formic acid and methyl formate with benzyl formate, and the extracted wastewater can be recycled.
In the development of new technology routes, the main research and development routes are:
The preparation technology of methyl formate, the precursor of formic acid (1), includes catalytic dehydrogenation of methanol, oxidative dehydrogenation of methanol, hydrogenation and condensation of CO2 and methanol, and direct synthesis of synthesis gas. Among them, methanol carbonylation and methanol catalytic dehydrogenation have been studied at home and abroad in recent years, which have certain industrial application prospects.
(2) Direct oxidation of formaldehyde catalyzes one-step production of formic acid. The technology developed by BIC uses V-Ti-O catalyst, and the temperature range is about 100~ 140℃. The initial selectivity of formic acid can reach about 96%~98%, and the catalyst yield can reach 70g formic acid/L h. At present, this method has been tested in laboratory and piloted.
(3) directly hydrogenating 3)CO2 to produce formic acid. Since the mid-1990s, this technology has used ruthenium catalyst to synthesize formic acid at 20.5MPa, 50℃ and triethylamine. From the perspective of environmental protection, this route has certain development significance, but it is still far from industrialization, and the progress is not great at present, and it is still in the basic exploration stage.
Foreign market situation
The world's four major formic acid producers and their production capacity are: BASF Germany (193,000 t/a); Kemira Company of Finland (80,000 tons/year); Russian Techmashimpor Company (80,000 t/a); British BP Company (65,000 t/a); Among them, British BP Company adopts liquid phase oxidation of light oil, and the other three companies all adopt methyl formate hydrolysis process.
The development and utilization of formic acid abroad are good, the application scope is expanding year by year, and the consumption of formic acid is also increasing. The largest amount of formic acid in foreign countries is leather, which is used for tanning and leather treatment to prevent mildew. The second largest use is agriculture, which is used to preserve green feed and grain. The demand ratio of formic acid in Europe, Asia-Pacific and America is 4:2: 1. Europe (including Africa and the Middle East) is the net export area of the United States and the Asia-Pacific region. In 2004, the global demand for formic acid was 430,000 ~ 450,000 t/a, and it is estimated that the global demand for formic acid is increasing at a rate of 2% ~ 3% every year, among which the demand for feed additives in Europe is very large, with an average annual growth rate of 8% ~ 10%. The main reason is that since 2006, the EU will completely ban over-the-counter feed antibiotics. Experts predict that the application prospect of formic acid in Asia is very broad. At present, formic acid in this region is mainly used as coagulant of natural rubber, and the feed market in Asia will have a great growth momentum in the future.
Domestic production status and market forecast
In China, formic acid was produced by sodium formate method from 1989. By March 2006, there were more than 60 manufacturers, with a total plant capacity of about 240,000 t/a, including Shandong Feicheng Asde Chemical Company (60,000 t/a), Nanjing Yangba Joint Venture (50,000 t/a), Jinan Chemical Plant (20,000 t/a) and Xin 'anjiang Chemical Plant. The consumption of formic acid in China is increasing year by year. At present, the domestic formic acid market consumption is about 6.5438+0.5 million t, and its consumption ratio is 50% for medicine, 654.38+0.5% for chemicals, 654.38+0.3% for pesticides, 9% for rubber chemicals and 654.38+0.3% for others.
Formic acid is one of China's traditional export products, 80% of which are exported to Southeast Asian countries, 12% to Europe and the rest to Oceania. In recent years, the export volume of formic acid in China has increased rapidly, especially in the last year or two. In 2004, the export volume was 1.4 1.000t, and in 2005, the export volume reached 27,300 t, an increase of 93.6% over 2004, almost doubling. It is reported that at present, Shandong Feicheng Astar Chemical Company is the largest producer of formic acid in Asia, and its formic acid export volume has accounted for more than 85% of the country's total exports.
China has also carried out some work in the research and development of formic acid technology. For example, Feicheng Astar Chemical Company introduced methyl formate hydrolysis process from American acid amine technology company, and constantly innovated, successfully realized the localization of catalyst and formed a technology with independent intellectual property rights. Southwest Chemical Research and Design Institute of Ministry of Chemical Industry, Kunming University of Science and Technology and other units have developed the technology of purifying yellow phosphorus tail gas to produce formic acid. After the yellow phosphorus tail gas is recovered and purified, it is converted into synthesis gas through carbonyl synthesis or conversion, producing high-quality and low-cost formic acid products. This is a major technological innovation in yellow phosphorus industrial waste gas treatment and formic acid production. At present, there are also some plants under construction or planning, such as Guizhou 20,000 t/a (under construction, planned to be completed in 2006, methyl formate method) and Shandong Luxi Chemical Co., Ltd. 20,000 t/a (investment attraction, methyl formate hydrolysis method).
With the vigorous development of animal husbandry in China, formic acid will have a huge potential market as a storage agent and mildew inhibitor for silage and crops. With China's great attention to environmental protection, formic acid has a good market prospect in tanning, printing and dyeing industries. In recent years, some foreign companies began to transfer their formic acid production to China. For example, the 50,000-ton/year formic acid plant built by BASF and China in Nanjing has become a part of the large-scale combined plant of Nanjing Petrochemical Company, and AAT Company of the United States has also shifted the focus of formic acid production to China. Therefore, small factories adopting sodium formate process in China may face competitive pressure, and need to continuously improve production level, reduce material and energy consumption, and improve product quality, so as to improve the overall level of formic acid production in China.