Thiourea, with molecular formula of (NH2)2CS, is a white orthorhombic or acicular bright crystal. The industrial methods for preparing thiourea include amine thiocyanate method, lime nitrogen method, urea method, etc. In the lime nitrogen method, lime nitrogen, hydrogen sulfide gas and water are used for hydrolysis, addition reaction, filtration, crystallization and drying in the synthesis kettle to obtain the finished product. This method has the advantages of short process flow, no pollution, low cost and good product quality. At present, most of factories adopt the lime nitrogen method to prepare thiourea.
From the market situation, China is the largest thiourea producer in the world. In addition to meeting domestic demand, its products are also exported to Japan, Europe, the United States, Southeast Asia and other countries and regions. In terms of downstream application, thiourea is widely used as raw materials for manufacturing pesticides, pharmaceuticals, electronic chemicals, chemical additives, as well as gold flotation agent.
In recent years, thiourea production in China has developed to a certain extent, with a capacity of 80,000 tons/year and more than 20 manufacturers, of which more than 90% are barium salt manufacturers.
In Japan, there are 3 companies producing thiourea. In recent years, due to the depletion of ore, the increase of energy costs, environmental pollution and other reasons, the output of barium carbonate has declined year by year, resulting in the reduction of the production of hydrogen sulfide, which limits the production of thiourea. Despite the rapid growth of market demand, the production capacity is sharply reduced. The output is about 3000 tons/year, while the market demand is around 6000 tons/year, and the gap is imported from China. There are two companies in Europe, SKW Company in Germany and SNP Company in France, with a total output of 10,000 tons per year. With the continuous development of thiourea in pesticides and other new uses, The Netherlands and Belgium have become big consumers of thiourea. The annual market consumption in The European market is about 30,000 tons, of which 20,000 tons need to be imported from China. ROBECO company in the United States has an annual output of thiourea of about 10,000 tons/year, but due to increasingly strict environmental protection, the output of thiourea decreases year by year, which is far from meeting market demand. It needs to import more than 5,000 tons of thiourea from China every year, mainly used in pesticide, medicine and other fields
Post time: Dec-06-2021