Aniline is regarded as an organic intermediates. It is widely used in synthetic materials, rubber additives,dyes,pigments,pharmaceuticals and other organic chemical products. Recent years, with the demand of global polyurethane raw material MDI growth, it has become the main consumer areas of aniline. According to statistics, global aniline capacity has been reached 3.773 million t/a in 2004, annual output is 2.315 million tons and the apparent consumption was 2.24 million tons.
Aniline industry has began in 1857. Aniline industry adopt nitrobenzene iron reduction method. This method needs big equipment and also in serious corrosion, big iron consumption, serious pollution. Catalytic hydrogenation of nitrobenzene method instead of it until 1950s. At present, this method has accounted for 85% of the total capacity of aniline. Phenol ammoniation is occupied about 10% and iron powder reduction method is occupied about 5%.
Nitrobenzene iron reduction method is using intermittent production and reduction nitrobenzene into aniline through hydrochloric acid medium under about 100 ℃. There are many devices adopt this method in China because that method can byproduct of iron oxide pigments. The rapid development of MDI and other downstream products brought hitherto unknown opportunities to the development of aniline industry. The experts recommended that small and medium sized enterprises must develop Adiabatic Nitration Technology with independent intellectual property rights, reduce energy consumption and cost in order to improve China’s aniline industry competitiveness in the international market.