Environmental impact assessment of caprolactam production – a case study in China

A life cycle assessment was carried out using IMPACT2002+ to estimate the environmental impacts of caprolactam production in China. The technology highly contributed to the potential impacts of carcinogens, respiratory inorganic matters, global warming, and non-renewable energy. The technology played a limited role in the categories of non-carcinogens and terrestrial ecotoxicity. Specifically, the emissions from the steam, electricity, benzene, sodium hydroxide, hydrogen peroxide, ammonia, and sulfuric acid production processes involved played important roles, whereas the potential impact generated from other elements was quite small. Caprolactam recovery from nylon filament yarn, the use of natural gas-based energy generation system, and increasing the efficiency of nitrogen oxide and ammonia emission control systems are the key factors for reducing the overall potential environmental impact of caprolactam production in China.