A Record of Chemical Industry in Tang China

In the seventeenth year of the Zhenyuan era, Shen Yanzhi, a modern chemical engineering PhD, was transported to the Tang dynasty when a laboratory explosion killed him. He became a displaced salt worker in Longyou. Drawing on his chemical engineering expertise, he found a way forward by improving salt production: he used wood ash to remove impurities with alkali and evaporation ponds to concentrate brine, revitalizing the salt trade in the Western Market and earning the favor of officials from the Ministry of Works. He then turned his attention to the salt lakes of Hedong and the farmland of Guanzhong, using organic fertilizer to increase grain yields, coke to improve iron smelting and military equipment, and alcohol-based medicines to quell epidemics. In this way, he embedded a modern chemical industry into the framework of the prosperous Tang dynasty.