METHOD OF RECOVERING PRODUCTS FROM WASTE FLOW OF ACRYLONITRILE PRODUCTION PROCESS

摘要

Process for recovering reactants and products e.g., acrylonitrile and hydrogen cyanide from an aqueous stream obtained in the ammoxidation of propylene which comprises heating an aqueous stream containing the afore-said compounds in a heat exchanger by circulating the stream at a velocity of at least 6 ft/sec through the exchanger while maintaining the stream in the liquid state to increase the temperature of the stream to at least 105 DEG C and thereafter rapidly reducing the pressure of the heated stream sufficiently to vaporize 0.2-5% thereof and thereafter returning the vapor to the acrylonitrile process for recovery of energy used to heat the aqueous waste; usable materials e.g., acrylonitrile and hydrogen cyanide and compounds such as ammonia which can be used to neutralize acid streams and subsequently either incinerating the unvaporized material directly or using the unvaporized material as fertilizer after appropriate treatment.