What would happen if hydrochloric acid is poured into a sulfuric acid tank?

On July 7, 2004, at a brewery in Marke, Baru é region, a delivery man transporting 2 tons of hydrochloric acid (HCl) connected a tanker truck to the feed inlet of a sulfuric acid (H ₂ SO ₄) storage tank, which was adjacent to the feed inlet of the HCl storage tank, without the presence of factory employees. After the pump started, a cloud of smoke immediately formed and was released through the discharge tube of the storage tank. After verification, the delivery was stopped, but at this time, 500 liters of hydrochloric acid had already been delivered to 1500 liters of sulfuric acid. Employees in buildings affected by smoke were evacuated. This area has been marked and entry is prohibited. Prior to the arrival of an emergency team from the transportation company, the storage tank was continuously cooled with water. The team transferred the contents of the tank to a pre filled tank with 10 cubic meters of water, thereby slowing down and ultimately stopping the exothermic reaction. A chemical accident emergency response team measured the concentration of hydrogen chloride to be 0.5ppm. Preliminary analysis of the cause of the accident indicates a lack of formal conveying procedures, which require all conveying operations to have factory employees present. In addition, the delivery personnel responsible for transporting sulfuric acid were temporarily arranged to transport hydrochloric acid on the same day. The feeding ports of the two acids are adjacent to each other and protected by the same locked cabinet.
Because concentrated hydrochloric acid is discharged into concentrated sulfuric acid, the water absorption and exothermic effects of concentrated sulfuric acid cause the hydrogen chloride in hydrochloric acid to rapidly evaporate, resulting in liquid splashing and container heating.
To avoid the above situation, the following actions can be considered:
1. Each feeding port is equipped with a separate padlock, with double checking and double confirmation by two people.
2. Interface uniqueness modification. Different types and incompatible chemicals of storage tanks are equipped with differential specifications of quick couplings at the inlet, such as DN50 couplings for sulfuric acid and DN80 couplings for hydrochloric acid, or mechanical locking devices with different codes. Only the discharge pipelines corresponding to the chemicals can be matched and connected, physically eliminating the possibility of misconnection.
3. The inlet pipeline has clear pipeline direction markings.