Benzene Adiabatic Nitration

At the end of 2021, we handed over a new benzene adiabatic nitration unit with a capacity of 120 kt / year to a customer from BC-MCHZ Ostrava. As part of the overall investment project in BC-MCHZ, our company, as a EPC supplier, implemented the  main technology process line.

The proces line of Adiabatic Nitration of Benzene is divided into sub-units:

• Nitration

This unit is designed for the reaction of raw materials to form the desired product - nitrobenzene. In this part, benzene and nitric acid react in a circulating stream of sulfuric acid to form mononitrobenzene.

• Washing raw NB

The crude nitrobenzene is fed to a system of washing machines, where it is gradually separated. Process water is used to wash it.

•  Distillation NB

The last step in purifying nitrobenzene is separation the benzene. The nitrobenzene from the scrubbing section flows through a heat exchanger to the benzene distillation column, where vacuum distillation takes place.

•  Wastewater treatment

The purpose of wastewater treatment is to regenerate entrained and dissolved nitrobenzene before this water is led to a wastewater treatment plant.

•  Degassing system

All tanks and reactors in the technology are sealed with nitrogen. The flue gases are then led to the gas collector, where they are discharged below the liquid level. The liquid used is water condensate from the acidic part of the wash, which circulates and entrains a small amount of acids (nitric and nitrous).

•  Defective water pumping

A concrete sumps are used to collect leaks of technological liquids arising during the operation of the technology and during the emptying of the technological equipment and piping.

•  Utilization of residual heat

Utilization of residual heat of the tank with steam condensate for heating (tempering) of several devices.

• Liquid waste bottling

The technology generates two liquid wastes, namely waste oil and aliphatic compounds. Waste oil is generated during the treatment of alkaline scrubbing process water. Waste oil is pumped by a circulation pump from the nitrophenol separator to a mobile container, which is filled to an external company for further processing after filling.

Aliphatic compounds are formed during the distillation of nitrobenzene. Part of the benzene condensed in the condenser and subsequently separated in the benzene / water separator is pumped back to the benzene distillation column. This stream is used intermittently to purify the system of aliphatic compounds.

Parameters:

Performance of the line: 120kt / year of nitrobenzene

Construction: 2019 - 2021

Customer: BC-MCHZ s.r.o., Ostrava, Czech Republic

Licensor: NORAM Engineering and Constructors Ltd.