MDI-Plant

Brief Overview

Closed in May 2003, the complete MDI facility is now immediately available. The plant is based on ICI technology and was last operated by The Dow Chemical Company. The MDI plant underwent over 45,000,000 USD in upgrades between 1996-2001. The facility has ISO 14001 and EMAS certification.

This is an ideal opportunity to purchase well maintained high-end processes and enter an expanding market at a fraction of the cost of new. The raw material yields and utility consumptions are the same as with a new plant. The MDI facility in Brindisi, Italy was acquired from Enichem in 2001. Enichem licensed the process technology for MDI from ICI in 1979. Enichem then completed various improvements over the years.
 

Capacity:

65,OOO Tons/year
 

Technology:

ICI
Badger (Engineering)
 

Shut Down:

2003
 

Major Upgrades:

- $45MM from 1996-2001
- New Urethonimmine Prod. Unit
- Upgraded no-break system
- Distillation & isomers column
- MDI Capacity Expansion
- MDI/CO/CL2 plant revamping
 

Raw Materials:

- Aniline
- Formaldehyde
- Sodium Hydroxide
- Chlorine
- Methanol
- Monochlorobenzene
- Antioxidants
   - BHT, TPP, Irganox 1135
- Catalysts
   - TMOF, Thionyl Chloride, MPPO
 

Products Produced:

- PMDA
- CO
- CL2
- Phosgene
- PMDI
- HCl
- MMDI

Documentation:

Available
 

Process Description

PMDA Production
PMDA production begins with a set of batch reactors in which Formaldehyde, Aniline (in excess), and HCl solution are added to the reaction vessel and the subsequent reaction to benzylamine. The benzylamine solution is then forwarded to an isomerization tower where the rearrangement takes place to form methylene dianiline (MDA). The methylene dianiline solution is then forwarded to neutralization where the HCl is neutralized with NaOH and then to separation of the two liquid phases. The organic phase containing the neutralized methylene dianiline is then washed in a Graesser contactor to minimize residual salts formed in neutralization and then forwarded to the aniline stripper where they are process under vacuum for removal of excess aniline and any residual water remaining from the wash step.

CO Production
CO is produced in the CO plant by reacting Methane with O2 and the subsequent purification of the CO to remove CO2 and other by-products. The purified CO is then fed to the phosgene reactor.

Cl2 Purification
Chlorine is received in railcar and purified to remove and heavy compounds. The excess Cl2 and heavy compounds are then absorbed to produce Sodium Hypochlorite. The purified Cl2 is then fed to the phosgene reactor.

Phosgene
Phosgene (COCl2) is produced by stoichiometric mixing CO and Cl2 with a slight excess CO (10% molar) through a carbon bed and subsequent purification to remove the excess CO. The phosgene is then condensed into a double walled vessel for feeding to the Phosgenation reaction step.

PMDI Production
(Phosgenation, HCl Gas Purification, Solvent Recovery & Solvent Purification)
PMDA is mixed with monochlorobenzene (MCB) as a solvent and fed to the Primary Phosgenation Reactor. The fresh COCl2 is mixed with recycled COCl2 and fed to the Primary Phosgenation Reactor. The Phosgenation reaction process consists of four continuous stirred tank reactors (CSTR’s) in series. The phosgenation product slurry is then forwarded for phosgene and MCB removal. The HCl/Phosgene stream then goes through HCl Gas Purification where the HCl is taken as a purified overhead stream and the COCl2 is absorbed in MCB and then overhead distilled back to be recycled to be mixed with fresh COCl2 and fed to the Primary Phosgenation Reactor. MCB is subsequently processed to remove any heavies and recycled back to mix with the PMDA. The purified phosgenation product (PMDI) is then ready for separation.

HCl Solution
The purified HCl gas is absorbed in water for use in PMDA production and excess HCl is sold to customers.

MMDI Production
(MDI Evaporation, Crystallization, Distillation)
PMDI is fed to MDI evaporation where a crude MMDI is vaporized and fed to Crystallization. The product of Crystallization is Pure MMDI and mother liquor; the mother liquor can be fed to distillation to produce additional MMDI and high op to use and sales. The bottoms liquid from MDI evaporation (PMDI) and the op streams produced then go to Storage & Blend.

Uretone Imine
Uretone Imine is made in a batch reactor using a catalyst that is subsequently deactivated with an active chloride.