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Industrial plant : Hitachi

Hitachi

This is our system for refining, recovering and reusing or combusting volatile organic compounds (VOC) emitted by factories. It offers direct support for our customers' environmental practices.

Case introduction

Ethyl acetate recovery and refining system

Photograph: Ethyl acetate recovery/refining facility

Overview
Delivery year 2009
Delivery location Japan
Treatment capacity 18,000 m³N/h.
Solvent recovery quantity 370 tons/year (estimated)

This is one of the type VOC processing systems to recover and refine ethyl acetate as VOC, which is emitted by the laminator in packaging film factory.
This system complies with the VOC emissions regulations in Japan's Air Pollution Control Act. Its aims are to lessen the burden on the environment and boost recovery of investment through reuse of resources.

Emissions gas concentration and combustion system (stored heat combustion)

Photograph: Facility for concentration and combustion of emissions gases (stored-heat combustion type)

Overview
Delivery year 2005
Delivery location Japan
Treatment capacity 72,000 m³N/h.

This system is used in conjunction with printing equipment and laminators for packaging film, for the concentration and combustion of the mixture of toluene and ethyl acetate exhaust solvent gases emitted during the drying process. During ordinary operations, the system saves energy by using no fuel.

What is a VOC processing systems?

Depending on usage conditions, some portion of the volatile organic compounds (VOC) used in factories in the product manufacturing process may evaporate and become mixed in the exhaust gases. Our system recovers (removes) VOC from the exhaust gas, so that the gas returned to the atmosphere is pure. We offer two different type of systems for processing VOC.

Recovery & refining type

After the VOC are recovered, the organic solvents contained in the recovered fluid are refined to a very pure state, for reuse; this helps reduce running costs and makes the system more economical.

Combustion type

The VOC are highly concentrated for combustion, which contributes to energy savings.

Image: Schematic diagram of VOC processing systems
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Scope of supply

We offer EPC projects from planning and design of the facilities through procurement and installation.

Fields of application

Solvents that can be recovered and refined

Simple solvents such as methylene chloride and ethyl acetate

Combustible solvents

Mixed solvents and/or simple solvents such as ethyl acetate, methyl ethyl ketone, isopropyl alcohol, toluene, etc.

Technology

Recovery & refining type

  1. Emissions containing VOC are passed through an adsorption device (activated charcoal) where the VOC are adsorbed and removed, so the gas returned to the atmosphere is clean.
  2. The adsorbed VOC is removed from the activated charcoal using heat, and then chilled for the recovering liquid.
  3. The recovering liquid includes water as well as VOC, so the refining equipment is used to separate a high pure solvent for reuse.

Image: Recovery & refining type system flow diagram
System flow diagram
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Combustion type

  1. Emissions gases with a low density of VOC can be passed through a concentrator where the zeolite adsorbs and removes the VOC, returning purified air to the atmosphere.
  2. The adsorbed VOC is removed from the zeolite using heated air in small volumes, recovering a more concentrated VOC gas that can be combusted in the stored-heat combustion device.
  3. This system also saves energy by reducing the amount of fuel needed for combustion of low-density-VOC emissions gases.

Image: Combustion type system flow diagram
System flow diagram
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