Boiler Upgrade: Chemical Recovery for Nylon Production

Aug. 1, 2011
UBE Chemicals operation in Rayong, south of Bangkok in Thailand, is engaged in the production of nylon from raw materials. In the production process, chemicals are released and can be combusted.

The planned replacement of a chemical recovery boiler will mean recovered chemicals can be combusted more efficiently, creating energy extraction benefits with a minimal burden on the environment.

The current combustion process will be replaced with a more efficient solution in the form of a newly designed incinerator to be situated within the existing structure. Metso Corp., a Helsinki, Finland supplier of automation and recycling technology and services for power generation, pulp and paper and other industries, is providing the replacement, based on a recovery boiler concept it uses in the pulp and paper industry.

“Metso has previously performed a similar replacement for UBE Chemicals in Spain, when a new combustion plant for chemicals was installed with exceptional results,” says Watchara Pattananijnirudorn, executive vice president of UBE Chemicals Thailand.

According to Mikael Berg, project manager for service and project execution for Metso’s Power business, the new pressure vessel concept will utilize burners at two levels, where fuels are sprayed into the burning chamber section of the boiler. Combustion air is then added in a three-level air system, and the air ports are equipped with automatic rodding devices for remote operation.

The firing technique significantly reduces the amount of sodium carbonate carry over in flue gases, says Berg, and heat is recovered in the heat absorbing surfaces consisting of water screens, convection and economizer. The various heat absorption areas are cleaned by soot blowers. The smelt is discharged to the dissolving tank through the water-cooled smelt spout, which is designed for automatic rodding by Metso’s DeckHand, an industrial robot. 

“Our choice in Metso for this project is due to their innovative and efficient skills proven during earlier cooperation”, says Pattananijnirudorn. The total value of the order is more than 10 million Euros, and commercial start-up and take over is scheduled for summer 2012. 

In related news, Metso announced that it has opened a new valve service center in France, at Gainneville in the Normandy area. The facility, which covers 500 square meters of workshop, storage, training and office space, performs valve repair and overhaul work as well as value-added services such as criticality analysis, valve HealthChecks, and customer-specific predictive and preventive maintenance programs. The new center is one of 31 Metso valve service centers globally, according to Karine Jadot, national service manager for Metso’s Flow Control business unit, automation.

Renee Robbins Bassett, [email protected], is Managing Editor for Automation World magazine.