The Alter NRG Plasma Gasification System using Westinghouse Plasma Corp. (WPC) Technology is designed to provide users with a syngas tailored to the downstream process needs of the customer. The major components of the Alter NRG Plasma Gasification System are included in Alter NRG’s scope of supply, while the balance of plant engineering is completed by an engineering procurement construction and management (EPCM) firm using equipment proven in power and gas processing applications throughout the world. The components displayed in the green box in the diagram below indicate the scope of supply for Alter NRG’s Plasma Gasification System.

Alter NRG Plasma Gasification System

Key Components of the Alter NRG Plasma Gasification System

Plasma Torch Systems

Through WPC, Alter NRG offers four models of plasma torch systems each designed to operate over a wide range of power inputs. This breadth of product offering allows Alter NRG and WPC to best match the plasma power requirements to customer applications.

WPC Plasma Torches

kWe = Kilowatt (Electrical)

Inside the plasma torch, a plasma stream is created by the interaction between air (other gases can also be used) and an electric arc created between two electrodes. The interaction of the gas with the electric arc dissociates the gas into electrons and ions enabling the gas to become electrically and thermally conductive. Torches can be turned up and down to maintain reaction temperatures as feedstocks with higher and lower Btu values are processed and/or feedstocks with higher or lower values of ash/glass/metals are processed.

WPC Plasma Torch Schematic

The Key Advantages of the Westinghouse Plasma Gasification Technology

• Self-stabilized and non-transferred arc

• Operation on many gases – air, oxygen, nitrogen, etc.

• Wide variety of torches available with power input from 80 kW – 2,400 kW

• High thermal efficiency

• Plasma torches have no moving parts resulting in high availability
  • Torch consumables are quickly replaced without shutting down the gasifier
  • Long electrode life

Alter NRG Plasma Gasifier
The Alter NRG Plasma Gasifier provides unmatched flexibility to process a variety of feedstocks including municipal solid waste (MSW), industrial waste, biomass, coal, petroleum coke and tires, when compared to most other gasification technologies.

Alter NRG Plasma Gasifier

The Plasma Gasification Process Inside the APG

The APG is a refractory-lined vessel that stands about 60 feet tall (based on Alter’s largest reactor size). Plasma torches, which provide heat for gasification and melting, are located around the periphery near the bottom of the reactor. The heat from the torches is used to heat up a bed of foundry coke. The temperature at the center of the coke bed very near the plasma torches is greater than 3,000^oC (5,400^oF). The temperature at the top and bottom of the coke bed is approximately 1,650^oC (3,000^oF). Air and/or oxygen inlets are located just above and below the top of the coke bed.

After the feedstock is converted to syngas it exits the top of the reactor at a temperature of approximately 900-1,000^oC (1,650-1,830^oF) where it begins several gas clean-up steps before the syngas can be converted into various energy products.

The extreme temperatures within the reactor ensure that:

• All organic material is converted to syngas

• Any material that cannot be gasified is melted and flows out as molten slag.

Long residence times within the reactor ensure there is sufficient time to crack any tars and minimize particulate carryover, a systemic problem for many other gasification systems.

Feedstock materials enter the APG through the feed port which can be located on the side of the reactor or at the top. The feedstock either gasifies immediately upon entering the reactor or falls onto the coke bed where complete gasification occurs.

APG benefits include:

Industrially-Rugged Design

At the General Motors Foundry in Defiance, Ohio, the original plasma torches have been operating reliably since 1989.