PEM Process Details
The PEM® system uses heating from electrically conducting gas (a plasma) to convert waste feeds to valuable products. PEM systems are highly effective in processing a wide variety of waste streams, including hazardous, medical, radioactive, industrial, municipal and tire wastes; transforming them into valuable commercial products including energy (ultra-clean power generation or transportation fuels production, using the syngas) and industrial materials (chemicals from the syngas; roofing tiles, insulating panels, sand-blasting media and other construction-related products from the glass; and recoverable metals). The PEM system is environmentally attractive based on its minimal environmental impact and ability to provide near-total destruction of organic materials (providing large volume and weight reduction).
Feedstock is introduced to the PEM process through a feed system designed specifically for the type of materials being processed.
The Pregasifier acts as a ìpreliminaryî processing zone in which a majority (approximately 80%) of the organic portion of the feedstock is converted to syngas. The remaining feedstock, consisting of inorganic materials (dirt, glass and metal for example), carbon, and other un-processed organics pass through to the outlet at the bottom of the Pregasifier and into the PEM Process Chamber.
PEM Process Chamber:
The remaining feed materials from the Pregasifier are dropped onto a molten glass surface near the plasma-arc zone, within the PEM Process Chamber. The plasma arc provides the intense energy needed to rapidly gasify the remaining organic materials, converting them to syngas. The remaining inorganic components are incorporated into the molten glass bath. The syngas exits the PEM Process Chamber and flows to the Thermal Residence Chamber (TRC).
Thermal Residence Chamber (TRC):
Syngas streams from the Pregasifier and the PEM process chamber are ducted to the TRC, which is designed to provide additional residence time at a high enough temperature to fully process any remaining organic materials present in the syngas and allow the gasification reaction to reach equilibrium.
AC and DC Power Supplies:
The primary power supply system for the PEM introduces both joule-heating and plasma energy into the PEM Process Chamber by means of separate power supplies for the DC plasma and the AC joule heating system. The DC power is used to produce the plasma-arc, which provides most of the energy for gasification of the feed material. The independent AC power heats and maintains the glass bath temperature, allowing the plasma-arc power to be focused on the gasification process and not on maintaining the molten pool (as in typical plasma-based systems).
Drain Power Supplies:
The drain power supplies are used to operate the drains, which allow molten glass and metal to be removed from the system during operation.
The syngas leaving the TRC is cleaned and conditioned in a series of standard processes to prepare it for use in any final products.
The syngas may be used for a variety of applications such as electric generation, liquid fuels production or conversion to industrial products such as hydrogen.