Northbrook, Illinois & Shanghai, China – October 10, 2013 – PEAT International, Inc., (“PEAT”) a leader in plasma-thermal waste destruction systems, announced the successful commissioning of a Plasma Thermal Destruction and Recovery (“PTDR”) system in Shanghai, China. The 60 kg/hr system – designed for medical waste and oil refinery sludge – was installed for Abada Plasma Technology Holdings, Ltd. – an Asian-based renewable energy project developer.

PEAT’s PTDR “single stage” plasma-thermal process transforms hazardous waste through molecular dissociation at 1,500°C (2,732°F) into recoverable, non-toxic end-products, synthetic gas and heat (sources for energy recovery), metals and a vitrified glass matrix. Emissions are below the most stringent environmental standards used anywhere.

“This is end-stage technology and sets the standard for clean hazardous waste remediation. Only with plasma can you achieve temperatures high enough for waste destruction in a single-staged process,” said Joseph Rosin, PEAT International Chairman. “It’s a 21st century solution that addresses three important needs: significant volume reduction, full pollution control and competitive pricing. We are currently preparing for other projects already under contract.”

PTDR systems are in operation in California, Taiwan and China. Go to http://www.peat.com/chinasystem.html for a video of operations and acceptance test run data.

About PEAT International

PEAT International, Inc., headquartered in Northbrook, Illinois, with offices in China, Taiwan and India, is a waste-to-energy (“WTE”) company with its two proprietary technologies – the Plasma Thermal Destruction and Recovery™ (“PTDR”) technology for the treatment and recycling of industrial, medical and other hazardous waste streams and the Thermal Volume Reduction & Conversion™ (“TVRC”) technology for municipal solid waste. For more information, contact Daniel Ripes, dripes@peat.com, at 847-559-8567 and visit www.peat.com.

Previously, we discussed and demonstrated how plasma arc plasma gasification nearly eliminates dioxin formation, this entry looks to address semi-volatile heavy metal compounds and other air emissions.

The high temperatures at which the plasma-arc plasma gasification processes operate can result in the generation of volatile inorganic constituents (i.e. metals and metal oxides), sometimes at a higher level than compared to convention thermal treatment processes, particularly if the waste feedstock comes in direct contact with the very hot plasma-arc plasma gasification plume as these compounds may become volatilize and carried downstream with the syngas generated. While many are removed by the gas cleaning and conditioning systems, in plasma-arc plasma gasification processes where the off gases are not cooled (i.e. plasma combustion, which is not utilized by PEAT) these heavy metal compounds could be carried out in the stack gases, increasing the levels of potential contaminants that are emitted.

Downstream of any quench system or syngas cooler, any entrained particulate matter and/or acid gases (H2S, HCl, etc.) are scrubbed with water typically using either a packed-bed tower/Venturi scrubber or through a dry filtration system. Additional equipment in the form of HEPA or baghouse filters may also be utilized.

The results presented in the below reflect emissions from PEAT International plasma-arc plasma gasification waste-to-energy systems where the syngas was not utilized and ultimately processed in a thermal oxidizer or secondary reaction chamber.

The innovative and patented core Plasma Thermal Destruction & Recovery waste to energy solution is a gasification technology. Gasification is a process that converts organic based carbonaceous materials into carbon monoxide (CO), hydrogen (H2) and carbon dioxide (CO2) by reacting the material (i.e. waste) at high temperatures (minimum 700°C) without combustion with a controlled amount of oxygen and/or steam. The resulting gas mixture is called syngas (from synthesis gas) and is itself a fuel.

PEAT uses the heat generated by plasma-arcs to first pull apart (dissociate) the molecules that make-up the organic portions of the waste, then, depending on the composition of the waste stream, oxygen is added to reform the dissociated elements of the waste into the syngas The syngas can then be used in a variety of ways: as a fuel for thermal and/or electricity production or as a feedstock for the production of liquid fuels, such as ethanol.

Waste, when heated to a very high temperature in the controlled atmosphere of the reducing plasma reactor undergoes predictable physical and chemical changes. This high temperature, over 1,250°C (2,280°F) prevents the formation of complex organic molecules and breaks down organics into a gas. Our operations reflect that the formation of dioxins or furans is practically impossible inside the plasma reactor due to the unique process features, including high uniform temperatures and a lack of excess oxygen within the system.

This hot gas is then fed through a gas cleaning and conditioning system (The gas that comes out of a plasma reactor has a trace of contaminants compared to huge quantities in the stand-alone incinerator), where it is rapidly cooled and cleaned to remove any entrained particulate and/or acid gases prior to potential re-use.

Any inorganic constituents of the waste are melted (vitrified) into an environmentally safe, leach resistant, glass matrix. Plasma Thermal Destruction & Recovery waste to energy plasma reactors are designed to collect the molten metal and glass. The glass and metal layers are removed through controllable tap ports into a slag/metal collection system. Removal of the molten glass or metals presents no hazards of any kind to personnel, requires no special tools and does not disrupt the operating process. The metal layer settles on the bottom of the basin in the processing reactor below the molten glass. Both layers are tapped as necessary, depending on the metal/inorganic content of the waste stream.

The vitrified product can be used in a variety of commercial applications including concrete aggregate, insulation, roadbed construction, and even in decorative tiles. The metal layer can contain relatively pure amounts of iron, copper and aluminum.

It is important to note that the composition of end-products varies with the waste being processed. For example, processing medical waste, with a relatively high percentage of paper and plastic or pharmaceutical manufacturing waste with high levels of carbon-based constituents would produce meaningful levels of syngas, and a lesser amount of glass product. Conversely, processing fly ash from the high temperature boiler in a TVRC would produce lower amounts of syngas and relatively more vitrified product.

Plasma Thermal Destruction & Recovery waste to energy systems are driven by proprietary, state-of-the-art instrumentation and computerized control systems. The Plasma Thermal Destruction & Recovery waste to energy process is a unique, cost-effective and environmentally effective technology that is superior to other mainstream methods of waste treatment:

• The Plasma Thermal Destruction & Recovery waste to energy process can utilize virtually any type of feedstock containing combinations of organic, inorganic and/or heavy-metal constituents thus the pre-processing, staging and management costs are minimized thereby reducing processing costs and enhancing recycling designations.

• Unlike incineration or metal-bearing waste stabilization, the Plasma Thermal Destruction & Recovery waste to energy process is designed to not create any secondary solid wastes that will require further treatment or land filling. As indicated, stand-alone incinerators produce large quantities of bottom and fly ash which are toxic in nature, require further treatment (with stabilization agents) and the resulting post-treated materials (often time whose volume has been doubled) will require final disposal, sometimes in specially designed hazardous waste landfills.

It is also important to note however that through a previous partnership with the Russian Academy of Science, PEAT utilized an AC plasma torch into earlier Plasma Thermal Destruction & Recovery waste to energy systems. The AC plasma torch, which generates the plasma field by utilizing AC electric current directly from the grid without the need for rectifiers (a device, such as a diode, that converts alternating current to direct current). Patents behind the Plasma Thermal Destruction & Recovery waste to energy technology would allow for usage of an AC plasma torch, giving PEAT some additional flexibility. Like electrodes, the AC plasma torch can be more tolerant of a wide range of waste streams (organic and inorganic) and is less expensive to build and to operate than a DC plasma torch. The NCKU facility represented the first applications where an AC plasma torch was utilized in a commercial plant anywhere in the world.

Plasma gasification is a phrase heard often when discussion plasma-arc treatment or waste-to-energy technologies, however this entry looks to give a closer look as to what plasma gasification is and its associated reactions. Plasma gasification is a thermal chemical conversion process designed to optimize the conversion of waste into the synthetic gas or (“syngas”). The chemical reactions take place under oxygen starved conditions. The ratio of oxygen molecules to carbon molecules can be less than one in a plasma gasification reactor (sometimes a stoichiometric amount of oxygen to achieve pyrolysis).

The following simplified chemical conversion formulas describe some of the thermo-chemical processes that are typically occurring in gasification.

Equation 1. C (fuel) + O2 –> CO2 + heat (exothermic)
Equation 2. C + H2O (steam) –> CO + H2 (endothermic)
Equation 3. C + CO2 –> 2CO (endothermic)
Equation 4. C + 2H2 –> CH4 (exothermic)
Equation 5. CO + H2O –> CO2 + H2 (exothermic)
Equation 6. CO + 3H2 –> CH4 + H2O (exothermic)

Some of the waste undergoes partial oxidation by precisely controlling the amount of oxygen fed into the plasma reactor (see first reaction above). The heat released in the above exothermic reactions provide additional thermal energy for the primary gasification reaction (endothermic formulas above) to proceed very rapidly.

At higher temperatures (around 3,600°F) the endothermic reactions are typically favored. Some plasma companies (not PEAT however) introduce supplementary fuels such as coal, petroleum coke or even other hot gases generated by their plasma torches (sometimes referred to as plasma-assisted gasification) to maintain the desired plasma gasification temperatures in the reactor.

The reducing atmosphere within the plasma gasification reactor avoids the formation of oxidized species such as sulfur dioxide (SO2) and nitrogen oxide (NOx). Instead, sulfur and nitrogen (organic-derived) in the feedstock are primarily converted to hydrogen sulfide (H2S) and nitrogen. Finally, typical halogens in the feedstock are converted to inorganic acid halides (HCl, HF, etc.)

Plasma can be described as an electrically-charged gas where a specific amount of energy is added to separate the molecules into a collection of ions, electrons and charge-neutral gas molecules. Plasma indicates a gas volume with sufficient energy supplied (electromagnetic, electric and/or thermal) so that electrons that normally exist in specific numbers and at distinct energy level orbiting around the nucleus are freed from their orbital bonds. This plasma, with its constituents of individual molecules and electrons acts as a conductor of electricity, the resistance of which converts electrical energy to heat.

Depending on the amount of energy added, the resulting plasma can be characterized as thermal or non-thermal.

Thermal plasma heating technologies were widely developed in the early 1960’s in conjunction with space exploration and military applications programs in the United States (NASA) and the former Soviet Union. In particular, plasma torches were developed to provide an effective method to test the effectiveness and durability of heat shields required for space vehicle re-entry.

Plasma-arc systems have been widely used for destruction of hazardous wastes.

This extreme heat from this temperature breaks down wastes, forming synthesis gas (hydrogen and carbon monoxide) and a rock-like solid byproduct called slag.

The significant difference between plasma-arc systems and other thermal waste processing technologies is that the heat required for waste degradation is generated by the plasma itself and not via combustion of all or part of the waste.

PEAT’s Plasma-arc heating system consists of DC-powered graphite electrodes rather than plasma torches, typically marketed by other companies. There are a number of benefits associated with using DC-powered plasma-arc electrodes.

Minimization of capital costs as plasma-arc graphite electrodes generate plasma-arc directly with exposed anodes and cathodes without requiring an independent torch. Plasma torches are expensive and increase the capital costs associated with overall systems.

Minimization of operational costs as plasma-arc graphite electrodes require no water cooling or any externally-supplied carrier gas (i.e. argon or nitrogen). This increases the electrical to thermal conversion rates (typically seen between 75-80% in PTDR systems). Plasma torches require water cooling, carrier gases and have lower efficiencies as their power output can be as low as 50% of the power input for small torches. This means that one half of the electricity of the plasma torch is dissipated to the cooling water or efficiency of the power supply.