All of the high temperature boiler/reactors – a key component of the TVRC technology –  installed and operating to date required an air permit from the applicable regulatory body. Typically, these systems are designed to comply with emissions levels for particulate matter (150 μg/m3), NOx (0.04 PPMV), SOx (0.03 PPMV) and carbon monoxide (9 PPMV), as well as the other typical reference pollutants as they pertain to air emissions.

Below is a summary of the most recent third party emissions testing conducted on a recently commissioned PTDR plasma-arc, plasma gasification. The test was conducted for medical waste treatment. The summary also compares the results to current United States air emission regulations.

The following parameters were also tested but were found to be non detectible (Detectible limit in parentheses) Chlorides as Cl (1.4 mg/m3), Ammonia (5 mg/m3), Hydrogen Sulfide (1.4 mg/m3). With regards to Volatile Organic Compounds (VOCs), the testing for Benzene, Ethyl Benzene, Toluene and Xylene were all below the detectible limit (1 mg/m3). Finally, with regards to heavy metals with the exception of cadmium, which is listed above, all were below the detectible limit of 1 μg/m3 (antimony had a detectible limit of 5 μg/m3).

It is worth noting that the above emissions for the PTDR plasma-arc, plasma gasification were measured when the energy recovery system (gas engine was not operating and thus the syngas was thermally oxidized. It is noted that if the syngas is utilized in a gas engine or other syngas utilization equipment, then the only gas emissions associated with the PTDR plasma-arc, plasma gasification system would be the exhaust from that source.

According to the United States Environmental Protection Agency’s “Solid Waste Management and Greenhouse Gases: A Lifecycle Assessment of Emissions and Sinks”, disposing of 650,000 tons per year in a landfill without gas collection, could reduce its Greenhouse Gas (GHG) emissions by about 260,000 Metric Tons Carbon Equivalent (MTCE) per year by managing waste in a mass burn combustor unit. For this preliminary discussion, this equates to 0.40 MTCE/ton avoided from landfilling.

However, the EPA’s document uses a combustion system efficiency of 550 kWh per ton of mixed MSW. The high temperature boiler/reactor system in the TVRC system, which combines a high temperature boiler/reactor with a plasma-arc, plasma gasification sytem, has an efficiency of approximately 690 kWh per ton – 25% greater efficiency; thus the high temperature boiler/reactor has the potential to generate approximately 0.50 MTCE/ton avoided from landfilling or in total up to 82,500 MTCE, when assuming 500 TPD.

Additionally, the EPA estimates greenhouse gas (GHG) emissions range from 10 to 20 million metric tons, depending on the different methods used to estimate the biogenic fraction of MSW. EPA’s eGrid (a database of information on electrical generators in the United States) indicates about 53% of the energy generated by MSW combustion facilities is from biogenic sources and 47% is fossil-fuel derived power. If we take that 53% and presume the same percent of GHG emissions are from biogenic sources, then MSW combustion facilities generate less GHGs than fossil-fuels.

EPA estimates the GHG savings from WTE to be about 1 on of GHGs saved per ton of MSW combusted.

Any fly ash generated in a Thermal Volume Recovery and Conversion System is converted on-site into a vitrified matrix product, thus converting an unusable by-product from the high temperature boiler/reactor system into a usable end-product.

As previously discussed in this blog section as well as on PEAT’s website, the vitrified matrix could be used in a variety of commercial applications including concrete aggregate, insulation, roadbed/fill construction and even in decorative and non-decorative tiles. Independent laboratory tests (i.e. “TCLP”) have proven that the vitrified matrix does not leach, is totally benign and safe for any re-utilization.

PEAT has conducted a range of testing on this material include Toxicity Characteristic Leaching Procedure (TCLP) tests. A summary of the test results can be seen below when fly ash was processed:

The most recent TCLP results on the vitrified matrix from PEAT’s plasma-arc plasma gasification PTDR system previously located at a China refinery is presented in the below table.

In the proprietary TVRC technology MSW processing occurs in a high temperature (over 850°C) reactor/boiler via a reciprocating grate system. This reactor/boiler consists of high alloy steel casing grates (thus air cooling is sufficient) and is lined with high-grade refractory/insulation materials.  Each (two modular units assumed in this example) high temperature reactor/boiler is capable of producing approximately 84 tons/hour of steam (450°C) at 3.82 MPa with a gross calorific value of the MSW assumed at 2,400 kcal/kg.

This indicates that the 500 TPD assumed in this example would be converted into over 13 MW of electricity. The plasma-arc plasma gasification PTDR system would also produce approximately 5,000 metric tons per year of vitrified matrix through the processing of fly ash. Any bottom ash generated (estimated at 20% of quantity processed in the high temperature reactor/boiler) would be collected and provided and/or sold as cement aggregate.

A basic, illustrative mass/energy balance can be seen below . The below assumes that the excess plasma-arc plasma gasification PTDR system capacity is utilized to treat medical waste.

PEAT’s solution for municipal solid waste is the Thermal Volume Reduction & Conversion™ (“TVRC”) technology – an innovative system that combines a thermal volume reduction system with its core PTDR plasma-arc plasma gasification system.

Each TVRC system (modular) can process up to 250 tons per day of municipal solid waste (MSW) with no secondary pollution or unusable by-products generated: all feedstock represents a 100% waste diversion, eliminating the need for landfill disposal and/or further processing. It eliminates any future liabilities to the generators resulting from the use of outside collection, treatment and disposal services/facilities that are potentially unscrupulous. Further, a TVRC system generates high volume (over 8 to 1) and weight (over 4 to 1) reductions.

In a TVRC, MSW is first thermally processed in a high temperature reactor/boiler to generate steam. This steam is then processed in a full condensing steam-turbine generator for electricity production.

Any gas generated is processed through a flue gas cleaning system that removes any potentially harmful gases to surpass European emission standards.

Any fly ash generated in the high temperature reactor/boiler is processed is the PTDR plasma-arc plasma gasification & vitrification system. The PTDR converts the ash into an inert, non-leachable vitrified matrix that can be used in a variety of commercial applications including concrete aggregate, insulation, roadbed/fill construction and even in decorative and non-decorative tiles. Independent laboratory tests (i.e. “TCLP”) have proven that the vitrified matrix does not leach, is totally benign and safe for any re-utilization.

Any residual by-products generated in the gas cleaning systems (i.e. baghouse catches, scrubber residue, etc.) is collected and also processed in the PTDR system, thereby creating zero residual waste from the TVRC.