A1. In the incineration process, waste is combusted in a single chamber. The large amount of air required for complete combustion (approximately six tons  of air for every ton of waste) leads to high mass transfer rates in the combustion chamber, with entrainment of particulate matter in the exhaust gas and poor control of flame temperature.

In rotary kiln thermal treatment, only about 30% of the air required for complete combustion is fed into the rotary kiln. The fuel in the kiln is further heated through partial combustion during which the material is volatilized to form a clean fuel gas (mainly N₂, CO, CO₂, H₂, H₂O, and CH₄). This fuel gas (known as producer gas) is sent to a LoNOx gas burner for final, complete combustion. Using recycled flue gas mixed with outside air, pollutant pre-cursors are destroyed, and flame temperatures can be maintained below the temperatures at which thermal NOx forms. This method prevents pollutants from forming while increasing efficiency and reducing equipment size and cost.

EPR’s rotary kiln thermal treatment of solid recovered fuel (SRF), comprised mainly of dry biomass and plastic, is more reliable and cleaner than incineration, especially mass burn incineration, in which little or no sorting of the waste is done prior to the combustion process.

A2. The first steam turbine driven dynamo was demonstrated in the 1880s and these reliable and efficient prime movers now account for more than 80% of the electrical power generated in the United States. While steam turbine generators may be less thermally efficient than piston engines as prime movers for electrical generators, at the 50 MW generating capacity scale, steam turbines are safer, cleaner, and less expensive, as well as more rugged and reliable.

The fuel gas produced in the rotary kilns exits high temperature and would need to be cooled to near ambient before it can be used in a piston engine. As the fuel gas cools, tars condense out of the gas phase and these can cause operating problems in piston engines. Additionally, CO and NOx formation are very difficult to control in reciprocating engines. In the EPR LoNOx system, the hot fuel gas is cleanly combusted using a combination of outside air and recycled flue gas. This hot combustion product gas >900 Degrees C is cooled to an optimal temperature for boiler operation (about 760 Degrees C) by recycled flue gas and directed to heat recovery boilers that produce the steam to drive the turbine generators. This use of proven conventional steam power plant equipment results in a safe, reliable and environmentally responsible power plant.

A3. Plastics are polymers made from fossil fuels such as petroleum, natural gas or coal. Polymers are long chains of tens of thousands of repeating chemical units, mostly carbon and hydrogen. When heated in the right conditions, some of the chemical bonds in the chain break in a process called cracking. From plastics such as polyethylene and polypropylene, for example, most of the resulting molecules are the same as those that are found in diesel and gasoline fuels. Smaller molecules that form such as methane, ethane, and propane remain in the gas phase and are used to fire generators that supply the plant with electricity. The solid phase by-product of the process is a carbon-rich char that is used as a fuel for the power plant rotary kilns.

A4. Stack gas from the WTE power plant will be comprised mainly of inert nitrogen (N₂), carbon dioxide (CO₂), water vapor (H₂O), and oxygen (O₂). The relative percentages of these components in the stack gas from the rotary kiln power plant is shown in Table 1.

Table 1. Exhaust Flue Gas Major Constituent Flows

A5. SWP designs, builds and operates its plants to comply with applicable emission standards in the jurisdiction in which the plant is being built as well as those of the US EPA.

Industrial air emission standards for the Province of Newfoundland and Labrador are set forth at: https://www.assembly.nl.ca/legislation/sr/regulations/rc040039.htm

Air emission standards commonly have three components. These include:

1. Limits on the concentrations of regulated components emitted from the stack. These concentrations are standardized to a specific % of oxygen in the exhaust or flue gas. In NL, concentrations are normalized to 11% oxygen.
2. Limits on the total amount, by mass, of regulated components emitted annually in units of tons per year. In NL a per ton per annum fee is charged for emission of regulated components over 50 tons p.a., for example.
3. Finally, and most importantly, limits on the overall concentrations of regulated components in ground level ambient air. These latter limits ensure that the total emissions from all sources (e.g. ships, trucks, home heating fires, and the proposed plant) do not exceed the air quality limits. Were a proposed new plant to cause an exceedance of the ambient air quality limits, that plant may not be approved by the regulatory

NL regulations specify minimum ambient air quality. NL also regulates the concentrations of mercury and dioxins for the overall plant site including the rotary kilns and plastics conversion plants. SWP has not finalized emission estimates for these trace components for this site. However, other designed EPR plants operate at a small fraction of the emission rates required to meet these standards.

A6. The nearest residence will be about 2.5 km from the onsite stacks. Based on an initial air dispersion analysis, the estimated average and maximum ground level particulate concentration, due to plant operations, at the nearest residence will be 0.5 and 3.0 μg/m3 respectively. This can be compared to the NL ambient air quality standards of 60 and 120 μg/m3 for average and maximum concentrations respectively.

A7. The primary pollutants of interest from the hydrothermal liquefaction portion of the plant will be NOx and CO. While detailed design of this portion of the plant is not complete, the air emissions will be very similar to the emissions from any reciprocating engine, The air pollution control systems will be designed to keep pollutant concentrations well below the NL Provincial industrial air emission guidelines.

A8. The bottom ash from the rotary kilns system will be granular and consist of primarily silica, alumina and lime. The surface area reduction that occurs in the kilns reduces the leaching potential of the ash. This ash can be used in a variety of construction applications. There will also be a smaller fraction of fly ash from the air pollution control systems. These fly ash components will contain relatively higher concentrations of salts and will be retained in a lined landfill.

A9. Projected solid residue production is based on the specifications for 750,000 tons p.a. of solid fuel to be used onsite. The fuel will contain around 12% inorganic material that will leave the system as ash. This means about 92,000 tons p.a. of ash will be produced when the plant is running at full capacity. Most of this material will be inert and suitable for beneficial use, in the Newfoundland or potentially in Europe.

Around 5% of the ash material will be leachable and thus unsuitable for beneficial use. This will be stored in a lined landfill.

A10. Depending on fuel composition, the sintered rotary kiln ash should be usable as a sand like material for road traction. This material will be tested for leachability. Batches that meet the US EPA TCLP non-leachability criteria as well as any applicable Canadian Federal and Provincial standards for construction fill can be used for roadbed fill and other construction and architectural uses for sand or fine aggregate. EPR has contacted construction material companies in Europe that have expressed interest in importing this material.

This material can also be used for daily cover at the local landfill and transported as backhaul when waste is delivered from the local landfill to the Lewisporte plant.

A11. The two solid waste streams from the hydrothermal liquefaction (HTL) plant will be plastic rejects such as PVC, the sediment from the plastics washing system, and a small amount of ash representing any inorganic material in the plastics. The sediment, ash and the rejected plastic, comprising 1-3% of the weight in the feedstock, will be landfilled.

A12. Certain non-recyclable materials brought onsite will not be suitable for either waste to energy or hydrothermal processing, including ceramics, glass and certain plastics, such as PVC and Teflon. These materials will be sent to a landfill. SWP will enforce strict fuel specifications to minimize the quantity of these materials imported into Newfoundland.

A13. The site will not include a landfill but will have a storage pad for storing the inert bottom ash until it is removed for beneficial use. Local and export demand for this material may be seasonal. The storage area will accept no putrescible materials and will not support anaerobic production of methane (CH4) carbon dioxide (CO2) or other gases.

A14. The main water source for the project will be surface water from a large pond on the project property. The water management system will include a water treatment plant with associated storage tanks and distribution system. Influent water will be filtered and stored in a tank before treatment, serving as both a reservoir for all process and sanitation functions as well as the fire water reserve. The primary process uses of water are for make-up to the steam cycle and cooling water for both the power plant and the hydrothermal liquefaction facility. Water is also used for personnel and facility sanitation. Water for make-up to the steam cycle is treated in a conventional reverse osmosis purification.

Storm run-off drainage and plastics washdown drains will be collected in a separate lined settling pond that will be monitored for contaminants and treated as necessary to comply with provincial environmental control policies prior to any effluents being discharged to local waterways.

The wastewater treatment system is designed to process and reuse wastewater for multiple purposes including facility sanitation, leachate pipe flushing, site irrigation, and ash conditioning.

A15. SRF is sorted, non-recyclable plastic, paper, cardboard and wood. The materials will be baled and wrapped in plastic to prevent fugitive material from leaving the ship while underway or the site while in storage. This system has been successfully used in Europe for storing and shipping SRF for more than a decade.

Suppliers in Europe bale and wrap dry plastic and biomass (SRF) and load it onto bulk carrier ships. At the new dock on the south shore of Burnt Bay, bales will be unloaded and stacked outdoors. As needed, bales will be moved indoors to be further sorted prior to final processing to make liquid fuel or electrical energy.

A16. The SWP plant will be a net generator of electrical energy to the grid. Fuel for the conventional steam power plant will come from mainly from the biomass portion of the SRF. There will also be some power generation from the Hydrothermal Liquefaction Plant. Excess renewable power from the plant will be available to the grid at a cost below that of current provincial power rates.

A17. The Lewisporte plant will be designed, permitted and operated in strict accordance Newfoundland Provincial Air Emission and Ambient Air Quality Standards, as well as all other Canadian Federal and Provincial environmental regulations. Prior to construction, the project will go through a thorough permitting process, which will include an environmental impact statement and baseline environmental study performed by a highly qualified independent engineering company with offices in St. John’s.

Environmental monitoring of air emissions and ambient air quality, as well as monitoring of ground and surface water quality will be carried out as required by law. Material to be placed in the onsite landfill will be tested prior to placement and fuel products will also be analyzed to ensure quality before shipment.

A18. There are several potential sources of thermal energy that could be provided to nearby facilities. The largest potential source is a combined heat and power system fueled by the biomass rotary kilns. This would be delivered as hot water to nearby users. There has been local interest in using this heat source for greenhouse farming and a recreational facility. These facilities would not be owned or controlled by SWP.

A19. There are several potential sources of thermal energy that could be provided to nearby facilities. The largest potential source is a combined heat and power system fueled by the biomass gasifier. This would be delivered as hot water to nearby users. There has been local interest in using this heat source for greenhouse farming and a recreational facility. These facilities would not be owned or controlled by SWP.