Recommitting to a Long Term Waste to Energy Future Through a Comprehensive Refurbishment Program

Created in 1978, the Solid Waste Authority of Palm Beach County (Authority) has developed an “award winning” solid waste management system that includes franchised solid waste collections and the following facilities to service the residents and businesses in Palm Beach County, Florida: • North County Resource Recovery Facility (NCRRF); • Residential and Commercial Recovered Materials Processing Facility; • Five Transfer Stations; • Class I Landfill; • Class III Landfill; • Biosolids Pelletization Facility; • Ferrous Processing Facility; • Woody Waste Recycling Facility; • Composting Facility; and • Household Hazardous Waste Facility. The Authority has proactively planned and implemented its current integrated solid waste management program to ensure disposal capacity through 2021. However, like many communities, the Authority anticipates continued population growth and associated new development patterns that will significantly increase demands on its solid waste system, requiring it to reevaluate and update its planning to accommodate future growth. The NCRRF, the Authority’s refuse derived fuel waste-to-energy facility, has performed very well since its start up in 1989 processing over 13 million tons of MSW, saving valuable landfill space and efficiently producing clean, renewable energy. As the NCRRF approached the end of its first 20 year operating term, it became necessary to complete a comprehensive refurbishment to ensure its continued reliable service for a second 20 year term and beyond providing for continued disposal capacity and energy production for the Authority’s customers. The Authority renegotiated and extended its operating agreement with the Palm Beach Resource Recovery Corporation (PBRRC), a Babcock & Wilcox Company, for an additional 20-year term. The Authority selected BE&K Construction Company (BE&K) and entered into an Engineering, Procurement, and Construction contract (EPC Contract) to perform the refurbishment. The Authority, with assistance from its Consulting Engineer, Malcolm Pirnie, Inc., developed the minimum technical requirements and negotiated the EPC Contract with BE&K. The design and procurement efforts were completed in early 2009 and on-site construction refurbishment activities commenced in November 2009. The refurbishment has a total estimated cost of $205 million. The refurbishment work is sequenced with the intent that one boiler train will remain operational to reduce the impact to the Authority’s landfill and maximize electrical production and revenues during the refurbishment period. This presentation will focus on the improvements to operations as a result of the refurbishment and its positive effects on the Authority’s integrated solid waste management system.

Establishing Project Feasibility for Emerging Technology Projects: An Independent Engineer’s Perspective

Technology suppliers, waste system managers and project developers across North America are endeavoring to find and implement new approaches to converting the energy in waste to electricity or alternate fuels. These entities, as well as potential financiers and communities that might benefit from these emerging technologies, often retain an independent engineer to assist in establishing the status and risks of the technology itself or the feasibility a specific project that has been proposed. Although independent engineering assessments are a well-established element of the non-recourse finance process, individuals and organizations new to the development process are often unfamiliar with the usefulness and content of these assessments. In the context of emerging technology-based projects, this paper will provide an overview of the role of an independent engineer in the development process, explain the typical assessment process, and discuss the content of a typical independent engineering report (“IE Report”).

Waste Combustion Technology and Air Emission Control Developments by Fisia Babcock Environment

The efforts for reducing the emissions into the atmosphere start already in the furnace and are completed by an effective flue gas cleaning system. This implies the necessity for design developments of key components for a modern EfW plant. For the core component of the firing system — the grate — Fisia Babcock Environment (FBE) is using forward moving grates as well as roller grates. The moving grate, which is used in the great majority of all our plants, has specific characteristics for providing uniform combustion and optimal burnout. These include, amongst others: - Uniform air supply by means of specific grate bar geometry. - Two grate steps in direction of waste transport for optimum burnout. - Flexible adaptation of the combustion process to the respective conditions and requirements by zone-specific air distribution and transport velocity of waste on grate. - Combustion control adapted to the specific plant for ensuring a consistent combustion process and production of energy. In addition to these features influencing the emissions the moving grate exhibits also specific characteristics regarding the mechanical aspects allowing low-maintenance and reliable operation. For optimum flue gas burnout a good oxygen distribution after leaving the combustion zone is required. For ensuring this, the injection of secondary air is designed to produce a double-swirl, developed by FBE. Final reduction of the nitrogen constituents NO and NO2 to the stipulated emission value is achieved by the SNCR process. As well in this respect, there is a great amount of experience available. Besides these measures regarding the combustion process, this paper also reports about flue gas cleaning systems. In this field the FBE CIRCUSORB® process is presented and compared with the known dry absorption process. CIRCUSORB® is a lime-based flue gas cleaning process with continuous recirculation of the moistened reaction product and simultaneous addition of fresh hydrated lime. The flue gas temperature downstream of the economizer can be selected very low and permits in this way maximized utilization of the energy. The evaporation of the moisture from the reaction product (flash evaporation) effects final cooling down of the flue gas to optimum process temperature and improves at the same time SO2 separation. This reduces the technical investment required for the flue gas cleaning process. The total of all measures taken and the robust design of all components permit economical plant operation while complying with the stipulated emission limit values.

Novel Gas Cleaning With Integrated Energy Recovery

High-energy recovery combined with low emissions to air and water was targeted when Jo¨nko¨ping Energi planned their new Waste to Energy plant at Torsvik in Sweden. The plant is compliant with the new EU Industry Directive and the Waste Frame Directive R-formula, which defines energy recovery levels for recycle of energy. In total about 160 000 tons of municipal (40%) and commercial waste (60%) is annually converted into usable energy. The average heat value is 11,7 MJ/kg. The energy produced is a combination of electricity (14 MWe) and heat (42–56 MWth, depending on electricity production). The heat is recovered both in a boiler and in a condenser. The flue gas condensing system is combined with a heat pump (10 MWth) to optimize the heat recovery rate. The plant is designed to fulfill the requirements set by the Swedish authorities, which are more stringent than the EU emission requirements. Some examples of the plant emissions to air guarantees: dust 5, HCl 5, SO2 20, HF1, Hg 0,03, Cd+Tl 0,05, other HM 0,5 all in mg/Nm3 and dioxin 0,05 ng/Nm3. The flue gas cleaning upstream of the condenser consists of a combination of a semi-dry system and a wet scrubber. The gas cleaning system operating range goes from 60 000 up to 127 000 Nm3/h depending on load and fuel heat value. The semi-dry system is carrying out the major part of the gas cleaning and is sufficient to comply with the air regulations. However, in order to minimize the treatment of the condensate from the condenser the wet scrubber is installed after the semi-dry system and upstream the condenser. The blow down from the scrubber is reused within the plant. Thus the polishing scrubber secures minimal treatment of the condensate to comply with the local stringent limits, particular chlorides, before release to the recipient lake Munksjo¨n. Emissions to water were 2010 nitrogen 1,7 mg/l, Cl <3,6 mg/l, As 0,66 μg/l, Cd <0,07 μg/l, Cr <6 μg/l, Cu 0,8 μg/l, Hg <0,4 μg/l, Ni <0,66 μg/l, Pb<1,2 μg/l, Tl<1,3 μg/l, Zn<7,2 μg/l and PCDD/PCDF 0,0088 ng/l. In the wet scrubber acid stage residual HCl and excess ammonia from the SNCR system are removed. The latter compound is important to capture in order to prevent eutrophication. The combination of a semidry and a wet system enables an optimization of the flue gas cleaning with regard to the different operating situations, taking into account seasonal demand variations as well as fuel alterations. The concept has demonstrated very low emissions combined with low consumption of lime. The possibility to optimize the flue gas cleaning performance is a prerequisite for minimal condensate treatment and optimal energy recovery. The paper will describe the system and the operating experiences.

Modeling and Measuring Impacts From Ash Landfilling: Using Data to Inform Regulatory Policy

Most ash generated by waste-to-energy (WTE) facilities in the U.S. is landfilled. Studies undertaken in the late 1980’s and early 1990’s indicated no significant environmental concerns associated with ash landfilling. However, in 2001, policy-makers at the Massachusetts Department of Environmental Protection (MA DEP) became concerned that the “cumulative” impacts of landfills, including ash landfills, might pose a risk to human health. To address this concern, we performed an in-depth assessment of impacts to air quality, and theoretical risks to health, from fugitive emissions associated with an ash landfill. Nine sources of fugitive ash emissions were modeled using methods that coupled detailed information about the site operations, ash properties, and meteorological conditions on an hour-by-hour basis. The results of these assessments, combined with ambient air data collected by others, demonstrated that the impacts from fugitive emissions of the ash were no more than negligible. Accordingly, in 2006, MA DEP revised its policy, exempting ash disposal landfills from the requirement to demonstrate no significant impact, effectively granting presumptive certainty to ash landfills that employ best management practices. Detailed analyses such as described herein, combined with robust data sets, can form the basis of more efficient regulatory policies.

Carbon and Green House Gas Evaluation of the Lancaster County Waste Management System

HDR partnered with the Lancaster County Solid Waste Management Authority (Authority) to use the Carbon Assessment Planning Tool (CAPT) to evaluate GHG emissions in their solid waste system. The Authority owns three primary facilities, which comprise the Authority’s solid waste processing and disposal system (the System). The primary facilities in the System are the Transfer Station (TS), the Frey Farm Landfill (FFLF) and the Lancaster County Resource Recovery Facility (RRF). The Authority has recently added wind turbines to its energy portfolio and is considering other changes within its system. The model will be used to evaluate the net effect of the changing system characteristics on the Green House Gas emissions from the system. Reduction in the waste landfilled, changes in Landfill Gas production and increases in energy production will all be evaluated. The paper will review the model assumptions and parameters and will discuss system characteristics. The paper will also discuss a methodology for monetization of additional “green benefits” associated with the GHG emissions reductions through the sale of emission offsets.

The Potential and Obstacles for Waste-to-Energy in Island Settings

Rapid economic development and also population growth of urban centers in developing island nations have resulted in the generation of large amounts of MSW that in the past were dumped at uninhabited areas indiscriminately. Also, islands have very limited space for new, sanitary landfills. This study examines islands where WTE has been implemented successfully (Bermuda, Martinique, St. Barth) and several others (Jamaica, Mauritius, Rhodes) where WTE has been considered and is in various stages of implementation. The study showed that the per capita generation of MSW increases as GDP per capita increases. Also, it is usually recommended that the waste management system be improved one step at a time, that is, to go from dumps to sanitary landfills, to waste to energy; it is interesting to note that the three islands examined in this study went directly from dumps to WTE. This phenomenon can be partly attributed to the scarcity of land for new landfills, but may also be due to the desire to develop a local and renewable energy source.

What About Small Facilities?

The EPA defines a small municipal waste combustor (MWC) Class II facility as having an aggregate plant capacity of 250 tons per day (TPD) or less. Some commercial Waste-to-Energy (WTE) operators consider that there is an economy of scale required that is much greater. So what about small facilities? Can public entities or private companies make the economics work? This paper will offer a status of existing small facilities, available combustion technologies and identify known planned expansions or new facilities. The paper will feature one such facility with an interesting past and a bright future including plans for expansion: the Perham Resource Recovery Facility in Perham, Minnesota. This cogeneration facility plans to increase its capacity from 112 TPD to 200 TPD along with adding upfront processing to improve fuel quality.

Advanced Pollution Control for Gasification of Varied Opportunity Fuels

Advances in gasification technology have opened up a number of commercial opportunities to generate energy from a wide range of non-traditional feed stocks. Gasification technology platforms from a number of providers are in development with the goal of creating modular solutions for supplying the energy needs of local communities, often in solutions as small as 10 to 20 MW increments. Such technologies offer potential project developers the ability to explore local opportunities for fuel supply from a number of sources. These opportunity fuels cover a wide range of potential energy sources as far reaching as recovered plastic, recovered tires, poultry litter, and a wide variety of woody biomass. The syn-gas produced from the gasification of such varied opportunity fuels contains a number of undesired trace components. These components will need to either be removed via gas conditioning, or alternatively be combusted with the syn-gas in an oxidation step which will produce a flue gas requiring air pollution control. Gas conditioning requirements vary depending on the desired end use of the syn-gas whether as a utility quality fuel or as an intermediate to a further chemical pathway. Flue gas target levels are defined by current environmental legislation. The potential pollutants produced in the flue gas pathway include Particulate Matter, Hydrogen Chloride, Sulfur Dioxide, Sulfuric Acid Mist, and Oxides of Nitrogen. To ensure operational compliance of the system stack emissions both now and in the future, proper pollution control technology is paramount. This presentation will address an emerging air pollution control technology that embodies all of these removal steps in a single device specifically designed to meet current and expected future environmental needs. EISENMANN’s recently patented multi-pollutant control system, the Wet Electrostatic Precipitator Dual Field or WESP-2F, includes the use of a pre-scrubbing chamber for large PM, SO2, and water soluble NO2 removal. Following the quench and pre-scrubbing region, a specially tuned downflow wet ESP field is responsible for finer PM and Sulfuric Acid aerosol removal, as well as an important Ozone producing stage that oxidizes non-water soluble forms of NOx. As the gas continues to travel through the system, a secondary scrubbing chamber is used to further reduce NOx by scrubbing the newly formed NO2 that has been formed from the oxidation of other forms of NOx through the use of Ozone produced by the electrostatic precipitator. The final polishing stage of the system includes an upflow wet electrostatic precipitator field for the removal of newly oxidized material as well as any heavy metals present. Research and testing on the aforementioned system took place using a pilot sized unit operating a slipstream off a 20 MW commercial sized gasifier testing a number of opportunity fuels. Expected performance was validated proving high removal efficiencies for pollutants specifically addressed earlier. Results from a wide variety of opportunity fuels will be discussed. Current implementation of the technology in gasification projects following the flue gas pathway is underway and is currently viewed as an acceptable solution to the environmental regulations associated with the plant requirements.