1	"Waste International" Waste International
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3	The Sentinel Process Through the years, municipalities have been attempting to reduce the amount of municipal solid waste (“MSW”) sent to landfill sites. Primarily, this has been accomplished through the introduction of various forms of recycling methods. This includes a combination of blue box, grey box and now green container and yellow bag systems to entice commercial and residential contributors to recycle and compost as much of their MSW as possible. In reviewing the anticipated success of these programs, it is believed that the maximum possible, certainly in the short term, may be in the region of 60% elimination of MSW sent to landfill. In many cases this still leaves a substantial amount of residual MSW to be dealt with, requiring either expansion of local landfill sites or trucking to destinations, which in some cases are well outside of the local area in which the MSW is generated. In looking at North America as a whole, it has been estimated that as much as 220 million tonnes of MSW is generated annually by 350 million people. Due to the inherent make-up of MSW, containing both organic and inorganic waste streams, when landfilled, they create serious airborne contaminants into our atmosphere. These contaminants are built up over time, as the MSW deteriorates, with the net effect being the creation of green house gases (“GHG”) such as CO2, which when introduced into our atmosphere has a negative effect on the ozone layer . i.e. GHG which is clearly a major contributor to the much discussed Global Warming Effect on our planet.
4	The Sentinel Process Sentinel to eliminate their largest pending problem facing them for the future regarding MSW and It was due to this emission problem that Sentinel International (“Sentinel”) was established in 1995 to review the possibilities of developing a process, whereby municipalities would be able to work with what to do about it. Using the experience gained by the principal shareholder of Sentinel in the businesses off Waste Management & Handling, Recycling, Material Handling Equipment Design and involvement in various forms of government committees relevant to Waste Management, a process of utilizing the MSW streams available, after all forms of recycling, to manufacture a fuel in the form of a MSW pellet has been established. Utilizing the Sentinel approach, we are able to collect the residual amounts of MSW and via the design of the processing facility, establish an added component to the recycling programs. It is estimated that the extent of added benefit to the recycling programs can be as much as 12-15% of the MSW received at the facility. After the processing of the incoming MSW, Sentinel then intends to mix in high btu value waste streams, such as carpet waste, petroleum coke and possibly tire derived fuel (“TDF”). When all of this is shredded, dried and mixed together, a high btu valued pellet is created, which can have a calorific value, varying from approximately 9,000 to 12,000 btu/lb by weight.
5	The Sentinel Process This form of fuel can then either be directly burned in a water wall boiler, or used in a gasification process to create the final form of energy desired. In either case, an environmental cleaning system is required to deal with both airborne emissions and wet/solid residue from the energy production process. Through lengthy reviews with MCW Consultants Ltd. Of Toronto, Canada and their local Environmental Engineers, Sentinel has been able to establish an approach to the environmental cleaning required, which are within the strictest emission guidelines enforced at this time, regardless of Provincial, State, Federal or other government bodies’ requirements. With this in mind, we have been able to formulate an overall construction process for the most advantageous of these approaches, i.e. a gasification technology to receive the high btu pellets, produce a clean synthetic gas and then utilize that gas to produce either steam directed to a steam driven turbine, or deliver the gas directly to a gas driven turbine. In the case where we envisage the use of the above form of energy creation, the overall environmental performance of the system will be designed to ensure that not only the airborne emissions are reduced well below guidelines, the wet/solid residues will be contained in a manner that eliminates any possible hazardous scenario due to leachate problems, which can occur in other waste to energy formats.
6	The Sentinel Process Recycling/Sorting/Pelletization The management of residential/commercial MSW at the proposed facility is an alternative for dealing with the waste disposal issue. The primary objective of this facility is to reduce the volume and weight of the waste to be disposed of via a landfill operation, and provide an environmentally acceptable alternative waste disposal method. A secondary, although important objective is to provide energy generation benefits, which should lead to acceptance as an alternative “green” fuel to energy process. This concept in the disposal of Municipal and Industrial Solid Waste effectively eliminates the requirement for expansion of existing and creation of new landfill sites. Rather than the waste material going to landfills, this technology consists of a process that provides a single source municipal solid waste recycling operation, in which all of the recyclable materials are extracted from the incoming waste stream, and the contained combustible waste is fed into a high-density process system. All trucks bringing waste product to the process plant would pass over the weigh scale at the gate, enabling efficient and accurate tonnage measurement to charge to each customer including other high value BTU waste products, such as carpet, wood, hydrocarbons, rubbers etc. Incoming MSW waste would then be off-loaded into large in-ground hopper systems. Several garbage trucks can dispose of their loads at any given time, to ensure the total daily load is maintained. Any hazardous materials would be removed at this time, before it reaches the sorting section. A continual video recording is maintained of trucks dumping onto the hoppers. If unacceptable waste was discovered, a review of the videotape identifies the truck that delivered and unloaded the questionable waste.
7	The Sentinel Process Unacceptable waste would then be placed into a container, and returned to the trucking company at their cost. The moving floor moves the garbage to the back of the hopper and drops it onto transverse conveyors, which feed onto the incline conveyors and on to the sorting and removal process for retrieval of recyclable products. The process would produce a pellet, with approximately 90-94% of the moisture content removed. This virtual removal of moisture eliminates odours and brings the BTU value of the product up to approximately 9,000-12,000 BTU per pound. As described above , recyclable materials are extracted from the waste stream and the remaining contained . waste is then pulverized into a “fluff”. Pellets are produced after mixing high value BUT waste with the fluff The High-Density system would be capable of consuming 100 to 500 short tons per day of materials, based on a five day week. By mixing the treated MSW with high BTU waste stream, hydrocarbons such as shredded carpet of any other acceptable waste product that contains high BTU value.
8	The Sentinel Process The designed equipment alignment enables the efficient processing of MSW and results in the conversion of approximately 12-15 percent of the waste flow into recyclable materials such as plastics, cardboard, aluminum cans, tin cans, glass and batteries. By removing all of the recyclable products, not just those collected through the Blue Box program, the process eliminates the majority of the heavy metal emissions normally associated with waste derived fuels. Carpet Waste as a High Density Additive The North American Carpet Institute estimates that as much as 53 million square yards of carpet is land filled each year. Governments are in the process of changing existing regulations to force this process to change dramatically, to incorporate recycling where possible, as carpet as a disposable item is not biodegradable. Carpet has a BTU value of approximately 16,500 BTU per pound. Other acceptable high BTU waste streams include as many as 48 specific items, including hardwood pallets, granulated rubbers, tires, hydrocarbon coke and other available petro-chemically derived bi products. Product Testing Two independent Laboratories have tested samples of the pellet products in the United States. They both arrived at substantially the same results indicating the positive viability of our processed product as a fuel source. DB Riley, Massachusetts, a Subsidiary of Babcock Borsig Power, one of the largest boiler manufacturer’s in the world, has independently tested the pellet to ensure that their water wall boilers can utilize the pellet as a fuel, and have indicated that their findings have assured them that this is the case.
9	The Sentinel Process The designed processing operation will contain a minimum of two independent operating lines (or modules). The modular design approach has several advantages including. Reduced downtime due to designed redundancy; Ensured throughput in the event of equipment breakdown in one of the lines or modules; Easy to increase capacity (additional modules may be added at any time); Ample time for preventive maintenance program and/or additional process capabilities. The resultant fuel is low in air pollutants, due to the maximizing of removal of polluting causing elements from the incoming waste. This allows the design of the boiler facility, at enrich location the pellets will be utilized as a fuel, to incorporate state of the art emission control devices to ensure that the stack emissions are controlled well within the anticipated guidelines. Control System The plant design incorporates a fully interlocked control system, The system is fully interlocked with Programmable Logic Controllers (PLC’s) to control all of the safety devices such as photo-cells, limit switches and flow switches. The PLC’s would be set up to control the start up and shut down sequences. The whole system is tied into a Distribution Control System (DCS) and controlled by a main computer. The Hydraulic Press Run-Off System All water from MSW and wash-down system will be collected in an under ground holding tank. The water will then be treated, cleaned and a portion reused with the remainder sent to sanitary sewer. The solids will be extracted every two to three months and mixed in with MSW to produce pellets.
10	The Sentinel Process Biological Air Filtration System A biological air filtration system is installed in the MSW receiving and sorting section of the facility. This unit will exchange the air every fifteen to twenty minutes and collects all of the remaining moisture and eliminates a minimum of 92% of all odours. Environmental Impact of the Pellet as a Fuel The environmental issues are; Air Emissions. Odour, Dust and Debris. Water Pollution Control. Noise. The design of the production plant is based on an environmental impact, which must cause no adverse effects on the natural environment, or on the health and safety of people working in the plant, of in the local community. Dust, odour and debris emissions are minimized in the process facility by maintaining a negative pressure in the tipping floor and hopper area and continuously introducing fresh air. All processed wastewater is treated internally and reused. Sanitary wastes would then be cleaned and discharged to the municipal sewer system. The facility is constructed and operated to meet all applicable requirement and noise standards.
11	Potential Municipal Internal Partnering Local Electric Utility Typically the local municipal utility is the retailer of choice for electricity to the City in which it resides. It operates the local power distribution grid to which in some cases it is very difficult to connect additional capacity from outside of that city’s downtown core. Using the process of pelletizing the MSW, gasification and a turbine technology, the overall energy production method will likely be acceptable, as the fuel is ultimately a gas, which is almost as clean as natural gas, for a downtown core generation location. Water and Waste Water Services The effluent (“Sludge”) from any local municipal Sewage treatment plant can be dried and pelletized, along with other forms of waste/MSW, to produce an acceptable fuel pellet as envisaged by the Sentinel process. Water and Waste Water Services in any city is normally searching for an environmentally acceptable solution for the disposal of Sludge, and this can be the answer. Local District Energy In many cases city’s of reasonable size already have a locally distributed district energy system in place, normally utilizing natural gas as a fuel source to create either steam or hot water. A district energy system, 0perated properly, is another answer to reduction of green house gases, caused by emissions from locally distributed gas or oil fired hot water systems in commercial buildings instead of using access to hot water or steam distributed in district energy street piping systems, which is inherently much more efficient as far as fuel used to produce the ultimate energy medium. Using a waste to energy project could create an opportunity for a city to either upgrade their security of fuel supply or to create a completely new district energy system, due to the efficiency of operating costs, mitigates the higher costs associated with the risk of using higher cost natural gas or oil.
12	Potential Municipal Internal Partnering
13	Potential Municipal Internal Partnering No matter what the New & Emerging Technologies consist of they must be complimentary to a City’s recycling and waste diversion objectives. The location to be considered must allow a cost effective means of interconnecting a Synthetic Gas Plant to a Co-generation Plant. This configuration becomes a distributed Waste to Energy Plant, which by producing electricity and steam in a city’s downtown area can be connected to district energy piping system, as well as support the intent of providing a source of generated electricity in the city’s downtown core.
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15	Pelletizing Process Schematic
16	Boiler Schematic
17	Gasification Schematic
18	Background & Solutions In most medium to large municipalities landfill of their municipal waste, has been a much debated issue with respect to the future solution to this problem. Competing technologies include Thermal Oxidation, (within which there are alternatives including mass burn incineration, processed RDF pellet combustion, Anaerobic digestion followed by combustion, and Gasification of the RDF pellet followed by combustion of a Synthetic Gas by product. The question posed by those looking for a solution to this pressing municipal waste problem is; which technology presents the best, (economical, environmentally responsible), long-term solution? In some cases, municipalities create an Advisory Group, consisting of local participants, who have an interest in the overall outcome, which assists in determining the answer to this question. Without pre-judging the outcome of any review, the following perspectives are useful as an overview:
19	Background & Solutions (Emerging Technologies) Mass Burn Incineration: This solution has been utilized in Europe in compliance with the emissions guidelines of the day. The increase in environmental awareness has resulted in a continual decrease in the emissions limits throughout Europe. This has resulted in the closure of many mass burn plants, or a requirement for significant investment in new flue gas cleaning technologies, to remain ahead of the ever tightening requirements. Mass Burn does not attempt to improve upon recycling of those materials which are left in the Municipal Waste Streams by the Public. Mass burn incinerators being considered for this process include water wall boilers, to maximize steam production, while utilizing a rotating grate to allow adjustment of the travel time of the grate to ensure the product being burned produces its maximum available energy. The system then incorporates a gas cleaning system, of a type dependent on the fuel supply source. That equipment can include electrostatic precipitators, bag-houses, carbon bed/lime injection, SNCR and DSCR to suit emission profiles required by specific environmental guidleines. But even these types of incinerators can be converted to use RDF pellets and be made Environmentally and energy efficient. RDF Pellets/Combustion: The High BTU enriched Pellet technology, which has been reviewed on a preliminary basis for Enwave, removes much of the difficulties encountered when using Mass Burn Incineration. This is due to the use of a sophisticated sorting process applied to the MSW on collection, which removes the components that are the major contributors to Dioxins, Furans and Heavy Metals, (Plastics, Ferrous and Non Ferrous materials are removed for enhanced recycling). This High BTU enriched fuel manufactured from the municipal waste stream can then be combusted in an RDF Boiler, complete with flue gas cleaning equipment consistent with all relevant Government Guidelines.
20	Background & Solutions (Emerging Technologies) Anaerobic Digestion: This technology is the acceleration of the natural process which converts organic material into methane gas. This is a very useful solution to reduce landfill requirements, but is not particularly effective at generating energy from waste. Due to the requirement for significant land, (approximately 10 acres to digest MSW sufficient to create methane to fuel approximately 6-10 Megawatts of Electric Power) the location of Anaerobic Digestion is often Suburban sites, which are not within viable distance of Steam Hosts to maximize the use of Cogeneration. The current trend is for Anaerobic Digestion to be included as part of “an Inner City Transfer Station” to remove organics prior to the landfilling of the remaining MSW stream. Studies continue regarding the use of MSW as a feedstock for this technology, but it appears that no significant success has been reached in any pilot programs, due to the type of waste materials in an MSW stream, and their environmental affects on the outgoing compost material. Consequently many municipalities have embarked on a pilot Source Separated Program for single family dwellings to create compost which is environmentally benign for use in Anaerobic Digestion processes.
21	Background & Solutions (Emerging Technologies) Gasification: Gasification is not a new technology. Its use during the first and second world wars is well documented. The most successful application of gasification has been with a homogeneous fuel such as coal or wood, as these products provide a consistent source of supply regarding both energy/lb. and moisture content. The viability of using these fuels is severely impeded by the original cost of securing the fuel. Consequently, throughout the G7 nations, there has been much research and development with respect to the use of non-homogeneous fuel streams, such as MSW being used in gasification processes. This development work has matured with various gasification processes, to a point where not only have pilot plants have been developed, but commercial plants have been constructed and are accumulating a successful operating track record. The viability is a result of the feed stock fuel becoming a revenue stream by virtue of tipping fees, as well as a more mature gas conditioning process being established, which provides a synthetic gas almost comparable to natural gas regarding emission profiles. The political acceptance of gasification appears to be very good as the Synthetic Gas (SYNGAS), has comparative emission profiles to that of Natural Gas and hence its use in conventional gas combustion and emissions equipment.
22	"High BTU Enriched Pellets &..." High BTU Enriched Pellets & Gasification: This combination will provide a homogeneous fuel complete, with a revenue stream (tipping fee). The fuel can then be very easily gasified to create clean SYNGAS for use in a cogeneration plant. Pellet manufacturing can be performed remotely at locations, which were previously classified as transfer stations. If considered desirable, these locations could also incorporate Anaerobic Digestion for parts of the organic components of the MSW stream. The pellets can then be transported to the optimum site to realize the full benefits of cogeneration, (i.e. close to a local steam host). Locally the pellet fuel can be gasified to produce SYNGAS, which can be used in place of natural gas. It is anticipated that this would likely attract the majority of support from the environmental community, as the most environmentally benign form of thermal power generation, as an alternative form of green energy.
23	Background & Solutions (Emerging Technologies) High BTU Enriched Pellets & Water Wall Incinerators: This combination will provide a homogeneous fuel complete, with a revenue stream (tipping fee). The fuel can then be very easily burnt in any type of Water Wall Boiler System with a rotating grate that retains the fuel product in the boiler longer. Therefore resulting in a more efficient burn, and producing the maximum BTU per pound of fuel. And producing the maximum steam requirements for use in a cogeneration plant. Pellet manufacturing can be performed remotely at locations, which were previously classified as transfer stations. If considered desirable, these locations could also incorporate Anaerobic Digestion for parts of the organic components of the MSW stream. The pellets can then be transported to the optimum site to realize the full benefits of cogeneration, (i.e. close to a local steam host). It is anticipated that this would likely attract the majority of support from the environmental community, as the most environmentally benign form of thermal power generation, as an alternative form of green energy.
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25	"This type of Project would..." This type of Project would obtain a “Green Energy” status, based on discussions with Federal representatives in Canada. There are significant environmental benefits, such as possible uses in producing steam for a district steam heating system, reductions in SOx , NOx , CO2, taking coal off line, carbon cycling, reducing vehicle emissions from trucking MSW to landfill sites, and so on. The development of a waste to energy plant in a downtown area will permit the closure of many building owned and operated heating plant, thus eliminating their air emissions in a downtown core. It will also drastically reduce municipalities` dependence on natural gas – a non-renewable and increasingly costly fuel, which is additive to the carbon cycle, to create its steam/hot water energy. The proposed power generation plant would use state-of-the-art technology and pollution control systems. Total emissions from burning synthetic gas produced from RDF pellets would be comparable to total emissions from natural gas combustion It is a sustainable system that can turn a “waste” commodity into a fuel product with value. Using waste as a fuel is a sustainable and renewable energy source, notwithstanding recycling initiatives. Those initiatives have limits, and the population of most municipalities continues to grow. The addition of these systems to the overall waste management system can help achieve a city’s diversion target from landfill, well before their target date. The pelletizing plant is a waste management facility with similar characteristics to a Municipal Recycling Facility (“MRF”) or a Transfer Station.
26	"Evaluation of MSW Streams" Evaluation of MSW Streams MCW and its Environmental Consultants have reviewed the available single and multi family dwelling waste streams in their region, incorporating all of the associated districts, setting out the recovery rates, after organic source separation and recycling forecasts, prepared by the region. Also a recent U.S. EPA study on MSW in North America revealed a 42 percent increase in recycling / composting activities during the period from 1995 to 2000. However, during this same period, the quantity of MSW which could not be recycled and required disposal, also rose due to an increase in the amount of waste generated. Thus, with certified landfill capacity decreasing and other sites requiring clean-up, new options of waste management to replace traditional methods are needed to manage the 220 million tons of MSW, and 520 million tires which are produced each year. There are two to three billion tires piled in hundreds of waste and landfill sites in North America.
27	Internal Partners Solution Pellet Testing Testing done elsewhere in the world, Has proven that combustion of this synthetic gas will have emissions very similar to those of natural gas, when burned as fuel in a boiler. It is anticipated that when testing has been completed, sufficient information will have been accumulated from actual testing to be in a position, whereby results will show graphically portrayed evidence that the use of MSW pellets as a fuel source in a gasification process produces a synthetic gas, which gas when used as an ultimate fuel, will have emission levels which are better than the “fuel burning guidelines”, used by al Provincial, Federal or State levels of government for compliance purposes.
28	Internal Partners Solution The associated costs of obtaining and transferring all forms of waste required for the manufacture of the MSW pellet have been reviewed and assembled into a form, which was used in the finalization of capital and operating costs in the financial model of a typical construction scenario. The results of this evaluation indicate that this type of project can make financial sense, dependent on the tipping fee acquired for removal of the MSW stream, but certainly within values in $/tonne found.
29	Additional Gasification Information In conventional solid fuel combustion technology the fuel is burned on a vibrating grate or in a fluidized bed, with the emissions from the combustion process controlled through a second burn and through electrostatic precipitators ahead of the stack. Dependent on the solid fuel, other forms of flue gas clean up may be required, which could include carbon bed, lime injection and the introduction of SCR control of NOx. The by-products of the combustion process are primarily water (H2O) and carbon dioxide (CO2) as well as carbon particulate (TSP) and oxides of chlorine, nitrogen and sulphur and traces of furans and dioxins if they are present in the fuel source, which may also be reformed in the flue gas relevant to flue gas temperatures. The particulate escaping into the atmosphere can be reduced by use of an electrostatic precipitator, to levels acceptable to the Ministry of the Environment (MOE).
30	Additional Gasification Information Synthetic gas production and generation technology unlike the conventional combustion process is a two-stage process. Stage 1 involves the gasification of the solid fuel into a clean synthetic gas. Stage 2 involves the combustion of the synthetic gas to heat a conventional boiler and manufacture steam to drive a turbine. The first process is a controlled environment with no emissions to the outside atmosphere, which is dried of liquid particulate and cleaned of solid particulate down to one micron before it is carried to the combustion process. The synthetic gas is almost as clean as natural gas and is composed primarily of hydrogen (H2), carbon monoxide (CO) and Methane (CH4).
31	Additional Gasification Information The gas production process takes place in a reactor, which is fired up to 1000oC at the bottom of the and 850oC at the top, with even temperatures throughout the top and bottom portions, which is important to the gasification process. The reactor is operated at a pressure of 1.5 atmospheres. The solid fuel is introduced in pellet form of about 1 to 1.5” in size by means of a screw augur. The reactor contains a bed of alumina, which, under pressure is suspended into a fluidized bed on which the fuel pellets are suspended. In the fluidized bed, the fuel pellets are exposed to a uniform temperature for complete gasification. The gasification is starved of the normal air that is used to support a combustion process and is instead assisted by a 20% mixture of enriched oxygen. The result is a synthetic gas, which has a calorific value of about 33% of the value of natural gas. The by-products of the process are gases, liquids and solids. The gases consisting of hydrogen, carbon monoxide and methane can be burned in a reciprocating engine or in a combustion chamber to fire a boiler. The gases will contain particles of 1 micron or less. The liquids are skimmed off by a venturi valve and sent to a waste treatment facility. The solids are removed in a cyclone chamber. The solids consist of carbons which can be used in construction material, vitrified into compounds, which can be used for construction, or turned into a fertilizer (in the case of wood) or land filled. The waste treatment facility through flocculation and coagulation causes the suspended tars in the liquid to float to the top. These are skimmed from the top of the liquid for a second pass through the kiln. The carbons and other inert products float to the bottom in the form of sludge. The sludge is disposed of in the same manner as the solids from the cyclone.
32	Additional Gasification Information A significant difference between a solid fuel combustion plant and a gasification plant is that the result is a reduction in the air/gas loop volume of about 6:1 resulting in a much smaller plant with a lower profile. The synthetic gas has 33% of the calorific value of natural gas but in all other respects is very much like natural gas and provides a much cleaner burn, free of particulates, in comparison to a solid fuel combustion process. The synthetic gas plant has a much greater degree of flexibility than that of a solid fuel combustion plant, as it is can be fuelled with contaminated wood, biomass extracted from solid waste or with plastics and tires. This results in a more diverse fuel supply with potentially higher tipping fees and a better economic rationale. It should be noted that generation with a plastics fuel source is not considered green at this time in Canada, but that should change over time to mirror the European model.
33	Conclusion If there was only one person left on the planet, there will be garbage produced. It is a growing concern for all nations. We have made a small steps in reducing the amount of waste entering the landfill sites. It is time that we took a more assertive approach and look beyond the scope of Blue Boxes and biodegradable materials.
34	"Waste International" Waste International 86 Parkview Drive, Strathroy, Ontario. N7G 4A3 Canada. Phone: (519) 245-9241 Fax: (519) 245-9243 For more information e-mail johnphilipson@sentinelpower.net