Joseph Schilli HDR Incorporated

Transcription

1 12th North American Waste to Energy Conference May Savannah. Georgia USA NAWTEC ntroduction THE FOURTH DMENSON FOR WASTE MANAGEMENT N THE UNTED STATES: THERMOSELECT GASFCATON TECHNOLOGY AND THE HYDROGEN ENERGY ECONOMY Joseph Schilli HDR ncorporated Joe.Schilli@HDRnc.com Waste management in the United States presently has the following major three dimensions: Sanitary landfills, recycling, waste to energy predominantly based on the technologies of mass bum technology or refuse derived fuel. These three dimensions have undergone significant evolution during the past three decades. The design of sanitary landfills has evolved to include environmental protection features such as bottom liners, leachate collection systems and landfill gas management systems.. Material recycling programs, many based on materials recycling facilities, have become more prevalent. Approximately 100 operating waste to energy facilities ("Facilities") now exist in the United States. mprovements in the air pollution control systems incorporated in the Facilities have significantly lowered their air emissions. A fourth dimension, waste gasification technology, is evolving as a viable component of a waste management system and the hydrogen energy economy. This paper addresses a gasification technology ("Technology") in use on a commercial basis at three waste to energy facilities. This Technology was developed by Thermoselect, nc. ("Thermoselect"), a firm based in Lacarno, Switzerland. nterstate Waste Technologies, nc. ("WT"), based in the Philadelphia, Pennsylvania area, has the rights to develop projects with this Technology in North America and certain other areas of the world. (WT conducts business as Caribe Waste Technologies, nc. in the Caribbean.) This Technology has the following cutting edge parameters: A "Syngas" is produced. The Syngas can be used as a fuel or used as a raw material in a manufacturing process. The Technology produces "Materials" saleable in the existing marketplace. Syngas, at present is used to fuel a boiler or an internal combustion engine, resulting in low air emissions. Technology Operation Figure 1 on the following page shows a schematic of the Technology. The Technology has the following major processes: Waste compaction with a horizontal ram Degasification of the waste under high temperatures and pressures. Conversion of gases and char into syngas ("Syngas") within a high temperature reactor, followed by a shock cooling vessel and a treatment system. Production of metallic and mineral granulates within a homogenization vessel. Process water production and cleanup Following is additional information regarding each of these processes: Compaction: Waste is transferred from the storage pit to a feed hopper. A horizontal ram moves the waste from the feed hopper and compacts it into the degasification chamber to a density of approximately 2,100 pounds per cubic yard (1,250 kg/cu.m). 251

2 Degasification: The waste breaks down within the degasification chamber into gases, carbon char and metallic and mineral components. The reaction is driven by high temperatures, approximately 1,500 degrees F (800 degrees C). Fuels such as natural gas or the Syngas can be used to heat the degasification chamber. Syngas Prodcution: The production of the Syngas has three major steps: Reaction, in the high temperature reactor, of the gases and char from the degasification chamber with steam and pure oxygen in the presence of temperatures of approximately 2,200 degrees F (1,200 degrees C). The reactions produce the Syngas with a heat content of approximately 250 BTUs per cubic foot. The Syngas' approximate composition on a dry basis is: 25 to 42% Carbon monoxide, 25 to 42% Hydrogen, 10 to 25% Carbon dioxide, 3 to 4% Nitrogen and other constituents The Syngas undergoes shock cooling to significantly minimize the formation of compounds such as dioxins. The Syngas' temperature is rapidly reduced from approximately 2,200 degrees F (1,200 degrees C) to approximately 160 degrees F (70 degrees C). (Note: This rapid cooling significantly minimizes the formation of dioxin.) The Syngas undergoes cleanup involving acid scrubbing, alkaline scrubbing, sulphur removal, drying and passage thru an active charcoal filter. Granulate Production Heating of the metallic and mineral components occurs in a homogenization vessel at temperatures up to 3,600 degrees F (2,000 degrees C). The heating is followed by the quenching and density separation process. The metallic and mineral components form metal and mineral pellets during quenching. These pellets, having different densities, are separated into distinct streams by the media separation process. Process Water Production and Cleanup The major process water requirements are as follows: the Syngas shock cooling vessel. The quenching process for the metal and mineral components. Feedwater/cooling if the Syngas is used for generation of electricity or only feedwater if process steam is generated Process wastewater is generated from the following the Syngas shock cooling vessel. The process wastewater is treated utilizing buffering, precipitation and reverse osmosis. The resulting water stream can be utilized for process water with additional treatment as dictated by its use (e.g. feedwater for cooling tower). Energy ProductionlSyngas Utilization The Syngas has been used to date to generate electricity, to generate steam for a district heating system and to fuel a steel manufacturing process. These uses have incorporated conventional technologies such as internal combustion engines/electric generators and steam turbines/electric generators. Technology Development Milestones Following are some major milestones in the evolution of the Technology: Later 1980s and early 1990s - The technology was in the initial development phase by Thermoselect S.A to A research and demonstration facility was operated in Fondotoce, taly. This facility had one processing line and a daily processing capacity of approximately 140 tons of solid waste. 252

3 A facility began operating on a commercial basis in Chiba, Japan. Figure 2 shows an aerial photograph of this facility. This facility has two process lines and an annual processing capacity of approximately 110,000 short tons of waste. Both municipal and industrial wastes are processed at this facility A second facility began operating on a commercial basis in Karlsurhe, Germany. Figure 3 shows an aerial photograph of this facility. This facility has three process lines and an annual processing capacity of approximately 250,000 short tons of waste, mostly municipal A third facility began operating on a commercial basis in Mutsu, Japan. This facility has two process lines and an annual processing capacity of approximately 45,000 tons of waste, mostly municipal. (Note: A pilot plant is also operated by Daewoo E&C Co. Ltd ("Daewoo") in Korea. Daewoo holds a license for the Technology.) Technology Drivers The following Technology performance characteristics are driving its evolution as the fourth dimension of waste management: The low level of air emissions produced by the Technology The capability for recycling the materials produced by the Technology. The quantity and type of energy produced by the Technology Limited Air Emissions The energy within the Syngas is the hydrogen. Hydrogen produces minimal air emissions defined as pollutants by United States regulatory agencies when combusted to generate energy. Figure 4 shows some typical air emission levels from a facility utilizing the Thermoselect technology. The typical air emissions are compared to the New Source Performance Standards issued by the United States Environmental Protection Agency. The typical air emissions assume the following: A typical United States municipal solid waste is processed. The S yngas is combusted in C engines driving electric generators. The C engines are equipped with catalytic systems for the control of NOx and CO emissions. The low air emission levels result from the following characteristics of the Technology: the Syngas consists predominating ofh, CO and C02. The heavy metals in the solid waste are captured in the mineral granulates and metal granulates. The shock cooling essentially eliminates the reformation of dioxins during the processing of the Syngas. Material Recycling Figure 5 shows a typical simple mass balance for a facility with the Technology. The materials generated by the Technology consist of mineral granulates, metal granulates, a sulfur compound, metal hydroxides in the form of a sludge and mixed salts, predominantly sodium chloride. Following are parameters of each of the materials. Mineral granulates, approx tons per on of waste consist largely of the oxides of the following metals [1]: Silicon (approx. 42% by weight), ron (approx. 11 % by weight), Calcium (approx. 13% by weight), 253

4 Aluminum (approx. 20% by weight) and Sodium (approx. 5% by weight) Also 0.4% to 3% by weight of magnesium, titanium, phosphorous, potassium and sulfur. The granulates have undergone testing and are not classified as hazardous waste pursuant to United States laws and regulations. Thermoselect has assessed the following markets: aggregate in concrete, substitute for sand in sand-blasting, and fill in road construction. Metal granulates, approx tons per ton of waste: an alloy consisting principally of the following metals [1]: ron (approx. 80 % by weight), Copper (approx.1 0% by weight) and Nickel (approx. 1% by weight). Minor amounts of phosphorous, molybdenum, tin, cobalt, zinc, chromium and lead. Sulfur compound, approx tons per ton of waste contains the following [1]: Sulfur (approx. 40% by weight), water (approx. 30% by weight), total carbon (approx. 20% by weight). Other approximately 10% by weight and largely chloride, copper, iron, lead and tin. Metal hydroxides, approx tons per ton of waste contains the following [1]: Waterapprox. 80% by weight. Metal hydroxides - approx. 20% by weight and consisting largely of zinc, calcium and aluminum with minor amounts of cadmium, copper, iron, lead, magnesium, manganese, nickel and zinc. Mixed salts, approx tons per ton of waste consists largely of Sodium chloride (approx. 80% by weight), water (approx. 8% by weight), Carbon or carbonates (approx. 7% by weight) and Fluorine, metals and salts (approx. 5% by weight) [1] Energy Figure 6 shows a typical energy balance for a facility with the Technology. The energy balance is based on the following: the waste has an energy content of 5,000 BTUs per pound (HHV). The electric generation system consists of internal combustion (C) engines driving generators. Following are the uses of the Syngas for energy to date: Karlsurhe Facility - firing of a boiler to produce steam to drive a steam turbine/electric generator and for a district heating system Chiba Facility - fuel for an C engine/electric generator and a fuel for steel manufacturing Mutsu Facility - fuel for two C engine/electric generators Uses for the Syngas under assessment include the following: Fuel for a fuel cell, a cornerstone of the hydrogen energy economy, at the Chiba Facility A gas subjected to further processing to produce pure hydrogen A material input in the manufacture of methanol The Technology and the Future The Technology is operating on a commercial basis in Europe and Japan. Energy is being produced from the Syngas via conventional electric generation technologies. The Technology's evolution and growth as the fourth dimension for waste management and a component of the hydrogen energy economy in the United States will be driven by: Attainment of economic competitiveness for utilization of Syngas in a fuel cell. Attainment of economic 254

5 competitiveness for utilization of Syngas as a material input for the production of hydrogen fuel or methanol fuel. Of note are the Governmental entities in the United States and Canada assessing the procurement of a waste management facility or facilities utilizing a technology with parameters similar to those of the Thermoselect Gasification Technology. These entities include: Honolulu, Hawaii; Alameda, California, and Toronto, Canada. References [l] Much, H.K. and Stahlberg, R. "Operation Results of the Thermoselect High Temperature Recycling Facility in Karlsurhe, Germany, Paper at SW A Conference in Malmo, Sweden,

6 Wute of all kinds 11 h i. J High T lllprl.1ture RenctOr Synthesis gas scrubbing Jir(lllJollklnQ Hydrog.. tmthanoi Ammonia or Power ven.ration Sulfur CMnwater Salt Oxygen tacility Figure 1 Simple Schematic-Thermoselect System Figure 2 Chiba, Japan 256

7 Figure 3 ".., Karlsruhe, Germany (1) C c: «c z «ii - e ' (). «... UJ... Z e ii5 (f) UJ c: 100 \ 40 '0 60/0 n 0 V J ' CO NOx PM ' 8%! [l S02 2% rj DOXN THEMOSELECT AR EMSSONS AS PERCENT OF UNtED STATES NEll SOURCE PERFORMANCE STANDARDS FOR larce MUNCPAUTY WASTE COMBUSTERS N.1.S, Figure 4 257

8 ..--- Oxygen (474 Kg) H1d N ibj raj Gas or Propene (20 kg) Additives (HC NaOl{, Ni, FaCl, FHM) 20 Kg PURFED SYNTHESS / GAS 89() kg WASTE kg Comprawon Gasification Pro Ql'H Wid"" T rgatmlll'1l -lj Minoras 230 kg M... s 29 kg Sulfer M.al 2 log Hyd roxides 3kg l Salt Cllilan 10 kg Wmar 350 kg Figure 5 TYPCAL MASt.Jto\lANCE FOR THEMOSELECT TECHNOLOGY DJ N.T.S. NATURAL GAS OR PROPANE 1 TON WASTE@ 5,00 BTU'S/b. 1,10),000 BTU' s(t ON Of WASTE WAST E & GAS l PROCESSNG SYSTEMS 5,625,lDJ Britt GAS r - ELEcmlC GENERATOR SYSTEM 200,000 Bllt s RECOJERED HEAl l f-- 3<10 Kwh (!OJ Kwh*) FOR EXPORT 280 Kwh FOR PROCESS USE!!.omBTU's WAS1EHEAT TYPCAL ENERGY BALANCE FOR PROPOSED CARBBEAN FACLTY N.T.S. BASED ON C ENGNE UNDER ASSESSMENT Figure 6 258