Converting Municipal Solid Waste, Biomass, Sludge and Coal Tailings into Clean Energy

Transcription

1 Converting Municipal Solid Waste, Biomass, Sludge and Coal Tailings into Clean Energy Efficient use of Energy Turning waste to energy, liabilities to assets and visions into reality.

2 Table of Contents CONVERTING SOLID WASTES INTO CLEAN ENERGY... 1 CLEAN & EFFICIENT KEY FEATURES BIOMASS FIRED - 55KW POWER DEMO PLANT Turning waste to energy, liabilities to assets and visions into reality.

3 CONVERTING SOLID WASTES INTO CLEAN ENERGY Heat Transfer International (HTI) engineers have designed, fabricated and installed waste-to-energy plants since the 1970 s. Plants in operation today continue to recover energy, destroy pollutants and meet all environmental codes. The heart of many of HTI s successful systems is the patented and patent pending all-ceramic, shell and tube, air-to-air heat exchanger. In this application driving a Stirling cycle power unit HTI is supplying a low differential pressure ceramic exchanger that will handle flue gas at temperatures up to 2400 F and indirectly heat clean air to 1800 F which, in turn, is sent to the engine. Other key components are the patented HTI starved air gasifier and the staged, low NOx oxidizer. Add to this the use of engine exhaust as preheated combustion air, and the end result is the most efficient small power system available in the market today. The most practical application is to construct plants at the source of the waste where upwards of 225 kw can be utilized. Turning waste to energy, liabilities to assets and visions into reality. 1

4 CLEAN & EFFICIENT KEY FEATURES Starved Air Gasifier This unique patented device is manufactured and supplied by Heat Transfer International. It is designed to process wastes such as municipal solid waste (MSW), forest products, poultry litter, manure, coal tailings and sludges. The waste is metered into a center auger and fed upwards into the gasifier, and forms a fuel pile. A controlled percentage of stoichiometric air is injected throughout the pile. The unique control of the air injection arrangement keeps the pile temperature below the sublimation, vaporizing or melting temperatures of the noncombustible solids and, at the same time, vaporizes the volatiles using the energy from partial combustion of the wastes. The syngas generated is collected above the pile and induced into the oxidizer. HTI has proven the gasifier by firing high-sulfur (6%) coal tailings. The percentage of sulfur dioxide emitted was reduced 99% (below theoretical), so the amount leaving the stack was below the most stringent code levels. Cyclonic, Staged, Low NOx Oxidizer This patent-pending HTI oxidizer takes the syngas from the gasifier and induces high temperature air through a series of tuyeres that control the rate of combustion and the temperature profile to insure complete combustion of the carbon monoxide and hydrocarbons without forming nitrogen oxides. Most biomass fuels are high in bound nitrogen. Commercial HTI oxidizers and test facilities have proven that the high nitrogen fuels can be processed successfully and that the percentage of nitrogen oxides emitted kept well below code levels. Alloy Metal Heat Exchangers The ceramic heat exchanger reduces the flue gas temperature to a level that allows the use of conventional stainless steel materials in the metal heat exchangers. The HTI metal air-to-air heat exchanger incorporates easily removable tube bundles. Ceramic Heat Exchanger The all-ceramic, shell and tube, air-to-air heat exchanger is proven to handle high temperature gases that contain particulate and/or acids. The machine can preheat clean air to temperatures as high at 2000ºF where it operates at a level that cannot be sustained by metal exchangers. In this case, the power unit needs 1800ºF gas to operate efficiently. The 1800ºF can be achieved comfortably with a ceramic exchanger and provide clean air to the power unit, thereby increasing the life of the engine. The ceramic exchanger also acts as a safety device in the event there is an upset and fly ash carries out of the gasifier and into the exchanger. In a direct-fired Stirling engine, there could be a catastrophic failure. The indirect-fired Heat Transfer International system is designed to handle upsets. Power Unit The Stirling cycle STM engine is capable of converting the energy from the 1800ºF hot air directly into electricity without producing any incremental emissions. Unlike direct-fired Stirling cycle units, there are no products of combustion exiting from the power unit. In the Heat Transfer International system, the exiting gas is clean air that is returned to the gasifier and oxidizer as preheated combustion air, thereby increasing overall efficiency. This is particularly advantageous when processing manure and high-moisture wastes such as coal tailings. When surplus heat is available because the fuel has a lower water content, it can be sent directly to a process such as wood kiln dryers. In this case, it is not necessary to have an intermediate machine, such as a boiler or hot oil heater, since the air is clean. Turning waste to energy, liabilities to assets and visions into reality. 2

5 Turning waste to energy, liabilities to assets and visions into reality. 3