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WASTE TIPPING

WASTE TIPPING

Trucks drive into Green3Power’s

Trucks drive into Green3Power's state-of-the-art Sorting Building where the trucks tip the waste onto the floor. Waste is spread on the floor by a front-end loader. Large appliances and propane tanks are removed and properly disposed of. The waste is then loaded into the sorting line by an overhead crane.

Waste which is accepted includes:

Waste which is accepted includes:

All waste is tipped and stored in the Sorting/Gasification Buildings

All waste is tipped and stored in the Sorting/Gasification Buildings, which are maintained at negative pressure. When doors in the buildings are opened, air moves into the buildings, not out. Since all waste is tipped and stored in the Sorting and Gasification Buildings, and since no tipping is allowed outside the buildings, all odor causing chemicals are collected and treated, and it is not possible for odor to escape from the buildings. As a backup measure, Aerosol Curtains are installed around every door in the buildings, and aerosol of odor treating chemicals are sprayed continuously around the doors whenever they are opened.

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SORTING

SORTING

Waste is moved from the tipping floor by front-end loader

Waste is moved from the tipping floor by front-end loader and grapple crane, and placed into a bag opener. The waste then goes on an inclined conveyor to the picking line. Personnel are located on both sides of the picking line and remove potentially recyclable materials and unacceptable waste.

The treated waste, from which the inerts

The treated waste, from which the inerts have been removed is called Refuse Derived Fuel (RDF), and then goes through a shredder to decrease particle size and moisture content. Shredded waste is stored in bins on the floor of the Sorting Building. A leachate collection system is installed in the floor to collect leachate that drains from the waste. The floor and walls of the Sorting Building are cleaned on a daily basis to minimize odor generation. The leachate and cleaning water are collected and treated to boiler feedwater standards in an onsite water treatment system. The removal of recyclables, inerts, e-waste, and unacceptable waste on the sorting line has several benefits to the facility:

The Sorting Facility technology has been in place since the 1970s, and hundreds of Sorting Facilities, including RDF Facilities have been constructed all over the world.

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DRYING

DRYING

Auger driven jacketed, in-line waste dryers are used to reduce the moisture content of the waste to between 10 and 15 percent by weight.

Auger driven jacketed, in-line waste dryers are used to reduce the moisture content of the waste to between 10 and 15 percent by weight. This reduction in moisture content increases the heading value of the waste, thus increasing the thermal efficiency of the plant by up to 65 percent. The water extracted from the waste is piped to the onsite water treatment facility where it is treated to boiler feedwater standards, and used as process and cooling water. The in-line waste dryer reduces the moister content in 15 to 30 minutes using waste heat from the slagging kiln, so there is no cost for the energy required for drying, no odor, and no additional handling. Auger driven, jacketed Waste Dryers have been used in industrial applications for more than 100 years. The inline, auger driven, jacketed Waste Dryers are designed to replace conventional Compost Systems, which require significantly more time and space, and have the potential to generate malodors. The auger driven, jacketed Waste Dryers dry the waste in approximately 15 to 30 minutes using waste heat from the slagging kiln, and are totally contained, so they generate no mal-odors.

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GASIFICATION

GASIFICATION

Waste is moved from the tipping floor by front-end loader

Gasification technology was originally developed in the early 1800s to produce coal gas, which was originally used for lighting. The coal gas was later used for industrial energy applications and later for the production of electricity.

Waste gasification was developed more than 40 years ago

Waste gasification was developed more than 40 years ago, and can be divided into 3 primary categories: (i) pyrolysis, which is a low oxygen system operating at temperatures between approximately 600 and 800 °C; (ii) Conventional Gasification (Air Fed or Oxygen Fed) Systems, which typically operate at temperatures ranging between 800 and 1,400 °C; and (iii) Plasma or Plasma Arc Systems, which operate at 2,000 to 2,800 °C. Studies by the US Department of Energy [2002], US Environmental Protection Agency (USEPA) [1996], and Alameda Power & Telecom [2004] concluded that conventional (Air Fed or Oxygen Fed) Gasification Systems provided the most cost-effective and clean form of waste to energy systems. The studies further concluded that pyrolysis systems did not provide high enough temperatures to prevent the formation of VOCs (including Dioxins and Furans), tars, and PAHs, and that Plasma and Plasma Arc systems were not cost effective for MSW. The Alameda Power & Telecom Study determined that conventional, Air Fed and Oxygen Fed Gasification Systems met the following criteria:

The G3P JV provides a complete Air Fed or Oxygen Fed Gasification System

The G3P JV provides a complete Air Fed or Oxygen Fed Gasification System that provides clean, reliable renewable electricity or synthetic fuel production, meets the requirements to qualify as green energy, and utilizes renewable resources as fuel. Waste is transported by auger from the waste drying system to the gasifier. The gasifier operates at 900 to 1,000°C, which converts approximately 95% of the waste by weight to synthesis gas. The synthesis gas is composed primarily of CO, H2, N2, H2O, CO2, and traces of other gases. Due to the high operating temperature of the gasifiers, complex hydrocarbons, including VOCs, Dioxins, and Furans are destroyed.

The gasifier is initially brought to temperature using fuel.

The gasifier is initially brought to temperature using fuel. Once at temperature RDF is injected into the gasifier, the RDF is converted either to synthesis gas or ash. These reactions are predominantly exothermic, which means that fuel does not need to be added once the gasifiers are at temperature and the RDF is injected.

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SYN GAS

SYN GAS

The SYN-GAS and Flue Gas goes through a very sophisticated cleaning system to remove contaminants.

The SYN-GAS and Flue Gas goes through a very sophisticated cleaning system to remove contaminants. The SYN-GAS treatment system consists of Cyclones, Acid Gas Removal Units, Ammonia Scrubbers, Carbon Absorption Units (fuel production systems only), and Electrostatic Precipitators.

The removal efficiencies of the various pieces of synthesis gas and flue gas treatment are as summarized below:

The removal efficiencies of the various pieces of synthesis gas and flue gas treatment are as summarized below:

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POWER GENERATOR

POWER GENERATOR

The purpose of the Gasifier

The purpose of the Gasifier is to convert the solids and liquids in the waste into synthesis gas, which can be processed into Diesel Fuel, and which can be used to heat the Heat Recovery Steam Generator (HRSG) Boiler, produce steam, and power a steam generator to produce electricity for the parasitic loads of the system.

Hot Syngas (1,000 to 1,400 ºC) produced by the gasifier

Hot Syngas (1,000 to 1,400 ºC) produced by the gasifier is directed to a water tube type HRSG Boiler, which is equipped with both economizer and superheater sections. Water in the tubes is converted to steam at a pressure of approximately 6.4 MPa and a temperature of approximately 482 °C. This high-pressure steam is then directed to a steam turbine.

The HRSG Boiler produces approximately 55 tons/hr

The HRSG Boiler produces approximately 55 tons/hr of steam for each 12 MW line. This steam is then used to produce clean, green, electrical power from a multi-phase steam turbine and economizer. The electricity produced by the steam turbine is then matched to the Grid requirements, and transmitted via the Grid to the users.

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RENEWABLE FUEL

RENEWABLE FUEL

As shown in the Process Flow Diagram

As shown in the Process Flow Diagram, synthesis gas from the gasifiers is first piped to the Cyclones, where 70 percent of the particulate matter and heavy metals are removed. From the Cyclones the synthesis gas is piped to an Acid Gas Removal Unit,

Ammonia Scrubber, and Electrostatic Precipitator to pre-treat the synthesis gas, then

Ammonia Scrubber, and Electrostatic Precipitator to pre-treat the synthesis gas, then compressed prior to piping to the Fischer Tropsch Reactor, where the synthesis gas is mixed with a catalyst at high temperature. The Fischer Tropsch Reactor is a fixed bed reactor with multiple, single-pass, tubular converters. The catalyst runs at constant conditions at any given point in the Reactor. The conversion of the synthesis gas to aliphatic hydrocarbons over metal catalysts was discovered by Franz Fischer and Hans Tropsch at the Kaiser Wilhelm Institute for Coal Research in Mullheim in 1923 [2,3]. The demonstrated that CO hydrogenation over iron, cobalt, or nickel catalysts at 180 to 250 ºC and atmospheric pressure results in a product mixture of linear hydrocarbons. An Iron or Cobalt catalyst is used to produce Diesel fuel from the CO and H2 in the synthesis gas. Fuels produced with the Fischer Tropsch synthesis are of a high quality due to a very low aromaticity and ultra-low sulfur content. The Diesel fuel is condensed from the synthesis gas in a Condensation Tower, where a Chiller is used to reduce temperatures and condense the synthesis gas to liquid form. The high quality Diesel Fuel produced by the Fischer Tropsch process has a Cetane value greater than 70, where the minimum specification is a Cetane value for No.2 Diesel Fuel is 40.

The properties of the Premium Renewable Synthetic Diesel Fuel

The properties of the Premium Renewable Synthetic Diesel Fuel produced by the Fischer Tropsch system are summarized in the following table