GEM's patented  technology converts residual waste to useable clean synthetic gas using a patented technology without any emissions from the conversion process.  

The GEM Converter accepts prepared waste material (waste feedstock) where it  instantly converts to gas. The process occurs within a closed system without combustion leaving no fly ash to manage.  There are no induction fans, "sand", carrier gases or other similar devices and with no oxygen present, no combustion can occur.

Prepared feedstock is conveyed from a dry storage area to the Roll Feed Conveyors, which meters the amount of waste feed.  The waste feed conveyor system is equipped with an extraction plenum chamber where air and dust, expelled from the feedstock by the rollers are extracted.

The prepared feedstock drops into the contra-rotating ‘feed wheels’ of the Roll Feeders where it is compressed between the circular flexible ‘tires’, which cover the wheels. This excludes any air/oxygen from the voids and any that is trapped within the fuel particles.

Converter Waste Feed Conveyors break up the ‘ribbon’ of feed material leaving the Roll Feeders into individual pieces and meter these into the Converters.

The Converter's Stainless Steel inner vessel operates at 850C temperature using the synthetic gas generated by the process and is energy self-sufficient.  Conversion of waste to gas takes place as the waste feed material is impinged onto the hot walls of the inner chamber.  The produced gas exits the Converter through ducting, entering a Gas Filtration system.  Residual mineral solids and other inerts produced as a bi-product of the conversion, fall to the base of the Converter and are removed under controlled conveyor conditions. 

The total mineral solids and other ineret residue from the conversion process amounts to some 8 to 10% for domestic waste, (typically 25% for incineration). 

CONVERSION TO CLEAN SYN GAS - NO DIOXINS/FURANS/FLY ASH

The Gas Filtration system is employed to filter the finer particles and cope with the elevated temperatures of the gas. The fine char particles fall to the base of the filters and are removed by the Filter Discharge Conveyors.

The cleaned hot syn gas then passes through insulated ducting into Gas Coolers, where it is rapidly cooled by the circulating coolant, which is a mineral oil blend. The mineral oil spray removes particulates and any chlorine.  The rapid speed of the cooling process and the lack of chlorine prevents the formation of harmful Dioxins and Furans, toxic elements monitored by environmental agencies.  Cooled syn gas then passes through Separator Pots where any condensed vapour droplets are separated from the gas and are returned to the Gas Cooler reservoirs.

The clean, cooled syn gas from the Converter now enters the Gas Header Manifold, which also forms the suction manifold of the Gas Compressor.  The Gas Compressor compresses 60% of the total gas production from the Converter.  GEM's gas handling system is designed with redundancy to insure continuous operation 24/7.

Compressed gas then passes through one of the "aftercoolers" and enters one of the Gas Buffer Tanks.  These units are duplicated so that maintenance can take place during operation. The Buffer Tank stores the gas up to a pressure of 1.5 bar for use with downstream equipment such as a reciprocating engine, turbine or flare. 

A small stream of the produced clean syn gas is diverted to heat the GEM Converter reducing the need for support fossil fuels.  The remainder is passed on as an energy source and can be used to fire boilers or to feed conventional engines or turbines for generation into renewable electricity. Conversion to electricity typically produces twice as much power as a modern incinerator. 

NOTE:   The higher the BTU value of the waste going into the GEM converter, the higher the BTU value of synthetic gas produced from the conversion process and subsequently more MW of electricity for sale.  Gas volume is very constatnt over a variety of waste types. 

OIL (Coolant) COOLING

Coolant in each of the Gas Cooler vessels is removed from the reservoir at the base of the Coolers into the Oil Heat Exchanger pump suction manifold. The coolant is sucked from here by Oil Heat Exchange pumps to one of the Coolant Heat Exchangers where it is cooled before it is circulated back into the Gas Cooler reservoirs. The temperature of the coolant is maintained at 30°C or less. As with the Gas Compressors, two of the pumps will be operating continuously with the third on standby and the Coolant Heat Exchangers are duplicated for maintenance during operation.

The coolant Heat Exchangers are ‘shell and tube’ type with coolant on the tube side and cooled water on the shell side. Cooled water is circulated by Cooling Water Pumps through one of two forced-draught Cooling Towers to remove the heat absorbed from the coolant.

 OIL RECIRCULATION

Coolant is also removed from each of the Gas Coolers to be recirculated through the top section by Oil Recirculating Pumps. The coolant enters the top section of the Gas Cooler towers and passes through atomising nozzles, the small coolant droplets allowing efficient and rapid cooling of the produced gas. 

OIL / WATER SEPARATION

As well as cooling the produced gas, the coolant also condenses water vapour, which has been vapourised from the feed material in the Converters.

This forms an aqueous fraction that is held in suspension in the coolant (due to the constant movement of the liquid in the reservoir) in the form of fine droplets.  This aqueous phase is separated from the coolant by transferring a proportion of the coolant using Separator Tank Transfer Pumps to one of two Oil / Water Separating Tanks in which the water phase settles out due to specific gravity difference. The ‘clean’ oil overflows a weir inside the Separator Tank and is returned to the Gas Coolers by Oil Return Pumps. 

CARBON IN MINERAL SOLIDS and SCRUBBING 

Unconverted carbon is not a major issue with the GEM Conversion process as molecules of Hydrogen readily combine with Carbon molecules.  Should there be an abundance of carbon remaining, additional Hydrogen can be added to the exiting mineral solids to convert remaining carbon energy to syn gas. 

All scrubbing for any elements in the syn gas such as sulphur from used tires is done inexpensively.using "in-line" liquid scrubbers.  An example of the process is to use a wet wash of water dosed (20-40ppm) with chlorine dioxide. The process is self regenerative of chlorine dioxide and converts the H2S and C2S into sulphate ions that can be discharged with the water to the sewer. Additional scrubbing applications are available all with the same safe, effective, simple and proven methods.