WtGas
Introduction
WtGas is the core technology of the Entech-Tru-RES™. It’s based upon a low temperature gasification process that converts waste from its solid to gaseous form of syn-gas (a methane like gas), so that it can be fired to generate energy; with emissions that are cleaner than firing of any fossil fuel (including natural gas!).
The WtGas renewable energy system adopts ENTECH™ patented technology that has been proven in a plethora of commercial applications. The WtGas system is as described below.
Technology
The Thermal Degradation Spectrum
Graph Representation of the Thermal Degradation Spectrum (Click to Enlarge)
Thermal degradation alternatives are:
| Pyrolysis | Low Temperature Gasification | High Temperature Gasification | Combustion / Incineration | |
| Reference | - | Per the WtGas system | - | - |
| Process Air Input (*) | Nil | 15% - 30% of stoichiometric (**) | 50% - 60% of stoichiometric (**) | 200% -250% of stoichiometric (**) |
| Process Temp. (*) | ≈ 550°C | ≈ 600°C - 875°C | ≈ 1150°C - 1275°C | ≈ 850°C - 1000°C |
| By-Product | Fuel oil-like CnHn hydrocarbon vapours | Methane-like gases high in CO, CH4 & CnHn hydrocarbons (but low in H2), | Gases high in CO & H2 (but low in CH4) | Oxidised off-gas |
| By-Product Name | Syn-oil | Syn-gas | Syn-gas | - |
| By-Product Volatility | High | High | High | Nil |
| By-Product Uses | Refining into syn-oil or synthesis into methanol, ammonia, etc. | Syn-gas firing or synthesis into methanol, ammonia, etc. | Syn-gas firing or synthesis into methanol, ammonia, etc. | Heat Recovery |
| Technology Status | Syn-oil refining and synthesis is commercially proven with consistent type feed-stocks (e.g. coal, some biomasses). | Syn-gas firing is commercially proven with multiple difficult type feed-stocks by the WtGas system. (whereas syn-gas synthesis is not yet commercialised). | Syn-gas firing and synthesis is commercially proven with consistent type feed-stocks (but is limited to various biomasses). | - |
| Available as a Fuel Source | Yes | Yes | Yes | No |
| Typical Fuel Uses | Fuel oil burners and diesel engines | Gas burners (***) | Gas burners and gas engines | - |
| Typical Emission Impact | Syn-oil firing emissions are similar to firing of fuel oil | Syn-gas firing emissions are cleaner than firing of most fossil fuels | Syn-gas firing emissions are cleaner than firing of most fossil fuels | Combustion / incineration emissions are politically sensitive |
| Community Impact | Well accepted technology | Well accepted technology | Well accepted technology | Objectionable technology |
(*) Refer to thermal degradation graph above for explanation of air and temperature relationships.
(**) Denotes percentage of air required for complete combustion.
(***) Technology not yet commercialised for gas engine firing.
Process Description
The heart of the WtGas system is the syn-gas production stage, where the ENTECH™ Pyrolytic Gasification Chamber:
- Receives the waste or biomass and subjects it to low temperature-substoichiometric gasification; so as to heat and convert it into methane like gases high in CO, CH4 & CnHn hydrocarbons, which are referred to as syn-gas.
- The process is around 1/20th the air input and around 1/50th the velocity and turbulence of conventional combustion, which maximises the volatility of the syn-gas, plus minimizes entrainment of pollution concerns into it.
- This results in the syn-gas being a relatively clean gas that's available for immediate utilisation without further refining or treatment.
- The feedstock of the gasification process is subjected to regular churning and stoking by the ENTECH™ Churning, Stoking & Distribution System (patent applied for) so as to expose all matter to the actual gasification process.
- The feedstock is processed over a period of around 16-24 hours to ensure complete gasification.
The WtGas system key to energy efficient and environmentally superior utilisation of the syn-gas is the ENTECH™ Syn-Gas Burner (patent applied for), which:
- Receives the syn-gas and fires it instead of fossil fuel.
- Adopts conventional high efficiency / low NOx burner design with staged processes of pre-mixing to LEL, ignition and oxidation.
- The burner staged process also results high DRE (destruction rate efficiency) of POP's (principle organic pollutants) such as VOC's, PAH's, nitro-PAH's and dioxins.
- With the syn-gas containing negligible pollution concerns and the firing of the syn-gas achieved at high efficiency and high DRE; the resulting off-gas consists primarily of CO2 and water vapour.
The syn-gas produced by the WtGas system is fired to power boilers and like devices to produce steam and/or electricity. After firing the off-gas is subjected to cleansing via an air quality control system, with resulting emissions complying with worldwide emission regulatory requirements. In fact, based upon US-EPA official reports the emissions are cleaner than firing of any fossil fuel (including natural gas!). Go to the Environmental Benefits page for verification.
Typical WtGas System Process Flow Diagram (Click to download PDF)
Download
Video of a WtGas System (9.5 MB, WMV format, 5:00)
