FUEL SOURCES: Fuel, Methane, Landfills Gas, Oil/Gas, Syngas, Waste Oil, Natural Gas, Gasogene, Mazout, Biomass Gasifier, Fuel+Water
Overview
The GEK TOTTI ( Gasifier Experimenter’s Kit, Tower of Total Thermal Integration ) is the gasifier system at the heart of the Power Pallet. This document will introduce the major subsystems of the GEK TOTTI gasifier in the sequence that starts from the feedstock hopper, proceeding through the drying bucket and reactor, and ends with the gas filter.
Notes about nomenclature and terms
The following are some terms you may come across in our product literature, videos, and in the course of speaking with our sales and support personnel which should be clarified to preclude confusion.
Feedstock, Fuel
The GEK TOTTI Gasifier onboard the Power Pallet is a refinery that takes crude biomass in the hopper and refines it into a cleanburning gaseous fuel for the engine, while producing charash as a waste product.
In engineering parlance, material fed into a refinery to drive a chemical process would be called feedstock , and the refined product going into the engine would be called fuel .
However, from the perspective of the user of the Power Pallet, the machine is fueled by biomass. Because of this, you may find the terms feedstock and fuel used interchangeably. For example, the paddle switch on top of the PyroReactor that regulates the feeding of biomass into the PyroReactor is called the fuel level switch (see Annotated Figure A), but in most of our literature, the biomass is referred to as feedstock.
Syngas, Wood gas, Producer gas
The terms syngas (short for synthesis gas ), wood gas , town gas and producer gas can be found in various literature on gasification. Each term has a few implications that differentiate it from the others:
● syngas (synthesis gas) refers to a gas mixture of CO (carbon monoxide) and H 2 (hydrogen) produced by reduction reactions where carbon is the reducing agent. Syngas is often used as a chemical precursor for the synthesis of other organic chemicals. Because of its use as a precursor for chemical synthesis in industry, this term usually implies a level
of purity and concentration not seen in gas produced by airaspirated biomass gasifiers.
● wood gas refers to gas produced by the gasification of wood. Wood gas is also rich in CO and H 2 , but may also contain tar gases, and may be diluted with nitrogen gas if the gasifier was aspirated with atmospheric air. However, since the Power Pallet does not necessarily gasify wood, and can be used to gasify various other feedstocks such as palm kernel shells, nut shells, and other biomass, we do not use this term in order to avoid implying the
need for wood.
● producer gas is a term generic enough to encompass wood gas, syngas, and other
produced gasses
The terms TOTTI , Pyrocoil , and PyroReactor
refer to parts of the engine exhaust waste heat recovery system. Some of these terms are legacy terms not relevant to the present machine, but still show up in discussions and literature, and bear clarification.
The term TOTTI in GEK TOTTI stands for “ Tower Of Total Thermal Integration .” The original GEK gasifier only incorporated one stage of waste heat recovery— recovering heat from producer gas to preheat incoming air. Later on, an addition to the gas circuit which we deemed the “Hot TOTTI” was developed to recover the heat from engine exhaust for pyrolysis and to enhance feedstock drying with more heat recovered from the producer gas. The combined GEK gasifier with the TOTTI heat recovery system was called the GEK TOTTI.
The TOTTI structure consisted of two major components, both of which recovered waste heat: the Pyrocoil , and the drying bucket . The Pyrocoil recovered heat from engine exhaust to create conditions for lower pyrolytic temperatures (400˚600˚) that result in primary tars, which are easier to crack. 1 The drying bucket was a wasteheatassisted drying vessel which enabled the gasifier to tolerate feedstock with higher moisture content. The Pyrocoil was inserted into the
reactor of the GEK, and received feedstock pushed in by the auger at the bottom of the drying bucket via an inlet on its side.
In the current version of the GEK TOTTI, the Pyrocoil has been integrated into the reactor to form a new and improved structure we call the PyroReactor . Because the Pyrocoil is no longer a distinct component, the TOTTI is no longer a distinct part of the gasifier. The name GEK TOTTI is now used as a brand.
Gasifier reactor
The reactor is the component of the gasifier that actually produces gas. When speaking of the structure circled in the image of the Power Pallet below, the terms gasifier and reactor are sometimes used interchangeably in our literature. In its entirety, the GEK TOTTI gasifier system