Pyrolysis is an Emerging Green Technology

Pyrolysis grows rapidly!

Pyrolysis is an emerging technology and its green credentials when the feed is biomass are top notch. Everyone who has lit a wood or coal fire and watched it burn has seen pyrolysis. Pyrolysis is usually the first chemical reaction that occurs in the burning of many solid organic fuels, like wood, cloth, and paper, and also of some kinds of plastic.

Pyrolysis, Gasification and Plasma Incineration: Part 2

Pyrolysis, Gasification and Plasma Incineration: Part 2

In a wood fire, the visible flames are not due to combustion of the wood itself, but rather of the gases released by its pyrolysis; whereas the flame-less burning of embers is the combustion of the solid residue (charcoal) left behind by it.

Although the basic concepts of the process have been validated, the performance data for an emerging technology have not been evaluated according to methods approved by EPA and adhering to EPA quality assurance/quality control standards.

Waste is converted to a fuel by heating the waste which burns just as coal or wood does under the right controlled conditions. Whereas incineration fully converts the input waste into energy and ash, these processes limit the conversion so that combustion does not take place directly.

Waste Plastic under pressure and catalytic cracking produces fuel and can be used as a fuel source. Under certain temperature conditions the plastic macromolecular chains are broken down into small molecular chains (simple hydrocarbon compounds) and those small molecular compounds contain C4 to C20, this compound is a component of petrol, coal oil, and diesel.

Anhydrous pyrolysis can also be used to produce liquid fuel similar to diesel from solid biomass.

Fast pyrolysis occurs in a time of a few seconds or less. Therefore, not only chemical reaction kinetics but also heat and mass transfer processes, as well as phase transition phenomena, play important roles. Fast pyrolysis is a process in which organic materials are rapidly heated to 450 - 600 degrees C in absence of air. Under these conditions, organic vapors, permanent gases and charcoal are produced.

Researchers at Virginia Tech have identified pyrolysis as a potential technology for disposing of poultry litter. The ultimate goal of the project is to develop transportable pyrolysis units to process the waste from poultry growers within one locality, thus reducing transportation cost. Researchers believe that the char, an inert and highly porous material, plays a key role in helping soil retain water and nutrients, and in sustaining microorganisms that maintain soil fertility. Researchers have obtained from wood - initially beech and then coniferous species - oils with almost ideal characteristics. Straw, which has a lower energy yield - 50% as opposed to 70% for wood - is also due to be analysed in the near future.

Bill Gates’ personal investment vehicle, is reportedly backing Sapphire Energy, a start up working towards a commercial-scale facility to produce oil from algae, but we think he would do well to look at gasification and pyrolysis as his energy technology because there are so many possibilities in this technology.

Gasification technology also offers the possibility to create a new domestic supply of gas. It works by converting the hydrocarbons in coal, biomass and waste petroleum products into a gas called "syngas" that can be used in place of natural gas to generate power, or used in manufacturing as fuel or feedstock. Gasification avoids many problems which can occur in biogas digesters, and is also able to process lignin and cellulose, which are hard to ferment.

Steve Evans is enthusiastic about gasification and other renewable energy sources like anaerobic digestion plants. He also runs a great web site about the biogas.

Biomass Gasification and Syngas

Wild about biomass and syngas!

Biomass-based gasifiers, such as the BioMax units, produce electricity and thermal energy from woody waste including wood chips from hard and soft wood, sawdust pellets, coconut shells, nut shells or corncobs.

The units heat these fuels with about one-third of the oxygen necessary for complete combustion to produce a mixture of carbon dioxide and hydrogen, known as syngas. Biomass energy accounts for about 11% of the global primary energy supply, and it is estimated that about 2 billion people worldwide depend on biomass for their energy needs.

Stove, Cooking, Light, Power from Gasification

Wood gasification seems to be catching on as a viable technology for avoidance of greenhouse gas emissions. It has many great uses.  Some years ago wood gas was seen as cheaper by all means, but charcoal gasifiers had the edge were so much easier to handle. There are many gasifiers that produce gas from wood and then burn the gas, leaving ash and charcoal.

Wood chips can be fed into gasification plant gasifiers and the gas produced is used to light the furnace in the chamber. Woody biomass plants can show economics which are very local and can provide a secure return on investment in many circumstances. Technologies range from boilers, to gasifiers, to pyrolyzers, to just plain wood stoves. Wood gas can be used to power cars with ordinary internal combustion engines if a wood gasifier is attached. This was quite popular during World War II in several European countries because the armies active in the war did not always have access to oil.

Performance parameters such as air factor, feeding point position and bed height are determined by running trials and looking for a maximum gasifier efficiency and gas heating value and a minimum tar content in the gas. Other parameters which can be optimized by using CSFB software are the pressure drop, the bubble diameter and the gas velocities in the bed

Syngas, produced in gasification process palnts, can be used as a fuel to generate electricity or steam, or as a basic chemical building block for a multitude of uses. When mixed with air, syngas can be used in gasoline or diesel engines with few modifications to the engine.

Syngas is a mixture of hydrogen and carbon monoxide and it can be converted into fuels such as hydrogen, natural gas or ethanol. Syngas (which leaves the converter at a temperature of around 2,200 degrees Fahrenheit) is fed into a cooling system which generates steam. Syngas can be used as a fuel to generate electricity and steam or as a chemical building block for the petrochemical and refining industries. The gasification process converts feedstock such as coal, crude oil, petroleum-based materials or gases into marketable fuels and products.

Models range in size from 5-kW units for home use to 15-kW machines, enough to power a small business. The company is currently demonstrating six gasifiers in off-grid field applications. Modeling results are compared with the experimental results published in the literature. Predicted effects of bed temperature, equivalence ratio and fuel moisture content on main gaseous composition, tar and NH3 emissions generally agree with the literature data.

Syngas can be used as a fuel to generate electricity or steam, or as a basic chemical building block for a multitude of uses. When mixed with air, syngas can be used in gasoline or diesel engines with few modifications to the engine. Syngas is a mixture of hydrogen and carbon monoxide and it can be converted into fuels such as hydrogen, natural gas or ethanol. Syngas (which leaves the converter at a temperature of around 2,200 degrees Fahrenheit) is fed into a cooling system which generates steam. Syngas can be used as a fuel to generate electricity and steam or as a chemical building block for the petrochemical and refining industries.

The gasification process converts feedstock such as coal, crude oil, petroleum-based materials or gases into marketable fuels and products.

Steve Evans is enthusiastic about gasification and other renewable energy sources from farm biomass syngas. He also runs a great web site about dog breeds.