Research and development on energy from waste technologies can be divided into
3 groups as follows;
Group 1: Anaerobic digestion technology, landfill-gas-to-energy technology, and refused
derived fuel (RDF)
This group of technology is ready and suitable for the types of waste in Thailand.
They can be used with small (less than 100 tons/day) to medium (100-250 tons/day) sources
of waste. These technologies require a waste management system. Even though the energy
produced per unit is not extensive, but the technologies can be dispersed to a range of locations.
Limitations of the technologies include waste separation for anaerobic digestion, which will
be suitable for fresh markets and canteens. On the other hand, RDF needs to be located
near to sources of waste and needs a waste separation system.
Anaerobic digestion technology is ready and can be immediately deployed. However,
the technology relies heavily on import contents. The energy produced is in a limited level.
There is also a need for waste separation to select only organic wastes which are compatible
with the system. The technology can handle small and medium sources of wastes. There are
currently many landfills which can produce energy if needed. As for the landfill-gas-to-energy
technology, it will require gas extraction system to allow the technology to produce
energy at full capacity. Moreover, there is a limitation on forecasting quantity of gas,
gas purification. This technology can be used with medium to large source of wastes.
On the other hand, RDF can only be used with a small source of wastes as materials for
power production, such as gasification. Nevertheless, there is no example in Thailand and
there is no market to sell the power to.
Group 2: Incineration, gasification technology, and pyrolysis technology
The technologies of this group are mainly thermal technologies. They are popular in
other countries as they can handle large quantity of wastes without the need for waste
separation. The level of energy produced per unit is higher than other technology. This group
of technologies requires a costly investment, but can be used in large to extra large source
of wastes. Incineration has high costs of investment and operation. It also causes environmental
problems. It does not require waste separation and can produce more energy than other
technology. Gasification technology is popular in other countries. It is still in experimental
stage with a number of prototype factories. It is a clean technology, but has limitation
with regard to investment. Pyrolysis technology is still in experimental and prototype stage.
It is a clean technology, but has limitation with regard to investment.
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Biomass and Related Technologies
Biomass is from organic substance of crops and animals through a process which
transforms biomass into various kinds of energy. The technologies can be divided into
3 groups as follows;
Thermochemical process transforms biomass into energy by using heat to induce
chemical transformation, such as combustion, pyrolysis, and gasification.
Biochemical process transform biomass into energy by using biochemical reaction
which requires microorganisms, such as bacteria and fungus in fermentation until biomass
is transformed into energy such as ethanol and methane gas (CH4).
Chemical process transforms biomass into energy through chemical reaction
such as biodiesel.
Group 3: Plasma arc technology and bioreactor-gas-to-energy
The technologies of this group not yet ready for deployment as they are in research
and development without any application in Thailand and other countries. Plasma Arc
technology is in research and development stage. Bioreactor-Gas-To-Energy is in technological
development stage. It can be used with old landfill sites that have a problem on waste erosion
by water