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4.5.2 Technology and Commercial Maturity
Direct combustion technology is by far the most technologically developed and
commercially available thermal process for biomass. According to Tan (2013),
commercial availability represents the market availability of the technology at a
commercial scale capacity (at least 25 MW or 300 t day
−1
). Although there have
been a few studies written on large-scale combustion of rice straw for power generation, Boucher et al. (2013) reported that there are at least three power plants producing 24–25 MW in China, which are known to use rice straw as part of the biomass
fuel and around 15 biomass power projects in operation by the end of 2012. Some
power plants using rice straw as feedstock were also installed in India and Thailand;
however, problems on straw collection and feeding especially at large-scale operations led to their closure. This experience suggests that small combustion systems
similar to the farm-scale paddy flatbed dryer developed at IRRI, which can be
placed near rice fields, may be more feasible (Boucher et al. 2013; Migo 2019).
Direct combustion is also highly favored by industrialized countries compared to
other conversion technologies due to its lower annual capital cost, operational cost,
and higher daily throughput.
Gasification, on the other hand, is relatively more advanced in terms of technological status as compared to pyrolysis. While no commercial rice straw gasification
plants have been installed, other biomass materials, such as wood chips or rice
husks, have been used for more than 100 years. Fluidized bed systems are in its
demonstration phase while downdraft and updraft gasifiers are already in their early
commercial stages (IFC 2017). Ouda et al. (2016) also reported that Asia has
advanced greatly in the gasification technology over the past few years and can be
considered as one of the most favorable markets for gasification technology followed by Europe, Africa, and USA.
Brandin et al. (2011), for example, assessed five gasification plants using different biomass materials as fuel in Europe with electrical power outputs in the range of
from 17.5 kWe to 6 MWe and concluded that the technology is generally sufficiently mature for commercialization, although some unit operations, for example
catalytic tar reforming, still need further development. All plants have a fully automatic operation and are equipped with complex tar removal systems. Since these are
all pilot plants, data about commercial feasibility were not yet available. Further
development is also needed to increase the biofuel-to-electricity efficiency, currently at from 20–25%, to 30–40% and overall performance efficiency to
around 90%.
Dimpl (2010) analyzed experiences with small-scale applications of the gasification technology worldwide over the last three decades. The study concluded that
there is not yet any standard gasifier technology complying with environmental
standards appropriate for rural small-scale applications readily available off the
shelf. In general, the small-scale power-gasifier technology proved to be unreliable
and expensive and to minimize cost systems for capturing carcinogenic waste are
often not installed or not very effective.
M. C. Maguyon-Detras et al.
4.5.2 Technology and Commercial Maturity
Direct combustion technology is by far the most technologically developed and
commercially available thermal process for biomass. According to Tan (2013),
commercial availability represents the market availability of the technology at a
commercial scale capacity (at least 25 MW or 300 t day
−1
). Although there have
been a few studies written on large-scale combustion of rice straw for power generation, Boucher et al. (2013) reported that there are at least three power plants producing 24–25 MW in China, which are known to use rice straw as part of the biomass
fuel and around 15 biomass power projects in operation by the end of 2012. Some
power plants using rice straw as feedstock were also installed in India and Thailand;
however, problems on straw collection and feeding especially at large-scale operations led to their closure. This experience suggests that small combustion systems
similar to the farm-scale paddy flatbed dryer developed at IRRI, which can be
placed near rice fields, may be more feasible (Boucher et al. 2013; Migo 2019).
Direct combustion is also highly favored by industrialized countries compared to
other conversion technologies due to its lower annual capital cost, operational cost,
and higher daily throughput.
Gasification, on the other hand, is relatively more advanced in terms of technological status as compared to pyrolysis. While no commercial rice straw gasification
plants have been installed, other biomass materials, such as wood chips or rice
husks, have been used for more than 100 years. Fluidized bed systems are in its
demonstration phase while downdraft and updraft gasifiers are already in their early
commercial stages (IFC 2017). Ouda et al. (2016) also reported that Asia has
advanced greatly in the gasification technology over the past few years and can be
considered as one of the most favorable markets for gasification technology followed by Europe, Africa, and USA.
Brandin et al. (2011), for example, assessed five gasification plants using different biomass materials as fuel in Europe with electrical power outputs in the range of
from 17.5 kWe to 6 MWe and concluded that the technology is generally sufficiently mature for commercialization, although some unit operations, for example
catalytic tar reforming, still need further development. All plants have a fully automatic operation and are equipped with complex tar removal systems. Since these are
all pilot plants, data about commercial feasibility were not yet available. Further
development is also needed to increase the biofuel-to-electricity efficiency, currently at from 20–25%, to 30–40% and overall performance efficiency to
around 90%.
Dimpl (2010) analyzed experiences with small-scale applications of the gasification technology worldwide over the last three decades. The study concluded that
there is not yet any standard gasifier technology complying with environmental
standards appropriate for rural small-scale applications readily available off the
shelf. In general, the small-scale power-gasifier technology proved to be unreliable
and expensive and to minimize cost systems for capturing carcinogenic waste are
often not installed or not very effective.
M. C. Maguyon-Detras et al.