Bioenergy is presently the largest global contributor of renewable energy. Biomass thermal conversion has significant potential to expand in the production of heat, electricity, and fuels for transport. Instead of using lots of fossil fuels, biomass thermal conversion can produce an energy carrier with increased energy density. Therefore, the technology can contribute significantly toward the objectives of reducing greenhouse gas emissions and alleviating problems related to climate change. In addition, the thermal conversion of biomass with carbon capture and storage or biochar production can help to establish the suitable carbon negative pathway. Because plants absorb CO2 as they grow, this is a way of removing atmosphere CO2. There are four main thermal processes—combustion, gasification, pyrolysis, and hydrothermal—to convert the biomass into various energy products. Combustion is well established and widely practiced with many examples of dedicated plant and co-firing applications. At present, biomass co-firing in modern coal power plants is the most cost-effective biomass use for power generation. Due to feedstock availability issues, dedicated biomass plants for combined heat and power (CHP)Combined heat and power (CHP) system are typically of smaller size. Gasification provides a competitive way to convert diverse, highly distributed and low-value lignocellulosic biomass to syngas for combined heat and power generation, synthesis of liquid fuels, and production of hydrogen (H2). A number of gasifier configurations have been developed. Biomass-integrated gasification combined cycles (BIGCC)Biomass-integrated gasification combined cycles (BIGCC) using black liquor are already in use. Gasification can also co-produce liquid fuels, and such advanced technologies are currently being investigated in research and pilot plants. Pyrolysis is the thermal destruction of biomass in the absence of air/oxygen to produce liquid bio-oil, syngas, and charcoal. Fast pyrolysis for liquid fuel production is currently of particular interest because liquid fuel can be stored and transported more easily and at lower cost than solid biomass. Pyrolysis technology is currently at the demonstration stage, and technologies for upgrading the bio-oil to transport fuels are applied at the R&D and pilot stage. Hydrothermal processing is a promising method of converting energy-rich biomass into useful products. This approach offers the advantage of handling biomass with relatively high moisture content by precluding an energy-intensive pretreatment step. Hydrothermal processing is of worldwide interest in view of depleting fossil-fuel reserves and increased environmental greenhouse gas emissions. There is potential to develop this novel technology at demonstration scale. This chapter introduces the three hydrothermal technologies, namely, hydrothermal liquefaction, gasification, and carbonization. This chapter provides an overview of the state-of-the-art knowledge on biomass thermal conversion: the recent breakthrough in the technology, the current research and development activities, and challenges associated with its increased deployment.

Thermal Conversion of Biomass

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发表日期：

2025年

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Zhongyang Luo,
Jinsong Zhou

摘要

Bioenergy is presently the largest global contributor of renewable energy. Biomass thermal conversion has significant potential to expand in the production of heat, electricity, and fuels for transport. Instead of using lots of fossil fuels, biomass thermal conversion can produce an energy carrier with increased energy density. Therefore, the technology can contribute significantly toward the objectives of reducing greenhouse gas emissions and alleviating problems related to climate change. In addition, the thermal conversion of biomass with carbon capture and storage or biochar production can help to establish the suitable carbon negative pathway. Because plants absorb CO2 as they grow, this is a way of removing atmosphere CO2. There are four main thermal processes—combustion, gasification, pyrolysis, and hydrothermal—to convert the biomass into various energy products. Combustion is well established and widely practiced with many examples of dedicated plant and co-firing applications. At present, biomass co-firing in modern coal power plants is the most cost-effective biomass use for power generation. Due to feedstock availability issues, dedicated biomass plants for combined heat and power (CHP)Combined heat and power (CHP) system are typically of smaller size. Gasification provides a competitive way to convert diverse, highly distributed and low-value lignocellulosic biomass to syngas for combined heat and power generation, synthesis of liquid fuels, and production of hydrogen (H2). A number of gasifier configurations have been developed. Biomass-integrated gasification combined cycles (BIGCC)Biomass-integrated gasification combined cycles (BIGCC) using black liquor are already in use. Gasification can also co-produce liquid fuels, and such advanced technologies are currently being investigated in research and pilot plants. Pyrolysis is the thermal destruction of biomass in the absence of air/oxygen to produce liquid bio-oil, syngas, and charcoal. Fast pyrolysis for liquid fuel production is currently of particular interest because liquid fuel can be stored and transported more easily and at lower cost than solid biomass. Pyrolysis technology is currently at the demonstration stage, and technologies for upgrading the bio-oil to transport fuels are applied at the R&D and pilot stage. Hydrothermal processing is a promising method of converting energy-rich biomass into useful products. This approach offers the advantage of handling biomass with relatively high moisture content by precluding an energy-intensive pretreatment step. Hydrothermal processing is of worldwide interest in view of depleting fossil-fuel reserves and increased environmental greenhouse gas emissions. There is potential to develop this novel technology at demonstration scale. This chapter introduces the three hydrothermal technologies, namely, hydrothermal liquefaction, gasification, and carbonization. This chapter provides an overview of the state-of-the-art knowledge on biomass thermal conversion: the recent breakthrough in the technology, the current research and development activities, and challenges associated with its increased deployment.