• Energy Research

Abstract Effective methods of biomass characterization are needed for energy production due to the increase in biomass to bioenergy conversion capacity and the availability of various biomass sources. The utilization of biomass has been enhanced through thermochemical conversion techniques such as torrefaction, pyrolysis, and gasification. The biomass analytical techniques have been developed to decrease the time and energy required for biomass conversion performance. Thermogravimetric analyzer (TG) and Fourier transform infrared spectroscopic (FTIR) analytical techniques facing several limitations when applied individually. Thus, TG coupled with FTIR (TG-FTIR) was used to analyze the main parameters of biomass and improved the energy crop growing developments. In addition, TG-FTIR can determine the suitable ratio for two different biomass or coal blending during the co-pyrolysis and co-gasification to achieve the optimum synergetic interaction. In this review, thermochemical conversion processes such as torrefaction, pyrolysis, and gasification are presented. The analysis of the thermochemical conversion of biomass with the use of TG and FTIR individually are then discussed. Lastly, this review aims to discuss the applications of TG-FTIR techniques that have been applied to the analysis of evolved gas from the thermochemical processing of biomass to biofuels.

Abstract Effective methods of biomass characterization are needed for energy production due to the increase in biomass to bioenergy conversion capacity and the availability of various biomass sources. The utilization of biomass has been enhanced through thermochemical conversion techniques such as torrefaction, pyrolysis, and gasification. The biomass analytical techniques have been developed to decrease the time and energy required for biomass conversion performance. Thermogravimetric analyzer (TG) and Fourier transform infrared spectroscopic (FTIR) analytical techniques facing several limitations when applied individually. Thus, TG coupled with FTIR (TG-FTIR) was used to analyze the main parameters of biomass and improved the energy crop growing developments. In addition, TG-FTIR can determine the suitable ratio for two different biomass or coal blending during the co-pyrolysis and co-gasification to achieve the optimum synergetic interaction. In this review, thermochemical conversion processes such as torrefaction, pyrolysis, and gasification are presented. The analysis of the thermochemical conversion of biomass with the use of TG and FTIR individually are then discussed. Lastly, this review aims to discuss the applications of TG-FTIR techniques that have been applied to the analysis of evolved gas from the thermochemical processing of biomass to biofuels.

The rapid spread of coronavirus disease 2019 (COVID-19) in early 2020 prompted a global lockdown from March to July 2020. Due to strict lockdown measures, many countries experienced economic downturns, negatively affecting many industries including energy, manufacturing, agriculture, finance, healthcare, food, education, tourism, and sports. Despite this, the COVID-19 pandemic provided a rare opportunity to observe the impacts of worldwide lockdown on global carbon dioxide (CO2) emissions and climate change. Being the main greenhouse gas responsible for rising global surface temperature, CO2 is released to the atmosphere primarily by burning fossil fuels. Compared to 2019, CO2 emissions for the world and Malaysia decreased significantly by 4.02% (−1365.83 MtCO2) and 9.7% (−225.97 MtCO2) in 2020. However, this is insufficient to cause long-term impacts on global CO2 levels and climate change. Therefore, in this review, we explored the effects of worldwide lockdown on global CO2 levels, the impacts of national lockdown on Malaysia’s CO2 emissions, and the influence of climate change in Malaysia.

The rapid spread of coronavirus disease 2019 (COVID-19) in early 2020 prompted a global lockdown from March to July 2020. Due to strict lockdown measures, many countries experienced economic downturns, negatively affecting many industries including energy, manufacturing, agriculture, finance, healthcare, food, education, tourism, and sports. Despite this, the COVID-19 pandemic provided a rare opportunity to observe the impacts of worldwide lockdown on global carbon dioxide (CO2) emissions and climate change. Being the main greenhouse gas responsible for rising global surface temperature, CO2 is released to the atmosphere primarily by burning fossil fuels. Compared to 2019, CO2 emissions for the world and Malaysia decreased significantly by 4.02% (−1365.83 MtCO2) and 9.7% (−225.97 MtCO2) in 2020. However, this is insufficient to cause long-term impacts on global CO2 levels and climate change. Therefore, in this review, we explored the effects of worldwide lockdown on global CO2 levels, the impacts of national lockdown on Malaysia’s CO2 emissions, and the influence of climate change in Malaysia.

AbstractHydrothermal carbonization (HTC) technology emerges as a sustainable method to convert wet biomass, including food waste and municipal solid waste into high‐energy dense biocoal. This process, conducted at temperatures ranging from 180 to 260°C and pressures of 10–50 bar, effectively transforms the organic material in wet biomass into solid, liquid, and gaseous outputs. The solid product, biocoal, possesses a high carbon concentration and heating values on par with lignite coal, presenting a cleaner alternative to traditional fossil fuels. Despite operational commercial‐scale HTC facilities globally, further adoption across various feedstocks can improve waste management and energy production. The process can achieve energy yields up to 80%, particularly at temperatures favoring the generation of secondary char with higher heating values. HTC not only aids in reducing greenhouse gas emissions through carbon sequestration in solid waste but also promotes environmental sustainability by yielding nutrient‐rich by‐products for agriculture. As a versatile and energy‐efficient solution, HTC technology is a pivotal innovation in waste‐to‐energy conversion, addressing the imperative for sustainable waste management. Other supplementary benefits are presented; they include higher employability, reduction of a nation's reliance on imported energy, and better waste control, therefore considering all pillars of sustainability. Future research should focus on optimizing process efficiency and exploring the broader applicability of HTC to various biomass feedstocks, enhancing its role in the global pursuit of sustainable energy solutions.

AbstractHydrothermal carbonization (HTC) technology emerges as a sustainable method to convert wet biomass, including food waste and municipal solid waste into high‐energy dense biocoal. This process, conducted at temperatures ranging from 180 to 260°C and pressures of 10–50 bar, effectively transforms the organic material in wet biomass into solid, liquid, and gaseous outputs. The solid product, biocoal, possesses a high carbon concentration and heating values on par with lignite coal, presenting a cleaner alternative to traditional fossil fuels. Despite operational commercial‐scale HTC facilities globally, further adoption across various feedstocks can improve waste management and energy production. The process can achieve energy yields up to 80%, particularly at temperatures favoring the generation of secondary char with higher heating values. HTC not only aids in reducing greenhouse gas emissions through carbon sequestration in solid waste but also promotes environmental sustainability by yielding nutrient‐rich by‐products for agriculture. As a versatile and energy‐efficient solution, HTC technology is a pivotal innovation in waste‐to‐energy conversion, addressing the imperative for sustainable waste management. Other supplementary benefits are presented; they include higher employability, reduction of a nation's reliance on imported energy, and better waste control, therefore considering all pillars of sustainability. Future research should focus on optimizing process efficiency and exploring the broader applicability of HTC to various biomass feedstocks, enhancing its role in the global pursuit of sustainable energy solutions.

The microalgal-bacterial co-cultivation was adopted as an alternative in making microbial-based biofuel production to be more feasible in considering the economic and environmental prospects. Accordingly, the microalgal-bacterial symbiotic relationship was exploited to enhance the microbial biomass yield, while bioremediating the nitrogen-rich municipal wastewater. An optimized inoculation ratio of microalgae and activated sludge (AS:MA) was predetermined and further optimization was performed in terms of different increment ratios to enhance the bioremediation process. The nitrogen removal was found accelerating with the increase of the increment ratios of inoculated AS:MA, though all the increment ratios had recorded a near complete total nitrogen removal (94-95%). In light of treatment efficiency and lipid production, the increment ratio of 0.5 was hailed as the best microbial population size in accounting the total nitrogen removal efficiency of 94.45%, while not compromising the lipid production of 0.241 g/L. Moreover, the cultures in municipal wastewater had attained higher biomass and lipid productions of 1.42 g/L and 0.242 g/L, respectively, as compared with the synthetic wastewater which were only 1.12 g/L (biomass yield) and 0.175 g/L (lipid yield). This was possibly due to the presence of trace elements which had contributed to the increase of biomass yield; thus, higher lipid attainability from the microalgal-bacterial culture. This synergistic microalgal-bacterial approach had been proven to be effective in treating wastewater, while also producing useful biomass for eventual lipid production with comparable net energy ratio (NER) value of 0.27, obtained from the life-cycle analysis (LCA) studies. Thereby, contributing towards long-term sustainability and possible commercialization of microbial-based biofuel production.

The microalgal-bacterial co-cultivation was adopted as an alternative in making microbial-based biofuel production to be more feasible in considering the economic and environmental prospects. Accordingly, the microalgal-bacterial symbiotic relationship was exploited to enhance the microbial biomass yield, while bioremediating the nitrogen-rich municipal wastewater. An optimized inoculation ratio of microalgae and activated sludge (AS:MA) was predetermined and further optimization was performed in terms of different increment ratios to enhance the bioremediation process. The nitrogen removal was found accelerating with the increase of the increment ratios of inoculated AS:MA, though all the increment ratios had recorded a near complete total nitrogen removal (94-95%). In light of treatment efficiency and lipid production, the increment ratio of 0.5 was hailed as the best microbial population size in accounting the total nitrogen removal efficiency of 94.45%, while not compromising the lipid production of 0.241 g/L. Moreover, the cultures in municipal wastewater had attained higher biomass and lipid productions of 1.42 g/L and 0.242 g/L, respectively, as compared with the synthetic wastewater which were only 1.12 g/L (biomass yield) and 0.175 g/L (lipid yield). This was possibly due to the presence of trace elements which had contributed to the increase of biomass yield; thus, higher lipid attainability from the microalgal-bacterial culture. This synergistic microalgal-bacterial approach had been proven to be effective in treating wastewater, while also producing useful biomass for eventual lipid production with comparable net energy ratio (NER) value of 0.27, obtained from the life-cycle analysis (LCA) studies. Thereby, contributing towards long-term sustainability and possible commercialization of microbial-based biofuel production.