Over the last decade, the uptake rate of first-generation biofuels (ethanol and biodiesel) has decelerated as low blend limits have increased only slowly and extreme volatility in oil prices has limited investment in ...Over the last decade, the uptake rate of first-generation biofuels (ethanol and biodiesel) has decelerated as low blend limits have increased only slowly and extreme volatility in oil prices has limited investment in biofuels production infrastructure. Concerns over the environmental impacts of large-scale biofuels production combined with tariff barriers have greatly restricted the global trade in biofuels. First-generation biofuels produced either by fermentation of sugars from maize or sugarcane (ethanol) or transesterification of triglycerides (biodiesel) presently contribute less than 4% of terrestrial transportation fuel demand and techno-economic modelling foresees this only slowly increasing by 2035. With internal combustion and diesel engines widely anticipated as being phased out in favour of electric power for motor vehicles, a much-reduced market demand for biofuels is likely if global demand for all liquid fuels declines by 2050. However, second-generation, thermochemically produced and biomass-derived fuels (renewable diesel, marine oils and sustainable aviation fuel) have much higher blend limits;combined with policies to decarbonise the aviation and marine industries, major new markets for these products in terrestrial, marine and aviation sectors may emerge in the second half of the 21st century.展开更多
There would be strong product inhibition on ethanol fermentation process if ethanol is not removed in situ from broth. PDMS membrane pervaporation coupled with fermentation is a promising process for efficient bioetha...There would be strong product inhibition on ethanol fermentation process if ethanol is not removed in situ from broth. PDMS membrane pervaporation coupled with fermentation is a promising process for efficient bioethanol production since ethanol inhibition is relieved or eliminated. From the perspective of process operation, membrane separation performance, ethanol fermentation performance and the subsequent processing on membrane downstream are the three key issues. This review aims at contributing a comprehensive overview on the operation performance of the integrated process. The state-of-the-art of the three key issues related to the operation performance is focused. Finally, the tentative perspective on the possible future prospects of the integrated process is briefly presented.展开更多
Successful commercialization of microalgal bio-industry requires the design of an integrated microalgal biorefinery system that facilitates the co-production of biofuels, high-value products and industrial chemicals f...Successful commercialization of microalgal bio-industry requires the design of an integrated microalgal biorefinery system that facilitates the co-production of biofuels, high-value products and industrial chemicals from the biomass. In this study, we investigated the use of sugar hydrolysate obtained from enzymatic saccharification of microalgal biomass (Chlorella sp. and T. suecica) as fermentation feedstock to produce industrially important chemicals, in particular acetic acid and butyric acid. By using hydrolysate with low sugar content as substrate for the anaerobic fermentation (1.5 - 2.4 g/L), we were able to prevent the bacterium C. saccharoperbutylacetonicum from activating its solventogenesis pathway. As a result, the fermentation process generated a product stream that was dominated by organic acids (acetic acid and butyric acid) rather than solvents (butanol, ethanol and acetone). Acetic acid constituted up to 92 wt% of Chlorella’s fermentation products and 80 wt% of T. suecica’s fermentation products. For T. suecica, the fermentation consumed almost all of the sugar available in the hydrolysate (up to 92% of initial sugar) and produced a reasonable yield of fermentation products (0.08 g fermentation products/g sugar). The Gompertz equation was successfully used to predict the formation kinetics of acetic acid and other fermentation products across both species. The results in the study demonstrate the production of industrially important chemicals, such as acetic acid and butyric acid, from the fermentation of microalgal sugar. The process described in the study can potentially be used as a value-adding step to generate biochemicals from cell debris in an integrated microalgal biorefinery system.展开更多
The use of renewable energy is steadily being adopted as a mitigative measure for reducing greenhouse gas emissions. By assessing biomass production and consumption estimates from Louisiana parishes, this study examin...The use of renewable energy is steadily being adopted as a mitigative measure for reducing greenhouse gas emissions. By assessing biomass production and consumption estimates from Louisiana parishes, this study examines the utilization of agricultural biomass as a convenient renewable energy source, and the potential of marginal lands for growing bioenergy crops in Louisiana. This was achieved by retrieving parish-level acreage production of some biofuel crops recorded in 2021 using the Quick Stats Database, to map out the spatial locations and distribution of the biofuel crops. To examine the potential of Louisiana’s marginal lands in bioenergy crop production, data was obtained from the Soil Survey Geographic (SSURGO) database and mapped-out according to the eight Land Capability Classes numbered I-VIII. The results of the mapped-out acreage data revealed that 25% of the 64 parishes including Morehouse recorded high corn production estimates, while 43%, such as East Carroll, recorded high soybean production. Meanwhile, cotton production estimates were relatively low, as recorded in only 9 parishes, with one parish, Tensas, having the highest acreage production of around 23,000. Although the identified marginal lands in parishes such as Allen and Vernon had no records of corn, soybean, or cotton production, the soil survey database revealed that these marginal lands have high nutrient soils like Alfisols, Entisols and Inceptisols with optimal nutrient balance essential for high yield bioenergy crop production. Hence, this paper highlights Louisiana’s agricultural biomass to be leveraged as sustainable renewable sources while adhering to clear production guidelines, biofuel sustainability certification, and internationally agreed sustainability criteria.展开更多
文摘Over the last decade, the uptake rate of first-generation biofuels (ethanol and biodiesel) has decelerated as low blend limits have increased only slowly and extreme volatility in oil prices has limited investment in biofuels production infrastructure. Concerns over the environmental impacts of large-scale biofuels production combined with tariff barriers have greatly restricted the global trade in biofuels. First-generation biofuels produced either by fermentation of sugars from maize or sugarcane (ethanol) or transesterification of triglycerides (biodiesel) presently contribute less than 4% of terrestrial transportation fuel demand and techno-economic modelling foresees this only slowly increasing by 2035. With internal combustion and diesel engines widely anticipated as being phased out in favour of electric power for motor vehicles, a much-reduced market demand for biofuels is likely if global demand for all liquid fuels declines by 2050. However, second-generation, thermochemically produced and biomass-derived fuels (renewable diesel, marine oils and sustainable aviation fuel) have much higher blend limits;combined with policies to decarbonise the aviation and marine industries, major new markets for these products in terrestrial, marine and aviation sectors may emerge in the second half of the 21st century.
基金Supported by the National Natural Science Foundation of China(Nos.20176030,20276041,20776088,21808144)China Postdoctoral Science Foundation(No.2016M592710)+1 种基金Fundamental Research Funds for the Central Universities(No.20822041B4013)Key Laboratory of Development and Application of Rural Renewable Energy,MOA,China(No.18H0491)
文摘There would be strong product inhibition on ethanol fermentation process if ethanol is not removed in situ from broth. PDMS membrane pervaporation coupled with fermentation is a promising process for efficient bioethanol production since ethanol inhibition is relieved or eliminated. From the perspective of process operation, membrane separation performance, ethanol fermentation performance and the subsequent processing on membrane downstream are the three key issues. This review aims at contributing a comprehensive overview on the operation performance of the integrated process. The state-of-the-art of the three key issues related to the operation performance is focused. Finally, the tentative perspective on the possible future prospects of the integrated process is briefly presented.
文摘Successful commercialization of microalgal bio-industry requires the design of an integrated microalgal biorefinery system that facilitates the co-production of biofuels, high-value products and industrial chemicals from the biomass. In this study, we investigated the use of sugar hydrolysate obtained from enzymatic saccharification of microalgal biomass (Chlorella sp. and T. suecica) as fermentation feedstock to produce industrially important chemicals, in particular acetic acid and butyric acid. By using hydrolysate with low sugar content as substrate for the anaerobic fermentation (1.5 - 2.4 g/L), we were able to prevent the bacterium C. saccharoperbutylacetonicum from activating its solventogenesis pathway. As a result, the fermentation process generated a product stream that was dominated by organic acids (acetic acid and butyric acid) rather than solvents (butanol, ethanol and acetone). Acetic acid constituted up to 92 wt% of Chlorella’s fermentation products and 80 wt% of T. suecica’s fermentation products. For T. suecica, the fermentation consumed almost all of the sugar available in the hydrolysate (up to 92% of initial sugar) and produced a reasonable yield of fermentation products (0.08 g fermentation products/g sugar). The Gompertz equation was successfully used to predict the formation kinetics of acetic acid and other fermentation products across both species. The results in the study demonstrate the production of industrially important chemicals, such as acetic acid and butyric acid, from the fermentation of microalgal sugar. The process described in the study can potentially be used as a value-adding step to generate biochemicals from cell debris in an integrated microalgal biorefinery system.
文摘The use of renewable energy is steadily being adopted as a mitigative measure for reducing greenhouse gas emissions. By assessing biomass production and consumption estimates from Louisiana parishes, this study examines the utilization of agricultural biomass as a convenient renewable energy source, and the potential of marginal lands for growing bioenergy crops in Louisiana. This was achieved by retrieving parish-level acreage production of some biofuel crops recorded in 2021 using the Quick Stats Database, to map out the spatial locations and distribution of the biofuel crops. To examine the potential of Louisiana’s marginal lands in bioenergy crop production, data was obtained from the Soil Survey Geographic (SSURGO) database and mapped-out according to the eight Land Capability Classes numbered I-VIII. The results of the mapped-out acreage data revealed that 25% of the 64 parishes including Morehouse recorded high corn production estimates, while 43%, such as East Carroll, recorded high soybean production. Meanwhile, cotton production estimates were relatively low, as recorded in only 9 parishes, with one parish, Tensas, having the highest acreage production of around 23,000. Although the identified marginal lands in parishes such as Allen and Vernon had no records of corn, soybean, or cotton production, the soil survey database revealed that these marginal lands have high nutrient soils like Alfisols, Entisols and Inceptisols with optimal nutrient balance essential for high yield bioenergy crop production. Hence, this paper highlights Louisiana’s agricultural biomass to be leveraged as sustainable renewable sources while adhering to clear production guidelines, biofuel sustainability certification, and internationally agreed sustainability criteria.
