Cellulose nanocrystals(CNCs)have garnered increased attention due to their renewable nature,abundant feedstock availbility,and good mechanical properties.However,one of the bottlenecks for its commercial production is...Cellulose nanocrystals(CNCs)have garnered increased attention due to their renewable nature,abundant feedstock availbility,and good mechanical properties.However,one of the bottlenecks for its commercial production is the drying process.Because of the low CNC concentrations in suspension after isolation,CNC drying requires the removal of a large amount of water to obtain dry products for the following utilization and saving shipping costs.A novel multi-frequency,multimode,modulated ultrasonic drying technology was developed for CNC drying to improve product quality,reduce energy consumption,and increase production rate.CNCs dried with dif-ferent drying technologies were characterized by Fourier transform infrared(FT-IR)spectra anal-ysis,X-ray diffraction(XRD)analysis,thermogravimetric analysis(TGA),differential scanning calorimetry(DSC),and redispersibility to measure the quality and property changes.Under the same temperature and airflow rate,ultrasonic drying enhanced drying rates,resulting in at least a 50%reduction in drying time compared to hot air drying.The mean particle sizes of CNC from ultrasonic drying changed little with settling time,indicating good redispersibility.In addition,ultrasonic dried CNCs exhibited good stability in aqueous solutions,with the zeta potentials rang-ing from-35 to-65 mV.Specific energy consumption and CO_(2) emissions of various CNC drying technologies were evaluated.Energy consumption of ultrasonic drying is significantly reduced compared to other drying technologies.Moreover,the potential CO_(2) emissions of the fully elec-trified ultrasonic drying could be net zero if renewable electricity is used.展开更多
Approximately one quarter of the global edible food supply is wasted. The drivers of food waste can occur at any level between production, harvest, distribution, processing, and the consumer. While the drivers vary gl...Approximately one quarter of the global edible food supply is wasted. The drivers of food waste can occur at any level between production, harvest, distribution, processing, and the consumer. While the drivers vary globally, the industrialized regions of North America, Europe, and Asia share similar situations; in each of these regions the largest loss of food waste occurs with the consumer, at approximately 51% of total waste generated. As a consequence, handling waste falls on municipal solid waste operations. In the United States, food waste constitutes 15% of the solid waste stream by weight, contributes 3.4 -107 t of carbon dioxide （CO2） equivalent emissions, and costs 1.9 billion USD in disposal fees. The levels of carbon, nutrients, and moisture in food waste make bioprocessing into higher value products an attractive method for mitigation. Opportunities include extraction of nutraceuticals and bioactive compounds, or conversion to a variety of volatile acids-including lactic, acetic, and propionic acids-that can be recovered and sold at a profit. The conversion of waste into volatile acids can be paired with bioen- ergy production, including hydrogen or biogas. This present review compares the potential for upgrading industrial food waste to either specialty products or methane. Higher value uses of industrial food waste could alleviate approximately 1.9-108 t of CO2 equivalent emissions. As an example, potato peel could be upgraded to lactic acid via fermentation to recover 5600 million USD per year, or could be converted to methane via anaerobic digestion, resulting in a revenue of 900 million USD per year. The potential value to be recovered is significant, and food-waste valorization will help to close the loop for various food industries.展开更多
基金supported by the United States Department of Energy(grant No.DOE-DE-EE0009125).
文摘Cellulose nanocrystals(CNCs)have garnered increased attention due to their renewable nature,abundant feedstock availbility,and good mechanical properties.However,one of the bottlenecks for its commercial production is the drying process.Because of the low CNC concentrations in suspension after isolation,CNC drying requires the removal of a large amount of water to obtain dry products for the following utilization and saving shipping costs.A novel multi-frequency,multimode,modulated ultrasonic drying technology was developed for CNC drying to improve product quality,reduce energy consumption,and increase production rate.CNCs dried with dif-ferent drying technologies were characterized by Fourier transform infrared(FT-IR)spectra anal-ysis,X-ray diffraction(XRD)analysis,thermogravimetric analysis(TGA),differential scanning calorimetry(DSC),and redispersibility to measure the quality and property changes.Under the same temperature and airflow rate,ultrasonic drying enhanced drying rates,resulting in at least a 50%reduction in drying time compared to hot air drying.The mean particle sizes of CNC from ultrasonic drying changed little with settling time,indicating good redispersibility.In addition,ultrasonic dried CNCs exhibited good stability in aqueous solutions,with the zeta potentials rang-ing from-35 to-65 mV.Specific energy consumption and CO_(2) emissions of various CNC drying technologies were evaluated.Energy consumption of ultrasonic drying is significantly reduced compared to other drying technologies.Moreover,the potential CO_(2) emissions of the fully elec-trified ultrasonic drying could be net zero if renewable electricity is used.
基金supported by Hatch Fund (IND010677)the Department of Agricultural and Biological Engineering at Purdue University
文摘Approximately one quarter of the global edible food supply is wasted. The drivers of food waste can occur at any level between production, harvest, distribution, processing, and the consumer. While the drivers vary globally, the industrialized regions of North America, Europe, and Asia share similar situations; in each of these regions the largest loss of food waste occurs with the consumer, at approximately 51% of total waste generated. As a consequence, handling waste falls on municipal solid waste operations. In the United States, food waste constitutes 15% of the solid waste stream by weight, contributes 3.4 -107 t of carbon dioxide （CO2） equivalent emissions, and costs 1.9 billion USD in disposal fees. The levels of carbon, nutrients, and moisture in food waste make bioprocessing into higher value products an attractive method for mitigation. Opportunities include extraction of nutraceuticals and bioactive compounds, or conversion to a variety of volatile acids-including lactic, acetic, and propionic acids-that can be recovered and sold at a profit. The conversion of waste into volatile acids can be paired with bioen- ergy production, including hydrogen or biogas. This present review compares the potential for upgrading industrial food waste to either specialty products or methane. Higher value uses of industrial food waste could alleviate approximately 1.9-108 t of CO2 equivalent emissions. As an example, potato peel could be upgraded to lactic acid via fermentation to recover 5600 million USD per year, or could be converted to methane via anaerobic digestion, resulting in a revenue of 900 million USD per year. The potential value to be recovered is significant, and food-waste valorization will help to close the loop for various food industries.
