Biochar is increasingly proposed as a soil amendment, with reports of benefits to soil physical, chemical and biological properties. In this study, different biochars were produced from 6 feedstocks, including straw a...Biochar is increasingly proposed as a soil amendment, with reports of benefits to soil physical, chemical and biological properties. In this study, different biochars were produced from 6 feedstocks, including straw and poultry manure, at 3 pyrolysis temperatures （200, 300 and 500℃） and then added separately to a calcareous soil. Their effects on soil properties and maize growth were evaluated in a pot experiment. The biochars derived from crop straw had much higher C but smaller N concentrations than those derived from poultry manure. Carbon concentrations, pH and EC values increased with increasing pyrolysis temperature. Biochar addition resulted in increases in mean maize dry matter of 12.73% and NPK concentrations of 30, 33 and 283%, respectively. Mean soil pH values were increased by 0.45 units. The biochar-amended soils had 44, 55, 254 and 537% more organic C, total N, Olsen-P and available K, respectively, than the control on average. Both feedstocks and pyrolysis temperature determined the characteristics of the biochar. Biochars with high mineral concentrations may act as mineral nutrient supplements.展开更多
The rheological behaviors of feedstocks for powder extrusion molding, in the temperature range of 40～80 ℃ and the Newton shear rate of 3～800 s -1 , were studied. The effects of feedstock constitution, shear rate an...The rheological behaviors of feedstocks for powder extrusion molding, in the temperature range of 40～80 ℃ and the Newton shear rate of 3～800 s -1 , were studied. The effects of feedstock constitution, shear rate and temperature on apparent viscosity, shear stress and active energy were investigated. The viscose flow active energy of PEM feedstocks is 15.89～90.77 kJ/mol. Based on this research, the PEM technical parameters have optimized. [展开更多
L-malate is an intermediate of the tricarboxylic acid cycle which is naturally occurred in various microorganisms,and it has been widely applied in polymer,beverage and food,textile,agricultural and pharmaceutical ind...L-malate is an intermediate of the tricarboxylic acid cycle which is naturally occurred in various microorganisms,and it has been widely applied in polymer,beverage and food,textile,agricultural and pharmaceutical industries.Driven by the pursuit of a sustainable economy,microbial production of L-malate has received much attention in last decades.In this review,we focus on the utilization of wastes and/or byproducts as feedstocks for the microbial production of L-malate.Firstly,we present the recent developments on the natural or engineered metabolic pathways that dedicate to the biosynthesis of L-malate,and also provide a comprehensive discussions on developing high-efficient producers.Then,the recent achievements in microbial production of L-malate from various carbon sources were concluded and discussed.Furthermore,some abundant non-food feedstocks which have been used for microbial production of other chemicals were reviewed,as they may be potential candidate feedstock for L-malate production in future.Finally,we outlined the major challenges and proposed further improvements for the production of L-malate.展开更多
The upgrading of diesel oil to produce ethylene rich cracking feedstock is an important and promising technical route to reduce the ratio of diesel to gasoline. In the present work, a hydrocracking catalyst suitable f...The upgrading of diesel oil to produce ethylene rich cracking feedstock is an important and promising technical route to reduce the ratio of diesel to gasoline. In the present work, a hydrocracking catalyst suitable for selective hydrocracking of straight run diesel oil to produce high-quality ethylene cracking feedstock at low cost was developed, by optimizing the composition of catalyst support materials, using amorphous silicon aluminum and aluminum oxide with high mesopore content as the main support, and modified Y zeolite with excellent aromatic ring opening selectivity as the acidic component. The catalyst has in-depth characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, N<sub>2</sub>-low temperature adsorption-desorption, NH<sub>3</sub>-temperature-programmed desorption, and IR techniques. And its catalytic cracking straight run diesel oil performance was evaluated. The results show that the prepared catalyst has high polycyclic aromatic hydrocarbon ring opening cracking selectivity. However, alkanes retained in diesel distillates can achieve the goal of producing more ethylene cracking feedstocks with low BMCI value under low and moderate pressure conditions. This work may shed significant technical insight for oil refining transformation.展开更多
Terpenoids are a diverse class of natural products widely used as pharmaceuticals,perfumes,flavors,and biofuels.Traditionally,terpenoids are obtained from natural sources,such as plants,but their production is limited...Terpenoids are a diverse class of natural products widely used as pharmaceuticals,perfumes,flavors,and biofuels.Traditionally,terpenoids are obtained from natural sources,such as plants,but their production is limited by the insufficiency of resources and low yields of extraction.Microbial production of terpenoids has emerged as a promising alternative due to that it is sustainable and easy to scale up.This review aims to summarize recent advances in microbial production of terpenoids from inexpensive biomass-derived feedstocks.Metabolic pathways and key enzymes involved in terpenoid biosynthesis are introduced.Microorganisms that can utilize low-cost lignocellulosic feedstocks for terpenoid production are highlighted.The challenges and prospects faced by microbial terpenoid production are proposed.We believe that continuous progress in the fields of biomass transformation and synthetic biology will ultimately achieve industrial production of microbial terpenoids.展开更多
Nanocrystalline NiCrC alloy powders with a qualified particle size distribution for thermal spraying were synthesized using the cryogenic ball milling （cryomilling） method. The morphology, microstructure, size distr...Nanocrystalline NiCrC alloy powders with a qualified particle size distribution for thermal spraying were synthesized using the cryogenic ball milling （cryomilling） method. The morphology, microstructure, size distribution, and phase transformation of the powders were characterized by scanning electron microscopy （SEM）, laser scattering for particle size analysis, X-ray diffraction （XRD）, and transmission electron microscopy （TEM）. After cryomilling for 20 h, the average grain size of the as-milled powders approached a constant value of 30 nm by XRD measurement. The average particle size slightly increased from 17.5 to 20.3 μm during the 20-h milling. About 90vol% of the powders satisfied the requirement for thermal spraying with the particle dimension of 10-50 μm, and most of the powders exhibited spherical morphology, which were expected to have good fluidity during thermal spraying. The Cr2O3 phase formed during the cryornilling process as revealed in the XRD spectra, which was expected to enhance the thermal stability of the as-milled powders during the followed thermal spraying or other heat treatment.展开更多
The non-isothermal leaching kinetics of primary titanium-rich material by microwave heating was investigated,and the temperature-pressure curves of leaching system and microwave absorption characteristics of mixture s...The non-isothermal leaching kinetics of primary titanium-rich material by microwave heating was investigated,and the temperature-pressure curves of leaching system and microwave absorption characteristics of mixture solutions before and after leaching were measured.The research of non-isothermal kinetics was evaluated by the leaching rate of Fe and the total apparent velocity equation of the non-isothermal kinetics of leaching for primary titanium-rich material by microwave heating was obtained.It is shown from the temperature-pressure curves that the high temperature and high pressure of closed leaching system are favorable to the enhancement of the leaching rate of Fe.Microwave absorption characteristics of mixture solutions before and after leaching show that there are abrupt changes of microwave absorption characteristics for 15%HCl solution and the mixture solution after leaching by 20%HCl.展开更多
Cellulosic and agricultural bio-energy crops can be utilized as feedstock source for bio-fuels production and provide environmental benefits such as hydrology, water quality. This study compared potential feedstock yi...Cellulosic and agricultural bio-energy crops can be utilized as feedstock source for bio-fuels production and provide environmental benefits such as hydrology, water quality. This study compared potential feedstock yield and water quality benefit scenarios of six bio-energy crops: Miscanthus (Miscanthus-giganteus), Switchgrass (Panicum virgatum), Johnsongrass (Sorghum halepense), Alfalfa (Medicago sativa L.), Corn (Zea mays), and Soybean {Glycine max (L.) Merr.} at the watershed scale using Soil and Water Assessment Tool (SWAT) model. The SWAT model was calibrated (1998 to 2002) and validated (2003 to 2010) using monthly measured USGS stream flow data. Model was further verified using available monthly sediment yield, and county level NASS corn and soybean yield data within the watershed. The long-term average annual potential feedstock yield as an alternative energy source was determined the greatest when growing Miscanthus grass scenario (21.9 Mg/ha) followed by Switchgrass (15.2 Mg/ha), Johnsongrass (12.1 Mg/ha), Alfalfa (7 Mg/ha), Corn (5.9 Mg/ha), and Soybean (2.35 Mg/ha). Model results determined the least amount of average annual sediment yield (1.1 Mg/ha) from the Miscanthus grass scenario and the greatest amount (12 Mg/ha) from the corn crop scenario. About 11% less annual average surface water flow from the watershed could be anticipated when converting land areas from soybean to Miscanthus grass. The results of this study suggested that growing Miscanthus grass in the UPRW would have the greatest potential feedstock yield and water quality benefits. The results of this study may help in developing future watershed management programs.展开更多
基金supported by the National Natural Science Foundation of China (41171211)the Special Fund for Agro-Scientific Research in the Public Interest, China (201303095-2)
文摘Biochar is increasingly proposed as a soil amendment, with reports of benefits to soil physical, chemical and biological properties. In this study, different biochars were produced from 6 feedstocks, including straw and poultry manure, at 3 pyrolysis temperatures （200, 300 and 500℃） and then added separately to a calcareous soil. Their effects on soil properties and maize growth were evaluated in a pot experiment. The biochars derived from crop straw had much higher C but smaller N concentrations than those derived from poultry manure. Carbon concentrations, pH and EC values increased with increasing pyrolysis temperature. Biochar addition resulted in increases in mean maize dry matter of 12.73% and NPK concentrations of 30, 33 and 283%, respectively. Mean soil pH values were increased by 0.45 units. The biochar-amended soils had 44, 55, 254 and 537% more organic C, total N, Olsen-P and available K, respectively, than the control on average. Both feedstocks and pyrolysis temperature determined the characteristics of the biochar. Biochars with high mineral concentrations may act as mineral nutrient supplements.
文摘The rheological behaviors of feedstocks for powder extrusion molding, in the temperature range of 40～80 ℃ and the Newton shear rate of 3～800 s -1 , were studied. The effects of feedstock constitution, shear rate and temperature on apparent viscosity, shear stress and active energy were investigated. The viscose flow active energy of PEM feedstocks is 15.89～90.77 kJ/mol. Based on this research, the PEM technical parameters have optimized. [
基金This work was supported by the National Key R&D Program of China(2018YFA0901500)the National Natural Science Foundation of China(21706124,21727818)+1 种基金the Key Science and Technology Project of Jiangsu Province(BE2016389)the Jiangsu Synergetic Innovation Center for Advanced Bio-Manufacture of China.
文摘L-malate is an intermediate of the tricarboxylic acid cycle which is naturally occurred in various microorganisms,and it has been widely applied in polymer,beverage and food,textile,agricultural and pharmaceutical industries.Driven by the pursuit of a sustainable economy,microbial production of L-malate has received much attention in last decades.In this review,we focus on the utilization of wastes and/or byproducts as feedstocks for the microbial production of L-malate.Firstly,we present the recent developments on the natural or engineered metabolic pathways that dedicate to the biosynthesis of L-malate,and also provide a comprehensive discussions on developing high-efficient producers.Then,the recent achievements in microbial production of L-malate from various carbon sources were concluded and discussed.Furthermore,some abundant non-food feedstocks which have been used for microbial production of other chemicals were reviewed,as they may be potential candidate feedstock for L-malate production in future.Finally,we outlined the major challenges and proposed further improvements for the production of L-malate.
文摘The upgrading of diesel oil to produce ethylene rich cracking feedstock is an important and promising technical route to reduce the ratio of diesel to gasoline. In the present work, a hydrocracking catalyst suitable for selective hydrocracking of straight run diesel oil to produce high-quality ethylene cracking feedstock at low cost was developed, by optimizing the composition of catalyst support materials, using amorphous silicon aluminum and aluminum oxide with high mesopore content as the main support, and modified Y zeolite with excellent aromatic ring opening selectivity as the acidic component. The catalyst has in-depth characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, N<sub>2</sub>-low temperature adsorption-desorption, NH<sub>3</sub>-temperature-programmed desorption, and IR techniques. And its catalytic cracking straight run diesel oil performance was evaluated. The results show that the prepared catalyst has high polycyclic aromatic hydrocarbon ring opening cracking selectivity. However, alkanes retained in diesel distillates can achieve the goal of producing more ethylene cracking feedstocks with low BMCI value under low and moderate pressure conditions. This work may shed significant technical insight for oil refining transformation.
基金the National Key Research and Development Program of China(No.2022YFC2104700).
文摘Terpenoids are a diverse class of natural products widely used as pharmaceuticals,perfumes,flavors,and biofuels.Traditionally,terpenoids are obtained from natural sources,such as plants,but their production is limited by the insufficiency of resources and low yields of extraction.Microbial production of terpenoids has emerged as a promising alternative due to that it is sustainable and easy to scale up.This review aims to summarize recent advances in microbial production of terpenoids from inexpensive biomass-derived feedstocks.Metabolic pathways and key enzymes involved in terpenoid biosynthesis are introduced.Microorganisms that can utilize low-cost lignocellulosic feedstocks for terpenoid production are highlighted.The challenges and prospects faced by microbial terpenoid production are proposed.We believe that continuous progress in the fields of biomass transformation and synthetic biology will ultimately achieve industrial production of microbial terpenoids.
基金supported by the National High-Tech Research and Development Program of China (No.2002AA331080)
文摘Nanocrystalline NiCrC alloy powders with a qualified particle size distribution for thermal spraying were synthesized using the cryogenic ball milling （cryomilling） method. The morphology, microstructure, size distribution, and phase transformation of the powders were characterized by scanning electron microscopy （SEM）, laser scattering for particle size analysis, X-ray diffraction （XRD）, and transmission electron microscopy （TEM）. After cryomilling for 20 h, the average grain size of the as-milled powders approached a constant value of 30 nm by XRD measurement. The average particle size slightly increased from 17.5 to 20.3 μm during the 20-h milling. About 90vol% of the powders satisfied the requirement for thermal spraying with the particle dimension of 10-50 μm, and most of the powders exhibited spherical morphology, which were expected to have good fluidity during thermal spraying. The Cr2O3 phase formed during the cryornilling process as revealed in the XRD spectra, which was expected to enhance the thermal stability of the as-milled powders during the followed thermal spraying or other heat treatment.
基金Project(2007CB613606)supported by the National Basic Research Program of China
文摘The non-isothermal leaching kinetics of primary titanium-rich material by microwave heating was investigated,and the temperature-pressure curves of leaching system and microwave absorption characteristics of mixture solutions before and after leaching were measured.The research of non-isothermal kinetics was evaluated by the leaching rate of Fe and the total apparent velocity equation of the non-isothermal kinetics of leaching for primary titanium-rich material by microwave heating was obtained.It is shown from the temperature-pressure curves that the high temperature and high pressure of closed leaching system are favorable to the enhancement of the leaching rate of Fe.Microwave absorption characteristics of mixture solutions before and after leaching show that there are abrupt changes of microwave absorption characteristics for 15%HCl solution and the mixture solution after leaching by 20%HCl.
文摘Cellulosic and agricultural bio-energy crops can be utilized as feedstock source for bio-fuels production and provide environmental benefits such as hydrology, water quality. This study compared potential feedstock yield and water quality benefit scenarios of six bio-energy crops: Miscanthus (Miscanthus-giganteus), Switchgrass (Panicum virgatum), Johnsongrass (Sorghum halepense), Alfalfa (Medicago sativa L.), Corn (Zea mays), and Soybean {Glycine max (L.) Merr.} at the watershed scale using Soil and Water Assessment Tool (SWAT) model. The SWAT model was calibrated (1998 to 2002) and validated (2003 to 2010) using monthly measured USGS stream flow data. Model was further verified using available monthly sediment yield, and county level NASS corn and soybean yield data within the watershed. The long-term average annual potential feedstock yield as an alternative energy source was determined the greatest when growing Miscanthus grass scenario (21.9 Mg/ha) followed by Switchgrass (15.2 Mg/ha), Johnsongrass (12.1 Mg/ha), Alfalfa (7 Mg/ha), Corn (5.9 Mg/ha), and Soybean (2.35 Mg/ha). Model results determined the least amount of average annual sediment yield (1.1 Mg/ha) from the Miscanthus grass scenario and the greatest amount (12 Mg/ha) from the corn crop scenario. About 11% less annual average surface water flow from the watershed could be anticipated when converting land areas from soybean to Miscanthus grass. The results of this study suggested that growing Miscanthus grass in the UPRW would have the greatest potential feedstock yield and water quality benefits. The results of this study may help in developing future watershed management programs.
