Lignin is generated as a waste biomass from pulp and paper industry.The majority of kraft lignin is currently combusted as a low-grade energy source.Lignin valorization has been considered a feasible option to sustain...Lignin is generated as a waste biomass from pulp and paper industry.The majority of kraft lignin is currently combusted as a low-grade energy source.Lignin valorization has been considered a feasible option to sustainable production of chemicals and liquid fuels in the long run.This study reports a novel thermolysis process that selectively converts black liquor lignin into guaiacol and its derivatives in highboiling-point hydrocarbon solvents:n-hexadecane(n-H)and 1-methyl naphthalene(1-MN).The operating pressure for lignin thermolysis in n-H and 1-MN is much lower than those in lignin liquefaction with low-boiling-point solvents,such as water,methanol,and ethanol.1-MN performed better than n-H in terms of lignin conversion and liquid yield.The liquid products were 56 wt%and 24 wt%for 1-MN and n-H as solvent respectively.Reaction temperature and reaction time rotating were investigated.Low temperature and short reaction time are favorable for generating Guaiacol.Compared to 1-MN as solvent,n-H promotes the production of guaiacol.The reaction mechanisms of lignin depolymerization to chemicals in different solvents were proposed.Solvent chemical properties and H abstraction processes from solvents play a key role in the selectivity of guaiacol.展开更多
利用芳香胺的重氮化-偶合显色反应原理,建立了纺织品中24种禁用芳香胺的快速定性筛选测定方法。样品经还原后,先用10 mL叔丁基甲醚萃取,再用5 mL HCl反萃取,达到净化和脱色的目的,HCl萃取液中加入0.05 mL NaNO2,重氮化反应10 min,滴加0....利用芳香胺的重氮化-偶合显色反应原理,建立了纺织品中24种禁用芳香胺的快速定性筛选测定方法。样品经还原后,先用10 mL叔丁基甲醚萃取,再用5 mL HCl反萃取,达到净化和脱色的目的,HCl萃取液中加入0.05 mL NaNO2,重氮化反应10 min,滴加0.5 mL氨基磺酸铵除去多余的NaNO2,加入1mL邻甲氧基苯酚与重氮盐偶联显色。根据萃取液是否显色,快速地对样品中是否含有禁用偶氮染料作出初步判断。方法的检出限低于15 mg/kg,上千个实际样品测试无假阴性,假阳性概率为28%。本方法无需大型色谱仪器设备,与仪器测定方法相比,前处理时间缩短了约60%,节约了约90%的试剂费用。展开更多
文摘Lignin is generated as a waste biomass from pulp and paper industry.The majority of kraft lignin is currently combusted as a low-grade energy source.Lignin valorization has been considered a feasible option to sustainable production of chemicals and liquid fuels in the long run.This study reports a novel thermolysis process that selectively converts black liquor lignin into guaiacol and its derivatives in highboiling-point hydrocarbon solvents:n-hexadecane(n-H)and 1-methyl naphthalene(1-MN).The operating pressure for lignin thermolysis in n-H and 1-MN is much lower than those in lignin liquefaction with low-boiling-point solvents,such as water,methanol,and ethanol.1-MN performed better than n-H in terms of lignin conversion and liquid yield.The liquid products were 56 wt%and 24 wt%for 1-MN and n-H as solvent respectively.Reaction temperature and reaction time rotating were investigated.Low temperature and short reaction time are favorable for generating Guaiacol.Compared to 1-MN as solvent,n-H promotes the production of guaiacol.The reaction mechanisms of lignin depolymerization to chemicals in different solvents were proposed.Solvent chemical properties and H abstraction processes from solvents play a key role in the selectivity of guaiacol.
文摘利用芳香胺的重氮化-偶合显色反应原理,建立了纺织品中24种禁用芳香胺的快速定性筛选测定方法。样品经还原后,先用10 mL叔丁基甲醚萃取,再用5 mL HCl反萃取,达到净化和脱色的目的,HCl萃取液中加入0.05 mL NaNO2,重氮化反应10 min,滴加0.5 mL氨基磺酸铵除去多余的NaNO2,加入1mL邻甲氧基苯酚与重氮盐偶联显色。根据萃取液是否显色,快速地对样品中是否含有禁用偶氮染料作出初步判断。方法的检出限低于15 mg/kg,上千个实际样品测试无假阴性,假阳性概率为28%。本方法无需大型色谱仪器设备,与仪器测定方法相比,前处理时间缩短了约60%,节约了约90%的试剂费用。
