A novel bead form of ploymer of high sorption capacity for urea were obtained by the reaction of glutaric dialdehyde wigh chitosan dispersed in acetic acid solution. The sorption capacity reached ￣ 82.0 mg / g sorbe...A novel bead form of ploymer of high sorption capacity for urea were obtained by the reaction of glutaric dialdehyde wigh chitosan dispersed in acetic acid solution. The sorption capacity reached ￣ 82.0 mg / g sorbent at 37℃ and pH 7.4 The concentration of urea in the buffer solution was 1300 mg/ L. The sorption of urea was related to the degree of crosslinking of the sorbent, concentration ofurea, ionic strength and temperature.展开更多
Effective one-stage method of urea preparation by catalytic oxidative carbonylation of ammonia in liquid phase is developed. The method allows to prepare urea with productivity of-530 g/（L·h） in sufficiently mi...Effective one-stage method of urea preparation by catalytic oxidative carbonylation of ammonia in liquid phase is developed. The method allows to prepare urea with productivity of-530 g/（L·h） in sufficiently mild conditions （total pressure -30 bar, 45 ℃）. The process is characterized by high selectivity （near 100%） i.e. byproducts separation is not needed. Almost all CO is consumed during the process, this substantially diminishes the waste-gas purification costs and raises the process environmental characteristics; the only byproduct is water.展开更多
文摘A novel bead form of ploymer of high sorption capacity for urea were obtained by the reaction of glutaric dialdehyde wigh chitosan dispersed in acetic acid solution. The sorption capacity reached ￣ 82.0 mg / g sorbent at 37℃ and pH 7.4 The concentration of urea in the buffer solution was 1300 mg/ L. The sorption of urea was related to the degree of crosslinking of the sorbent, concentration ofurea, ionic strength and temperature.
文摘Effective one-stage method of urea preparation by catalytic oxidative carbonylation of ammonia in liquid phase is developed. The method allows to prepare urea with productivity of-530 g/（L·h） in sufficiently mild conditions （total pressure -30 bar, 45 ℃）. The process is characterized by high selectivity （near 100%） i.e. byproducts separation is not needed. Almost all CO is consumed during the process, this substantially diminishes the waste-gas purification costs and raises the process environmental characteristics; the only byproduct is water.
