化肥尿素生产中气提塔液位波动原因及解决策略

气提塔作为化肥尿素生产过程中的关键设备,其主要作用是将氨气从蒸汽中分离出来并与二氧化碳反应形成尿素。气提塔的设计、运行和控制对生产的稳定性、产品质量和生产成本都有着重要的影响。因此,保持气提塔的正常运行和控制是化肥尿素生产中的重要问题之一。本文对于气提塔液位波动的原因从多个层面进行分析,由此提出相应的解决策略。

不同氮源供体对湛江等鞭金藻生长和生理特性的影响

【目的】探寻适合湛江等鞭金藻规模化低成本培养的氮源。【方法】以宁波3#微藻培养液为基础培养基,分别以不同质量浓度的无机氮[尿素(35.33 mg·L^(-1))、化肥尿素(复合肥)(76.14 mg·L^(-1))、氯化铵(62.94 mg·L^(-1))、乙酸铵(90.95 mg·L^(-1))]和有机氮[胰蛋白胨(63.54 mg·L^(-1))]为氮源供体,研究不同氮源供体对湛江等鞭金藻培养效果的影响,实验将接种藻密度控制为10.0×10^(4)mL^(-1),培养周期为21 d。【结果】以化肥尿素为氮源供体培养下湛江等鞭金藻生产力、比生长速率、藻密度、叶绿素a、叶绿素b和总叶绿素质量浓度显著优于硝酸钠、尿素、氯化铵、乙酸铵和胰蛋白胨(P<0.05);培养水体中化肥尿素总氮和总磷的吸收率分别为94.2%和99.0%。【结论】化肥尿素氮源供体是培养湛江等鞭金藻最优质的培养基配方氮源,显著优于硝酸钠和其他氮源供体(P<0.05)。

流化床造粒工艺运行探讨

通过与塔式造粒工艺的比较，指出了流化床造粒工艺能耗高、产品同比价格无优势的现状，展望了流化床造粒工艺的发展方向。

Comparison of Urea-Derived N_2O Emission from Soil and Soil-Plant System

A pot experiment with a sandy loam soil and spring wheat as test crop was conducted to compare the N2O emission from soil system with plant cut off and from soil-plant system with plant kept. The results showed that after urea fertilizer applied, the N2O emission from soil and soil-wheat system decreased exponentially with time, and its total amount was 0.34%~0.63% and 0.33%~0.58% of applied urea-N respectively, no significant difference being found between these two systems. The N2O emission had a very significant negative relationship (P = 0.01) with the biomass of wheat plant. A combined application of urease inhibitor hydroquinone and nitrification inhibitor dicyandiamide could reduce the N2O emission by 50%~83% and 46%~74%, respectivelyl from soil and soil-wheat system. The N2O was mainly produced and emitted from soil, and the soil biochemical regulation, i.e., applying related inhibitors into soil could effectively diminish the urea derived N2O emission.