尿素装置增产改造技术交流【行业特制】.ppt

荷兰荷丰技术公司工程部,FUNGHAN ENGINEERING,北京丰汉工程技术有限公司,尿素装置增产节能改造Urea Revamp,1,专家资料,Urea Revamp,尿素生产技术主要有水溶液全循环工艺和氨/CO2汽提工艺。该增产节能改造技术是在CO2汽提法尿素生产工艺以及大颗粒尿素造粒工艺的基础上完成的。,Urea production technology is mainly about full circulation of the aqueous solution process and ammonia/CO2 stripping process. Our revamp technology is mainly applied to the CO2 stripping urea production technology and green granulation technology.,2,专家资料,Urea Revamp,CO2汽提法尿素合成工艺改造 Urea Synthesis Revamp for CO2 Stripping Process,3,专家资料,蒸发真空冷凝段,废水处理段,合成塔 HP synthetic tower,高压洗涤器 HP Scrubber,高压冷凝器 HP Carbamate Condenser,脱氢反应器 Dehydrogenation reactor,CO2压缩机 CO2 Compressor,汽提塔,一段蒸发器 Evaporation,高压甲铵泵 HP Carbamate Pump,氨泵 Ammonia Pump,低压吸收塔 LP Absorber,精馏塔 Rectify,蒸发段,低压段,高压段,熔融尿素去,造粒装置,HP synthesis stage,LP stage,Evaporation stage,CO2汽提工艺流程示意简图CO2 stripping process flow scheme,CO2 Stripper,Melting urea to granulation,4,专家资料,装置的特点plant features,1. 高压氨泵和CO2压缩系统都有备机，可以满足扩产的需要。 Both high ammonia pumps and CO2 compressor system have been prepared to meet expansion requirements. 2. 高压循环系统设备成为瓶颈。增加该部分设备投资大。 In the expansion process, equipments in the high pressure stage is to be the bottleneck, which will cause a great investment if increase.,需要改造的装置一般都具有以下特点： Generally, the plant has the following features.,5,专家资料,丰汉工程建议方案 Funghan proposal,丰汉工程公司建议 使用增加中压分解段的方式完成扩产改造的目的,Funghan propose to add a MP stage to complete expansion.,6,专家资料,丰汉工程建议方案 Funghan proposal,尿素合成段增产改造的基本原则 Basic principles for urea synthesis section revamp,尽量少动或不动高压段 as little as possible, even not revamp high pressure synthesis section 改造后原装置仍可独立运行 original plant can still operation independently after revamp 尽可能的减少投资 as much as possible to reduce investment 4. 节能降耗及减排 save energy and reduce emission,7,专家资料,丰汉工程建议方案Funghan proposal,增加中压分解段的技术背景 technical background of MP stage,最早水溶液全循环技术即有中压段 initial full circulation of the aqueous solution process technology has a MP stage CO2汽提引进中国后，有多种方案改进系统，增加中压段来增产改造是其中的一种方案 When ammonia stripping technology was introduced in to China, there are many proposals to improve the system, adding a MP stage to increase production is one of proposals.,8,专家资料,丰汉工程建议方案Funghan proposal,增加中压分解段的技术背景 technical background of MP stage,3. 丰汉工程公司多年前即开始开发该技术 Funghan Engineering company began developing this technology many years ago. 4. 在国内的改造中使用了该方案 In China, this proposal has been used in the revamp of some urea plant.,9,专家资料,丰汉工程建议方案 Funghan proposal,增加中压段流程示意图 PFS for adding MP stage,蒸发真空冷凝段,废水处理段,汽提塔,蒸发段,低压段,高压段,熔融尿素去,造粒装置,HP synthesis stage,LP stage,Evaporation stage,合成塔 HP synthetic tower,高压洗涤器 HP Scrubber,高压冷凝器 HP Carbamate Condenser,脱氢反应器 Dehydrogenation reactor,CO2压缩机 CO2 Compressor,一段蒸发器 Evaporation,高压甲铵泵 HP Carbamate Pump,氨泵 Ammonia Pump,低压吸收塔 LP Absorber,精馏塔 Rectify,CO2 Stripper,Melting urea to granulation,10,专家资料,丰汉工程建议方案Funghan proposal,蒸发真空冷凝段,废水处理段,中压,甲铵,冷凝器 MPCC,中压分离器 MP Separator,汽提塔,低压甲铵泵 LP Carbamate pump,中压汽提塔 MP Stripper,蒸发段,低压段,中压段,高压段,熔融尿素去,造粒装置,HP synthesis stage,MP stage,LP stage,Evaporation stage,增加中压段流程示意图PFS for adding MP stage,高压洗涤器 HP Scrubber,高压冷凝器 HP Carbamate Condenser,脱氢反应器 Dehydrogenation reactor,CO2压缩机 CO2 Compressor,一段蒸发器 Evaporation,高压甲铵泵 HP Carbamate Pump,氨泵 Ammonia Pump,低压吸收塔 LP Absorber,精馏塔 Rectify,CO2 Stripper,Melting urea to granulation,合成塔 HP synthetic tower,11,专家资料,丰汉工程建议方案Funghan proposal,增加中压分解段的工艺流程概述 PFS description of MP stage,从高压合成塔出来的尿素溶液经过绝压约20bar的闪蒸后，一部分被送入中压分离加热器中。在分离器中，在用于分离的9至12bar压力的高压蒸汽作用下，尿素/水溶液从大量未转化的氨和二氧化碳中被分离出来。中压分离器的分离段包含一个填料床层，以便在使用汽提加热器部分出来的废蒸汽闪蒸后，进一步精馏液体。该床层有利于降低加热器的高压蒸汽损耗。 Urea solution leaving the high-pressure autoclave is partly sent to the medium-pressure dissociation heater after being flashed at a pressure of about 20 bar absolute. In the dissociator the urea/ water solution is separated from the bulk of non-converted ammonia and carbon dioxide by using reduced high-pressure steam at a pressure of 9 to 12 bar for the dissociation. The separator of the medium-pressure dissociator contains a packed bed in order to rectify the liquid after flashing by using the off-vapor leaving the heater part for stripping. This bed has a positive effect on the high-pressure steam consumption of heater.,12,专家资料,丰汉工程建议方案Funghan proposal,增加中压分解段的工艺流程概述 PFS description of MP stage,来自中压分离加热器中的尿素溶液，温度要控制在160 至165C，并被引到一台中压汽提塔中。为了把甲铵生成的N/C摩尔比控制在约2.3mol/mol的数值上，需要向这个中压段加入二氧化碳。在这台中压汽提塔中，这些二氧化碳用作汽提剂，以降低从中压汽提塔进入现有低压循环段的被汽提尿液的N/C摩尔比。 The urea solution leaving the medium-pressure dissociation heater is controlled at a temperature of 160 to 165 C and discharged to a medium-pressure stripper. Carbon dioxide is added to this medium-pressure section in order to control the N/C molar ratio of the formed carbamate at a value of about 2.3 mol/mol. In the medium-pressure stripper this carbon dioxide is being used as a stripping agent to decrease the N/C molar ratio of the stripped urea solution leaving MP stripper to existing low-pressure recirculation section.,13,专家资料,丰汉工程建议方案Funghan proposal,增加中压分解段的工艺流程概述 PFS description of MP stage,来自中压分解分离器和中压汽提塔的气体，与在现有低压循环段生成的甲铵一起，被送到一台浸没式的中压甲铵冷凝器中。在这台浸没式冷凝器中，气体被最大程度的冷凝。放出的冷凝热由一个冷却水调节系统吸收。 The vapor leaving the medium-pressure dissociation separator and the medium-pressure stripper are sent together with the carbamate formed in the existing low-pressure recirculation section to a submerged medium-pressure carbamate condenser. In this submerged condenser the vapors are condensed at a maximum. The released condensation heat is dissipated in a tempered cooling water system.,14,专家资料,丰汉工程建议方案Funghan proposal,增加中压分解段的工艺流程概述 PFS description of MP stage,含水约20%（重量比）温度控制在约105C的的中压甲铵，将被现有的高压甲铵泵送到合成段，该甲铵泵分别通向高压洗涤器和高压甲铵冷凝器。 The medium-pressure carbamate, containing about 20 wt % water will be controlled at a temperature of about 105 C. This carbamate is sent to synthesis section via the existing high-pressure carbamate pumps, where it is split to the high-pressure scrubber and to the high-pressure carbamate condenser.,15,专家资料,丰汉工程建议方案Funghan proposal,增加中压分解段的工艺流程概述 PFS description of MP stage,来自中压再冷凝器的、含有未转化氨和二氧化碳的惰性气体，被引入现有的4bar吸收塔和/或现有的低压循环段中的低压甲铵冷凝器中。 The inert, containing non-condensed ammonia and carbon dioxide, leaving the medium-pressure after condenser is discharged to the existing 4 bar absorber and/or to the low-pressure carbamate condenser in the existing low-pressure recirculation section.,16,专家资料,丰汉工程建议方案 Funghan proposal,新增的设备表 New Equipment List,17,专家资料,大颗粒造粒部分改造 Revamp for Granulation,大颗粒造粒部分改造 Revamp for Green Granulation Process,18,专家资料,装置的特点plant features,1. 造粒机的造粒能力成为增产的一大瓶颈。 The capacity of granulator will be a bit problem for the expansion revamp. 2. 产量增加后没有足够的冷却系统降温，使产品温度过高。 There is no enough cooler system to cool down the products.,需要改造的装置一般都具有以下特点： Generally, the plant has the following features.,19,专家资料,丰汉工程建议方案Funghan proposal,20,专家资料,丰汉工程建议方案Funghan proposal,增加造粒喷头，以满足增产的需要。 Add new granulation sprayer to meet the capacity requirement. 增加新冷却器，以弥补冷却系统的不足。 Add new cooler to compensate for cooling system capacity.