Urea Related Technology

Summary

TOYO has been developing and supplying the various owned technologies related with urea production as urea licenser.

• Urea Revamping Technology
• Process Variation (Finishing Technology, Product Forming Technology and Pollution Control Technology)
• Operation Assisting Technology (OTS,APC,RPMS)
• Maintenance Assisting Technology (LCMS,RBI/RBM, On Line Analyzer, Leak Detection System)

Urea Plant Revamping Technology

TOYO has the revamping technology for existing urea plant to increase production capacity and reduce the energy consumption

The revamping of existing urea plant of total recycle process by ACES21^® has following features.

• Maximum utilization of existing facility and Minimum modification.
• Maximum increasing of production capacity (50%) and energy saving (30%).

Revamping scheme for total recycle process by ACES21

Process Variation

Finishing and Product Forming Technology

Urea is produced as solid particle normally as final product. TOYO is providing the most suitable finishing and product forming technology to meet required quality as final product. In case of low biuret content in product (less than 0,3wt%）, crystal separation technology is applied and in case of standard biuret content(Less than 0.9wt%）, vacuum evaporation technology is applied.

In case of 1.4-1.8mm of product size (so called prilled urea), following prilling technology is applied.
-Natural Draft type / Forced Draft Type prilling tower
-Distributor (Acoustic　Granulator,Spinning Basket and Vibro　Priller) to make uniform droplet
In case of more than 2mm of product size, spout fluid beds type granulation technology is applied.

Various finishing and product forming technologies

Pollution Control Technology for Effluent

The process condensate containing urea and ammonia from Urea Plant is treated upto 1ppm of urea and 1ppm of ammonia in Process Condensate Treatment Unit (Stripper & Hydrolyser). Treated process condensate is recovered as boiler feed water in Utility Facility. Therefore, there is no effluent from TOYO’s urea plant during normal operation.

Flow scheme of process condensate treatment unit

Pollution Control Technology for Emission

Flow scheme of dust scrubbing system

Exhaust air form prilling tower or granulation unit containing urea dust is treated in Dust Scrubbing System and sent out to atmosphere at less than 30mg/Nm3 of urea dust. The ammonia in exhaust air is reduced to less than 20mg/Nm3 by introducing acid to Dust Scrubbing System.

Operation Assisting Technologies

Operating Training Simulator（OTS）

TOYO has developed operating training simulator (OTS) as TOYO’s self-developed system by own resources.
The dynamic model is based on the static simulator and physical properties which are utilized for actual process design. Therefore, the dynamic model is able to realize and simulate precisely same as the actual urea plant operating condition.
TOYO’s OTS is functioned on PC basis including control system (DCS) , OTS is provided by very low price configuration.
TOYO’s OTS is contributed to skill-up of operator by training of start-up, normal operation, shut down and emergency shut down without actual operating plant.

Advanced Process Controller (APC）

NH₃/CO₂ molar ratio in synthesis loop and H₂O/CO₂ molar ratio in recovery section are the most important parameter for Urea Plant to achieve high efficient and stable operation.　TOYO has developed Advanced Process Controller (APC) to control them from estimation of composition from physical properties analyzed by real-time on-line analyzer. APC realizes the most optimum operation without skilled operator, reduction of running cost and analysis cost.

Remote Plant Monitoring System （RPMS）

TOYO developed and supplies the Remote Plant Monitoring System (RPMS) which is able to monitor the operating condition of urea plant from the remote offices. This system has a feature to realize configuration in low-cost　utilizing internet network for communication and PC(persona; computer) application for system architecture.

Maintenance Assisting Technologies

Leak　Detection　System-1

The internal wall of high pressure vessel in Urea Plant contacting with corrosive fluid is lined by proper corrosion resistant metal plate. Once this lining plate has a leakage, it leads damage the pressure holding shell made of carbon steel. Toyo has developed on-line leak detection system by detecting NH₃ in circulating nitrogen gas between lining plate and pressure holding shell. This system has an advantage to detect very small leakage before damage becomes severe and identify the location of defect. This system contributes to make maintenance work easy and simple, and increasing reliability of plant.

Leak　Detection　System-2

In case of leakage from tube and/or tube sheet of heat exchange heated by steam or steam condensate, ammonia in process fluid increases the conductivity of steam condensate. TOYO developed the leak detecting system by monitoring the conductivity in steam condensate to detect the leakage of heat exchanger at early stage of leakage. This system also has an advantage to detect very small leakage before damage becomes severe and identify the location of defect. This system contributes to make maintenance work easy and simple, and increasing reliability of plant.

On-Line Analyzer for Treated Process Condensate

The effluent from Urea Plant is recovered as boiler feed water after reduction of Urea and NH₃ content to 1 ppm by Process Condensate Treatment Unit in Urea Plant. There is a relation between ammonia content and conductivity and analyzed by conductivity meter, but no relation with urea content. TOYO has developed the online analyzer to analyze both of urea and ammonia at the same time by detecting the conductivity after hydrolyzing urea under high temperature. This system realize to protect boiler system in case of increasing of Urea content in treated process condensate immediately without waiting laboratory analysis and reduce the cost for laboratory analysis.　

Life Cycle Management System (LCMS)

TOYO has developed the Life Cycle Management System (LCMS) to optimize the maintenance activity considering total life cycle of Urea Plant. This system leads reduction of maintenance cost and prolongs the plant life by realizing effective preventive and predictive maintenance for Urea Plant.

RBI (Risk Based Inspection) / RBM　（Risk Based Management）

There is a concern for new concept and approach for safety control and maintenance activity in view of environmental control and reduction of life cycle cost. TOYO has developed maintenance evaluating tools based on concept of RBI and RBM for Urea Plant with ESR Technology in UK. This system　also leads reduction of maintenance cost and prolong the plant life by realizing effective preventive and predictive maintenance for Urea Plant.