Urea Production Process Low-Pressure Decomposition
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Solution Overview
Problem
Existing urea production processes face challenges in increasing plant capacity while maintaining high conversion yield and low energy consumption, due to the need for additional condensing water in medium pressure treatment steps, which affects efficiency and energy consumption.
Innovation Solution
A process involving a high-pressure urea synthesis section, a medium-pressure treatment section for dissociation and condensation, and a low-pressure urea recovery section with decomposition and condensation, where a part of the aqueous solution is subjected to dissociation and subsequent low-pressure decomposition, reducing the amount of condensation water required for recycling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a medium pressure treatment step is added to increase plant capacity, then production capacity is improved, but conversion yield deteriorates due to additional condensing water requirement
Solution Approach 1:
The invention changes the pressure parameter of the treatment section from conventional medium pressure (10-40 bar) to low pressure (1-5 bar). This parameter change reduces the amount of condensing water required in the condenser, thereby maintaining high conversion yield in the synthesis section while still enabling increased plant capacity through the treatment section
Solution Approach 2:
The invention segments the urea production process into distinct pressure zones: a high pressure synthesis section (135-175 bar) and a low pressure treatment section (1-5 bar). This segmentation allows each section to operate optimally - the synthesis section maintains high conversion yield while the treatment section handles capacity expansion with minimal impact on conversion efficiency
2Productivity
If medium pressure treatment is used to increase capacity, then productivity is improved, but energy consumption worsens
Solution Approach 1:
By changing the pressure parameter from medium to low (1-5 bar), the invention reduces the energy required for compression and condensation operations in the treatment section, thereby lowering overall energy consumption while maintaining increased production capacity
3Quantity of substance
If additional condensing water is used in medium pressure treatment, then capacity expansion is achieved, but conversion yield deteriorates
Solution Approach 1:
The invention changes the pressure parameter to low pressure (1-5 bar), which fundamentally reduces the amount of condensing water needed in the condenser. This allows capacity expansion through increased recycling of carbamate and ammonia without introducing excess water that would harm conversion yield in the synthesis section
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This process achieves a higher conversion yield and reduced energy consumption, allowing for increased production capacity with less condensation water, resulting in a more efficient and cost-effective urea production process.
Implementation Method 1
subjecting said urea aqueous solution to decomposition in said decomposer of said urea recovery section obtaining a concentrated urea solution and a second vapour phase comprising ammonia, carbon dioxide and water
Implementation Method 2
subjecting said second vapour phase to condensation in a condenser of said urea recovery section in fluid communication with said decomposer obtaining a recycle ammonium carbamate aqueous solution
Data Source
Figure 1
AI summary
A process for urea production from ammonia and carbon dioxide, in which part of the aqueous solution comprising urea, ammonium carbamate and ammonia obtained in a urea synthesis section is subjected to dissociation in a treatment section operating at a predetermined medium pressure for the recovery of the ammonium carbamate and of the ammonia contained in it, comprises the step of subjecting the urea aqueous solution resulting from the aforementioned dissociation step to decomposition in a low pressure urea recovery section.