Hydrogenation Unit Wet Start-Up Without Heating Furnace
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Solution Overview
Problem
Hydrogenation units using sulfurized type catalysts require a heating furnace for start-up, leading to high energy consumption and equipment investment, with existing methods either necessitating a furnace or resulting in severe system pressure drops if not used.
Innovation Solution
A wet start-up method utilizing a low-temperature heat source to activate the catalyst, followed by reaction heat from olefin hydrogenation and feedstock hydrogenation to achieve the required temperatures without a heating furnace, incorporating a hydrogenation apparatus with a heat exchange system for efficient temperature management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a heating furnace is used during start-up process, then the required temperature can be reached, but equipment investment and energy consumption increase significantly
Solution Approach 1:
The catalyst is pre-sulfurized before installation in the hydrogenation unit. This preliminary sulfurization treatment enables the catalyst to generate sufficient reaction heat during start-up to heat the reactor to operating temperature without requiring an external heating furnace, thereby resolving the contradiction between achieving start-up temperature and reducing energy consumption
Solution Approach 2:
The hydrogenation reaction itself is used to heat the reactor during start-up. By introducing feedstock that undergoes highly exothermic hydrogenation reactions, the system uses its own reaction heat to reach operating temperature, eliminating the need for external heating and reducing both energy consumption and equipment investment
2Temperature
If a heating furnace is used during start-up process, then the required temperature can be reached, but equipment investment increases
Solution Approach 1:
The heating furnace is completely removed from the hydrogenation unit by using the reaction heat of the hydrogenation reaction itself to heat the reactor during start-up. This extraction of the heating furnace eliminates the associated equipment investment while still achieving the required start-up temperature through the exothermic hydrogenation reactions
Solution Approach 2:
The reactor heats itself using the heat generated from the hydrogenation reactions during start-up. This self-heating capability eliminates the need for external heating equipment, thereby reducing equipment investment and simplifying the overall system
3Ease of operation
If olefin-containing start-up oil is used, then the start-up process can be simplified, but severe system pressure drops occur
Solution Approach 1:
The feedstock is pre-treated to adjust its composition parameters, specifically removing or reducing olefin content while maintaining other necessary components. This parameter change in the feedstock composition allows the start-up process to be simplified without causing severe pressure drops in the system
4Stress or pressure
If activating oil with low olefin content is used, then system pressure drop is reduced, but the start-up process requires more complex temperature control
Solution Approach 1:
The hydrogenation reaction provides self-heating during start-up, generating sufficient heat to raise the reactor temperature to operating conditions. This self-heating effect simplifies temperature control by eliminating the need for external heating systems and complex temperature management protocols
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 method enables a smooth and energy-saving start-up process, reducing equipment investment and operational costs by leveraging reaction heat for temperature control, eliminating the need for a heating furnace and maintaining normal operation through exothermic hydrogenation reactions.
Implementation Method 1
Hydrogenation reactions are usually strong exothermic reactions. In the normal production process of a hydrogenation unit, the outlet temperature of the reactor is much higher than the inlet temperature of the reactor.
Implementation Method 2
utilizing the reaction heat generated from the olefin hydrogenation reaction to further heat up the materials in the hydrogenation unit to 230±10° C., and keeping at constant temperature for at least 4 h
Data Source
AI summary
The present invention relates to a wet start-up method for hydrogenation unit, an energy-saving hydrogenation process, and a hydrogenation apparatus. The method involves heating a start-up activating oil to a specific temperature and flowing the heated oil through a bed of hydrogenation catalyst bed, so that the temperature at the catalyst bed layer is increased to 180±10° C. or above by means of heat exchange and the reaction heat generated from activation in the start-up method.