Hydrocarbon Feed Preheating for Lower-Temperature Hydrotreating

Solution Overview

Problem

Hydrotreating reactors face dew point issues that require high hydrogen to hydrocarbon ratios, leading to elevated operating temperatures and sulfur recombination, necessitating the use of Sulfur Guard Beds and limiting catalyst cycle length.

Innovation Solution

A process that preheats the hydrocarbon feed stream using a combination of heat exchangers and charge heaters, allowing the reactor to operate at lower temperatures (304° C. to 332° C.) while achieving the dew point margin with a reduced hydrogen ratio, thereby reducing sulfur recombination and eliminating the need for SGBs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the reactor operates at higher temperatures to meet dew point margin, then the dew point issue is resolved, but sulfur recombination increases and catalyst cycle length decreases

Engineering Contradiction:

Improvereactor operating temperatureVSAvoidsulfur recombination

Core Design Contradiction:

TemperatureVSObject-generated harmful factors

Solution Approach 1:

The feed stream is preheated in a heat exchanger before entering the charge heater, achieving the required dew point margin at a lower temperature. This preliminary heating action allows the reactor to operate at reduced temperatures (304-332°C) while still meeting dew point requirements, thereby preventing sulfur recombination without sacrificing process effectiveness.

Inventive Principle:

Principle #10Preliminary action

2Temperature

If the hydrogen to hydrocarbon ratio is increased to meet dew point margin, then the dew point issue is resolved, but the cost and complexity of the system increases

Engineering Contradiction:

Improvedew point marginVSAvoidhydrogen to hydrocarbon ratio

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The invention changes the temperature parameter of the feed stream through preheating in a heat exchanger, allowing the system to achieve the required dew point margin with a reduced hydrogen to hydrocarbon ratio. This parameter change enables the reactor to operate at lower temperatures (304-332°C) while maintaining dew point control, thereby reducing the need for excessive hydrogen supply and associated system complexity.

Inventive Principle:

Principle #35Parameter changes

3Temperature

If the reactor operates at higher temperatures to meet dew point margin, then the dew point issue is resolved, but catalyst cycle length decreases

Engineering Contradiction:

Improvereactor operating temperatureVSAvoidcatalyst cycle length

Core Design Contradiction:

TemperatureVSDuration of action of stationary object

Solution Approach 1:

The feed stream is preheated in a heat exchanger before entering the charge heater, achieving the required dew point margin at a lower temperature. This preliminary heating action allows the reactor to operate at reduced temperatures (304-332°C) while still meeting dew point requirements, thereby preventing sulfur recombination without sacrificing process effectiveness.

Inventive Principle:

Principle #10Preliminary action

4Temperature

If the charge heater temperature is increased to achieve dew point margin, then the dew point issue is resolved, but energy consumption increases

Engineering Contradiction:

Improvecharge heater temperatureVSAvoidenergy consumption

Core Design Contradiction:

TemperatureVSUse of energy by stationary object

Solution Approach 1:

The feed stream is preheated in a heat exchanger before entering the charge heater, achieving the required dew point margin at a lower temperature. This preliminary heating action allows the reactor to operate at reduced temperatures (304-332°C) while still meeting dew point requirements, thereby preventing sulfur recombination without sacrificing process effectiveness.

Inventive Principle:

Principle #10Preliminary action

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

The process enables efficient operation of hydrotreating reactors at lower temperatures, extending catalyst life and reducing the need for secondary sulfur management systems, while also allowing for smaller compressor usage.

Implementation Method 1

transferring heat to a hydrocarbon feed stream for the reactor from the heated hydrocarbon process stream to provide a pre-heated hydrocarbon feed stream

Methodology Applied

Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 2

heating the pre-heated hydrocarbon feed stream in a charge heater to form a heated hydrocarbon feed stream

Methodology Applied

Scientific EffectHeating: Heating

Data Source

PatentUS12435282B2Processes and apparatuses for heating a hydrocarbon feed stream for a reactor

Publication Date: 2025.10.07 UOP LLC

AI summary

Processes and apparatuses for heating a feed stream for a reactor which has a charge heater. At least one process stream provides heat so that a pre-heated feed stream passed to the charge heater is a vapor stream. The process stream may be the heated stream from the outlet of the charge heater. Alternatively, the process stream may be the effluent stream from the reactor that has been heated.