Staged Alkyl Bromide Synthesis for C6+ Paraffin Yield

Solution Overview

Problem

The production of high molecular weight hydrocarbons from mono-brominated alkanes is hindered by the presence of poly-brominated alkanes, which increase coke formation and catalyst deactivation, leading to reduced yield and efficiency in producing C6+ hydrocarbons with desired paraffin and aromatic content.

Innovation Solution

A process involving sequential or concurrent stages with different catalysts and temperatures is employed to convert alkyl bromides, where a first stage produces hydrocarbons with a substantial C6+ paraffin content at lower temperatures and a second stage produces hydrocarbons with substituted aromatics at higher temperatures, minimizing poly-brominated alkane conversion and extending catalyst life.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If alkyl bromides are converted at high temperatures to produce high molecular weight hydrocarbons, then the yield of C6+ hydrocarbons increases, but poly-brominated alkanes form more rapidly increasing coke formation and catalyst deactivation

Engineering Contradiction:

Improveyield of C6+ hydrocarbonsVSAvoidcoke formation

Core Design Contradiction:

ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent divides the conversion process into multiple stages with different temperature zones. The first stage operates at lower temperatures (400-600°C) to convert alkyl bromides to hydrocarbons with substantial C6+ paraffin content, while the second stage operates at higher temperatures (600-800°C) to convert remaining alkyl bromides to hydrocarbons with substituted aromatics. This segmentation prevents excessive coke formation in the first stage while still achieving high overall yield, and the sequential approach allows poly-brominated alkane conversion to be minimized in the first stage.

Inventive Principle:

Principle #1Segmentation

2Productivity

If alkyl bromides are converted at high temperatures to produce high molecular weight hydrocarbons, then the yield of C6+ hydrocarbons increases, but catalyst deactivation occurs more rapidly reducing cycle times

Engineering Contradiction:

Improveyield of C6+ hydrocarbonsVSAvoidcatalyst life

Core Design Contradiction:

ProductivityVSDuration of action of stationary object

Solution Approach 1:

The patent divides the conversion process into multiple stages with different temperature zones. The first stage operates at lower temperatures (400-600°C) to convert alkyl bromides to hydrocarbons with substantial C6+ paraffin content, while the second stage operates at higher temperatures (600-800°C) to convert remaining alkyl bromides to hydrocarbons with substituted aromatics. This segmentation prevents excessive coke formation in the first stage while still achieving high overall yield, and the sequential approach allows poly-brominated alkane conversion to be minimized in the first stage.

Inventive Principle:

Principle #1Segmentation

3Object-affected harmful factors

If poly-brominated alkanes are present during conversion, then the rate of coke formation increases, but reducing poly-brominated alkane conversion decreases the carbon efficiency of the process

Engineering Contradiction:

Improvecoke formation rateVSAvoidcarbon efficiency

Core Design Contradiction:

Object-affected harmful factorsVSLoss of substance

Solution Approach 1:

The patent performs preliminary conversion of alkyl bromides at lower temperatures in the first stage before proceeding to the second stage. This preliminary action at controlled temperatures minimizes the formation of poly-brominated alkanes that would otherwise lead to excessive coke formation in subsequent high-temperature processing, thereby maintaining carbon efficiency while reducing harmful coke formation.

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

This approach significantly reduces coke formation, increases the yield of high molecular weight hydrocarbons with desired paraffin and aromatic content, and prolongs catalyst activity, enhancing the efficiency of the hydrocarbon synthesis process.

Implementation Method 1

reacting at least a first portion of the alkyl bromides in the presence of a first catalyst and at a first temperature sufficient to form a first hydrocarbon product containing at least hydrocarbons having at least 5 carbon atoms and having a substantial C6+ paraffin content

Methodology Applied

Scientific EffectCatalysis: Catalysis

Implementation Method 2

A second portion of the alkyl bromides is reacted in the presence of a second catalyst and at a second temperature sufficient to form a second hydrocarbon product containing at least hydrocarbons having at least 5 carbon atoms and having a substantial substituted aromatic content

Methodology Applied

Scientific EffectCatalysis: Catalysis

Data Source

PatentUS9133078B2Processes and systems for the staged synthesis of alkyl bromides

Publication Date: 2015.09.15 SULZER MANAGEMENT AG

AI summary

Processes and systems for synthesizing hydrocarbon products, such as high molecular weight hydrocarbons, olefins or mixtures thereof, from alkyl bromides wherein one or more streams of alkyl bromides may be reacted in sequential or concurrent stages at different temperatures. The catalyst used in the synthesis stages may be the same or different and at least in one instance is chosen to form hydrocarbon products having a significant C6+ paraffin content. The stages may be conducted in one or more reactors and the catalyst may be deployed in fixed beds or fluidized beds.