Coal Liquefaction Aromatics Separation Without Reaction Conversion
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Solution Overview
Problem
The separation process of p-xylene from coal-based oil products is complicated, and existing methods introduce additional chemical reaction steps with environmental and economic considerations, failing to meet the growing demand for toluene, ethylbenzene, and p-xylene.
Innovation Solution
A method involving fine fractionation, column chromatography, atmospheric and vacuum distillation, and extractive distillation is used to separate and purify monocyclic aromatic hydrocarbons, specifically toluene, ethylbenzene, and p-xylene, from direct coal liquefaction oil, without additional chemical reactions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If catalytic conversion method is used to separate p-xylene from coal-based crude oil, then p-xylene can be produced through reaction conversion, but the control variables become complicated and additional chemical reaction steps are introduced
Solution Approach 1:
The patent extracts p-xylene from coal-based crude oil through a series of separation operations including extraction, adsorption, and crystallization, removing the target component directly from the mixture without requiring complex catalytic conversion processes
Solution Approach 2:
The patent uses intermediary substances such as extractants, adsorbents, and solvents to facilitate the separation of p-xylene from coal-based crude oil, enabling purification through physical separation rather than complex chemical reactions
2Manufacturing precision
If catalytic conversion method is used to separate p-xylene from coal-based crude oil, then p-xylene can be produced, but economic benefits and environmental impacts need to be considered comprehensively
Solution Approach 1:
The patent converts the complex coal-based crude oil composition into a benefit by using selective extraction and separation processes that target p-xylene specifically, transforming what could be viewed as a processing challenge into an efficient purification pathway with reduced environmental impact
3Productivity
If petroleum-based naphtha is used as raw material for producing toluene, ethylbenzene and p-xylene, then these aromatic hydrocarbons can be produced, but the supply is tight and not enough to match the growing demand
Solution Approach 1:
The patent enables coal-based crude oil to serve as a universal raw material substitute for petroleum-based naphtha, allowing the production of toluene, ethylbenzene, and p-xylene from alternative feedstock, thereby diversifying raw material sources and increasing overall production capacity
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 method achieves high-purity production of toluene, ethylbenzene, and p-xylene, utilizing coal-based resources efficiently and economically, addressing the supply shortage of petroleum-based naphtha and reducing environmental impact.
Implementation Method 1
selecting a fraction with a highest content of monocyclic aromatic hydrocarbons, and sequentially performing column chromatography
Implementation Method 2
column chromatography
Implementation Method 3
atmospheric and vacuum distillation
Implementation Method 4
extractive distillation
Data Source
AI summary
A method for separating and purifying monocyclic aromatic hydrocarbons from direct coal liquefaction oil is provided. The method is as follows: (1) performing fine fractionation and component analysis on the direct coal liquefaction oil, to determine a highest fraction of monocyclic aromatic hydrocarbons; (2) Removing light alkanes and cycloalkanes from the selected fraction by column chromatography; (3) separating toluene, monocyclic aromatic hydrocarbon mixtures and high-carbon alkanes through atmospheric and vacuum distillation column; (4) purifying ethylbenzene from a mixture of monocyclic aromatic hydrocarbons through extractive distillation column and (5) purifying p-xylene through solvent recovery column The separation method may fully utilize the compositional characteristics of direct coal liquefaction oil, to obtain two to three high-purity monomers of monocyclic aromatic hydrocarbons in a single processing step, without introducing additional chemical reaction steps, thereby demonstrating significant economic and environmental benefits.