Segregating Cellulosic Process Streams for Water Recycling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Cellulosic ethanol conversion processes face challenges with high water requirements and the buildup of inhibitors, which increase capital and operating costs, and impact bio-catalyst performance due to recycled streams containing acetic acid and other inhibitory compounds.
Innovation Solution
A cellulosic conversion process that involves segregating and treating specific process streams to reduce inhibitor levels, using anaerobic and aerobic digestion, physical separation, and chemical treatment to produce treated water streams that can be recycled, thereby minimizing treatment system size and costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If water recycle is implemented in cellulosic conversion process, then fresh water requirements and wastewater disposal amounts are reduced, but inhibitor levels in process streams increase negatively impacting bio-catalyst performance
Solution Approach 1:
The patent divides the water recycle system into multiple segments with different treatment levels. Process streams are segregated into different recycle loops based on their inhibitor concentrations and treatment requirements. This allows clean water to be recycled to water-sensitive unit operations while water with higher inhibitor levels is directed to unit operations with greater tolerance, thus maintaining bio-catalyst performance while maximizing water reuse.
Solution Approach 2:
Different quality standards are applied to different portions of the water recycle system. The patent implements location-specific water quality requirements where water is recycled to unit operations based on their specific tolerance levels for inhibitors. This ensures that water quality matches the local needs of each process section, optimizing both water usage and bio-catalyst performance.
2Quantity of substance
If water recycle is implemented to reduce fresh water requirements, then water usage efficiency improves, but treatment system size and costs increase
Solution Approach 1:
The water treatment system is segmented into multiple smaller treatment units distributed throughout the process rather than one large centralized treatment plant. Each treatment unit handles specific process streams with similar characteristics, reducing the complexity and capital cost of individual treatment systems while maintaining overall water reuse effectiveness.
Solution Approach 2:
The patent enables process streams to treat themselves through the natural processes occurring in the system. For example, anaerobic digesters naturally treat water streams while producing biogas, and certain unit operations inherently reduce inhibitor levels without requiring additional treatment infrastructure. This reduces the need for complex external treatment systems.
3Loss of substance
If water recycle is implemented, then wastewater disposal requirements are reduced, but capital and operating costs increase due to treatment requirements
Solution Approach 1:
The patent converts harmful waste streams into valuable resources. Water streams containing inhibitors are routed to anaerobic digesters where the inhibitors serve as substrate for biogas production. This transforms what would be harmful waste requiring expensive treatment into a source of renewable energy, reducing both wastewater disposal requirements and operating costs.
Solution Approach 2:
The patent combines multiple functions into integrated process units. For example, anaerobic digesters simultaneously treat water streams, produce biogas for energy, and reduce inhibitor levels. This merging of treatment and energy production functions reduces the need for separate treatment facilities and lowers overall capital and operating costs.
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 effectively reduces water requirements and inhibitor concentrations, maintaining bio-catalyst performance while reducing capital and operating costs by segregating and treating process streams to produce suitable treated water for recycling.
Implementation Method 1
The treatment process comprises: at least a step of feeding one or more of the process streams to an anaerobic digestion
Implementation Method 2
one or more of the process streams to an aerobic digestion
Data Source
AI summary
Disclosed herein is a process for recycling water in a cellulosic conversion process that comprises selecting process stream(s) that may contain reduced levels of inhibitors and subsequently subjecting the stream(s) to a treatment process to produce treated water. The treated water is thereafter recycled to the cellulosic conversion process, associated utilities or the seal water system. The process streams selected for treatment may comprise less than 5 wt % organic content and/or less than 5 wt % inorganic content. The process of the invention comprises at segregating process streams based on their treatment requirements. The segregated process streams may be sent to respective separate treatments selected from anaerobic digestion, aerobic digestion, physical separation and chemical treatment.