Steam-Enzyme Processing for Unbleached Straw Biomechanical Pulp
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The papermaking industry in China faces a shortage of papermaking raw materials and the challenge of effectively utilizing by-products from the pulping process, leading to environmental pollution and high energy consumption.
Innovation Solution
A method for preparing unbleached biomechanical pulp from straws involves treating straw with steam, alkaline compound enzymes, and hot alkali water, followed by refining and recycling by-products to produce biomass compound fertilizer, eliminating the need for alkali recovery and reducing environmental impact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If traditional chemical pulping process is used to process straw, then pulp production is achieved, but hemicellulose is degraded and dissolved in black liquor causing energy waste and resource loss
Solution Approach 1:
The patent extracts and removes hemicellulose from the straw material through enzymatic hydrolysis before the pulping process. The hemicellulose is separated into a distinct stream that can be utilized separately, preventing its degradation and dissolution in black liquor during chemical pulping.
Solution Approach 2:
The patent applies preliminary enzymatic treatment to hydrolyze hemicellulose before the main pulping process. This preliminary action converts hemicellulose into fermentable sugars that can be subsequently fermented into ethanol or other valuable products, avoiding energy loss from burning.
2Loss of energy
If alkali recovery method is used to treat black liquor, then heat energy and alkali are recovered, but the process is complex and energy-consuming
Solution Approach 1:
The patent extracts hemicellulose away from the black liquor stream before pulping, eliminating the need for complex alkali recovery processes. By removing the problematic component (hemicellulose) that causes low calorific value and processing difficulties, the remaining black liquor can be simpler to handle.
Solution Approach 2:
The patent performs preliminary enzymatic hydrolysis to convert hemicellulose into usable products before the pulping and black liquor generation stages. This preliminary action prevents hemicellulose from entering the black liquor stream, thereby eliminating the need for complex alkali recovery systems.
3Loss of energy
If straw is directly burned for energy recovery, then energy is obtained, but valuable biomass resources are wasted
Solution Approach 1:
The patent applies preliminary enzymatic hydrolysis to convert hemicellulose into fermentable sugars before any energy recovery process. These sugars are then fermented into ethanol or other high-value biochemical products, maximizing the utilization of biomass resources rather than simply burning for energy.
Solution Approach 2:
The patent changes the utilization pathway of hemicellulose from direct combustion to biochemical conversion. By changing the processing parameters and methods (enzymatic hydrolysis followed by fermentation), the value of the biomass resource is significantly enhanced, producing high-value chemicals instead of just heat energy.
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 method enhances the production of high-quality mechanical pulp suitable for packaging paper and improves crop growth through nutrient-rich fertilizers, aligning with resource conservation and emission reduction policies.
Implementation Method 1
straw as raw material for pulping is treated with steam or hot water, then a small amount of alkali was added, the straw was softened by hydrothermal saturation
Implementation Method 2
alkaline compound enzymes were added for biological treatment
Implementation Method 3
alkaline compound enzymes were added for biological treatment
Implementation Method 4
treated with steam or hot water, then a small amount of alkali was added, the straw was softened by hydrothermal saturation
Data Source
AI summary
The present disclosure relates to a method for preparing an unbleached biomechanical pulp from straws and full utilization of by-products, which belongs to the technical field of papermaking technology and waste comprehensive utilization. In the present disclosure, straw as raw material for pulping is treated with steam, then a small amount of KOH is added, the straw is softened by hydrothermal saturation, then the temperature of the straw is adjusted, alkaline compound enzymes are added for biological treatment, and finally the straw is refined, where the prepared mechanical pulp can meet the requirements of producing unbleached packaging paper and paper-based materials. At the same time, the by-products are recycled to prepare biomass compound fertilizer, which turns solid waste into treasure and realizes the high-value full utilization of wheat straw. Therefore, it has good practical application value and broad application prospects.