Hydrothermal Carbonisation Biomass Preheating and Recirculation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hydrothermal carbonization processes face challenges such as high energy requirements, viscosity issues leading to sedimentation, and increased maintenance costs due to the high viscosity of biomass like dehydrated sludge, which limits heat exchange efficiency and reactor volume capacity.
Innovation Solution
A method and device that preheat a fraction of biomass and return it to a mixing station to create a higher-temperature mixture, reducing viscosity and pressure drop, eliminating the need for heating within the treatment station, and using controlled pressure and additive injection to enhance mixing and heat exchange.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If biomass is heated directly in the reactor, then temperature increase is achieved, but biomass sedimentation occurs due to temperature gradient, requiring mixer-scraper which increases complexity and maintenance costs
Solution Approach 1:
The invention preheats a fraction of biomass in a separate heat exchanger before reintroducing it to the reactor. This preliminary heating action creates a temperature gradient that prevents sedimentation without requiring mechanical mixing devices, thus resolving the contradiction between achieving temperature increase and avoiding device complexity.
Solution Approach 2:
The heating process is segmented into two distinct stages: external preheating in a heat exchanger and internal heating in the reactor. This segmentation allows temperature increase to occur outside the reactor, eliminating the need for mixer-scraper mechanisms inside the reactor while still achieving the desired temperature rise.
2Productivity
If reactor volume is increased to process more biomass, then processing capacity improves, but residence time increases which limits throughput
Solution Approach 1:
By preheating biomass externally before it enters the reactor, the invention reduces the time needed for heating within the reactor. This allows the reactor to be smaller while maintaining processing capacity, thus improving productivity without increasing residence time.
Solution Approach 2:
The invention replaces mechanical mixing and heating mechanisms with a thermal field approach using external heat exchange. This substitution allows for more efficient heat transfer and reduced residence time, enabling higher throughput without increasing reactor volume.
3Temperature
If heating power is increased to overcome high viscosity, then temperature rise improves, but energy consumption increases significantly
Solution Approach 1:
The invention performs preliminary heating in a dedicated heat exchanger where heat transfer is more efficient. This preliminary action reduces the energy required for subsequent heating in the reactor, as the biomass enters the reactor at a higher initial temperature, thereby reducing overall energy consumption while achieving the desired temperature rise.
Solution Approach 2:
The invention introduces a heat transfer fluid as an intermediary between the heat source and the biomass. This intermediary enables more efficient heat exchange, reducing energy losses and improving the overall energy efficiency of the heating process compared to direct heating methods.
4Reliability
If mixer-scraper is installed to prevent sedimentation, then biomass deposition is eliminated, but reliability decreases due to additional failure points and maintenance requirements
Solution Approach 1:
The invention extracts the heating function from the reactor interior and relocates it to an external heat exchanger. This extraction eliminates the need for mixer-scraper mechanisms inside the reactor, removing the associated reliability issues and maintenance requirements while still preventing biomass deposition through controlled thermal gradients.
Solution Approach 2:
The system uses the heated biomass itself as the heating medium for subsequent biomass through the heat exchanger. This self-service approach creates a continuous circulation where processed biomass heats incoming biomass, maintaining temperature uniformity without mechanical intervention and eliminating deposition problems.
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 reduces energy consumption, prevents biomass sticking, eliminates the need for mixing or scraping mechanisms, and allows for a smaller reactor volume, improving heat exchange efficiency and treatment quality.
Implementation Method 1
a fraction of the biomass heated by the means of heating being returned by a return branch to a mixing station upstream of the heating means in order to constitute there with the incoming biomass a mixture having a temperature higher than the temperature of the incoming biomass
Implementation Method 2
the biomass is pressurized between the mixing station and the heating means, and the pressure of the biomass fraction is lowered in the return branch
Data Source
Figure 1
Figure 2
Figure 3a~3c
AI summary
The invention relates to a method for heating biomass in motion in an industrial processing path comprising an inlet (1) for the incoming biomass, a heating means (4) and a processing station (5), a fraction of the biomass heated by the heating means (4) being returned by a return branch (R) to a mixing station (2) upstream of the heating means (4) to form with the incoming biomass a mixture having a temperature higher than the temperature of the incoming biomass, the heated fraction of biomass being taken from an outlet (51) of the processing station (5).