5. Strengths and Challenges
Biomass based LFFC technology is a new strategy for renewable energy development, showing very promising results. Direct biomass LFFC technology offers many advantages over conventional fuel cell technology.
First, with this pioneering fuel cell technology, biomass such as grass, wood, algae, agricultural waste and even sewage sludge can be directly converted into electricity at low temperatures.
Secondly, biomass-based LFFC uses liquid POM instead of precious metal-based electrocatalysts as biomass degradation catalysts. Because POM catalysts are very stable and have low sensitivity to most organic and inorganic contaminants, biomass can be used as fuel without the need for pre-purification or treatment.
Third, LFFC technology can achieve high power output.
Finally, LFFC technology has little impact on the environment. In theory, only CO2 and H2O are produced by biomass oxidation.
Therefore, in the future, biomass-based LFFC is expected to become a low-cost alternative to small power plants to achieve sustainable energy conversion and production from biomass.
LFFC still faces challenges in research and commercialization:
(1) There is still a need to develop efficient catalysts. The alternative catalyst should have a strong oxidation capacity, which can oxidize various organic substrates and crack C-C bonds at low temperatures.
(2) The performance of LFFC still needs improvement. The experimental results show that LFFC is difficult to convert 100% biomass to CO2, and the oxidation reaction rate is relatively slow. The kinetics of the electrode reaction must be studied to maximize the power output.
The separation of inorganic and organic residues from catalysts is also a challenge for the commercial use of LFFC.
(4) The life of LFFC should be considered. POM will corrode the graphite electrode plate and proton exchange membrane, shortening the service life of the battery pack.
(5) The structure of the battery and battery stack must be carefully designed to reduce the internal resistance.
One of the challenges for biomass-based LFFC is how to completely oxidize the biomass to improve overall energy efficiency and minimize the residue of organic waste. The chemical composition of biomass is very complex and may contain lignin, cellulose, hemicellulose, aliphatic resins, proteins, and many other organics. Therefore, it is often difficult to completely oxidize all the biomass components in the solution at low temperatures. However, complete oxidation will not only improve the utilization of biomass, but also significantly reduce the cost of residue treatment. The following methods can be used to improve the oxidation of biomass in the battery anode. First, the higher temperature is conducive to the deep oxidation of the biomass in the anode solution. It has been reported that lignin can be completely oxidized by POM at high temperatures. The second is the use of POM catalysts with high electrode potentials, such as vanadium-doped POM. A more effective option is to use adjuvants (such as Pt/C particles) to further increase the degree of reaction and improve the overall conversion of biomass to CO2. In the reaction using solar energy or light instead of heating, it is still necessary to increase the oxidation rate and degree.
Email:wang@kongjiangauto.com