Biomass-Derived Liquid Reforming
Similar to natural gas reforming, liquids obtained from biomass resources, such as ethanol and bio-oils, may be reformed to create hydrogen. Liquids obtained from biomass are more readily transported than their biomass feedstocks, allowing for semi-central or perhaps dispersed hydrogen generation at fuelling stations. The liquid reformation of biomass is a mid-term technical route.
HOW DOES IT FUNCTION?
The conversion of biomass resources into cellulosic ethanol, bio-oils, or other liquid biofuels is possible. Some of these liquids may be transferred to a refueling station or other point of application and converted to hydrogen at a reasonably cheap cost. Others, such as bio-oils, may be reformed locally.
Reforming liquids obtained from biomass to hydrogen is very similar to reforming natural gas and contains the following steps:
In the presence of a catalyst, the liquid fuel is reacted with steam at high temperatures to generate a reformate gas made mostly of hydrogen, carbon monoxide, and carbon dioxide.
In the “water-gas shift reaction,” more hydrogen and carbon dioxide are generated by combining carbon monoxide (made in the previous stage) with high-temperature steam.
The hydrogen is finally isolated and purified.
Reforming of ethanol with steam: C2H5OH + H2O (+ heat) 2CO + 4H2
Water-gas transformation
CO and H2O are converted into CO2 and H2 together with a tiny quantity of heat.
Liquids obtained from biomass, such as ethanol and bio-oils, may be produced at large, centralized facilities situated near the biomass source to take advantage of economies of scale and decrease the expense of transporting the solid biomass feedstock. The liquids have a high energy density and may be transferred to dispersed refueling stations, semi-central production facilities, or stationary power sites for reforming to hydrogen with little additional delivery infrastructure and at a reasonably moderate cost, after undergoing certain upgrades.
WHY IS THIS APPROACH CONSIDERED?
Biomass is a plentiful natural resource.
More biomass is available in South Africa than is necessary for food and animal feed. With predicted advances in agricultural techniques and plant breeding, a recent analysis estimates that up to 1 billion dry tons of biomass might be accessible for energy usage yearly. This translates to 13–14 quadrillion Btu per year of potential energy. Biomass has the potential to be an important renewable energy source.
BIOMASS RECYCLES CARBON DIOXIDE
As part of their natural development process, plants absorb carbon dioxide from the environment as they produce biomass, offsetting the carbon dioxide emitted by creating hydrogen via biomass gasification and resulting in minimal net greenhouse gas emissions.
RESEARCH FOCUSES ON OERCOMING CHALLENGES
Reforming liquids obtained from biomass is a process comparable to reforming natural gas. However, liquids formed from biomass include bigger molecules and more carbon atoms than natural gas, making their reformation more challenging. To boost yields and selectivity, further research is required to develop superior catalysts. Other obstacles include:
- Reducing the price of liquids obtained from biomass
- Reducing capital equipment expenditures as well as operation and maintenance expenses and enhancing process efficiency