Generation Of Biofuels
The generation of biofuels, a priori, represents several advantages with respect to obtaining fossil fuels used to obtain fossil energy. The main advantage is that the regeneration of resources is not millions of years as it happens with coal, oil or natural gas. Anyway, the regeneration of biofuels is not fast enough to be considered a renewable energy source either. They are considered, then, a non-renewable source of energy.
On the other hand, biofuels continue to be an indirect way of harnessing solar energy. In this case, solar energy is exploited thanks to the photosynthesis of the cultivated plants. The rest of the energy of this fuel comes from the chemical energy that the plant generates when processing the nutrients of the earth.
With the aim of improving the production of biofuels and mitigating inconveniences and the negative effects of their production, we can divide their evolution into 4 different generations:
First generation biofuels
First-generation or conventional biofuels are biofuels made from food crops grown on farmland. With this generation of biofuel production, food crops are cultivated explicitly for the production of fuel, and nothing more. The sugar, starch or vegetable oil obtained from the crops is converted into biodiesel or ethanol, using transesterification or yeast fermentation.
Second generation biofuels
Second-generation biofuels are fuels manufactured from various types of biomass. Biomass is a broad term that means any source of organic carbon that is rapidly renewed as part of the carbon cycle. Biomass is derived from plant materials, but may also include animal materials.
While first-generation biofuels are made from sugars and vegetable oils found in herbaceous crops, second generation biofuels are made from lignocellulosic biomass or woody crops, agricultural residues or waste vegetable material (from crops destined for food but which they have already fulfilled their food purpose).
The raw material used to generate second-generation biofuels should grow on land that can not be used to grow food effectively and its cultivation should not consume much water or fertilizers.
This form of fuel generation has advantages and disadvantages. The advantage is that, unlike regular food crops, no arable land is used solely for the production of fuel. The disadvantage is that, unlike regular food crops, it can be quite difficult to extract the fuel. For example, a series of physical and chemical treatments may be required to convert lignocellulosic biomass into liquid fuels suitable for transport.
Third generation biofuels
Third-generation biofuels is based on the philosophy of using aquatic plants.
A self-published article by Michael Briggs of the UNH Biofuels Group offers estimates for the realistic replacement of all vehicular fuel with biofuels through the use of algae that have a natural oil content of more than 50%, which Briggs suggests can be grown in algae ponds in wastewater treatment plants.
These algae can then be extracted from the system and transformed into biofuels. Subsequently, the dry residue is reprocessed to create ethanol.
The production of algae to harvest oil for biofuels has not yet been carried out on a commercial scale, but feasibility studies have been carried out to arrive at the estimation of the previous performance. In addition to its high projected yield, the use of algae does not imply a decrease in food production, since it does not require cropland or fresh water.
Fourth generation biofuels
Similarly, fourth-generation biofuels are manufactured using non-cultivable land. However, unlike third-generation biofuels, they do not require the destruction of biomass.
Last review: April 13, 2018