The “recicled” fuel.
Biofuels are a very recent discovery in the landscape of alternative fuels. They are often discussed but many times with confusion regarding their production and classification. Let’s take a look at the differences in production between fossil fuels and biofuels, as well as the various types of biofuels.
Production of fossil fuel – Fossil fuel is obtained through the extraction and processing of non-renewable resources, known as “fossils”. The quintessential fossil fuel is petroleum, from which gasoline, diesel, aviation fuel, and bitumen for roads are derived. Its processing takes place between the furnace and a distillation column, where different products are obtained depending on the temperature of the petroleum. There are various processing methodologies, and here, the “topping” methodology is explained.
Production of biofuel – Biofuel, on the other hand, does not use any fossil resources but relies on renewable agricultural resources. Its processing starts from agricultural residues or urban waste, which are then referred to as “biomass.” In order to be transformed into biofuel, the biomass must undergo a fermentation process if cells are used or biotransformation if enzymes are utilized. All of this occurs in a refinery similar to that used for fossil fuels, known as a “biorefinery,” and its products are listed below.
Types of Biofuel – They are:
Biogas: Also known as biomethane, it is produced from biomass such as industrial, domestic, and agricultural waste. It can be injected into the gas grid and used to heat homes or can be used to power vehicle engines, replacing natural gas extracted from the ground.
Bioethanol: Used as an additive to gasoline, it can only be used by vehicles specifically designed for it. It is produced from sugarcane or corn, but in recent times, sorghum or common reed, both rich in lignocellulose and unsuitable for human consumption, have also been used.
Biobutanol: Similar to bioethanol, it has a high energy content and is produced from first or second-generation biomass. Its potential danger lies in its high toxicity at elevated concentrations.
Biodiesel: Considered a candidate to replace diesel as an energy source for engines. It can be used in all diesel engines without requiring specific modifications or adjustments. It is categorized into three generations:
- First generation: This includes biodiesel produced from vegetable oils and hydrogenated vegetable oils (HVO).
- Second generation: Biodiesel in this category is derived from waste oils or by-products of wood processing. Additionally, it may be sourced from plants that can grow on non-cultivated land.
- Third generation: Biodiesel in the third generation is produced from microalgae. Microalgae require water, light, carbon dioxide, and a temperature range of 20°C to 30°C for their growth.
These three generations represent the different sources and production methods used for biodiesel, each with its own advantages and challenges in terms of sustainability, availability, and environmental impact.
Advantages – There are numerous advantages to using biofuels. One of them is their low environmental impact, both during production and utilization. They are also capable of reducing greenhouse gas emissions by up to 65% as they come from renewable sources.
Disadvantages – On the other hand, there are some drawbacks associated with biofuels. High production costs and significant water usage are notable disadvantages, which can reduce access to this vital resource for humans. Additionally, the use of fertilizers to increase plant growth rate can introduce harmful elements such as phosphorus and nitrogen, which can have adverse effects on our health.
Overall, while biofuels offer several benefits in terms of sustainability and reduced emissions, careful consideration is needed to address the associated challenges and ensure their long-term viability as an alternative energy source.