In the article, “Progress and recent trends in biofuels”, Demirbas (2007) explores the issues surrounding biofuels and why this topic is gaining popularity in both developing and developed countries. The issue of biofuels has been raising heated debates in the wake of the challenge of global warming, the ever-increasing energy consumption, and the rapid reduction of fossil fuels across the world. In addition, biofuels are environment-friendly and renewable sources of energy. Therefore, given the aforementioned challenges, the focus is now shifting to the generation of biofuels from readily available biomass sources, which explains the increased interest in the developed world to employ technology in making biofuels to supplement or substitute conventional fossil fuels.
Across the world, the sources for biofuels are more equitably distributed as compared to other energy sources like fossils or nuclear materials. Therefore, the United States and the European Union are pushing for the adoption of biofuels in different sectors of the economy.
Biofuels can be obtained in different ways and they can be available in disparate forms such as biohydrogen, biodiesel, bioethanol, biomethanol, and bio-oils. Biohydrogen can be extracted from biomass through steam reforming in a process known as biomass gasification or flash pyrolysis even though the latter is currently under development. The hydrogen gas obtained from this process can be used in power generation. The commonly produced gases include hydrogen and syngas (CO), which are then converted to bio-syngas. The bio-syngas are then converted to fuels using the Fisher-Tropsch synthesis (FTS). With the technology advancement, researchers have attempted to come up with synthetic hydrocarbons, which ease the conversion of biomass to biofuels.
In making bioethanol, plant materials and especially carbohydrates can be changed to sugars through hydrolysis. In addition, through the anaerobic breakdown of bio-wastes, one can get biogas. Cellulose, which is found in plants, is used in the making of bioethanol, which can be used to supplement or substitute petrol. Methyl and ethyl derivatives of vegetable oil make biodiesel, which can be used instead of diesel fuels. Compared to the diesel from fossils, biodiesel is environmentally friendly coupled with being a renewable source of energy. The methyl and ethyl esters from vegetable oil are obtained via transesterification even in the absence of any catalyst, which makes the process an appealing alternative to diesel derived from fossil fuels.
Bio methanol is also an important biofuel as it can be used instead of mainstream engine fuels. However, the process of making bioethanol is expensive and energy-consuming, which paints the process as an economically unviable venture. Therefore, instead of converting biomass to methanol, many industries prefer biomass conversion to hydrogen, which is then used as explained earlier in this paper.
The last viable option of biofuels is bio-oils. Bio-oils are made from a wide array of biomass materials through thermochemical or biochemical processes. The commonly known and used form of bio-oil is biogas, which is easily made from animal wastes.
In conclusion, biofuels underscore the liquefied fuels made from biomass. Biofuels offer the best alternative to fossil fuels, as they are environment-friendly, cheap, and readily available. The FTS process plays a key role in the generation of biofuels through a series of processes that convert biomass to liquid fuels. The commonly known forms of biofuels include biohydrogen, biodiesel, bioethanol, biomethanol, and bio-oils. However, biomethanol is not economically viable given the complex and energy-consuming processes of its production.
Reference
Demirbas, A. (2007). Progress and recent trends in biofuels. Progress in Energy and Combustion Science, 33, 1-18.