|
Special
|
|
Written by Sabrina Deparine
|
|
Tuesday, 16 June 2009 10:28 |
|
Page views: 1730 |
First Generation and Second Generation Biofuels: An Overview
First-generation biofuels pertain to the biofuels that are derived from sugar, starch, vegetable oil, or animal fats. Synthetic biofuels which are derived from microbial fermentation are also classified under first generation biofuels. The process of producing first-generation biofuels utilizes conventional technology. The most common examples of first-generation biofuels are bioethanol derived from sugarcane, corn or cassava and biodiesel from coconuts.
On the other hand, second generation biofuels pertain to the type of biofuel that is derived from non-food or non-edible feedstock. Some examples of non-food/non-edible feedstock are biomass like agricultural residues and dedicated energy crops. Technologies and technical know-how on the process of producing second-generation biofuels were devised owing to the limitations of first-generation biofuels. For instance, biofuel producers and industries are unable to produce sufficient biofuel to address the growing demand in the market because of issues regarding food shortage and price hikes. This means that, in some cases, first-generation biofuels may not be competitive to regular gasoline in terms of costs. Also, second-generation biofuels are used to extend the volume of biofuel that can be produced to sustain the market by utilizing the waste or non-edible parts of crops like stems, leaves, and husks as well as other non-food crops. Second-generation biofuels can give a more sustainable supply of biofuels while, at the same time, impart greater environmental benefits.
Processing Biomass into Second-Generation Bioethanol
First-generation bioethanol is produced through fermentation of plant-derived sugars to yield ethanol. The process of producing second-generation biofuels is relatively the same except that this would require a pre-treatment step of the biomass prior to proceeding to the production of ethanol.
This pre-treatment step is needed in order to release the useful feedstock from the biomass. In biomass, the useful sugar that can be used as feedstock is locked in by cellulose and lignin. Cellulose and lignin are complex forms of carbohydrates common among all plants.
In order to produce lignocellulosic ethanol, sugar molecules have to be separated from cellulose through the use of enzymes or other processes like steam heating. This is the pre-treatment step of the ethanol production process when using biomass feedstock. The sugar produced from this step is then fermented to produce ethanol.
On the side, one by-product produced from this pre-treatment process is lignin. This can also be used as a carbon neutral fuel that can produce heat and power for commercial and residential purposes.
Certain studies revealed that the greenhouse gas emissions from cellulosic ethanol are reduced by about 80% as compared to regular gasoline whereas conventional ethanol indicate only a 20 to 20% reduction. The greater reduction of emissions in cellulosic ethanol can be attributed to lignin. As mentioned, lignin is a renewable fuel itself and has no net greenhouse gas emissions.
Recent Developments in Cellulosic Ethanol
 In recent news, HCL-Cleantech, a start-up company based in Tel Aviv, Israel, created a stir by reinventing a hundred year-old process called Bergius process to utilize it as a cheaper method to produce ethanol from cellulosic materials.
Indeed, this is good news since if the production process for cellulosic ethanol is cheaper then it is also tantamount to having cheaper alternative fuel in the market. What makes this new process less expensive is that HCL-Cleantech will utilize a stronger and more concentrated HCL solution. This will allow the company to combine the first two steps in ethanol production by stripping off cellulosic sources while, at the same time, breaking the material down to fermentable sugars. This acid solution is also proven effective in deriving as much as 97% of sugars from cellulosic materials.
Aside from this, the use of HCL acid solution will help reduce the amount of unwanted by-products. Acid reactions may also take place even at low temperatures, thus, reducing the amount of energy required to operate the system.
In Canada, Shell adds another milestone by offering cellulosic ethanol blended into regular gasoline in a service station in Ottawa, Ontario. This is the first time that cellulosic ethanol is made available to the public. The said biofuel is derived from wheat straw.
The cellulosic ethanol-blended gasoline contains 10% cellulosic ethanol and 90% regular gasoline. It is referred to as CE10. This will initially be available for only a month and was launched last June 10, 2009 but still, Shell’s offering of cellulosic ethanol-blended gasoline is considered as a commendable advancement in biofuel production.
What Can We Do to Further Develop Cellulosic Ethanol Industries in the Country?
Technically, the key to the success of not only cellulosic ethanol but the whole biofuels industry is increased spending and government funding. For one, there should be increased spending particularly in the research and development of processing and conversion technologies to enhance the cellulosic ethanol production in the county. Government funding is likewise needed to encourage other investors and to fund demonstration projects and other incentive schemes to ignite awareness and commercialization.
|
Share this Article.
|
Related Articles
|
Subscribe
