Bio-diesel production has been increasing rapidly during the last few decades, but there are a lot of issues arise from this expanding industry. In particular, the sustainability issue of First Generation of bio-diesel which using agricultural crops as the main feedstock has been debated over concerns such as rising in food price, effects on the environment and climate change.
Production of Bio-Diesel from Renewable Resources
First Generation of Biodiesel is produced primarily by using food crops as the feedstock. Some of the plants whose seeds have been used as feedstock are sunflower, canola (also known as rapeseed), peanut, mustard, soybean, coconut, and palm oil. A process which is named Transesterification is used to alter the plant oils chemically. The resulting product is biodiesel (also known as fatty acids methyl esters) and a co-product called glycerin (also known as glycerol or glycerin). Transesterification is relatively cheap and also technologically simple.
taken from: http://www.biofuelstp.eu/fuelproduction.html
Alternative energy crops such as Canola can be used as the feedstock for the production of Biodiesel in temperate regions. It is much more efficient as the oil yields with Canola is roughly 130 gallons per acre, which is twice that attained with soybeans. However, in tropical regions, coconuts and oil palm plants are preferred for feedstock. Coconut yields about 290 gallons of oil per acre whereas oil palm plant yields 635 gallons of oil per acre.
Furthermore, the energy demands of Biodiesel refining process are modest. A fairly high net energy balance is yielded from adding the energy used during refining to the energy expenditures required to produce common biodiesel feedstock and divide by the result into the heating value of biodiesel. Estimated net energy balance is in excess of 3- means that more than 3 times of energy is obtained by burning biodiesel compared with the energy used to produce it.
* 1 gallon=3.7854118 litre
1 acre= 4046.856 m²
Biodiesel in USA
In the United States, Biodiesel is produced by using soy-bean as the feedstock. It yields only about 48 gallons of Biodiesel per acre. At this yield, it is difficult to change the consumption patterns as there are not enough lands to produce enough Biodiesel. It is unrealistic to expect a large contribution from soy bean based Biodiesel to the diesel fuel market as the potential of Biodiesel market is simply too large and hard to meet the supply by using agricultural crops. Due to all these constraints, Biodiesel is used as a fuel additive rather than a transportation fuel! The most common Biodiesel blends that can be found in the market are B2 and B5. The letter ‘B’ represents the percentage of Biodiesel. B2, B5 and B20 are respectively, blends consisting of 2 per cent of Biodiesel, 5 per cent of Biodiesel and 20 per cent of Biodiesel). When sold as B2 or B5, it does not have a change in the properties in the diesel fuel except improving the lubricity of the fuel. By adding a very small amount of Bio-diesel to ultralow sulfur, the lubricity of the mixed fuel is remarkably improved.
As headline statement, the National Renewable Energy Laboratory study on biodiesel for public transport concluded the following:
1. Substituting 100% biodiesel (B100) for petroleum diesel reduced the life cycle consumption of petroleum by 95%, whereas a 20% blend (B20) reduced consumption by 19%.
2. B100 reduced CO2 emissions by 74.5%, B20 by 15.7%
3. B100 completely eliminated tailpipe emissions of sulfur oxides and reduced life cycle emissions of CO, sulfur oxides, and total particulate matter by 32%, 35%, and 8%, respectively.
4. Life cycle emissions of NOx and hydrocarbons were higher (13.4% and 35%, respectively) with B100, but there were small reductions in methane emissions.
According to U.S.Environmental Protection Agency, estimation on ‘life cycle’ of biodiesel has been made-that is, net greenhouse gas emissions are reduced by about two-third in relative to that of petro-diesel.
Despite the fact that its greenhouse emission is still clouded by uncertainties, most of the other impact of burning fuel favored bio-diesel rather than petro-diesel.
Pollutants emitted | Emission of burning Bio-diesel compared to petro-diesel |
Particulate Matter | Reduces by approximately 55% in relative to that of petro-diesel |
Carbon Monoxide | Reduces by 45% in relative to that of petro-diesel |
Nitrogen Oxide | Increase slightly by 5% in relative to that of petro-diesel |
Table above shows the comparison between emission of burning bio-diesel and petro-diesel.
Statistic taken from: Tabak, John. Biofuel. Facts on File Publications, 2009 from pg 87.
However, First Generation Bio-diesel are facing dilemma as below:
1. Compete for food with human being
2. Compete for arable land with food crops
3. Low land-use efficiency
4. Partial utilization of feedstock
5. Limited market
6. More costly than petro-diesel
7. Lower energy value than petro-diesel
8. Modest energy replacement of fossil fuels
Sustainability of First Generation
Now, we shall assess the sustainability of the First generation bio-diesel. Growing feedstock for manufacturing Bio-diesel may pose a threat to our food supply as it displace food crops from arable land thus, cause rising in food prices. At the current stage of development of Bio-diesel, the yields that we get from agricultural crops are simply not enough for to significantly change the consumption patterns. Soybeans is primarily use for the production of Bio-diesel in United State and it’s not encouraged for them to do so because it is an important source of protein in our life. In addition of that, the yield of soybeans is only 48 gallons of Bio-diesel per acre of land which is not a significant amount. Although the production of Bio-diesel from soybean co-product is considered as efficient and environmentally friendly, it is unrealistic to expect more than a small contribution to the fuel market from soybean producers. If a country is interested in using First Generation of Bio-diesel for developing purposes, it may need to invest in R&D work in order to find species of crops which has a higher yields and efficiency. The amount of land needed to grow the feedstock is daunting and most of the country cannot afford to dedicate so much land just for the production of Bio-diesel. To counter this problem, government policy plays an important role. For example, farmers in European Union are bounded by EU’s Common Agricultural Policy. The policy prohibits the farmers from growing food on 10% of their arable land. However, ‘industrial’ crops are allowed to grow on these lands. This can reduce the impact on food prices caused by shifting production from food to energy crops.
As Bio-diesel is more costly, incentives would be needed to increase its competitiveness in the market. Under the Energy Policy Act of 2005, a one dollar per gallon biodiesel tax credit remained in effect until 2008. Besides that, there is a program in United State called Commodity Credit Corporation Bioenergy Program which offers generous cash payments to producers. This has positive impact to the production of Bio-diesel. Generous subsidies is another way of encourage Bio-diesel production and consumption. If the market does not become too large, the subsidies are easy to maintain. However, if the consumption increase, the costs spend on subsidies will become a burden for the country.
