Prof. eng. Alexandru Naghiu, PhD
Eng. Mircea Stefan Chintoanu
Prof.eng. Nicolae Burnete, PhD
Key words: biodiesel, integrate system, agriculture, farm
Abstract. The paper presents a biodiesel producing & use integrate system adaptable for agricultural farms in a decentralized manner. Different elements (key actions) of the design system are analyzed in respect of energy efficiency and environment protection.
The study pointed out that Romanian agriculture has all the necessary conditions to develop a sustenable biodiesel production & use and a network of farms working independently of fossil fuels and supplying the biodiesel for the engines used in the protected areas.
The proposed biofuel integrate system has been started to be implemented in a farm & association from Cluj county.
Energy is the essence of life and one of the most basic of human needs, not as an end in itself but as a means to numerous ends. The taming of fire was one of human kinds earliest technological achievements. It provided energy for heat and light on demand. But today the environmental impacts of the world’s power plants, internal combustion engines and boilers have serious implications for the future health and well being of the planet.
According to the demands of the technological development and the life quality increasing, during the last 50 years, global consumption of commercial energy has risen more than fourfold, far outpacing the rise in population and all this energy comes from natural resources whether fossil fuels such as coal and oil, living resources such as timber and biomass, nuclear fuel such as uranium, or renewable resources such as flowing water and wind and the power of the sun.
A generation ago, there was concern that fossil fuels would run out, plunging the world into an energy crisis. Today the fear is that their continued use might be wrecking the global climate by emitting carbon dioxide (CO2) as we burn carbon-containing fuels (see fig. 1 and table 1). This anxiety is substantially increased in view of the considerable unmet demand for energy in the developing world. It is estimated that since 1751 roughly 283 billion tons of carbon have been released to the atmosphere from the consumption of fossil fuels and cement production. Half of these emissions have occurred since the mid 1970s. The 2000 global, fossil-fuel CO2 emission estimate, 6611 million metric tons of carbon, represents a 1.8% increase from 1999. The average annual fossil-fuel release for the decade 1990-1999 was 6.35 billion tons of carbon.
Globally, liquid and solid fuels accounted for 76.8% of the emissions from fossil-fuel burning in 2000. Combustion of gas fuels accounted for 19.3% (1277 million metric tons of carbon) of the total emissions from fossil fuels in 2000 and reflects a gradually increasing global utilization of natural gas. Emissions from cement production (226 million metric tons of carbon in 2000) have doubled since the mid 1970s and now represent 3.4% of global CO2 releases from fossil-fuel burning and cement production. Gas flaring, which accounted for roughly 2% of global emissions during the 1970s, now accounts for less than 1% of global fossil-fuel releases.
CO emissions of the first country polluters
[1000 tons of C]
|Per capita emissions
[in %, 1990-96]
|Peoples Rep. of China||917997||0,76||(18)||40,0|
|France (since 1992)
Exposure to air pollution is associated with numerous effects on human health, including respiratory problems, hospitalization for heart or lung diseases, and even premature death. Children are at greater risk because they are generally more active outdoors and their lungs are still developing. The elderly and people with heart or lung diseases are also more sensitive to some types of air pollution. Air pollution can also significantly affect ecosystems. For example, ground-level ozone has been associated with reductions of agricultural and commercial forest yields, and airborne releases of NOx are one of the largest sources of nitrogen pollution in certain water bodies.
In this context the use of “clean” fuels for the internal combustion engines is more than a desire is a necessity. Rodolfo Diesel, the father of the compression combustion engines, has foreseen the biofuels use. So, in 1900 he presented at the World Exhibition from Paris an engine working with peanut oil.
By economical considerations the biofuels use was abandoned till the beginning of ’70 when the petroleum crisis putted on table the problem alternative fuels.
Under the pressure of the XXI century environmental demands (expressed synthetically in the Kyoto Protocol that was signed by more than 160 countries) the use of biofuels in the case of diesel engines has been reconsidered, especially for the engines working in the most protected areas as communal domains, agriculture, sylviculture and tourist regions (including lakes for nautical sports).
Romania was one of the first industrialized countries that have ratification the Kyoto Protocol and so, has assumed responsibilities in pollution reduction. In this direction, biofuel use is an important element.
Biodiesel integrate system for producing and use in agriculture
Agriculture is an efficient energy provider, by converting the solar energy during the photosynthesis in biomass energy. Part of the harvest biomass can used for different biofuels production covering the fuel technological necessities.
In the present paper the authors are proposing an integrate system for biodiesel production and use in the agricultural farms based on the rape crop (fig. 2). This system includes eight main levels: crop technology, oil expeller, oil esterification, biodiesel use in internal combustion engines equipping agricultural tractors, oil cake use in animal breeding, bee keeping (melliferous use of rape crop), esterification sub products use and environmental monitoring.
There are about 1700 plants the can offer an oil suitable for use as fuel in the internal combustion engines. From these only 72 can represent a commercial interest. According to the natural conditions for agriculture from Romania, the winter rapeseed oil (WRO) and its methyl ester (RME) represents one of the best choices of the alternative fuels.
Crop technology. The rape crop requires a precise technology that includes high level seedbed preparation, low/medium level of chemical treatments and high quality harvesting combines. The crop yield varies between 2,5 and 3,2 t/ha.
The actual gross energy consumption for rape cultivation including fertilizers and pesticides corresponds to the general average in farming excluding fertilizers and pesticides. An increase in the rape production area will therefore not increase the total gross energy consumption in agriculture.
Oil expeller & esterification. Unlike ethanol, which is an alcohol, biodiesel is an ester (similar to vinegar) that can be made from several types of oils such as soybean, rapeseed, and vegetable or animal fats. Through a process called transesterification, organically derived oils are combined with alcohol (ethanol or methanol) and chemically altered to form fatty esters such as ethyl or methyl ester. The biomass-derived ethyl or methyl esters can be blended with conventional diesel fuel or used as a neat fuel (100% biodiesel).
The cold pressed rape seed oil presents the energetically and environmentally best alternative to fossil diesel with a strongly positive energy and CO2 balance. The use of rape seed oil for transport can substitute, after a minor modification of the engine, the agricultural sector’s own fuel consumption. The oil presents no fire and health hazards, and it is unpolluting. The oil is pressed in an unexpensive plant with a low energy consumption, and the whole production can take place at the individual farm so the fodder cakes can be used on site or be sold locally.
Biodiesel can substitute fossil diesel right away. However, biodiesel presents health and fire hazards in itself, and it is polluting. The pressing and the following esterification faze comprise an industrial process with a high energy consumption which requires an expensive, decentralised or decentralized production plant.
It can be estimated that at an oil production of 580.000 tons corresponds to 604 million litres rape seed oil equaling 580 million litres of diesel (this amounts about 32 TJ).
Animal fodder. A fodder cake production of 560.000 tons equals 623 million fodder units (FU), 20% of the total consumption of protein fodder of 3131 million FU.
We can estimate that by cultivation of winter rape, the total fuel consumption of the Romanian agricultural sector could be covered on a good 18 % of the arable area along with covering 25 % of the protein fodder consumption and about 80 % of agriculture’s total gross energy consumption.
The secondary system product is the rape cake that can be used successfully in the animal breeding sector. The fodder value and energy content in rape cakes from cold pressing of rape seed oil are presented in the table 1 and table 2.
|Fodder value in fodder units (FU) of rape cakes, cold pressing of rape seed oil|
|FU/kg solids||% solids||FU/kg rape cake|
|Energy content in rape cakes, cold pressing of rape seed oil||Energy
MJ/kg rape cake
|Kind||% of solids||Energy, MJ/kg|
|Total at 89% solids||19.32|
Bee keeping. Very interesting is the melliferous use of rape crop as bee keeping is an important component of the Romanian agriculture (for centuries) and honey an important export product.
The proposed integrate system for biodiesel producing and use has a high-energy efficiency and represents a feasible solution for a further national energy strategy development (see table 3).
Energy efficiency of the integrate system for biodiesel producing & use in agriculture (at a minim yield of 3,2 t/ha)
|System stage||Crude oil||Esterificated oil|
|agricultural production||3,2 t/ha||3,2 t/ha||3,2 t/ha||3,2 t/ha|
|energy production||76000 MJ/ha||76000 MJ/ha||76000 MJ/ha||76000 MJ/ha|
|energy consumption||17460 MJ/ha||17460 MJ/ha||17460 MJ/ha||17460 MJ/ha|
|energy benefit||330 %||330 %||330 %||330 %|
|OIL EXTRACTION||Cold pressing||Pressing & extraction|
|– energy consumption||900 MJ/ha||900 MJ/ha|
|Rape oil||Rape cakes||Rape oil||Rape schrot|
|production||1,02 t/ha||2,1 t/ha||1,22 t/ha||1,9 t/ha|
|energy production||37700 MJ/ha||38400 MJ/ha||45100 MJ/ha||31000 MJ/ha|
|total energy consumption||9100 MJ/ha||9260 MJ/ha||13550 MJ/ha||9310 MJ/ha|
|energy benefit||310 %||310 %||230 %||230 %|
|energy consumption||–||–||7630 MJ/ha||7630 MJ/ha|
|production||–||–||1,21 t/ha||0,112 t/ha|
|energy production||–||–||44890 t/ha||1900 MJ/ha|
|total energy consumption||–||–||20310 t/ha||870 MJ/ha|
|energy benefit||–||–||155 %||155 %|
The study carried on pointed out some conclusions from which the most important are considered to be:
- Humanity has at its disposition enough fossil energy carriers for several centuries, if it accept increasing prices
- At the actual technological & economical stage the humanity is not able to change to renewable energies quickly enough to solve global warming
- Renewable energies will come in operation step by step when they become competitive or they have support from the governments
- According to the natural conditions for agriculture from Romania, the winter rapeseed oil (WRO) and its methyl ester (RME) represents the best choice of the alternative fuels.
- There is a great unused potential for rape cultivation in Romanian agriculture.
- All the integrate system fazes are suitable for farm implementing.
- A lot of the Romanian farmers are determinate to implement the proposed integrate system for biodiesel producing & use.
- Bryce, J. T. et al. The Kyoto Protocol: Greenhouse Gas Emissions and the Agricultural Sector. CSALE Working Paper Series, vol. 1, no.1, Saskatchewan: Centre for Studies in Agriculture, Law and the Environment, 1999.
- Burnete, N., Naghiu, Al., Teberean, I., Filip, N., TodoruÅ£, A., Barabas, I., Borza, E., Coldea Cr., Vlad, N., Bacu, Fl., Costea, A., Mixes of the diesel fuel with vegetal oil – alternative fuel for the diesel engines, în: Proceedings of the CONAT 2004 Congress, Conat20042114
- W.Körbitz, Biodiesel: A Summary of Environmental Benefits, Austrian Biofuels Institute ABI, Vienna, 1998
- Naghiu, Al, Naghiu, Livia., Baza energeticÄƒ pentru agriculturÄƒ, horticulturÄƒ ÅŸi silviculturÄƒ, Editura Risoprint, Cluj-Napoca, 2003
- Naghiu, Al., Burnete, N., Studies upon the biofuels production and use, în: Buletinul USAMV-CN, A-H, 60/2004 (-) ISSN 1454-2382, pg. 453
- C.L.Peterson, Biodiesel fuel production/properties, Proceedings of the 3rd Liquid Fuel Conference of ASAE, Nashville, USA ( 1996)
- G.Vellguth, Energetische Nutzung von Rapsöl und Rapsölmethylester, Dokumentation Nachwachsende Rohstoffe (1991),
- * * * , ‘Biofuels’, European Commission, DG XII, Eur.15647 EN (1994)