2007. Here comes the biofuel

Welcome to the special section “BAM 35 Years.” We are presenting “cult” articles from the Motor Boats archive, starting in 1990. A journey through time among stories unobtainable today, even in the great sea of the internet! A dive into the world of epic moments in motor boating. We begin with one of the stories we were most passionate about.

Diesel that reduces pollutant emissions

From Boats to Motor 2007, No. 3, April, pp. 114-116.

Oil is the biggest contributor to excessive CO2 emissions, the planet-warming killer. Diesel engines can use up to 30 percent vegetable oil as fuel and have no problems. You draw your own conclusions.

Oil first gushed from the bowels of the earth in the United States in 1830. German Rudolf Diesel in 1893 filed a patent for a “compression ignition” engine, shortly after Carl Benz and Gottlieb Daimler fired up the first gasoline engine in 1885. At that time what we call “diesel fuel” did not exist. The German engineer’s patent is commonly referred to as the “oil engine.” The visionary manifesto of his invention he himself describes: “the Diesel engine can be powered by vegetable oil and will serve to contribute to the development of agriculture of the nations that will use it.” Rudolf Diesel showed up at the 1900 Paris World’s Fair and ran his engine using 100 percent peanut oil as fuel. More than 100 years have passed, and the predictions of the inventor of the engine named after him may be coming true. Today the so-called “environmentally friendly diesel” uses, a percentage of about 5 percent biofuels of vegetable origin, such as canola or sunflower oil. These same clean components do not originate CO2 emissions: (Carbon Dioxide) a major contributor to the greenhouse effect. Instead, the remaining 95 percent originates from oil, during its combustion in the heat engine. Few people know, and no one talks about it, that the modern marine diesel engine, just as its inventor had stated, can take up to 30 percent vegetable oil during its combustion, without causing major problems in operation. All this today, with the engines currently on the market, with an obvious benefit to our health and that of our ailing planet. Let us also remind you that the diesel engines (practically all of them) installed today on boats leaving shipyards are subject to regulations regarding the emission of harmful gases. These emissions depend for the most part on the type of fuel used. Propulsion manufacturers evidently stick to the legal fuel placed on the market in meeting emission limits. But the addition of vegetable oil to diesel fuel has an added advantage: it proportionally decreases the amount of sulfur in the mixture and allows it to comply more easily with European Euro IV and, before long, Euro V standards. Let us return, for a moment to the reality of the market, to the famous “environmentally friendly” diesel fuel that companies advertise so much today. First of all, it costs more than the “dirty” one; in return, it is promoted by extolling the virtues of fuel economy, higher engine performance and preservation of mechanical organs. Last, but only last, it reduces harmful gas emissions, rightly so since only 5 percent of the blend contains vegetable additives.

Vegetable oil as a 30% fuel

The increase of carbon dioxide (CO2) in the atmosphere is one of the main causes of the environmental risks our planet is facing. CO2 comes from the burning of fossil energy extracted from the ground, oil, adding to the natural carbon cycle. Burning petroleum on a massive scale since the beginning of industrialization releases carbon into the atmosphere that had been hidden underground for millions of years; thus, the Earth’s balance has been altered in a short time. The advantage of plant fuel, which can be used by diesel engines, lies in the instantaneous use of Biomass (this is how all plants are defined), which, by contrast, absorbs carbon (naturally occurring in the atmosphere through photosynthesis. This plant cycle works in a “closed loop,” preserving the balance. Decreasing the consumption of fossil-derived energy (oil) slows the release of CO2, the main cause of global warming. Biomass is available in abundance, so there is no risk of extinction. In Europe, vegetable oil production, as we know, is particularly high, and the oil groups are good buyers of it because, as we have said, they use it to incorporate 5 percent of it into diesel fuel, as the current fuel law prescribes as the maximum percentage. But there are thousands of agricultural vehicles in Europe (mainly in France and Germany) that legally use “green” blends with a proportion of 30 percent oil (mainly rapeseed). All this without any modification to the diesel engine, nor any contraindications, except perhaps a slight decrease in power caused by the lower energy power of vegetable oil. No drawbacks related to engine life, nor drawbacks related to emission of harmful gases. All of this, then, can also be applied to marine diesel engines, especially those that are not equipped with turbines and electronic injection.

Fuel: the drawbacks of vegetable oil

We have talked so far about mixing a percentage of vegetable oil with diesel fuel. Today, in spite of the fact that engineer Diesel ran his engine with 100 percent peanut oil, using only vegetable oil as a propellant can have some drawbacks. Vegetable oil has a higher viscosity than diesel oil, which varies with temperature. At low temperatures it becomes very thick, so to think of using it one would need to have a preheating system. When starting the engine cold ,with a cold fuel such as vegetable oil, some of it may remain unburned, settling along the cylinder walls, in the head of the combustion chamber in the case of indirect injection. When the engine is hot, a resin deposit may be created that can stick to the piston rings, resulting in loss of compression and excessive consumption. Vegetable oil, then, is likely to mix with the lubricating oil in the crankcase. It also tends to polymerize when the temperature rises, encrusting the lubrication circuit over time. It also happens with diesel fuel and gasoline, but the oil evaporates at a much higher temperature. As far as maintenance and warranties are concerned, most engine manufacturers expressly stipulate the use of European standard EN 590 fuels, i.e., those we find from port distributors. On the other hand, vegetable oil costs less than diesel fuel, about 0.75/0.80 euros per liter, and does not emit any odor (to the delight of those who get seasick).

If you want to use biofuel

Pulling the threads of our argument in favor of an environmentally friendly fuel in marine engines as well, some conclusions can be drawn: already today it is possible to use an environmentally friendly fuel by blending, in a maximum percentage of 30 percent vegetable oil, with the normal diesel fuel offered by port distributors. If you have space and suitable material, you can make your own diesel/vegetable oil mixture. The modifications to be made for the necessary equipment are relatively expensive. One must equip oneself with mixers, filters, pumps, additional tank, etc. Here are some modifications and accuracies that one must use:

– It is necessary that at start-up the fuel used should be diesel oil only, to eliminate any problems arising from the use of oil, which has a high degree of viscosity when cold. Only when the engine is hot can vegetable oil be combined with diesel fuel. It is therefore necessary to install a separate oil tank.

– An oil heating kit should be provided, to bring the oil to the right temperature, especially during the winter months. Clearly, the best solution would be to produce and distribute, as early as now, a truly environmentally friendly diesel fuel that uses a high percentage of vegetable oil. But oil producers, as long as the cost of oil remains advantageous, have no interest in using vegetable oil as a propellant, which is more expensive. It would take national or supranational state intervention, but no country is willing to give up the revenue from the taxes they collect from fuel prices. The only thing certain is that by 2010 the percentage of vegetable oil in diesel fuel must reach 10 percent, by European law. Too little to save us from the CO2 disaster.