Grantville Gazette IV, page 31
Two methods are available to extend the petroleum derived diesel in up-time tanks. The first method is mixing. Any diesel engine, modern or archaic, will function quite well on a mix of 75% petroleum refined diesel and 25% light vegetable oil. Of course, this presumes the availability of cheap vegetable oil, which may be problematic in seventeenth-century Germany. The second alternative, if a competent mechanic is available, is to add propane injection to the diesel engine. Propane injection, also known as fumigation, will give an increase in diesel combustion efficiency. The propane acts as a combustion catalyst during the power stroke of the cylinder. If you are not a good mechanic let an expert do the conversion, otherwise you may get the propane amount too high and cause severe engine damage. When a turbo-charged diesel engine is properly fumigated with propane it will get a boost in torque and fuel economy resulting from the more complete combustion of the liquid fuel. Typical tractor engines are not turbo-charged and will only receive a small boost in efficiency from propane fumigation; many diesel farm trucks and pick-up trucks on the other hand are turbo-charged and would greatly benefit. No information is available on propane fumigation for engines that burn unrefined plant or animal oils; however with diesel or bio-diesel the engine boost amounts to a 10% increase in fuel economy. Combined with a 25% light vegetable oil mix in the fuel, this will total up as a 38% increase in fuel economy per unit of petroleum derived diesel used. The propane tanks used for this fumigation are generally the same ones found on backyard barbecue grills. With proper treatment some propane can be recovered from raw natural gas and used to refill these tanks if the knowledge and ability to install them on the diesels is available.
One of the most surprising things to come to light in researching this article was how easy it is to produce propane and butane from raw natural gas. Both propane and butane may be adapted to power gasoline engines where they provide 80% of the range of an equal volume of gasoline. This is an increase in range of 240 to 1 over low-pressure natural gas. To refine butane and propane out of raw natural gas you can follow any of several methods. The easiest one to explain is condensation.
Butane vaporizes at just below the freezing point of water, and propane vaporizes at about 45 degrees F below that. Using a metal coil run through a freezer you can condense butane out of the raw natural gas at about 10 degrees below freezing. The liquefied butane is separated out through a drip tube and stored in a regular propane cylinder like those used on portable backyard barbecues. When removed from the freezer, the butane will naturally warm to ambient temperature but will remain a liquid in the tank due to vapor pressure. If sufficient (probably cascaded) freezing is available, the partially refined natural gas can then be fed through a second condensing coil in a much colder freezer at about –30 C where the propane condenses. The propane may also be stored as a liquid under pressure in another tank. Natural gas in the eastern USA averages about 10% butane-propane-ethane and 90% methane. Using the freezing condenser method above refines about 2% butane and 4% propane by volume from the raw natural gas.
The second method to conserve up-time diesel works best with older diesel engines, but with a relatively simple heating set it will work for modern diesel engines as well. The newer machines in the diesel group can run on straight vegetable oil (SVO), or the animal equivalent, with a simple tank and fuel system heater added. These modifications involve installing a simple resistance heating element in the fuel tank, very similar to the ones used in engine blocks for winter weather. This can even be an electric heating pad fastened onto the bottom of the fuel tank. When the engine is not running, the heating element can be connected to an electrical outlet, to maintain a hot liquid oil temperature in the fuel tank and fuel system. While the engine is running, the waste heat from the liquid cooling system takes over. A copper tube is wrapped around the exterior of the fuel tank and attached to the tractor cooling system between the engine block and the radiator. This copper tube forces the hot engine coolant to circle the fuel tank several times before going to the radiator and maintains the oil as a hot liquid.
Hot and thin waste cooking oil or fresh vegetable oil burns just fine in older diesel engines; those that predate late twentieth-century pollution controls can be expected to have zero problems. Lighter oils such as corn or soybean oil work best. If the oil is kept sufficiently hot and thin; tallow, butter or lard can also be used as fuel. If bio-diesel or stockpiles of fossil fuel derived diesel are available, it is recommended that a small diesel tank be added to the newer equipment. This will allow the more refined fuel to be utilized when starting the engine and bringing it up to full power. Once at full power, one can switch to the biologically derived unmodified fuel oil. About five minutes prior to shutting down the engine, it should be switched back to the refined fuel. While these modifications are not mandatory, they do ensure that the equipment will have very little problem with clogged fuel injectors. The refined fuel serves as a fuel system cleaner during startup and shutdown, purging the lines and filter. Using refined fuel in this supplemental tank requires less than one percent of the total fuel supply for the newer vehicle and keeps the fuel pump and filter full of refined fuel when the equipment is shut off. This in turn helps prevent any pitting or premature wear that in some rare cases may be caused by free fatty acids that are present in all unrefined biologically derived fuel oils. Of course, again, this technique is dependent on the availability of animal or vegetable fats.
The third supply of fuel for the up-time diesel engines that came through the Ring of Fire will be crudely refined from down-time petroleum, most likely the Wentz oil fields. These oil fields are well known. Drilling for petroleum in this location has begun in 1633. Modern style multiple fractional distilling however, is several years in the future and only the much cruder pot distilling method will be available for several years. Pot distilled diesel fuel is very crude compared to that which came through the Ring of Fire with Grantville. The older diesel equipment, both the farm tractors and older farm trucks, can burn this crude diesel with minimal problems. The more modern heavy equipment, cars, and turbo-charged trucks on the other hand will suffer if they must use it. Crudely refined diesel tends to be high sulfur and it also has a broader range of chemicals in its mix. The turbo-charged engines of the late twentieth century are specifically designed to produce low exhaust emissions burning highly refined fuel with very low sulfur content and do not run well on crude diesel. To a small extent removing pollution controls on these engines will help, however the fuel filter and pump systems will be very hard to duplicate or modify until Grantville has built up an extensive manufacturing capability. Added to these difficulties is the expense of hauling either the crude petroleum or crudely refined diesel from the Wentz area to Grantville. This adds even more cost and complexity to the task of keeping the modern diesel engines of Grantville operational. The available hauling methods amount to wagons loaded with heavy oil barrels hauled over dirt pathways, with the option of using a barge for portions of the trip. All of the loading, hauling, unloading and reloading involved, when combined with wages and supplies for the teamsters and fodder for the livestock, make this process slow, complicated and expensive.
The medium-term solution to the general diesel fuel supply problem and the medium- to long-term solution for the modern diesel equipment is to create an alternative to the crude pot distilled diesel that will be coming from the Wentz petroleum fields down-time in 1634 and later. Bio-diesel can fill the gap during the period between 1634 when the crude refinery will be available and the projected fractional distillery five to ten years in the future.
What is bio-diesel? Regular cooking oil, no matter if it is vegetable oil or pork drippings, consists of triglyceride molecules. A triglyceride molecule consists of three fatty acid molecules that are bound to one glycerol molecule. The longer the fatty acid molecules, the more viscous the oil is. To make bio-diesel the triglyceride molecules have to be broken down to separate out the glycerol, which is a useful byproduct of the whole process but not a good thing to burn in a modern computer-controlled diesel engine. The easiest method of separating the glycerol from the triglyceride molecule is to break it down with a catalyst and substitute another alcohol molecule for the glycerol molecule. Most recent tractors and modern diesel farm trucks can have problems burning raw cooking oil; these engines work much better when operating on bio-diesel fuel.
Feedstocks to be used to manufacture bio-diesel will not be cheap to acquire. There is very little waste oil and fat to make fuel from. Most fats are eaten. Transportation costs in the 1630's were extremely high, effectively doubling the cost of any raw materials transported a long distance due to taxes, tolls and labor expenses.
One possible plant oil source in 1631–1633 will be the traditional seed crops grown by the local farmers as livestock feed. This leads to resource competition for any food crop such as oats or rice and it is believed that they will be only minor sources for biological oils. In 1631 linseed oil averaged 40 guilders per aum in Amsterdam, with one aum roughly equal to 30 gallons. With a monetary exchange rate of 50 to 1, a gallon of linseed oil in Amsterdam would cost $60.00, or about $120.00 per gallon by the time it is transported to Grantville.
The most economic animal derived oils in 1631–1633 will be cod liver oil, which sold for 60 guilders per tun, with one tun roughly equal to 252 gallons, or just over 4 gallons per guilder. This gives a price of about $11.91 in Amsterdam or $25.00 per gallon delivered in Grantville. As a final example tallow, made from the fat of cattle and sheep, sold for 16 guilders per 100 pounds. One gallon weighs six pounds so each gallon costs just over 1 guilder in Amsterdam and would be about twice that in Grantville, $100.00 per gallon.
While many people like the idea of corn oil because corn is available in Grantville, at the 2004 minicon the West Virginia extension agent explained that the Mannington area was a grass-based agriculture and that corn was not grown in Marion county. Corn crops will have to be built up from small amounts of seed, which will take years. Additionally, other oil crops have a much higher yield. Corn has an average yield of 18 gallons of oil per acre while pumpkin seeds yield 57 gallons per acre. Sunflowers seeds yield 102 gallons and pecans 191!
While the corn and sunflowers used in this example are modern hybrids with very good yield per acre, that would likely decline over the course of years. Pumpkins on the other hand are bred for size and weight, not seed content, and should remain fairly constant.
Another biological oil source is cow's milk. This can be made into butter at a ratio of about 21 pounds of milk to 1 pound of butter. Cow's milk weighs about 8 pounds per gallon and this means that for every 3.5 gallons of fresh milk you get 1 pound of butter. Six pounds of butter yields about a gallon of bio-diesel. A good down-time milking cow will yield about 1 gallon a day of milk when in season. Therefore, every cow in the pasture has the potential to produce about 8 ounces of bio-diesel per day while in season. Because down-time milk is a seasonal product the local people are not conditioned to getting butter with every meal as the up-timers do. To entice them to sell the butter instead of eating it will be expensive, but not impossible. A package deal could be made to purchase the cooking oil, the pork drippings, and the lard given off by cooked beef or mutton along with the butter. To make it attractive for the down-time farmers up-timers would need to offer a moderate income, otherwise they will eat the butter and grease. The added benefit to down-time farmers of having up-time farmers help with planting and harvest will also encourage them to provide oil and some butter.
Animal fats tend to have longer fatty acid molecules and hence are thicker than most plant oils. Some common examples of this are tallow, lard, pork drippings and butter. On the contrary side, some plant oils like coconut oil are very thick in their own right, but few of these are present in Europe in the seventeenth century. Much more common will be linseed oil, which is made by pressing the seeds from the flax plant that is grown throughout northern Europe to provide flax for linen cloth. Any viable sunflower or safflower seeds that made it through the Ring of Fire will need to be conserved and planted; they yield considerable oil and the pressed seeds make good livestock feed after the oil has been extracted. Corn, soybeans and cottonseeds are also good sources of vegetable oil but do not yield as much per acre as sunflower seeds.
Making bio-diesel from any of these biological oil supplies will require a moderate knowledge of chemistry. The high school chemistry teacher, his lab assistants and Frank Stone all would be able to follow the simple recipes given in this article and produce a product that would burn correctly in modern diesel engines.
Most people who "home brew" bio-diesel use methyl alcohol, also known as methanol, because it is cheap and is the easiest alcohol to use. Methanol is made industrially by combining natural gas, heat and steam through a series of catalytic chambers. The end result is a very pure form of methanol which can be burned in modified Otto-cycle engines, used as an industrial solvent, or used as the starting point in manufacturing products like bio-diesel fuel. Methanol is being produced down-time, and is a major component of the fuel for the down-time air force.
Larger bio-diesel processing plants usually use ethanol, also known as moonshine, because it is easy to produce on an industrial scale. Ethanol is much less toxic than methanol if it is accidentally spilled or the vapors are inhaled. Methanol is a nerve poison. It can cause blindness followed by death if it is swallowed, absorbed through the skin, or the vapor is inhaled. Ethanol used in the bio-diesel process must be 199 proof or higher. You cannot just distill it; you have to dry it completely afterwards. Fortunately, you can dry ethanol to 199 proof by straining it through a tank filled with diatomaceous earth. The diatomaceous earth can be reused indefinitely. After a batch of moonshine is fully dried out the earth is gently heated and the water is driven off as low energy steam. When the heated diatomaceous earth stops steaming the heat is removed immediately and it is allowed to cool before more distilled ethanol is poured through it for drying. Methanol is not as sensitive to water contamination and if all you have is 190 proof moonshine you might be able to force the process to work by substituting 40% methanol in the process, but there are no guarantees.
Diatomaceous earth is also known as kieselguhr and has been mined in Thuringia since at least the 1860's. It consists of the fossil remains of millions of nearly microscopic water plants that form beds of tiny seashells. It is almost pure silicon dioxide; the same stuff sand is made from, but with hollow centers. This makes diatomaceous earth very absorbent, and an excellent filter. It was be the preferred material used by Alfred Nobel in the late nineteenth century in the manufacture of dynamite up-time.
Two different catalysts can be used for the bio-diesel conversion process and both are commonly called lye. Cleaning lye (NaOH), also known as sodium hydroxide, is very slowly and carefully added to the methanol to form a compound called methoxide. Alternatively potash (KOH), also known as potassium hydroxide, can be used and is available by dripping boiling hot water through wood ashes and through a filter, then evaporating off the water to leave crystalline potassium hydroxide.
Bio-diesel is made by substituting the glycerol in biologically derived oil with light alcohol molecules such as methanol or ethanol. Because it is a substitution process you get the same volume of materials out as you put in. Biological oil and alcohol go in, bio-diesel, glycerol and a little soap come out.
Small Batch Process
Beware! The methoxide reaction is exothermic. It releases large quantities of heat and if done too quickly will release deadly methanol vapor or explode in your mixing chamber. For unused oil the average ratio of lye to methanol is 3.5 g sodium hydroxide lye or 4.9 g potassium hydroxide to 200 ml of methanol per liter of oil. Potassium hydroxide is less reactive than sodium hydroxide so you need 1.4025 times as much. 1.4 works fine for the small batches you would be making at home. When the methoxide solution is slowly added to the heated oil and stirred, the lye acts as a catalyst. It strips the fatty acids from the triglyceride molecules in sequence by reacting with the fatty acids directly. The process creates first one free fatty acid and a duoglyceride molecule, then a second free fatty acid and a monoglyceride molecule, and then ultimately a third free fatty acid and a free glycerol molecule. As each of the free fatty acids separates, it is in a reactive state and quickly binds with one of the methanol molecules in the mix, forming a methyl ester molecule.
If too much lye is added to the mix it will attack the methyl ester molecules once all of the glycerides have been broken down into glycerol and free fatty acids. In a normal reaction with fresh oil most of the lye will mix with the glycerol, which is denser than the methyl ester solution and naturally separates into layers after the stirring is stopped. The methoxide and oil mixture is stirred for an hour while being kept at a moderate temperature of 130 degrees Fahrenheit, which is the temperature of hot water straight out of your average hot water heater. Much hotter than this and the methanol will boil out of the mix. This results in poisoning and also means it will not be available to react with the free fatty acids in the mix to form methyl ester. Any of the above mentioned biologically derived fats are appropriate for this use.
If you are using oil that has been kept at high temperatures for an extended period of time, such as waste fryer oil, it will have a lower pH level. In this case you would need to increase the lye portion in the methoxide solution to compensate for the increased acidity of the used oil. To do this most accurately you would need a pH meter or simple litmus paper, which should be available before the end of 1632. As a general rule you will need a 20% increase in lye for used cooking oil and the end product will contain more soap than you would get with fresh oil. For recycled used cooking oil you need to not only increase the lye concentration 20%, it is also helpful to dry out the used cooking oils as much as possible. This is done by heating the used oil to about 190 degrees Fahrenheit and maintaining that temperature for 15 minutes to drive off all suspended water in the oil. Make sure you allow the oil to cool to 130 degrees Fahrenheit before adding the methoxide or the methanol will vaporize back out and poison you. Having too much methanol in the mix results in more methanol in the crude glycerin, but does not cause any problems as a result. Having too much lye does cause problems. When in doubt err on the low side for the lye component and increase the agitation or stirring time from 60 minutes to 90 minutes.
