Manufacturing of fuel, post-apocalypse

Question

I'm currently writing a post- zombie-apocalypse story, where Average Joe and his group have outlived the zombies, and wants to be a large settlement. They quickly agree to be industrial and manufacturer a product to use, and trade with other camps/settlements, around the Midwest. Joe, being the smart guy he is, has thought about turning soybeans into bio-diesel, to be used in generators, cars, trucks, ships and maybe even trains and jet-planes.

They have planned to make 100,000 gallons of bio-diesel per year, but does he (and his group) have the capability to do so? and if not, what then? Here thinking about other alternatives or a smaller amount of bio-diesel.

Some information on the different things:

Joe's group are a large mix-mash of different people, approximately 100 people, including approximately 25 farmers.

Joe and his group can build a facility, that doesn't required advance manufacturing/wielding skills.

They have access to a public library, stocked with books.

They are located in Ohio, U.S., to be more precise, the city of Defiance.

It has been 1-2 years since the zombie outbreak. I haven't decided precisely when, but it is around that time.

Answer 1

According to this page from the University of Nebraska - Lincoln, average soybean production is 44 bushels per acre, and each bushel can make 1.5 gallons of bio-diesel fuel. So let's math.

To get 100,000 gallons of fuel, you'd need to produce 66,667 bushels of soybeans. To produce that many bushels, you'd need 1,515.15 acres of land. For comparison's sake, that's a bit bigger than half of Central Park. You have 25 farmers, so each of them would need to be working 60.6 acres. Now, I'm no farmer, so I don't know for sure whether that's feasible or not without mechanization. Now, of course after the first year, once fuel production is running, you can use the fuel to mechanize, so it seems like it should be workable.

The issue, then, is that you're using all of your farmers to grow fuel instead of food, but that can be worked around through trading - fuel is probably more valuable than food in the post-apocalypse, so you're probably okay there.

Ultimately, I'd say your best bet would be to start with lower production so that you can have guaranteed food the first year, then use the fuel to increase soybean production for trade in later years.

Answer 2

Have you looked into how many acres you need? How much work is that? You didn't say how many people you had, but start from that: how many people do you need farming. Add to that all the infrastructure you need for a community that size, and work it out from there.

You added the number of people. John Robinson posted an Answer giving basics of needed yeild and land.

So, can that many people farm that much land, and support the village to basic needs and the level of technology chosen?

I think a better question woukd be given the number of people and available resources and skills, how much biofuel can be produced (weather permitting)? Then, close the gap by planning the needed imcrease in technology etc.

Answer 3

Making biofuel from plants is not only land and labour intensive (as several other answers have noted) but is resource intensive as well. You will essentially need a pretty robust and capable chemical plant to process the raw soy oil and convert it to a usable bio fuel.

From Wikipedia:

Biodiesel refers to a vegetable oil - or animal fat-based diesel fuel consisting of long-chain alkyl (methyl, ethyl, or propyl) esters. Biodiesel is typically made by chemically reacting lipids (e.g., vegetable oil, soybean oil,[1] animal fat (tallow[2][3])) with an alcohol producing fatty acid esters.

So you are not just growing soy beans and pressing the oil out of them, you also need to be growing corn, potatoes, grain or some other materials that can be turned into alcohol for part of the process, and be prepared to deal with some interesting waste products as well (Glycerol is one of the major waste products of biofuel production). There are a large number of potential ways of making biodiesel, each with particular strengths and weakness, but probably for the number of people and equipment you have at hand, some sort of "batch" process will be the most feasible. This is a typical recipe for soy based biodiesel:

Biodiesel is made through a simple refining process called transesterification. The process involves mixing methanol with sodium hydroxide, then mixing that with an oil such as soybean oil. The final products are methyl esters (biodiesel) and glycerine. Glycerine is a valuable material used in the manufacture of soaps and other products.

So you also have to deal with toxic chemicals as well.

The energetic inputs to make biofuels are generally high enough to make this an uneconomical fuel source, and the amount of soy oil alone needed to make enough biodiesel to replace current fuel would require farming twice the land area of the United States (not taking alcohol production into account).

You might be better off accepting a far lower energy yield by just burning straight soy oil.

Answer 4

In terms of creating fuel with the least amount of equipment and technical expertise possible, I'd think moonshine. While it's not GOOD for an engine, you can actually run a car on moonshine. Ferment and distill the soybeans, and then you have a product that people will want to drink to forget the sorrows of the apocalypse AND fuel their cars with.