Did you know? Part 5.

A friend of mine asked me this question: "“how many days of US energy consumption could we replace if we liposuctioned all body-fat over 10% for men and 18% from women in the US?" I'm sure you've all been asking yourself the same question so here's my attempt at an answer. This article says that “By 2002, average weight for men was almost 191 pounds; for women, average weight was 163 pounds”. And this page says that “The average adult body fat is closer to 15%-18% for men and 22%-25% for women”. So let’s assume 16.5% for men and 23.5% for women. That would mean the average man is 31.5 pounds of fat and 159.5 pounds of muscle; 38.3 pounds of fat and 124.7 pounds of muscle for women. So, if men got down to 10% body fat, they’d keep their 159.5 pounds of muscle but only have 17.7 pounds of fat (a reduction of 13.8 pounds of fat). For women, to get to 18% body fat, they’d keep their 124.7 pounds of muscle and have only 27.4 pounds of fat (a 10.9 pound reduction). According to Wikipedia, there are 105.74 million adult men and 112.81 million adult women in the US. So, if each one of those men had 13.8 pounds of fat liposuctioned out and each woman had 10.9 pounds removed, that would be a total of 2,688.84 million pounds of liposuction fat. Per the numbers in my earlier post, the density of liposuction fat is 7.66 pounds per gallon. So 2,688.84 pounds of fat would be 351.02 million gallons. One gallon of fat yields 0.867 gallons of biodiesel. So 351.02 million gallons of fat would become 304.22 million gallons of biodiesel. Biodiesel has about 10% less energy content than regular diesel so 304.22 million gallons of biodiesel would offset the use of 273.8 million gallons of diesel. And, according to EIA, the US uses 64 billion gallons of diesel per year. So 273.8 million gallons would be 0.428% of that or about 1.56 days or about 37.5 hours. Now, note that diesel usage accounts for only 20.4% of overall petroleum usage in the US. And petroleum only accounts for 39.8% of overall energy consumption in the US (source). So, the real answer to your this question is 0.127 days or about 3 hours. Not much of a renewable energy source. The more interesting question from my perspective is "if people in the US consumed less food such that they were at their ideal weight and body fat percentage, how much energy would be saved in terms of farming, packaging, transportation, preparation, etc and how much biofuel could be generated from the equivalent amount of farm land without triggering all these food vs fuel debates?" Don't have time to try to figure that one out but perhaps someone else can take up the challenge. =)

Did you know? Part 4.

In this mini-series of fun facts, we’ve looked at the fuel efficiencies of chickens, liposuction fat, and coffee beans. But what about cow farts and cow manure? I’m sure that topic’s been on everyone’s mind so let me address it. As everyone may or may not know, cows produce a lot of methane gas and many believe they’re a major contributor to global warming (especially since methane is a much stronger greenhouse gas than carbon dioxide). In fact, cow flatulence produces about 90 kilograms of methane per cow per year (source). Methane has an energy density of about 52.75 MJ per kg (source) so that’s 4,748 MJ of methane per cow per year or 13 MJ of methane per cow per day. One way to convert methane into diesel fuel is a process called Gas-to-Liquid (GTL). That process requires 10.5 GJ of natural gas (mostly methane) to produce 42 gallons (1 barrel) of fuel (source) – so 250 MJ of natural gas for 1 gallon of diesel. If a cow produces 13 MJ of methane per day and 250 MJ are required for 1 gallon of diesel, you can get 0.052 gallons of diesel per cow per day. Assuming a diesel engine has a fuel efficiency of 30 miles per gallon, you’d be able to drive 1.56 miles per day of cow farts. Stats on bovine flatulence frequency are hard to come by but this source would indicate that cows pass gas every 40-90 seconds. Assuming they do that 24 hours a day (btw, humans fart in their sleep so let’s assume cows do too), that would be about 1,329 farts/belches per day so you can drive only 0.0012 miles per cow fart. [As an aside, while the typical person farts about 14 times a day (source), human farts are much lower in methane content and therefore not nearly as useful for producing diesel fuel via GTL]

At this point, you’re probably asking yourself one of two questions: (a) “what about the methane in cow manure?” or (b) “why am I still reading this crap?” (no pun intended). I’ll assume you’re asking yourself the former question and do my best to answer. This press release says that a herd of 150,000 cattle generate a total 2,500 tons of manure a day. One (short ton) is 907.18474 kilograms so 2,500 tons would be 2,267,962 kilograms of manure for the entire herd – or 15.12 kilograms of manure per cow per day. From this page, we find out that cow dung gas is 55-65% methane. The source doesn’t specify but I’ll assume this is by weight and that all the dung can be converted to cow dung gas. So 15.12 kilograms of manure per cow per day would be about 9.1 kilograms of methane per cow per day. Following the same math as above, that would translate into 1.91 gallons of diesel per cow per day. At 30 miles per gallon, that’s a whopping 57.42 miles per day of cow manure. According to this site, cows poop 11 to 12 times each day. So we can get a very respectable 4.8 miles per cow dump.

With that, I think it’s likely time for a new hobby since I’ve probably taken this one as far as I can. =)

Did you know? Part 3.

I’m sure this post will provoke a couple of “don’t you have better things to do with your time” but, hey, we all need our hobbies and mine appears to be random biodiesel calculations at the moment. =) New fun fact regarding the fuel efficiency of coffee.

There was an announcement last week about a researcher in Brazil working on turning low quality coffee beans into biodiesel. In the press release, it says that “every 100 kilograms of coffee will produce roughly 9 kilograms of oil” and “a liter of biodiesel requires about 15% of a liter of ethanol”. So, what does that mean in terms of fuel efficiency of coffee bean biodiesel? Well, if you consult the always-handy Biodiesel Handbook and the always-handy Google, you find that the fatty acid profiles of coffee bean oil and cottonseed oil are pretty similar (source for coffee bean oil). Using Google again, we find that the density of cottonseed oil is 0.92 g/cm3 or 0.92 g/ml (source). So coffee bean oil has a density of about 7.67 lbs/gallon or 3.49 kg/gal. If 100 kilograms of coffee yields 9 kilograms of oil, that means 100 kilograms of coffee yields 2.58 gallons of coffee oil. And, if ethanol is 15% of the biodiesel by volume, you end up with 3.03 gallons of biodiesel from 100 kilograms of coffee. Now, from before, we know an average diesel engine gets about 30 miles to the gallon but biodiesel has about 10% worse fuel efficiency. So, 3.03 gallons of biodiesel takes you 81.9 miles (3.03 x 27). So, 100 kilograms of coffee gets you 81.9 miles and a diesel engine has a fuel efficiency of 0.82 miles per kilogram of coffee beans or 0.37 miles per pound of coffee beans (about 8x less than liposuction fat).

Now, if we take this one step further, 1 pound of coffee beans yields 10.8 pots of brewed coffee (source). So, another way to think about this is that a diesel engine has a fuel efficiency of 0.034 miles per pot of coffee.

Enjoy … and feel free to make fun of my hobby. =)

Did you know? Part 2.

Last night, I got to use this factoid at a dinner. Upon hearing that diesel vehicles have a fuel efficiency of 1 mile per chicken, people immediately wanted to know what the fuel efficiency is in terms of human fat. Last December, I read that a company in Norway struck a deal with a hospital in Miami to supply it with 3,000 gallons a week of liposuction fat for conversion into biodiesel. In the article, it says that 3,000 gallons of liposuction fat is enough to make 2,600 gallons of biodiesel. The average diesel engine gets about 30 miles to the gallon of #2 diesel. But biodiesel (in pure form) gets 10% lower fuel efficiency relative to traditional diesel fuel (source). So, an average diesel engine will get say 27 miles to the gallon of pure biodiesel. 3,000 gallons of liposuction fat = 2,600 gallons of biodiesel = 70,200 miles driven. So, 23.4 miles per gallon of liposuction fat.

But that's per gallon, not per pound. Body fat has a density of 0.918 grams per cubic centimeter (source). There are 453.59 grams in a pound and there are 3,785.41 cubic centimeters in a gallon. Thus, a gallon of liposuction fat would weigh 7.66 pounds. And 23.4 miles per gallon would translate into 3.05 miles per pound.

As an additional sanity-check here, diesel fuel typically has an energy density of 40.9 MJ/L (source). There are 3.785 liters in a gallon so 40.9 MJ/L equals 154.8 MJ/gal. If a diesel engine gets 30 miles to the gallon, it takes 154.8 MJ to go 30 miles. A pound of human fat contains 3,500 kcal (source). A kcal contains 4.184 kJ of energy so 3,500 kcal would equal 14,644 kJ or 14.644 MJ. If 154.8 MJ goes 30 miles, 14.644 MJ would only get you 9.46% of that distance - or 2.84 miles.

In terms of the difference between 2.84 miles per pound of liposuction fat vs 3.05 miles per pound, one thing to keep in mind is that some of the energy content of biodiesel comes from the alcohol component of its production (typically methanol). So the 2.84 figure is probably more accurate than 3.05.

Regardless, that’s too much detail for casual conversation. The short answer is that the fuel efficiency of a diesel engine is about 1 mile per chicken or 3 miles per pound of liposuction fat. Use that factoid at your next cocktail party and let me know how it goes. =)

If you really want to impress your guests, you could also mention that according to the American Society of Plastic Surgeons (ASPS), 325,000 of liposuction operations were carried out last year to remove fat from various parts of the body - particularly the thighs, abdomen and buttocks – and that the average woman sheds an average of 20 pounds of abdominal fat by liposuction (source). So, 325,000 operations x 20 pounds per operation = 6.5 million pounds of liposuction fat. At 3 miles per pound, 6.5 million pounds of liposuction fat would get you 19.5 million miles. And, at 30 miles per gallon, that would offset 650,000 gallons of diesel fuel. Unfortunately, the US consumes about 64 billion gallons of diesel a year - 100,000x the amount you could get from liposuction fat. But every little bit helps and Americans get fatter by the year so perhaps this will make more of a dent over time. =)

Did you know?

Today, ConocoPhillips and Tyson Foods announced a partnership to make "renewable diesel" fuel from animals fats. In a WSJ article about the partnership, it says:

Tyson produces about 300 million gallons of beef, pork and chicken fat each year … Producing one 42-gallon barrel of renewable diesel requires about one barrel of animal fat. And each barrel requires, on average, two steers, or 16 hogs or 1,300 chickens, Tyson officials say.

So, it takes 1,300 chickens to get one barrel of diesel fuel (via their proprietary process). One barrel is 42 gallons. So that’s 31 chickens to generate one gallon. At around 30 mpg fuel efficiency, that’s one chicken per mile.

So, your “did you know” fact of the day is: you can drive one mile on the fat of a chicken. Therefore, diesel vehicles have a fuel efficiency of 1 mpc (1 mile per chicken). Go ahead and use that at your next cocktail party as an icebreaker. =)

Biofuel crash course

For any of you interested in learning more about biofuels, Grist just posted a special two-week series on biofuels. Looks like a good cross-section of relevant topics.

Newco

Some of you may be wondering why I haven't posted a new entry in so long. Others may not have noticed. Regardless, there is a good reason why I haven't posted recently. Specifically, over the last two weeks, I met and decided to join a small (9-person) startup. They're in stealth mode so no website or other information at the moment. Current investors include Khosla Ventures and Flagship Ventures. On the Flagship site, they describe Newco as "designing microbial factories to produce energy related products". So very different than what I've been doing in the past but certainly well-aligned with my desire to help fight global warming (since biofuels are carbon-neutral since the feedstock for the biofuel is plant-based and takes an equivalent amount of CO2 out of the air as cars put into it).

I'll be the "business entrepreneur" (officially "Senior Director of Business Development") - basically the first full-time business person. Everyone else in the company is a scientist-type. Should be interesting. Certainly an opportunity for me to shine ... or fall flat on my face. Hopefully it will be the former. =)

I'm actually writing this from the Advancing Renewable Energy conference in St. Louis. Even though I won't officially begin my new position for about a month, I'm here "drinking from the firehose" to learn about this new space. President Bush will actually be speaking at the conference tomorrow but, unfortunately, I'll miss his speech since I need to catch a flight and couldn't get onto a later plane (darn!). It's not everyday that you get a chance to see the President of the United States in person.

I have to admit that I'm very curious to see how I do in this new role. If nothing else, there is going to be a massive learning curve associated with both the technology involved (biochemistry and synthetic biology) and the market for the technology (biofuels). I basically have zero domain knowledge/experience with either and will be relying upon (a) being smart, (b) learning quickly, (c) being a strong overall "business athlete" with diverse functional experience, and (d) leveraging the experience of others wherever possible. We'll see if that's enough to be successful .

I'm both excited and scared about what's to come. But I take a lot of comfort from knowing that I have so many people in my corner. Let the new adventure begin.