Biodiesel is way better than fossil diesel: a 1998 life-cycle analysis

After 15 years of burning B100 in our 2003 VW Jetta TDI, it’s nice to have happened upon the helpful insights within this 1998 study by the National Renewable Energy Laboratory:

Reductions in Petroleum and Fossil Energy Consumption

As one component of a strategy for reducing petroleum oil dependence and minimizing fossil fuel consumption, the use of biodiesel offers tremendous potential. Substituting 100% biodiesel (B100) for petroleum diesel in buses reduces the life cycle consumption of petroleum by 95%. This benefit is proportionate with the blend level of biodiesel used. When a 20% blend of biodiesel and petroleum diesel (B20) is used as a substitute for petroleum diesel in urban buses, the life cycle consumption of petroleum drops 19%.

In our study, we found that the production processes for biodiesel and petroleum diesel are almost identical in their efficiency of converting a raw energy source (in this case, petroleum and soybean oil) into a fuel product. The difference between these two fuels is in the ability of biodiesel to utilize a renewable energy source.

Biodiesel yields 3.2 units of fuel product energy for every unit of fossil energy consumed in its life cycle. The production of B20 yields 0.98 units of fuel product energy for every unit of fossil energy consumed. By contrast, petroleum diesel’s life cycle yields only 0.83 units of fuel product energy per unit of fossil energy consumed. Such measures confirm the “renewable” nature of biodiesel.

Reductions in CO2 Emissions

Given the low demand for fossil energy associated with biodiesel, it is not surprising that biodiesel’s life cycle emissions of CO2 are substantially lower than those of petroleum diesel. Biodiesel reduces net emissions of CO2 by 78.45% compared to petroleum diesel. For B20, CO2 emissions from urban buses drop 15.66%.

In addition, biodiesel provides modest reductions in total methane emissions, compared to petroleum diesel. Methane is another, even more potent, greenhouse gas. Thus, use of biodiesel to displace petroleum diesel in urban buses is an extremely effective strategy for reducing CO2 emissions.

It’s refreshing to see a clear flux diagram showing how soybean carbon cycles!

Other interesting bits:

  • A barrel of typical (1995) crude provides about 100 kg of liquid fuel. Upon combustion each kg of fuel generates 3.15 kg of CO2. (ref)
  • Union of Concerned Scientists: “Oil is Changing” site

Throw off the bowlines

Twenty years from now, you will be more disappointed by the things you didn’t do than those you did. So throw off the bowlines. Sail away from safe harbor. Catch the wind in your sails. Explore. Dream. Discover.

Mark Twain
Barnacle Betty exults in being alone with the wild coastline, up close and at her own pace.
Fastest traditional outrigger canoes on the planet.
Elegant simplicity.

The symmetry of life

Raising kids as you and your parents grow old & older illustrates vividly the surprising number of similar experiences humans have when they are very young and very old. Today Shel Silverstein reminded me of that with this poem: “The little boy and the old man.”

Said the little boy, “Sometimes I drop my spoon.”

Said the little old man, “I do that too.”

The little boy whispered, “I wet my pants.”

“I do that too,” laughed the little old man.

Said the little boy, “I often cry.”

The old man nodded, “So do I.”

“But worst of all,” said the boy, “it seems

Grown-ups don’t pay attention to me.”

And he felt the warmth of a wrinkled old hand.

“I know what you mean,” said the little old man.

Starving sea pandas at the Festschrift of Russ McDuff

My PhD advisor Russ, celebrated his career by inviting all his students to give ignite talks in Oregon for the Festschrift of Russ McDuff. This is my 5-minute presentation in his honor with 20 slides advancing every 15 seconds as required:

We might be able to get this to display better using some sort of modal that can “pop-up” the WP post content, or part of it, with appropriate dimensions (1080 pixel height)… This WP Post Modal plugin might help.

Ric Bradley’s 1947 high Sierra backcountry ski trip from Tioga Pass to Tuolomne Meadows

Ric Bradley’s footage from a 2-month-long (!) back-country skiing adventure in Tuolomne Meadows (Yosemite National Park, CA, USA) via Tioga Pass just after World War II (Feb-Mar, 1947). Narration added by Ric Bradley in 2002.

Ric taught my parents and me to telemark when we reached Colorado from Chicago around 1972. Thanks to him, his wife Dorry, and long-lost friends like Randy Bobier, I continue to seek out hut-to-hut style adventures in the Pacific Northwest akin to the great outings Ric catalyzed, often threading together powder-covered 10th Mountain Division huts.

Flipping out above Scottish Lakes cabins.

2017 increased refrigerator and in-wall oven efficiency

Replacement fridge

Old fridge

Fridge set to 3 (5 oC); freezer set to A (-14 oC)

Power demand after reaching target temperatures:

33W closed

98W right and left open

73 left (freezer) closed; right (fridge) open

57 left open; right closed

R+L = 65; R=~40; L=~24 (probably mostly the wattage of the light bulbs)

Power demand with compressor at work:


330 Compressor starts

300 >30s

298 >60s

292 >180s

290-95 >10min (steady state while working to reach target temperatures)

Watt-up measurements of old fridge:

10.54 kWhr for 60:27 hr

= 174 W

Watt-up measurements of new fridge:

Fridge set to 3 oC; deli drawer set to 3 oC; freezer set to -19 oC (changed to -15 oC on 11/16/17)

5.62 kWhr for 80:15 hr

= 70 W

~ 40% of old load

New oven

DIY permanent bathroom floor made with cheap cork underlayment

There’s no home-improvement motivation like sewer water dripping through the ceiling onto your couch!  I had noticed the cracked tiles around the base of the toilet a couple years ago, but chose to ignore them.  Our “master bath” (shower+toilet) had clearly been a cheap finish to a big addition and I wanted to believe the cracked tile dated to the 1998 toilet installation, rather than suggesting an underlying problem.

Of course, I was wrong.  A quick examination of the toilet bolts showed that they were rusted through on one side and nearly corroded-through on the other.  The subsequent rocking of the toilet had allowed flushed water to leak past the wax seal and slowly saturate the particle board underlying the tiles, as well as the 19mm plywood sub-floor.  The moisture and rot further destabilized the toilet and the surrounding tile began to crack with the rocking.  Luckily, the ceiling rafters were unscathed (dry, no rot), so I only had to demo about 1 m^2 of the subfloor and 2 m^2 of the drywall ceiling in the playroom below (after cleaning the poop water out of the couch).

Looking at all the carefully labeled bathroom tiles and starting to imagine chipping all the old grout off of them, I realized that I’ve always wanted to try a cork floor!  So, out came all the rest of the tiles and particle board, and into the trash went all those labeled tiles, along with the moldy drywall and sewage-soaked wood.

With the rafters drying out and new drywall on the ceiling, the main problem became how to install a cork floor.  The Internets made it clear that not only is there some controversy about using cork below grade, and in basements, bathrooms, and kitchens, but also manufactured cork comes in many forms: cork tiles with adhesive backing; cork tiles that click together; cork tiles that you glue down, often with a water-borne contact cement (like the oft-recommended Waktol D3540, Roberts 7250, and Dritac 6200); and tongue & groove cork planks.  Most of these products cost 3-4$/ft^2 (with tiles usually being 1 square foot each), plus $10-50/gallon for glue.  One basement job estimate was about 2x that cost installed, ~8$/ft^2 for snap-in cork floor delivered and installed by Home Depot.  Another estimate in a floor-contractor forum was 10-15$/ft^2 installed.  I only needed to cover about 20 ft^2, so the DIY materials cost of a few bucks/square-foot didn’t seem too expensive, but many of the manufactured cork products (e.g. GreenClaimedTorly or Forna) come pre-coated with a sealant on the upper surface or require sealing of that surface and/or seams after installation (most commonly polyurethane, sometimes with an embedded more durable material like ceramic beads).  I’ve grown to hate polyurethane from having it fail on our oak floors (e.g. with water damage from a houseplant or wear in a high-traffic area) and then be near-impossible to spot-repair.

Instead, I wanted a bare or uncoated cork so I could seal it with an eco-friendly, low-VOC product made by Osmona.  I had loved re-finishing oak floors in our previous house with Osmo Polyx-Oil (hardwax-oil”) and was delighted to notice that it was also recommended for cork floors.

As a boat-builder familiar with water infiltration and damage, I was also worried about the seams between cork tiles or planks in the floor of a bathroom (or kitchen).  Would water from a dripping shower or cleaned human or overflowing toilet work its way through the seams?  Most folks seemed to recommend only the pre-sealed tiles in bathrooms, and then sealing the seams with 3-4 coats of a sealant.  That sounded like a lot of work and waiting, as well as the normal nightmare of having to re-finish the polyurethane every 3-7 years or replace the whole thing when only a spot repair was really necessary.

Thus, to pioneer a super-cheap yet functional solution I went looking for DIY bathroom or kitchen floors made with bare cork (ideally cork underlayment which costs only ~$0.80/ft^2 — 3-6x cheaper than tiles!), but found little guidance about how to install a permanent, waterproof cork floor.  This temporary cork floor from a renter in New York was heading in the right direction, but they just laid underlayment down without any gluing or sealing.  This general guide to installing bare cork from familyhandyman was helpful and taught me that the traditional finish for a cork floor was a paste wax.

Without much guidance available, I decided to experiment.  I bought some 6mm (1/4″) thick underlayment for $0.78/ft^2 from Amazon as well as range of adhesives and the Osmo-made sealant I hoped to use.  Using 20cm squares, I tried gluing down single layers on a piece of clean 1/2″ plywood, as well as laminating triple layers of cork underlayment. I also coated experimental squares of cork with the Osmo Polyx-Oil.

The sealant test surprised me a bit.  The epoxy was just too hard, making the cork feel stiff and reducing the likelihood that I’d ever get it off (or even get through it to the screws holding down the underlying plywood) in a worst case scenario.  The 3M spray glue and the DAP contact cement wasn’t holding down the edges well, plus I couldn’t imagine coating 2 surfaces, keeping them from sticking to themselves while getting tacky, and then successfully lining them up on the first (and only) try.   I was going to go with the official cork underlayment adhesive (easy to spread with the right tool and forgiving if the cork needed to be repositioned once in contact with the adhesive), but it was stinky and didn’t cure completely, even after a few days (especially in the 3-layer lamination test).

In the end, I went with interior/exterior Titebond II wood glue.  Though I could have used an extra bottle of it, I ended up using some plain old interior Titebond glue and it seems to have mostly held the cork down.  In places where I detected it was lifting a bit as I cleaned it and then sealed it, I was able to inject some 2P-10 superglue (cyanoacrylite) using a syringe attached to a ball inflator needle, getting the loose portions to stick down by applying pressure for a minute or two.  After replacing the molding, I caulked the top of it (as well as the base of the shower) and let it dry for ~24 hours.

I put the Osmo Polyx-Oil put down in two coats.  First coat went on thick (used about 1/2 of the 750ml can) and dried and soaked in for 36 hours.  Then I installed the toilet flange, wax seal, and toilet.  The second coat of Polyx-Oil took less (about 150ml).

I may add a third or fourth coat if the water doesn’t bead up enough, or I decide to try to fill up the voids in the cork over time…


So far (a few days into use of the bathroom), all family members seem satisfied.  There’s general agreement that the cork has a warm feeling — both to the touch with bare feet and in terms of the colors in the bathroom.  My only gripe so far is that the cork and sealant are giving off a noticable waxy/woody smell.  With luck it will go away, but I’m worried the solvents in the Polyx-Oil are interacting with the cork organics and/or the Titebond adhesive under the cork.  Luckily, the cork seems to be staying adhered to the underlying plywood fine…  I’ll provide updates as we make further observations and use the bathroom more.


  • Final DIY materials/tools cost: $65 total, including experiments; $47 for cork flooring (underlayment, adhesive, and sealant) which for 20 sq.ft. area comes to ~$2.40/ft^2
  • Spreadsheet with source and links

Test results: adhesives

  • Titebond wood glue
  • 3M spray glue
  • Dap water-borne contact cement
  • Roberts 1407 (wanted Roberts 7250 as recommended on cork underlayment label, but could only find locally in 4-gallon containers)
  • System Three epoxy

Test results: sealants

  • Osmo Polyx-Oil (interior)
  • Osmo Deck oil (exterior)
  • Fill voids in cork with Osmo UK wood filler or another wood filler?



The spirits of Jock and Holly Cobb

Driving north out of Albuquerque with my parents last month to celebrate my aunt’s and uncle’s 50th anniversary, we learned from the Internet that our dear friends Jock and Holly Cobb have passed away.  Jock was my god-father and immortalized himself in my mind early on, mostly by convincing me (as a ~6-year-old) that it would be a good idea to rent a very large rock from him at a compounding interest rate, which I’ve done for more than 40 years!  He was always an inspiration — whether reclining naked in the outflow stream of a Colorado glacier when I first met him, or demonstrating the latest prototype of his solar-powered water purifier in the New Mexican sunshine when Annie and I last saw them in the early 2000s.

Both Jock and Holly were wonderful people, full of ideas, compassion, principle, and creativity.  I’m going to take the time to get to know them a bit better this winter.  Perhaps you should do so, too.  Here’s my reading list:

Jock’s book

Jock took some amazing photographs during WWII when he was a conscientious objector working as an ambulance driver in north Africa for the American Field Service.  Thankfully, they made it back to the States and through the decades to be published recently (in 2013) as Fragments of Peace in a World at War.  You can buy the book directly from the Cobb family via the publisher, Renny Russell or Amazon.

Here’s a video of Jock discussing parts of his book and offering related relections:

He ends his Vimeo recollections (in ~2011) with this quote from John F. Kennedy

“War will exist until that distant day when the conscientious objector enjoys the same reputation and prestige that the warrior does today.”

Letter to a Navy friend, quoted in Arthur M. Schlesinger, Jr., A Thousand Days: John F. Kennedy in the White House (Boston: Houghton Mifflin Company, 1965), p. 88.

NYT article (2013) regarding the photographs

An example photograph

San Vito, Italy: This fatherless boy, like so many in the war, was searching for something he did not understand and could not find.


Tribute to Jock in the Denver Post

John Cander (Jock) Cobb II, MD, MPH

1919-2016 (age 96)

John Candler Cobb II, known to all as "Jock", was born July 8, 1919 in Boston, MA. He died June 20, 2016 in Albuquerque, NM. After earning his B.A. in Astronomy from Harvard, he volunteered as an ambulance driver with the American Field Service in World War II. This experience and his association with the Quakers around this time, led him to his lifelong devotion to the cause of peace and to his career in medicine. He returned from the war to earn his MD from Harvard, and an MPH from Johns Hopkins. While in medical school he met Radcliffe student Holly Imlay-Franchot on a skiing trip. They were married for 67 years until Holly died in 2014.

After teaching at Johns Hopkins in maternal and child health, Jock began a career in public health when he moved to Albuquerque, NM in 1956 to work for the Indian Health Service. In 1960, he moved with Holly and their four children to Lahore, Pakistan, where he directed a Family Planning Research project. In 1965, the family settled in Denver, CO, where he became professor and chairman of the Department of Preventive Medicine at the University of Colorado School of Medicine. Realizing the importance of environmental health early on, he was a member of the task force studying the Rocky Flats Plutonium Plant and Uranium Enrichment Plant, which were shut down as a result of this work. He also served on the Governor's Scientific Advisory Council, and tackled Denver's notorious "brown cloud" as a member of the Air Pollution Control Commission. His work with international public health continued with shorter assignments in Indonesia, the Philippines, Togo, and China. He is honored to have his work and papers archived in the University of Colorado Archives in Boulder, CO.

In 1985, Jock retired from the University of Colorado Medical School, and he and Holly returned to live in the house they had built in Corrales, NM. They continued to travel abroad and enjoyed summers at their mountain cabin in Alice, CO. Jock's inventive spirit and dedication to health and the earth led him to develop a solar sanitation system for water and waste. While active in the world, he also treasured quiet time in nature, played cello, wrote poetry, and took many photographs. In the last decade of his life, Jock revisited the photographs he took while serving as ambulance driver in Italy, North Africa, and Syria. He distilled his dedication to peace in the book Fragments of Peace in a World at War, which includes his photographs, poetry, and narrative.

He is survived by his children Loren, Nat, Bethany, and Julianne; grandchildren and great grandchildren; and many people whose lives he touched.

In lieu of flowers, please make a donation to the American Friends Service Committee  or  Planned Parenthood.

Tribute to Holly in the Albuquerque Journal

Helen Imlay (Holly) Cobb

1925 – 2014 (age 89)

Helen Imlay Franchot Cobb was an artist, a musician and a teacher. Holly grew up in New York State, and graduated from Radcliffe College with an AB in International Affairs. She and her husband Dr. John C (Jock) Cobb lived Baltimore MD, Corrales NM, and in Pakistan before settling in Denver, where he was a professor at CU Medical School. She taught art and kindergarten at Graland School. She leaves a beautiful portfolio of paintings and note cards of the peaks by their cabin in Alice, Colorado. She is survived by Jock, her husband of 67 years, her brother Dick Franchot, children Loren, Nat, Bethany and Julianne, and grands and greats. In lieu of flowers, donate to Planned Parenthood or AFSC.
  • Published from June 26 to June 29, 2016
  • Source link

Archives of Jock’s work

Cobb, Dr. John C. 83 linear feet, 1960-1993</div><div>Dr. John Cobb (b. 1919), M.D., Harvard University (1948), and Master of Public Health, Johns Hopkins University (1954), became a professor of community health in the Department of Preventative Medicine and Biometrics at the University of Colorado School of Medicine in 1965, where he is currently an emeritus professor. Dr. Cobb was appointed by Governor Lamm and Congressman Wirth to the Lamm-Wirth Task Force on Rocky Flats in 1974. From 1975 to 1982, he worked as principal investigator on an EPA contract to study human plutonium burdens in people who lived near the Rocky Flats Nuclear Weapons Facility. He has also served on several other councils and commissions concerning Rocky Flats and Three Mile Island. The collection contains files relating to Dr. Cobb's medical career including: plutonium study papers; material on air and water pollution, recycling, bioethics, holistic medicine, and urban health ecology; Rocky Flats and Pakistan radiation studies; and teaching materials, reports, and conference papers. Guide available in Archives.

Source: University of Colorado library archives