Topics

1

Policy and solutions / Biodiesel farm production

« on: July 29, 2017, 06:18:20 AM »

There are several biodiesel production technologies currently in use that can power heavy equipment on farms. Vegetable oil can be produced by cold press or solvent extraction techniques. Solvent extraction produces a higher oil to bulk seed ratio but requires extra steps to process flake and dry the bulk seed and requires extra steps to retrieve the solvent with stills . Methanol retrieval from the glycerine byproduct is another step requiring the use of a still, retrieval of methanol from glycerine is common in most biodiesel production operations.
Farmers can send their oil seed crops to oil extraction facilities or process with oil seed presses on farm.
Farming oil seed crops is dependent upon large tractors and combines and trucks to transport seed either into silos or to processing facilities. The oil produced can be distributed to restaurants for deep fryers and be reused later in biodiesel production.
 Oil production from various oil seed crops like soybeans, canola, safflower and sunflowers all require similar equipment but the size of the farm operation generally determines weather the farmer is required to send his crop away for processing or process on farm with all the extra processing machinery necessary for on farm oil production.
 I have described two oil production models that are determined by the amount of production and the size of the farm.
 Although these same techniques can be scaled down to very small farms but the combines required for harvest are never small or cheap and oil presses and dryers necessary are all expensive.
 I have been experimenting in biodiesel production from rendered pork fat because at very small scales you can avoid the costs of combines, large tractors, driers and oil presses. Buying the required methanol and sodium hydroxide is not difficult and there is the potential to produce both of those chemicals from scratch if necessary. I consider the scale of the various options as steps that can be repeated in various sizes of farm operations.  Under very extreme collapse scenarios biodiesel production still offers a potential way to power farm equipment.
 Just rough numbers but vegetable oil production is about 80 gallons per acre but I would defer to Sidd on more accurate numbers.
 One lardhog can produce about fifty pounds of extra fat along with about 180 lbs. of meat .
Here is a recipe for biodiesel from lard. I currently don't use solvents but oil quality would be better if I did. The biodiesel is still effective at running my old tractor but only during hot weather.

http://www.scienceasia.org/2012.38.n1/scias38_95.pdf

2

Policy and solutions / Improving EROEI numbers

« on: March 18, 2014, 02:02:51 AM »

I posed the question earlier whether producing food calories with solar cells and the power it yields should increase the EROEI numbers for solar. The question depends obviously on whether you actually do yield a net calorie gain.
 
My question was specific to gardening with a battery powered tiller powered with solar cells, but it could be expanded to pumping water, producing fertilizer or hauling the produce to market. You could expand it further to cooking or heating water with passive systems and probably much more I haven't considered, but this needs to be taken on in incremental fashion or things will quickly become unmanageable.

I have already started trying to get numbers to quantify K/cal of invested energy with K/cal of produced crops for the battery powered tiller. Since I believe even the calories used by the worker doing the gardening needs to be calculated to get to a real answer for my question, but I would like to start simple.

Anyone who has ever gardened, knows that with a shovel, a hoe and some effort you can overdose on zucchini squash. Producing food calories with very little fossil fuel inputs is not fantasy. So I would propose starting with a limited parameter (garden space) and doing as much work by hand as possible with a solar cell powered battery operated tiller as an assist. Count all inputs very carefully. The labor invested should also be tracked.

Because human time and energy is important, I also think timesaving technics that are not energy sinks should also be included. Paper mulch, scavenged cardboard paths, grafting for vigor, and trellises are all things I have included in my initial efforts and the energy costs of those need inclusion. JimD brought up fences and those would probably be a show stopper, so even fencing needs extra thought, but working to feed bunnies or deer will quickly cut into food calories produced so they do need consideration. For example, a woven willow fence might do the trick. My point is ALL inputs need tracking.

Water is a very real energy input unless you happen to live where rain is always right on time and adequate. Water will likely be reasonably equal to a conventional gardening effort, however, so initially I intend to focus on the solar tiller. To really get good EROEI results will require tricks and those take time to develop, but if I can prove up with tillers first, I think scale issues will be the next hurdle. Equipment will need to last a number of seasons, so amortizing equipment K/cal numbers will be necessary. The longer the equipment lasts, the better the resulting EROEI numbers that can be achieved.

To get a good handle on all this, I would need to run some sort of control, but honestly I don't have the energy for that. I suppose I will need to compete with traditional agriculture and their advantage of vast scale, but that is someone else's homework project. Mine is to show that a solar powered tiller can yield a positive EROEI and at the same time yield more tonnage of crops and calories produced than you can get with a shovel and hoe. Yes tonnage.

How does that sound for starters?         

3

Arctic sea ice / Ice Tethered Profilers

« on: April 10, 2013, 11:38:21 PM »

The WHOI Ice Tethered Profilers are a resource that has taken awhile for me to figure out how to use. I put the various ITP's in bins depending on where they were and where they are heading. ( fast Fram ) #49,50,51,57 and 60 ( Fram) #47,48 and 56. (Beaufort Gyre) #52,53,55,64,65 and 66 ( wedge) 63.  The composite temp./ salinity water column profiles can then be compared.Once in bins the profilers reflect the influence of either Atlantic halocline or Pacific halocline waters in the water column beneath them. Here is a summary on upwelling in the arctic by Jiayan Yang.          http://www.whoi.edu/fileserver.do?id=92424&pt=2&p=44107
Upwelling and how to read to profilers is a subject that interests me but there seems to be a lot of noise. Upwelling from very deep waters appears  to happen as it did during the great arctic cyclone but there also seems to be noise. So for me the upwelling data is confusing.   

           

4

Science / Carbon Cycle

« on: March 01, 2013, 04:59:16 PM »

Here is a model which gives future temps., pH, and productivity for the earths large water masses. In discussions you can download the full article.
 

Multiple stressors of ocean ecosystems in the 21st century: projections with CMIP5 models
Posted: 28 Feb 2013 12:44 AM PST
Ocean ecosystems are increasingly stressed by human-induced changes of their physical, chemical and biological environment. Among these changes, warming, acidification, deoxygenation and changes in primary productivity by marine phytoplankton can be considered as four of the major stressors of open ocean ecosystems. Due to rising atmospheric CO2 in the coming decades, these changes will be amplified. Here, we use the most recent simulations performed in the framework of the Coupled Model Intercomparison Project 5 to assess how these stressors may evolve over the course of the 21st century. The 10 Earth System Models used here project similar trends in ocean warming, acidification, deoxygenation and reduced primary productivity for each of the IPCC’s representative concentration parthways (RCP) over the 21st century. For the “business-as-usual” scenario RCP8.5, the model-mean changes in 2090s (compared to 1990s) for sea surface temperature, sea surface pH, global O2 content and integrated primary productivity amount to +2.73 °C, −0.33 pH unit, −3.45% and −8.6%, respectively. For the high mitigation scenario RCP2.6, corresponding changes are +0.71 °C, −0.07 pH unit, −1.81% and −2.0% respectively, illustrating the effectiveness of extreme mitigation strategies. Although these stressors operate globally, they display distinct regional patterns. Large decreases in O2 and in pH are simulated in global ocean intermediate and mode waters, whereas large reductions in primary production are simulated in the tropics and in the North Atlantic. Although temperature and pH projections are robust across models, the same does not hold for projections of sub-surface O2 concentrations in the tropics and global and regional changes in net primary productivity.


Bopp L., Resplandy L., Orr J. C., Doney S. C., Dunne J. P., Gehlen M., Halloran P., Heinze C., Ilyina T., Séférian R., Tjiputra J. & Vichi M., 2013. Multiple stressors of ocean ecosystems in the 21st century: projections with CMIP5 models. Biogeosciences Discussions 10: 3627-3676. Article.


 Also includes O2.  Many of these trends are stressors to biological communities and they also have synergistic effects , one stressor compounding another.