Production Process Four stages to production Algal growth Harvesting through bioflocculation Oil...
-
Upload
amina-lamison -
Category
Documents
-
view
219 -
download
4
Transcript of Production Process Four stages to production Algal growth Harvesting through bioflocculation Oil...
Production ProcessFour stages to production•Algal growth•Harvesting through bioflocculation•Oil separation•Biodiesel production
Encapsulation of Algae for the Production of Biofuels
Algae based fuel production systems can operate on unused resources. While the cost is restrictive, policy changes or fuel market changes may positivity shift the economic viability. Current algae growth systems are often dominated by undesired local species. Encapsulation by a permeable membrane could allow for sustained growth without contamination. Our project focuses on the design and feasibility of capsules. We are examining capsule permeability, algae growth, and the
cost of fuel production.
Algae Basics
Needs cheap or negative value resources•Carbon dioxide•Brine water•Arid land
Algae components and their products•Carbohydrates (Ethanol production)•Lipids (Biodiesel Production)•Proteins (Waste)
Encapsulation•Porous membrane allows passage of nutrients, but not cells•Capsules must be sealed and sterile•Experimental capsules must allow sampling•Used dialysis membrane (expensive)•Could use Cellophane (low-cost)
Permeability Tests
Displayed right, concentration changes over time due to ion transfer through the porous membrane. Permeability can be calculated from this data.
Measuring ion concentration outside capsule with a conductivity probe. The solution in the capsule is a known, high concentration. A first order with respect to concentration gradient relationship was used.
Cost AnalysisAlgae is inexpensive to produce, but also has a very low value. If the oil produced from algae is sold at the same price as Canola oil, another biodiesel feedstock, then the algae is worth just sixteen thousandths of a cent per gallon per day.
Race Way Design
• A continuously rotating canal for agitation•CO2 aeration as carbon source•Temperature readings•Light Intensity measurements•Experimentation in raceway was not conducted due to the lack of an effective method to supply nutrients to the entire system continuously
Tests were conducted for Bristol Media (a salt solution of essential nutrients) and sodium bicarbonate (an approximation disassociated carbon dioxide). The rate constant for carbonate was 0.01064 cm2L/min. The rate constant for Bristol Media was 0.00454 cm2L/hour. The carbonate rate constant should be used in conjunction with molarities, while the Bristol media rate constant should be used in conjunction with conductivities.
Unused LandUnused Water
Waste CO2
Saltwater Aquifer
Coal Fired Power PlantLand Algae
Growth
Harvesting-Bioflocculation
BiodieselProduction
Oil Extraction
Project Results•Demonstrated a proof of concept, encapsulated algae was maintained as a monoculture with growth sustained by nutrient transfer through the membrane•Assessed dialysis membrane permeability to carbonate and essential salt nutrients•Conducted an economic analysis that suggests the infeasibility of cost-effective encapsulation
Project Sponsors: Dr. Yokochi, Dr. Murthy, Dr. Harding, Chevron
ObjectiveTo determine the feasibility of algae
encapsulation through economic analysis and experimental determination of
growth capability
Algae filled capsule, sample tube shown on the
right
$ 1100 /m3
Over three years$ 55 /m3
Over three years
The figure compares revenue to cost on a m3 basis over a three year period. They are sized proportionally to show their substantial discrepancy. Major reductions in agitation and encapsulation costs are necessary to make the process economically feasible.
Revenue Cost
Data logger and conductivity probe
Colin Sexton, Blake Gardiner, Mike ReedSchool of Chemical, Biological and Environmental Engineering
Light and temperature sensors
Pump for circulation, flow is in blue
The Algae Story
Algae Growth•Encapsulated and non encapsulated algae was grown side by side with aerated carbon dioxide•Measurable growth was not achieved during the experiments time frame in either environment•After aeration was stopped the encapsulated algae grew to a healthy cell density while remaining uncontaminated
Non-encapsulated algae
Encapsulated algae