Systematic analysis of algalbio-fuel production integrated with domestic wastewater treatment in Armenia By: Mambreh Gharakhani Supervisors: Dr. Artak Hambarian Dr. Edwin Safari Referee: Dr. Aram Hajian Special Thanks to: Dr.Knel Touryan Special Thanks to: Prof. Evrik Afrikian
Algae: simple plants, they do not have complex system (Xylem and phloem) to circulate water and nutrients Autotrophic: Using sunlight Heterotrophic: does not require sunlight and Use organic Carbon (CH2O)n instead carbon dioxide + water + sunlight-> carbohydrate + oxygen multicellular forms: seaweed (Macro algae) and unicellular species which Microalgae: unicellular ,exist individually, or in chains or groups
– “Dirty Water”. Species flourish in brackish, Saline and wastewater. • Wastewater nutrients support highly productive algal cultures
Generate up to 300 times more biomass per acre
Grow Crops in both fresh and sea water, also in wastewater (sewage)
Bonus: microalgae can be used in the wastewater treatment as the micro organisms influencing the cleaning process Well we can! >> Micro-algae will do all these things
What algae needs for growth and productivity of biomass? A little bit of everything… • Sunlight •Temperature •Water (Fresh, brackish, wastewater, etc.) •Supply of carbon dioxide (use exhaust of power plants) •Macronutrients: C, N, P, Mg, Ca, K, Na, Cl, NO3, NH4 •Micronutrients (Trace elements): Fe, B, Zn, Mn, Mo, Cu, SO4, Co, Al, Br, Etc..
Energy from photosynthesis The energy - in the form of biomass - that can be obtained via photosynthesis thus depends on the level of PAR and the efficiency of the conversion process Q. Ebiomass= PAR x Q Micro algae eight photons to capture one molecule of CO2into carbohydrate (CH2O)nGiven that one mole of CH2O has a heating value of 468kJ and that the mean energy of a mole of PAR photons is 217.4kJ, then the maximum theoretical conversion efficiency of PAR energy into carbohydrates is: 468kJ/(8 x 217.4kJ) = 27% In Practical Case: decreases to 10%
Which Algae Production Technology? Microalgae were first mass cultured on rooftop at MIT during the early 1950s, first mention of algae biofuels in report of that project. The energy shocks of the 1970s led renewed study of microalgae biofuels, methane combination with wastewater treatment . Many Oil companies are doing research program to make biodiesel for transportation needs 1980 - 1995
Open raceway paddle wheel mixed ponds now used by 98% commercial microalgae production
High Rate Algal Ponds are the most economical technology but are presently not cost effective for biofuel production alone.(Dr.JasonPark,2009)
Which Algae Production Technology? Closed photobioreactors are economic for high value applications (nutraceuticals) but are presently not cost effective for biofuel production
Technologies Based On wastewater treatment Biodiesel production from algae grown in wastewater has the potential to address three important goals: Development of new energy sources (oil production) Management of agricultural wastes to protect aquatic environment Reduction of the global anthropogenic green house effect
Direct Cost Direct production costs(combined annual maintenance and operating costs) contribute highest: 68% Nutrient expenses: 33.7% Labor and overheads: 24% Water: 16% Electricity: 7%
Ideal Goal: Biofuels from Algae: using Non-Fresh Water Sources
Preliminary treatment (removing large objects like rocks or bottles, etc), primary treatment (removing solid material), and secondary treatment (removing biological material)
Implementation of proposed technology in real life in one of the major treatment centers
site location is selected to model a possible facility for wastewater treatment trough algal technology
The site is in city of Gavar near to second largest wastewater treatment plant
It dumps the incomplete treated wastewater with a flow rate of 2400 cubic meter per day.
The average temperature in the coldest month is take 5
By this example I try to model the economics: cost, efficiency, investment, and environmental impact of the proposed method.
22000) 30000 Momodelind sample 50% -60% min. monthly average (January) ° C - 15 max. monthly average (August) ° C + 17 Flow rate: 3200 m3/day Average temp of coldest month: 5 ° c
The wastewater treatment plants is located on the territory of Gegharkunic Marz
The local economy is improving in a very slow rate
BOD5 and suspended solids values were very low: not metered water consumption, leaking water pipes causing large infiltration amounts in the sewers and connections existing between sewerage and storm water network.
Same latitude as Denver city~ 30000 liters oil/ hectare . Year
(Kristina M. Weyer, Al Darzins, “Theoretical and maximum algal production”, Springerlink.com)
Table. 1: Input parameters for wastewater in Gavar 30000 × 100 × 80% × 10-3 = 2400
The Alternative options for the solution (Cultivation of algae) 1. The traditional wastewater ponds system 2. Advance integrated wastewater treatment 3. Photobioreactor integrated with wastewater treatment Algal biomass harvesting Oil extraction
Parameters of the wastewater The characteristics of sewage indicate the quality of the wastewater
The physical characteristic is the level of suspended solids: the presence of various chemicals and microbiological pollutants.
The biological characteristic is the amount of oxygen required to oxidize the various organic chemicals.
BOD: biochemical oxygen demand (BOD), concentration of Organic compounds in wastewater (waste) that are the source of food for bacteria and are digested by them.(g/m3 or mg/liter) >>>> BOD5
Traditional wastewater ponds Primary Facultative pond Secondary facultative pond (algal high rate pond) Algae settling ponds Maturation pond
Primary Facultative pond Aerobic: algae 1-3 Detention time :28 days intermediate zone anaerobic bacteria
Facultative ponds receive raw wastewater.
Facultative organisms function with or without dissolved oxygen
Treatment in a facultative pond is provided by settling of solids and reduction of organic oxygen demanding material by bacterial activity.
Facultative ponds are designed for BOD removal (100-400 mg/liter)
NH4- ammonia is the source of nitrogen PH will rise above 9 which will kill coliforms Biological Oxygen Demand
Secondary facultative pond (algal high rate pond) Wastewater treatment High Rate Algal Ponds are presently the only option for cost-effective biofuel production due to co-benefits of wastewater treatment, nutrient recovery and GHG abatement + The various byproducts.
Settlingponds To increase the concentration of algae in up to 3 g/l Decrease the operational and power consumption costs 50 to 80 percent of algae can be removed. If higher degrees of algae are required secondary harvesting method is required.
Algal Settling Ponds Advanced Facultative Pond Maturation Pond High Rate Pond Paddlewheel (3–6 rpm) Fermentation pit Raw Wastewater Effluent 4.0 - 6.0 m deep 0.1- 0.3 m deep 1.0 m deep 1.0-2.0 m deep Advanced Integrated Ponds system
Algal oil to Biodiesel Transesterification Transesterification is the process that the algae oil must go through to become biodiesel. It is a simple chemical reaction requiring only four steps and two chemicals: 1. Mix methanol and sodium hydroxide creates sodium methoxide 2. Mix sodium methoxide into algae oil 3. Allow to settle for about 8 hours 4. Drain glycerin and filter biodiesel to 5 microns
If enough investment is affordable in the field, Photo bioreactors can be used for biodiesel production, also for local wastewater treatment.
Onsite systems which are flexible and can be moved can be used
Decentralized systems provide very effective and sustainable wastewater treatment near the source
Conclusion Algae is the part of solution and had lots of advantages
Wastewater treatment is cost competitive now
Biofuel production cost covered by treatment fees 1,100 ton/year CO2 abattement per 100,000 population Industrial and agricultural wastewater also can be treated Harvesting costs decrease due to biofloculations • Lipids produced – 25% lipid content, current maximum – 1500 gallons per acre per year (best est.) Global warming is a fact that needs to be stopped
The future of transportation is in biofuels specially algae
Special thanks…. Dr. Antonyan Dr. Al. Darzin, NREL Dr. Treq Lundquist, CalPol University Kate Riley ,Yield Energy Ryan Davis, NREL Mark van Schagen, Evodos Special thanks to family And friends Also Siranush Vopyan