Systematic analysis of algal bio-fuel production integrated with domestic wastewater treatment in

Armenia

By: Mambreh GharakhaniSupervisors: Dr. Artak Hambarian

Dr. Edwin SafariReferee: Dr. Aram HajianSpecial Thanks to: Dr.Knel TouryanSpecial Thanks to: Prof. Evrik Afrikian

Assessment of the economic and technical feasibility and efficiency of wastewater treatment using algae and influencing parameters based on past experience

ObjectivesEvaluation of the effect of the proposed scheme on reducing

carbon emission (Green house Gas),and sustainable development

Contents of presentation

a. Problemb. What is Algaec. Algae cultivation technologiesd. Algae harvesting e. Oil extractionf. Biodiesel productiong. Future workh. Conclusion

Green house gasses(CO2, NO2, CH4) Biomass, Biofuel fertilizer, etc..

The plan (?)

Algae

Waste water

Armenia like other former Soviet Union member states, has suffered from lack of technical and financial support to properly operate wastewater treatment plants.

Problems Related to Armenia

The existing networks collect waste water from 60-80% of urban areas, while rural areas do not basically have sewage systems, so that waste water is entirely discharged into the river basin.

We are DyingEutrophication (algal bloom)

What is Algae?

Algae : Sea weedsAlgae : Pond Scum

Bad Attitude

Algae : Frog Spittle

Algae: simple plants, they do not have complex system (Xylem and phloem) to circulate water and nutrients

multicellular forms: seaweed (Macro algae) and unicellular species which Microalgae: unicellular ,exist individually, or in chains or groups

Autotrophic: Using sunlight

Heterotrophic: does not require sunlight and Use organic Carbon (CH2O)n instead

carbon dioxide + water + sunlight→ carbohydrate + oxygen

Algae are the source of planet’s oxygen and absorb most of CO2 – “Dirty Water”. Species flourish in brackish, Saline and wastewater. • Wastewater nutrients support highly productive algal cultures

scientists are trying to speed up the same process by mass producing the algal cells and consequently develop methods to use them in transportation fuel production, (Biofuel-Biodiesel)

According to scientists fossil fuels have been biologically produced from prehistoric Algae during past million years.

It has been estimated that about 200,000-800,000 species exist of which about 35,000 species are known.

Composition of microalgae (dry basis): protein (12–35%); lipid (7.2–23%); carbohydrate (4.6–23%).

Microalgae

•Biodiesel and bioethanol are two potential renewable fuels that have attracted the most attention.

Wide-scale production of crops for biodiesel feedstock can cause an increase in worldwide food and commodity prices

Biomass: is low cost plant matter for production of commodities (feeds, fuels, foods, fibers, chemicals)

Algae yield: 30 tones/acre. year Other crops: 15 tones/ acre. year

comparison of oil yield for various oilseed crops

Source: Bennenmen,2008

Well we can! >> Micro-algae will do all these things

Micro algae

Imagine if we could

•Grow a fuel without using land

•Grow a fuel without polluting the atmosphere

•Harvest a crop every day instead of yearly

•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

• Sunlight

What algae needs for growth and productivity of biomass?A little bit of everything…

•Micronutrients (Trace elements): Fe, B, Zn, Mn, Mo, Cu, SO4, Co, Al, Br, Etc..

•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

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 CO2 into

carbohydrate (CH2O)n Given 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%

Energy from photosynthesis

1

234

5

Microalgae were first mass cultured on rooftop at MIT during the early 1950s, first mention of algae biofuels in report of that project.

Which Algae Production Technology?

The energy shocks of the 1970s led renewed study of microalgae biofuels, methane combination with wastewater treatment .

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

Which Algae Production Technology?

Technologies Based On wastewater treatment

Biodiesel production from algae grown in wastewater has the potential to address three important goals:

1.Development of new energy sources (oil production)

2.Management of agricultural wastes to protect aquatic environment

3. Reduction of the global anthropogenic green house effect

Direct CostDirect 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

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.

The current wastewater treatment in Gegharkunik Marz

Capital Cost Comparison between WWT technologies + 80000 $ each year for maintenance

Total electricity requirements measured in kWh/MGD at various flowrates

Comparative capital cost for Different WWT Technologies

Same latitude as Denver city~ 30000 liters oil/ hectare . Year (Kristina M. Weyer, Al Darzins, “Theoretical and maximum algal production”, Springerlink.com)

22000)30000

50% -60%

•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.

Flow rate: 3200 m3/dayAverage temp of coldest month: 5 ° c

min. monthly average (January) ° C - 15max. monthly average (August) ° C + 17

Momodelind sample

Population In Gavar 30000

Per capita water consumption 100Percent wastewater generatation 80%Wastewater inflow (m3/day)Li : wastewater BOD5 (mg/liter) 350K20 (day-1) 0.3T : average temperature of coldest month

5 ° C

Le: effluent BOD5 -Standard - (mg/liter) 60

30000 × 100 × 80% × 10-3 = 2400

Table. 1: Input parameters for wastewater in Gavar

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

1. Traditional wastewater ponds

II. Secondary facultative pond (algal high rate pond)

IV. Maturation pond

I. Primary Facultative pond

III. Algae settling ponds

anaerobic bacteria

intermediate zone1-3

aerobic bacteria and algae

I. Primary Facultative pond

Biological Oxygen Demand

NH4- ammonia is the source of nitrogen

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.

II. Secondary facultative pond (algal high rate pond)

Settling ponds

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.

IV. Maturation pond

I. Advanced Facultative pond

III. Algae settling ponds

2. Advanced Integrated Wastewater Ponds System

II. Secondary facultative pond (algal high rate pond)

Effluent

Algal Settling Ponds

Raw Wastewater

0.1- 0.3 m deep

High Rate Pond

Paddlewheel (3–6 rpm)

Advanced Facultative Pond

4.0 - 6.0 m deep

Fermentation

pit

1.0-2.0 m deep

Maturation Pond

1.0 m deep

Advanced Integrated Ponds system

Example: High Rate Ponds in Florida

Algae growth in HRP

200 m2 Raceway Vero Beach

3. Photo bioreactor integrated with wastewater

To produce 2 million gallons of biodiesel per year Unit NoteNumber of 1200L Biofence System(60% Oil Content) units 3,441

Size of Facility Needed (50% Oil Content) m2 63,931

- Assumed 10'W X 20'L- Assumed 1 layer layout

Stacked up (2 layers) m2 2,970 Stacked up (3 layers) m2 1,980

Area Calculated for Photo bioreactor for 2 million gallons of biodiesel

Flocculation

Auto flocculationPrimary harvesting

Algae Harvesting

Concentration of diluted algae suspension until a thick Algae paste is obtained

Centrifugation

Oil extraction

Extracting oil from algae paste (algal bio mass) with 90-95% efficiency

Solvent extraction: Using Hexane + Mechanical Pressing

Oil extraction from photobioreactor

TransesterificationTransesterification 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 methoxide2. Mix sodium methoxide into algae oil3. Allow to settle for about 8 hours4. Drain glycerin and filter biodiesel to 5 microns

Algal oil to Biodiesel

Option 1 Option 2 Option 3

WW Inflow rate (m3/day) Up to 3000 Up to 3000 Up to 1000

Land requirement (ha) 70 17 Up to 1 hectare

ANNUAL ENERGY REQUIREMENT (MJ/YEAR)

7200 14400 3600

Total WW treatment efficiency (%) 80-85% 85-90% 85%

Algae production (ton/year) 100000 200000 300000

Algal oil production (ton/year) 100 100-500 >10000

Biofuel production (ton/year) 90 450 100000

Equivalent fossil fuel (ton/year) 126 630 900

Emission Reduction (ER) (ton CO2 equivalent/year)

500 1200 1500

WW treatment plant investment cost($)

440000 215000 400000

WW treatment plant operating costs ($/year)

60000 85000 200000

Technical summary of options table .1

Future Work

o If enough investment is affordable in the field, Photo bioreactors can be used for biodiesel production, also for local wastewater treatment.

o Onsite systems which are flexible and can be moved can be usedoDecentralized systems provide very effective and sustainable wastewater treatment near the source

ConclusionAlgae is the part of solution and had lots of advantages• Wastewater treatment is cost competitive nowA. Biofuel production cost covered by treatment feesB. 1,100 ton/year CO2 abattement per 100,000 populationC. Industrial and agricultural wastewater also can be treatedD. 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. AntonyanDr. Al. Darzin, NREL

Dr. Treq Lundquist, CalPol University

Kate Riley ,Yield EnergyRyan Davis, NREL

Mark van Schagen, Evodos

Special thanks to familyAnd friends

Also Siranush Vopyan

Qu…es…tion???

Thanks for your attention!