Introduction: Problem

Recognition of Problem

“This year, for the first time since before the Ice Age, CO2 will not fall below the 400 ppm mark.” -NOAA (2016)

Algae could be used to sequester carbon

Unless made into a product with a long useful lifespan it will decay and re-release the CO2

http://www.esrl.noaa.gov/gmd/ccgg/trends/full.html

Introduction: Goals

Biological- Design a CSTR capable of producing enough algae for a positive revenue in

full scale implementation - Improve bleaching processes through chlorophyll-related options

Structural - Create a paper product that is as strong as store bought wood pulp paper

Mechanical - design a simplified paper making process utilizing the benefits of algae-based

pulp

Introduction: Constraints

Skills - Lack of paper making knowledge

Budgetary - Algal paper production must be comparable in price to similar wood pulp based papers

Space - Can only keep a limited amount of algae for testing at a given time

Logistics - Lab scale tests and procedures are very different from industrial application

Time - Algae growth rate and seasonal weather limits algal biomass available for testing

Introduction: Considerations

Ethical - North Charleston’s Kapstone plant uses chemical pulping which must be heavily treated before being released into the Cooper River.

Safety - Bioaccumulation of toxins could occur in marine life living in or near the effluent flows of paper mills if not treated properly.

Ecological - Inappropriate handling of CSTR effluent could release excess nutrients into the ecosystem. http://www.kapstonepaper.com/location/

charleston-sc/

Introduction: Questions

User- Will traditional pens and pencils write legibly on Algal paper?

- Is the algal paper as durable as comparable traditional papers?

- Will the paper last as long as traditional papers?

Client- What is required to grow algae for paper making?- Can algal pulp be processed using similar equipment to traditional pulp- Can wood and algae pulp be mixed?

Designer- What type of paper is desired by the client (loose leaf, card stock, etc)?- What will be the required strength of the pressed paper?- What type of algae will be used?

Identifying the Algae

Scientific Name: Pithophora oedogonia

Common Name: Cotton-ball Algae/Horsehair Algae

Steps in Design

The final process design based on our preliminary lab data is broken into six major unit operations:

Culture

Drying

Blending

Screening

Pressing

Final Drying

Sourcing Algae

Two options for obtaining algae were explored

Harvest from natural environments

Raised many problems regarding cleaning the algae which translated into the final product

Growth from a culture in a CSTR

Proved much more logical as it removed cleaning difficulties and the Pithophora proved to grow well

Harvesting Algae

Algae was removed from a natural environment

Led to many difficulties in cleaning and keeping the samples alive

Snails, bacteria, and other contaminates soiled multiple harvests

Would be a practical approach if a feasible method of cleaning harvest crop could be developed without damaging the algae

Algae Culture: CSTR with Recycle

Grown in a 2 L CSTR using BG-11 Media to support growth

Flow rate: 1.76mL/s = 6.35L/hr for 4 minutes a day

Time: 11 days

Inoculation Weight: 2g

Final Weight: 3.33g

● Cell Retention Time

● Specific Growth Rate (SS Mass Balance)

● Monod

Governing Equations: CSTR with Recycle

● θ= Cell retention time (hr) ● V= Volume (L)● Qw= Harvest flow rate (L/hr)● XB= Biomass Concentration● μ= Specific growth rate (hr-1)● μm= maximum specific growth rate(hr-1)● b= decay constant (hr-1)● Ss= Soluble substrate concentration (g/L) ● Ks= Half-saturation Constant (g/L)

Bleaching Alternative: Ultraviolet Light

Day 1 Day 3 Day 4

Bleaching: Other Alternatives

Ultra Violet light seems to be the best and least intrusive option

Requires significant time investment and does not completely whiten paper

Repetitive drying and re-soaking of algae to wash out chlorophyll

Will be energy intensive

Chemical Bleaching is another option to explore as it will most likely be the most successful at completely removing all color

Effluent wastewater will have to be treated

Preliminary data: Convection DryerPreliminary Trial:

Oven dried at 68 over 4 days℃Algae was successfully dried with a

brown border

Trial 1:Oven was set to 103 ℃Algae was weighed every 30

minutes for 5.5 hours

Drying occurred at 0.85 g/min

Lab Scale Vacuum Shelf Dryer

Water at 78 C circulated through tray

Water at 25 C circulated through condenser

Vacuum pump at

Drying occurred at 0.13 g/min

Governing Equations: Drying

Fouier’s law of heat conduction

Preliminary data: Pulping dried and undried

Undried

Blends very quickly and easily

Cells do not rupture or shorten

Color stays very green

Dried

Must rehydrate for easy pulping

Cells rupture and shorten

Color fades over time

Preliminary data: Pulping Dried and Undried

Undried Dried

Preliminary data: Pulping

Proctor Silex 59735 immersion blender

Tested dried and undried samples

Fiber lengths of pulped paper averaged 6.45 mm.

http://www.paperonweb.com/pulppro.htm

Governing Equations: Pulping

Reynolds Number

Power in an unbaffled tank

Limiting Vortexing Pbaffled = P⅙ unbaffled

Power in a baffled tank P = kρN3D5

http://mimoza.marmara.edu.tr/~bilge.alpaslan/enve301/Lectures/Chp_6.pdf

Forming Handsheets

Based on TAPPI standards T 218 sp-11

Utilized rehydrated dried algae from drying tests

Proctor Silex 59735 immersion blender was used for pulping

Forming Handsheets

100 mm diameter Büchner funnel

was used to strain pulp

Pressed between granite slabs

Allowed to air dry overnight

Achieved finished test basis weight

of 127 g/m2

Paper Strength

Paper strength in industry is genuinely described by the break length and tensile index of

the paper

Calculated based on the tensile strength of the paper and the basis weight

These values are important in the paper production process as they are indicative of fiber

strength, fiber bonding, fiber length, and also the pulp materials ability to survive in the

heavy duty machines that are used.

Other properties tested in industry include bursting strength, tear index, stiffness,

compressibility, and wet strength

Tensile Strength Testing

25 mm strips of algal paper were tested for tensile strength against regular printer paper

A Mark-10 Force Gage Model M5-200 Instron was used to test the tensile strengths of the sample papers

The samples of each paper were used in the instron and the peak force before breaking was recorded

Each paper type was sampled five times

Tensile Strength Testing Lab Results

Type of Paper (25mm strips)

Caliper (mm)

Average Peak Force (N)

Tensile Strength (N/m)

Basis Weight (g/m2)

Breaking Length(km)

Tensile Index(Nm/g)

Printer 1.016 49.3 1970 72.9 2.76 27.1

Algae 3.07 22.9 916 127 0.735 7.21

Governing Equations: Tensile Testing

Tensile Strength (TS) [N/m]

F = Peak Force

w = Width of test strip

Breaking Length (BL) [km]

BW = Basis Weight (g/m2)

Tensile Index (TI) [Nm/g]

Stella Model

Volume: 1000000 L

Flow rate: 40000 L/hr

Hydraulic retention time: 25hr

Cell concentration: 30g/

Cell retention time: 47 hr.

Harvest flow: .64 g/L/h

Yield: 14 kg/day

Stella Model

SuperPro

Sustainability

Can be used to help sequester carbon

Make use of problematic algal blooms

Chemical pulping techniques are not required for algae as in traditional paper pulping

Bleaching can be accomplished through drying and UV light

http://www.clemson.edu/extension/natural_resources/water/stormwater_ponds/problem_solving/aquatic_weeds/algae_filamentous/

Budget from Super pro

Budget Cont.

Gantt Chart

Conclusion: User Answers

- Will traditional pens and pencils write legibly on Algal paper?

- Yes, if the color can be contrasted properly

- Is the algal paper as durable as comparable traditional papers?

- No, but it is functional

- Will the paper last as long as traditional papers?

- Unknown, could not test in allotted time

Conclusion: Client Answers

- What is required to grow algae for paper making?

- A simple CSTR with proper nutrients

- Can algal pulp be processed using similar equipment to traditional pulp

- Very similar equipment can be used, process is actually much simpler

- Can wood and algae pulp be mixed?

- Unknown. Should be able to but it would impact strength

Conclusions: Designer

- What type of paper is desired by the client (loose leaf, card stock, etc)?

- In this case a writing stationery was selected

- What will be the required strength of the pressed paper?

- Ideally around 50 N

- What type of algae will be used?

- Pithophora oedogonia, in this climate

Conclusions

Biological- A 1,000,000L tank was needed to produce the 14400 kg of algae/day for the

process.- Found that UV could be an effective means of whiting paper

Structural - Our test paper was not as strong as printer paper

- A more controlled process could yield better results. Mechanical

- We designed a process that should yield 1.8 million 8.5 x 11in sheets per day.

Thank You!Dr. Caye Drapcho

Dr. Terry Walker

Mr. Tom Jones

Cassidy Laird

Dr. Scott Whiteside

Clemson University

ReferencesAyhan Demirbas, M. F. (2011). Importance of algae oil as a source of biodiesel. Energy Conversion and Management, Vol. 52, 163-170. <http://www.sciencedirect.com/science/article/pii/S0196890410002761>

Teschke, K. (n.d.). Chapter 72 - Pulp and Paper Industry. Encyclopedia of Occupational Health and Safety, Chapt. 72. <http://www.ilocis.org/documents/chpt72e.htm>

Global Greenhouse Gas Reference Network (2016). Trends in Atmospheric Carbon Dioxide: Full Mauna Loa CO2 record. Earth System Research Laboratory.<http://www.esrl.noaa.gov/gmd/ccgg/trends/full.html>

Ben Xu, P. L. (2013). Study of the Flow Mixing in a novel ARID raceway for algae production. Renewable Energy Vol. 62, 249-257. <http://www.sciencedirect.com/science/article/pii/S096014811300342X>

Environmental Protection Agency (1990). Chemical Wood Pulping. Compilation of Air Pollutant Emission Factors, Ch 10 S02 <https://www3.epa.gov/ttnchie1/ap42/ch10/final/c10s02.pdf>

South Carolina Department of Natural Resources (2015). Fish Pond Management Information. Common Aquatic Plant Management Problems.<http://www.dnr.sc.gov/water/aquaff/pithalgae.html>

Georgia Tech School of Economics (2003-16). Pulp Mills, Pulp & Paper Mills, Paper Mills in South Carolina. Center for Paper Business and Industry Studies.<http://www.cpbis.gatech.edu/data/mills-online-new?state=South+Carolina>

ReferencesStein, T. (2016). Carbon dioxide levels race past troubling milestone. National Oceanic and Atmospheric Administration. <http://www.noaa.gov/stories/carbon-dioxide-levels-race-past-troubling-milestone>

Kapstone. (2016). About Kapstone. Kapstone Paper and Packaging Corporation. <http://www.kapstonepaper.com/about-kapstone/>

Pokhrel, D., Viraraghavan, T. (2004). Treatment of pulp and paper mill wastewater--a review. Science of the Total Environment. Vol. 333, Issues 1-3. <http://www.sciencedirect.com/science/article/pii/S0048969704004279>.

Kocamemi, B. A., (n.d.). Environmental Engineering Unit Operations, Chapter 6 Mixing. Marmara University Department of Environmental Engineering. <http://mimoza.marmara.edu.tr/~bilge.alpaslan/enve301/Lectures/Chp_6.pdf>.

Questions?

Preguntas?

Les questions?

Appendices

Handsheet notes and thickness calculations Blending notes and handsheet pressure calculations

Appendices

Hand Calculations for Superpro Scale up

Appendices

Hand Calculations for Superpro Scale up

Appendices

http://www.paperonweb.com/paperpro.htm

Appendices

http://www.paperonweb.com/paperpro.htm