Value Proposition for Algae

Algae’s value chain
Algae’s potential as a food or biofuel has been largely under foot but out of mind for most people, institutions and governments. This plant has received considerable attention as a pest but few have considered its potential to serve our planet.

Algae are uniquely positioned to provide a value chain of products and solutions for critical human needs. The 16 factor value chain includes sustainable foods, fuels, ecological and novel solutions represented in Algae’s Green Promise.

Table 10.3 Algae’s Green Promise (From Green Algae Strategy)

Food. Algae supply high-protein, low-fat, nutritious, healthy and delicious human foods. Algae provide more vitamins, minerals and nutrients than land plants and are a natural health food. Algae do not provide a full solution for malnutrition due to their few calories.
Note: Algae’s food value will be suboptimal until solutions are found for a few key issues; making hard cell walls digestible and producing fewer nucleic acids. All other green promises await only macro and micro-scale algaculture production systems.
Food ingredients. Algal ingredients enhance about half the food products in a grocery store. Algae components support dairy products, beer, jams, bakery products, soups, sauces, pie fillings, cakes, frostings, colorings, ulcer remedies, digestive aids, eye drops, dental creams, skin creams and shampoos.
Fodder. Algae produce high-protein, low-cost, nutritious animal feed with numerous vitamins, minerals and nutrients. Replacing half the food grains fed to animals sold as U.S. exports would save 20 M acres of cropland and a trillion gallons of water. Local production in villages would feed millions of animals and would save 20 M acres a year of forests and grasslands from desertification due to animal forage.
Fisheries. Algae provide high-protein; low-cost, nutritious fish feed, vitamins and nutrients. Algae can be grown in-situ, in the water with the fin fish or shell fish. Fish tend to grow with more vitality on algae than land grains because they eat algae in their natural habitat.
Fuels – biodiesel. Algal oils pressed directly from algal biomass produce renewable and sustainable, high energy biofuel from sunshine, C02 and wastewater. Replacing U.S. ethanol production would take 2 M acres of desert, half of one Arizona county. Replacing corn as a biofuel feedstock would save 40 M acres of cropland, 2 trillion gallons of water, 240 M tons of soil erosion and extensive water pollution annually.
Fuels – jet fuel, ethanol and hydrogen. Algal production can be refined to a variety of high energy liquid transportation fuels including gasoline. While refining generally requires more energy input than squeezing out algal oil, the U.S. is likely to have a surplus of ethanol refinery capacity. Algal products can be refined in fossil fuel refineries into many of the products made from fossil fuels. Hydrogen gas production would occur in the algaculture system and need a refinery.
Fossil fuels. Replacing U.S. ethanol production also would save 7 B gallons of fossil fuel used to produce ethanol. Moving 1/10th of U.S. agricultural production from dirty diesel to clean algal-diesel would clean the environment and save 20 B gallons of fossil fuels annually. Even larger fossil fuel savings would accrue from using algal oils to substitute for a portion of the diesel used by trucks and trains.
Fire &ndash cooking. Black smoke from cooking fires and heating with wood, weeds and dung causes smoke death for 1.6 M and disability for 10 M mostly women and children every year. Clean-burning, high energy algal-oil can end smoke death and the many smoke disabilities. Substituting algal oil for wood and agricultural materials will save a tremendous amount of labor from gathering firewood and allow forests to be replanted.
Fresh water. Running wastewater through algaculture feeds the plants and cleans the water. Producing fuel, fodder or fertilizer using wastewater or brine water saves water that would otherwise be used for land-based crops. Replacing half of U.S. food exports with algaculture foods would save 30 M acres of cropland, 4 trillion gallons of water and 15 B gallons of fossil fuel.
Fresh air. Flueing smoke stack gasses through algaculture removes CO2, nitric oxides, sulfur and heavy metals such as mercury from power plant or industrial plants, sequesters greenhouse gasses and cleans the air. Algae represent only a partial solution since the plant only grows with sunshine and power plants operate 24 hours a day.
Fertilizer. Nitrogen-fixing algae may provide high nitrogen fertilizers at very low cost in both production and energy inputs. The product is natural and supports organic food production and could provide cheap local fertilizer to subsistence farmers globally. The ash retains fertilizer value after being burned in cooking fires.
Forests. High energy algal-oil fuel can end the need to denude forests and grasslands for cooking and heating fuel. Villagers may replant their forests with nut trees or legumes for food to offset the low calories provided by algal foods.
Fabrics. Algal carbohydrates are similar to wood and may be made into textiles, paper and building materials. Algal paper and building materials save forests and fabrics and provide warmth. Algal oils may be made into biodegradable plastics or other refined products.
Foreign Aid. American foreign aid provides subsidized U.S. food, undermines or destroys local food production because farmers cannot compete with U.S. subsidized food. Gifting food fails to address the root cause of hunger and poverty &ndash local control over food resources and community engagement. Algaculture foreign aid would transfer knowledge and some start-up materials to grow algal foods, fuels, fodder, fertilizer and medicines locally.
Famine and disaster relief. Algae, with its rich set of vitamins and minerals, may activate the immune system and ward off starvation while providing fuel, fodder, fabrics, fertilizers and fine medicines. Disaster relief with local algaculture production may prevent community starvation for millions. Local algal production solves the critical problem of food distribution.
Fine medicines. High-quality, affordable medicines, vaccines and pharmaceuticals may be made from algal coproducts or grown in algae bioengineered to produce advanced compounds such as antibiotics, vitamins, nutraceuticals and vaccines. These compounds are grown today in land plants and animals so algae offer significantly faster and lower cost production. Designer algae grown locally in villages could save millions of lives by providing low cost vaccines or other medicines that need no packaging or distribution. Fine medicines, especially personalized drugs tailored to an individual, may offer more value than all other algal coproducts combined.

Carbon Negative Food and Energy Production

The current models for growing food crops and producing bio or fossil energy release massive amounts of carbon dioxide and other heat trapping gases, especially nitric oxides, to the atmosphere. Top leaders and scientists on every continent have called for a reduction in the carbon footprint to slow the effects of climate change. Unfortunately, consent to behavior has been increasing rather than decreasing and shows no signs of diminishing.

A new model called carbon negative production will allow food and energy production that is either carbon neutral or carbon negative. The key to carbon neutral or negative production occurs from a green solar energy island that uses pyrolysis to consume polluting gases and either recycle or sequester them. Recycling occurs when algae capture the carbon in the plant biomass and the stored algal energy is used as fuel or food. The carbon is re-released to the atmosphere upon consumption. Energy production may be carbon neutral when no fossil fuels are used to grow the algae or produce the fuels or food. Carbon neutral production displaces a gallon of fossil fuel oil for every gallon of algal oil consumed but it simply recycles CO2.

Carbon neutral and carbon negative energy production may be a function of the availability of carbon near the production facility.

Carbon neutral. When sited next to a CO2 source such as a power plant, cement or other manufacturing facility, the Energy Island uses solar energy to capture the CO2 from the waste emissions and stores the carbon in green algal biomass while releasing pure oxygen to the atmosphere. Piping CO2 from a waste source is carbon neutral because this carbon returns to the atmosphere when the fuel burns as energy or people or animals consume the products for energy.
Carbon negative. When sited away from a CO2 source, the culture receives its carbon from the exhaust plume of burning waste biomass such as weeds, wood, manure or municipal solids in a gasifier illustrated in the graphic. The Energy Island produces not only algal biomass but bio-char that farmers can sequester as a nutrient source and carbon in their fields.

When plants burn or decay, the process releases carbon to the atmosphere that combines with oxygen to become CO2. Burning biomass also releases large amounts nitric oxides and any other elements that happen to be in the biomass. Burning coal, for example, releases heavy metals such as sulfur, arsenic and mercury into the atmosphere. The black soot particulates create respiratory and other health problems for humans and animals as well as smog. Black soot also falls on snow packs, ice caps and glaciers. The black particles absorb solar energy and create holes that accelerate the melting of ice.

When organic biomass burns in a kiln with minimal oxygen, a process called pyrolysis, about half of the carbon turns into a charcoal-like substance called biochar. Pyrolysis occurs in a closed system where all the gases can be used. The carbon dioxide may be piped to algae that capture the carbon and store it in green plant bonds while releasing the oxygen. The hydrogen can fuel an electric generator that to create electricity. Biochar captures about 50% of the biomass carbon and is so inert it stores the carbon for hundreds of years when cultivated into fields. The following figure illustrates the difference between typical biomass combustion and pyrolysis.

Pyrolysis is usually the first chemical reaction that occurs when burning organic fuels such as wood, weeds or wastes, including manure. The visible flames in a wood fire are not due to combustion of the wood but the gases released by its pyrolysis. The embers are the flame-less combustion of the solid residue which is typically ash or charcoal. The word is coined from the Greek-derived elements pyro "fire" and lysys "decomposition."

The chemical industry uses pyrolysis extensively to produce charcoal, activated carbon, methanol and other chemicals from solid wastes or wood. Pyrolysis produces coke from coal and cracks medium-weight hydrocarbons from oil to produce lighter ones such as gasoline. Energy companies use pyrolysis to convert organic biomass into syngas and to turn waste into safely disposable substances.

Pyrolysis breaks down long hydrocarbon chains like cellulose to shorter molecules. These simpler molecules are more easily broken down by microbes and plants as food and bond more easily with key nutrients, especially nitrogen and phosphorus. Terra preta provides a strong fertilizer because it locks so much carbon in the soil. Char-amended soils have shown up to 80% reduction in nitrous oxide emissions – which typically occurs when fields are cultivated. The bio-char bonds with phosphorus and nitrogen and reduces runoff of phosphorus and nitrogen to surface waters and leaching of nitrogen into groundwater. As a soil amendment, bio-char significantly increases soil organics and reduces the need for inorganic chemical fertilizers while greatly enhancing crop yields. Experiments have shown yields for some crops can be doubled and even tripled.

Pyrolisizing agricultural waste to make bio-char provides a renewable, low cost way to produce energy. The chemical reactions resulting from heat that break down the long hydrocarbon chains give off hydrogen gas, methane, and various other burnable fuel gases. The fuel gas can be burned for heat, or if clean, the tar levels are low, it can be used to power an engine or electric generator. Over a million wood gasifiers were used to power cars and trucks during World War II when Europeans lacked access to oil.

Biochar

Biochar, the carbon and nutrient rich product of waste biomass combustion in a closed container may be used to improve agriculture and the environment in several ways. Biochar, also called agri-char and terra preta (black soil) offers three times more nitrogen and phosphorous and holds twenty times the carbon of normal soils. Biochar stabilizes soils and provides superior nutrient retention properties that significantly increase crop yields compared with commercial fertilizers.

Biochar improves the soil texture, density, color and ecology, increasing its ability to retain fertilizers and release them slowly. Biochar naturally contains many of the micronutrients needed by plants such as copper, selenium and zinc. It is also safer than other "natural" fertilizers such as manure or sewage since it has been disinfected at high temperature. Manure often contains large amounts of antibiotics and other pharmaceuticals commonly used in animal production. The release of nutrients at a slow rate enables food crops to have a continuous supply of available nutrients which some researchers have found improves food texture and taste.

Biochar structure

Biochar or terra preta comes from a farming practice recently discovered that dates back over 3000 years. Amazonians added carbonized biomass to their soil from animal bone and tree bark for nutrient enrichment and erosion prevention. The practice was re-discovered by archeologists who were studying a site in the central-Amazon basin. The soil remains today some of the richest and most fertile soil yet found.

The Amazon rain forest soils are fragile and impoverished. When farmers cut down the tree canopy to make cropland, they expose the earth to the combination rain, wind and sun that quickly erodes the minute store of minerals and nutrients available in topical soils. The hot sun bakes the topsoil into a hard brick called a "wet desert." The brick-like soil allows neither water penetration nor moisture retention so plants cannot grow. In many areas of South and Central America, over 75% of the cropland has been eroded and abandoned. Environmentalists believe large-scale agriculture is impossible in the tropics but the Amazonians overcame the erosion problem with a form of biochar.

Charcoal fertilization can permanently increase soil organic matter content and improve soil quality. Mingxin Guo and colleagues at Delaware State University found that soils receiving charcoal produced from organic wastes were much looser than other soils, absorbed significantly more water and nutrients and produced higher crop biomass. Scientists from the American chemical Society have begun a five-year study of the use of biomass charcoal for soil enrichment in order to understand its impact on fertilization, soil carbon changes, crop productivity and any impact on the microorganisms in the soil.

Pyrolysis has been used since ancient times for turning wood into charcoal. Heating wood to its complete pyrolysis (carbonization) leaves only carbon and inorganic ash. In many parts of the world, charcoal is still produced, by burning a pile of wood that has been mostly covered with mud or bricks. The heat generated by burning part of the wood and the volatile byproducts pyrolyzes the rest of the pile. The limited supply of oxygen prevents the charcoal from burning too. Modern methods heat the biomass in an airtight vessel, which traps the gases, avoids CO2 and black particulate smoke pollution and allows the volatile products to be condensed.

Modern farmers often use potash on their fields. The term comes from the process used by farmers for centuries of burning wood in the pot. The ashes were spread on the fields because the farmers knew the added carbon and nutrients would act as a fertilizer to improve yields.

Pyrolysis offers several advantages:

Carbon negative biomass production. Pyrolysis enriches the soil and traps and holds carbon which may offer significant benefits to decreasing global warming from agriculture and reducing greenhouse gases in the atmosphere.
Carbon source for algal production. Pyrolysis produces carbon monoxide which can be piped into algal cultures to feed the algae. The waste heat can heat the algal culture and speed growth.
Abundant and cheap feedstock. Biochar may be made from waste biomass and recovers and recycles many of the lost nutrients.
Bio-oil for energy. Smoke generated in pyrolysis can be collected and cooled to use as a bio-oil renewable energy source.
Reclaim abandoned soils. Pyrolysis offers a low-cost way to enrich soils to they will contain more humus, nutrients and microorganisms as well as improve moisture retention.
Non-polluting waste solution. The pyrolysis process occurs in a closed container and the emissions are either recycled as energy (heat or bio-oils) or CO gas is fed to algae, creating a positive ecological footprint.
- Municipal or industrial waste. Each ton used in C-negative production would have otherwise been buried in a landfill where bacteria digest garbage to make methane, a potent greenhouse gas. Garbage trucked to landfills emits large amounts of CO2 from the truck’s diesel engines.
- Agricultural waste. Each ton used in C-negative production would have otherwise been burned, giving off several greenhouse gases or buried in a landfill which gives off methane.