Category Archives: Biomass Energy

Combined Heat and Power Systems in the Biomass Industry

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Combined heat and power systems in the biomass industry means the simultaneous generation of multiple forms of useful energy (usually mechanical and thermal) from biomass resources in a single, integrated system. In a conventional electricity generation systems, about 35% of the energy potential contained in the fuel is converted on average into electricity, whilst the rest is lost as waste heat. CHP systems use both electricity and heat and therefore can achieve an efficiency of up to 90%.

CHP technologies are well suited for sustainable development projects because they are socio-economically attractive and technologically mature and reliable. In developing countries, cogeneration can easily be integrated in many industries, especially agriculture and food processing, taking advantage of the biomass residues of the production process. This has the dual benefits of lowering fuel costs and solving waste disposal issues.

CHP systems consist of a number of individual components—prime mover (heat engine), generator, heat recovery, and electrical interconnection—configured into an integrated whole. Prime movers for CHP units include reciprocating engines, combustion or gas turbines, steam turbines, microturbines, and fuel cells.

A typical CHP system provides:

  • Distributed generation of electrical and/or mechanical power.
  • Waste-heat recovery for heating, cooling, or process applications.
  • Seamless system integration for a variety of technologies, thermal applications, and fuel types.

The success of any biomass-fuelled CHP plant is heavily dependent on the availability of a suitable biomass feedstock freely available in urban and rural areas.

Rural Resources Urban Resources
Forest residues Urban wood waste
Wood wastes Municipal solid wastes
Crop residues Agro-industrial wastes
Energy crops Food processing residues
Animal manure Sewage

Technology Options

Reciprocating or internal combustion engines (ICEs) are among the most widely used prime movers to power small electricity generators. Advantages include large variations in the size range available, fast start-up, good efficiencies under partial load efficiency, reliability, and long life.

Steam turbines are the most commonly employed prime movers for large power outputs. Steam at lower pressure is extracted from the steam turbine and used directly or is converted to other forms of thermal energy. System efficiencies can vary between 15 and 35% depending on the steam parameters.

Co-firing of biomass with coal and other fossil fuels can provide a short-term, low-risk, low-cost option for producing renewable energy while simultaneously reducing the use of fossil fuels. Biomass can typically provide between 3 and 15 percent of the input energy into the power plant. Most forms of biomass are suitable for co-firing.

Steam engines are also proven technology but suited mainly for constant speed operation in industrial environments. Steam engines are available in different sizes ranging from a few kW to more than 1 MWe.

A gas turbine system requires landfill gas, biogas, or a biomass gasifier to produce the gas for the turbine. This biogas must be carefully filtered of particulate matter to avoid damaging the blades of the gas turbine.

Stirling engines utilize any source of heat provided that it is of sufficiently high temperature. A wide variety of heat sources can be used but the Stirling engine is particularly well-suited to biomass fuels. Stirling engines are available in the 0.5 to 150 kWe range and a number of companies are working on its further development.

A micro-turbine recovers part of the exhaust heat for preheating the combustion air and hence increases overall efficiency to around 20-30%. Several competing manufacturers are developing units in the 25-250kWe range. Advantages of micro-turbines include compact and light weight design, a fairly wide size range due to modularity, and low noise levels.

Fuel cells are electrochemical devices in which hydrogen-rich fuel produces heat and power. Hydrogen can be produced from a wide range of renewable and non-renewable sources. A future high temperature fuel cell burning biomass might be able to achieve greater than 50% efficiency.

Biomass Energy in Thailand

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Thailand’s annual energy consumption has risen sharply during the past decade and will continue its upward trend in the years to come. While energy demand has risen sharply, domestic sources of supply are limited, thus forcing a significant reliance on imports.

Thailand_paddy

To face this increasing demand, Thailand needs to produce more energy from its own renewable resources, particularly biomass wastes derived from agro-industry, such as bagasse, rice husk, wood chips, livestock and municipal wastes.

In 2005, total installed power capacity in Thailand was 26,430 MW. Renewable energy accounted for about 2 percent of the total installed capacity. In 2007, Thailand had about 777 MW of electricity from renewable energy that was sold to the grid.

Biomass Potential in Thailand

Several studies have projected that biomass wastes can cover up to 15 % of the energy demand in Thailand. These estimations are primarily made from biomass waste from the extraction part of agricultural activities, and for large scale agricultural processing of crops etc. – as for instance saw and palm oil mills – and do not include biomass wastes from SMEs in Thailand. Thus, the energy potential of biomass waste can be much larger if these resources are included. The major biomass resources in Thailand include the following:

  • Woody biomass residues from forest plantations
  • Agricultural residues (rice husk, bagasse, corn cobs, etc.)
  • Wood residues from wood and furniture industries    (bark, sawdust, etc.)
  • Biomass for ethanol production (cassava, sugar cane, etc.)
  • Biomass for biodiesel production (palm oil, jatropha oil, etc.)
  • Industrial wastewater from agro-industry
  • Livestock manure
  • Municipal solid wastes and sewage

Thailand’s vast biomass potential has been partially exploited through the use of traditional as well as more advanced conversion technologies for biogas, power generation, and biofuels. Rice, sugar, palm oil, and wood-related industries are the major potential biomass energy sources in Thailand. The country has a fairly large biomass resource base of about 60 million tons generated each year that could be utilized for energy purposes, such as rice, sugarcane, rubber sheets, palm oil and cassava.

Biomass has been a primary source of energy for many years, used for domestic heating and industrial cogeneration. For example, paddy husks are burned to produce steam for turbine operation in rice mills; bagasse and palm residues are used to produce steam and electricity for on-site manufacturing process; and rubber wood chips are burned to produce hot air for rubber wood seasoning.

In addition to biomass residues, wastewater containing organic matters from livestock farms and industries has increasingly been used as a potential source of biomass energy. Thailand’s primary biogas sources are pig farms and residues from food processing. The production potential of biogas from industrial wastewater from palm oil industries, tapioca starch industries, food processing industries, and slaughter industries is also significant. The energy-recovery and environmental benefits that the KWTE waste to energy project has already delivered is attracting keen interest from a wide range of food processing industries around the world.

Biomass Resources from Rice Industry

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The cultivation of rice results in two major types of biomass wastes – Straw and Husk –having attractive potential in terms of biomass energy. Although the technology for rice husk utilization is well-proven in industrialized countries of Europe and North America, such technologies are yet to be introduced in the developing world on commercial scale.

Rice-Biomass

The importance of Rice Husk and Rice Straw as an attractive source of energy can be gauged from the following statistics:

Rice Straw

  • 1 ton of Rice paddy produces 290 kg Rice Straw
  • 290 kg Rice Straw can produce 100 kWh of power
  • Calorific value = 2400 kcal/kg

Rice Husk

  • 1 ton of Rice paddy produces 220 kg Rice Husk
  • 1 ton Rice Husk is equivalent to 410- 570 kWh electricity
  • Calorific value = 3000 kcal/kg
  • Moisture content = 5 – 12%

Rice husk is the most prolific agricultural residue in rice producing countries around the world. It is one of the major by-products from the rice milling process and constitutes about 20% of paddy by weight. Rice husk, which consists mainly of lingo-cellulose and silica, is not utilized to any significant extent and has great potential as an energy source.

Rice husk can be used for power generation through either the steam or gasification route. For small scale power generation, the gasification route has attracted more attention as a small steam power plant is very inefficient and is very difficult to maintain due to the presence of a boiler. In addition for rice mills with diesel engines, the gas produced from rice husk can be used in the existing engine in a dual fuel operation.

The benefits of using rice husk conversion technology are numerous. Primarily, it provides electricity and serves as a way to dispose of agricultural waste. In addition, steam, a byproduct of power generation, can be used for paddy drying applications, thereby increasing local incomes and reducing the need to import fossil fuels. Rice husk ash, the byproduct of rice husk power plants, can be used in the cement and steel industries further decreasing the need to import these materials.

Rice straw can either be used alone or mixed with other biomass materials in direct combustion. In this technology, combustion boilers are used in combination with steam turbines to produce electricity and heat. The energy content of rice straw is around 14 MJ per kg at 10 percent moisture content.  The by-products are fly ash and bottom ash, which have an economic value and could be used in cement and/or brick manufacturing, construction of roads and embankments, etc.

Straw fuels have proved to be extremely difficult to burn in most combustion furnaces, especially those designed for power generation. The primary issue concerning the use of rice straw and other herbaceous biomass for power generation is fouling, slagging, and corrosion of the boiler due to alkaline and chlorine components in the ash. Europe, and in particular, Denmark, currently has the greatest experience with straw fired power and CHP plants.

Your Choices for Alternative Energy

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While using alternative sources of energy is a right way for you to save money on your heating and cooling bills, it also allows you to contribute in vital ways to both the environment and the economy.  Renewable energy sources are renewable, environmentally sustainable sources that do not create any by-products that are released into the atmosphere like coal and fossil fuels do.

Burning coal to produce electricity releases particulates and substances such as mercury, arsenic, sulfur and carbon monoxide into the air, all of which can cause health problems in humans.

Other by-products from burning coal are acid rain, sludge run-off and heated water that is released back into the rivers and lakes nearby the coal-fired plants.  While efforts are being made to create “clean coal,” businesses have been reluctant to use the technology due to the high costs associated with changing their plants.

If you are considering taking the plunge and switching to a renewable energy source to save money on your electric and heating bills or to help the environment, you have a lot of decisions to make. The first decision you need to make is which energy source to use in your home or business.  Do you want to switch to solar energy, wind power, biomass energy or geothermal energy?

Emissions from homes using heating oil, vehicles, and electricity produced from fossil fuels also pollute the air and contribute to the number of greenhouse gases that are in the atmosphere and depleting the ozone layer.  Carbon dioxide is one of the gases that is released into the air by the burning of fossil fuels to create energy and in the use of motor vehicles.  Neither coal nor fossil fuels are sources of renewable energy.

Replacing those energy sources with solar, biomass, geothermal or wind-powered generators will allow homes and businesses to have an adequate source of energy always at hand.  While converting to these systems can sometimes be expensive, the costs are quickly coming down, and they pay for themselves in just a few short years because they supply energy that is virtually free.  In some cases, the excess energy they create can be bought from the business or the homeowner.

While there are more than these three alternative energy options, these are the easiest to implement on an individual basis.  Other sources of alternative energy, for instance, nuclear power, hydroelectric power, and natural gas require a primary power source for the heat so it can be fed to your home or business.  Solar, wind, biomass and geothermal energy can all have power sources in your home or business to supply your needs.

1. Solar Energy

Solar power is probably the most widely used source of these options.  While it can be expensive to convert your home or business over to solar energy, or to an alternative energy source for that matter, it is probably the most natural source to turn over to.

You can use the sun’s energy to power your home or business and heat water.  It can be used to passively heat or light up your rooms as well just by opening up your shades.

2. Wind Power

You need your wind turbine to power your home or office, but wind energy has been used for centuries to pump water or for commercial purposes, like grinding grain into flour.  While many countries have wind farms to produce energy on a full-scale basis, you can have your wind turbine at home or at your business to provide electricity for your purposes.

The cost of alternative energy systems has dropped sharply in recent years

3. Biomass Energy

Biomass energy has rapidly become a vital part of the global renewable energy mix and account for an ever-growing share of electric capacity added worldwide. Biomass is the material derived from plants that use sunlight to grow which include plant and animal material such as wood from forests, material left over from agricultural and forestry processes, and organic industrial, human and animal wastes.

Biomass comes from a variety of sources which include wood from natural forests and woodlands, agricultural residues, agro-industrial wastes, animal wastes, industrial wastewater, municipal sewage and municipal solid wastes.

4. Geothermal Energy

A geothermal heat pump helps cool or heat your home or office using the earth’s heat to provide the power needed to heat the liquid that is run through the system to either heat your home in the winter or cool it off in the summer.  While many people use it, it doesn’t provide electricity, so you still need an energy source for that.

Biomass Energy in Vietnam

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Vietnam is one of the few countries having a low level of energy consumption in the developing world with an estimated amount of 210 kg of oil equivalent per capita/year. A significant portion of the Vietnamese population does not have access to electricity. Vietnam is facing the difficult challenge of maintaining this growth in a sustainable manner, with no or minimal adverse impacts on society and the environment.

Being an agricultural country, Vietnam has very good biomass energy potential. Agricultural wastes are most abundant in the Mekong Delta region with approximately 50% of the amount of the whole country and Red River Delta with 15%. Major biomass resources includes rice husk from paddy milling stations, bagasse from sugar factories, coffee husk from coffee processing plants in the Central Highlands and wood chip from wood processing industries. Vietnam has set a target of having a combined capacity of 500 MW of biomass power by 2020, which is raised to 2,000 MW in 2030.

Rice husk and bagasse are the biomass resources with the greatest economic potential, estimated at 50 MW and 150 MW respectively. Biomass fuels sources that can also be developed include forest wood, rubber wood, logging residues, saw mill residues, sugar cane residues, bagasse, coffee husk and coconut residues.

Currently biomass is generally treated as a non-commercial energy source, and collected and used locally. Nearly 40 bagasse-based biomass power plants have been developed with a total designed capacity of 150 MW but they are still unable to connect with the national grid due to current low power prices. Five cogeneration systems selling extra electricity to national grid at average price of 4 US cents/kWh.

Biogas potential is approximately 10 billion m3/year, which can be collected from landfills, animal excrements, agricultural residues, industrial wastewater etc. The biogas potential in the country is large due to livestock population of more than 30 million, mostly pigs, cattle, and water buffalo. Although most livestock dung already is used in feeding fish and fertilizing fields and gardens, there is potential for higher-value utilization through biogas production.

It is estimated that more than 25,000 household biogas digesters with 1 to 50 m3, have been installed in rural areas. The Dutch-funded Biogas Program operated by SNV Vietnam constructed some 18,000 biogas facilities in 12 provinces between 2003 and 2005, with a second phase (2007-2010) target of 150,000 biogas tanks in both rural and semi-urban settings.

Municipal solid waste is also a good biomass resource as the amount of solid waste generated in Vietnam has been increasing steadily over the last few decades. In 1996, the average amount of waste produced per year was 5.9 million tons per annum which rose to 28 million tons per in 2008 and expected to reach 44 million tons per year by 2015.

Everything You Need to Know About Biomass Energy Systems

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Biomass is a versatile energy source that can be used for production of heat, power, transport fuels and biomaterials, apart from making a significant contribution to climate change mitigation. Currently, biomass-driven combined heat and power, co-firing, and combustion plants provide reliable, efficient, and clean power and heat.

Feedstock for biomass energy plants can include residues from agriculture, forestry, wood processing, and food processing industries, municipal solid wastes, industrial wastes and biomass produced from degraded and marginal lands.

biomass-energy-systems

The terms biomass energy, bioenergy and biofuels cover any energy products derived from plant or animal or organic material. The increasing interest in biomass energy and biofuels has been the result of the following associated benefits:

  • Potential to reduce GHG emissions.
  • Energy security benefits.
  • Substitution for diminishing global oil supplies.
  • Potential impacts on waste management strategy.
  • Capacity to convert a wide variety of wastes into clean energy.
  • Technological advancement in thermal and biochemical processes for waste-to-energy transformation.

Biomass can play the pivotal role in production of carbon-neutral fuels of high quality as well as providing feedstock for various industries. This is a unique property of biomass compared to other renewable energies and which makes biomass a prime alternative to the use of fossil fuels. Performance of biomass-based systems for heat and power generation has been already proved in many situations on commercial as well as domestic scales.

Biomass energy systems have the potential to address many environmental issues, especially global warming and greenhouse gases emissions, and foster sustainable development among poor communities. Biomass fuel sources are readily available in rural and urban areas of all countries. Biomass-based industries can provide appreciable employment opportunities and promote biomass re-growth through sustainable land management practices.

The negative aspects of traditional biomass utilization in developing countries can be mitigated by promotion of modern biomass-to-energy technologies which provide solid, liquid and gaseous fuels as well as electricity as shown. Biomass wastes can be transformed into clean and efficient energy by biochemical as well as thermochemical technologies.

The most common technique for producing both heat and electrical energy from biomass wastes is direct combustion. Thermal efficiencies as high as 80 – 90% can be achieved by advanced gasification technology with greatly reduced atmospheric emissions. Combined heat and power (CHP) systems, ranging from small-scale technology to large grid-connected facilities, provide significantly higher efficiencies than systems that only generate electricity.

Biochemical processes, like anaerobic digestion and sanitary landfills, can also produce clean energy in the form of biogas and producer gas which can be converted to power and heat using a gas engine.

In addition, biomass wastes can also yield liquid fuels, such as cellulosic ethanol, which can be used to replace petroleum-based fuels. Cellulosic ethanol can be produced from grasses, wood chips and agricultural residues by biochemical route using heat, pressure, chemicals and enzymes to unlock the sugars in lignocellulosic biomass. Algal biomass is also emerging as a good source of energy because it can serve as natural source of oil, which conventional refineries can transform into jet fuel or diesel fuel.

Things You Should Know About Biofuels

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Biofuels refers to liquid or gaseous fuels for the transport sector that are predominantly produced from biomass. A variety of fuels can be produced from biomass resources including liquid fuels, such as ethanol, methanol, biodiesel, Fischer-Tropsch diesel, and gaseous fuels, such as hydrogen and methane. The biomass feedstock for biofuel production is composed of a wide variety of forestry and agricultural resources, industrial processing residues, and municipal solid and urban wood residues.

Biodiesel

The agricultural resources include grains used for biofuels production, animal manures and residues, and crop residues derived primarily from corn and small grains (e.g., wheat straw). A variety of regionally significant crops, such as cotton, sugarcane, rice, and fruit and nut orchards can also be a source of crop residues.

The forest resources include residues produced during the harvesting of forest products, fuelwood extracted from forestlands, residues generated at primary forest product processing mills, and forest resources that could become available through initiatives to reduce fire hazards and improve forest health.

Municipal and urban wood residues are widely available and include a variety of materials — yard and tree trimmings, land-clearing wood residues, wooden pallets, organic wastes, packaging materials, and construction and demolition debris.

Globally, biofuels are most commonly used to power vehicles, heat homes, and for cooking. Biofuel industries are expanding in Europe, Asia and the Americas. Biofuels are generally considered as offering many priorities, including sustainability, reduction of greenhouse gas emissions, regional development, social structure and agriculture, and security of supply.

First-generation biofuels are made from sugar, starch, vegetable oil, or animal fats using conventional technology. The basic feedstocks for the production of first-generation biofuels come from agriculture and food processing. The most common first-generation biofuels are:

  • Biodiesel: extraction with or without esterification of vegetable oils from seeds of plants like soybean, oil palm, oilseed rape and sunflower or residues including animal fats derived from rendering applied as fuel in diesel engines
  • Bioethanol: fermentation of simple sugars from sugar crops like sugarcane or from starch crops like maize and wheat applied as fuel in petrol engines
  • Bio-oil: thermochemical conversion of biomass. A process still in the development phase
  • Biogas: anaerobic fermentation or organic waste, animal manures, crop residues an energy crops applied as fuel in engines suitable for compressed natural gas.

First-generation biofuels can be used in low-percentage blends with conventional fuels in most vehicles and can be distributed through existing infrastructure. Some diesel vehicles can run on 100 % biodiesel, and ‘flex-fuel’ vehicles are already available in many countries around the world.

Bioethanol-production-process

Second-generation biofuels are derived from non-food feedstock including lignocellulosic biomass like crop residues or wood. Two transformative technologies are under development.

  • Biochemical: modification of the bioethanol fermentation process including a pre-treatment procedure
  • Thermochemical: modification of the bio-oil process to produce syngas and methanol, Fisher-Tropsch diesel or dimethyl ether (DME).

Advanced conversion technologies are needed for a second-generation biofuels. The second generation technologies use a wider range of biomass resources – agriculture, forestry and waste materials. One of the most promising second-generation biofuel technologies – ligno-cellulosic processing (e. g. from forest materials) – is already well advanced. Pilot plants have been established in the EU, in Denmark, Spain and Sweden.

Third-generation biofuels may include production of bio-based hydrogen for use in fuel cell vehicles, e.g. Algae fuel, also called oilgae. Algae are low-input, high-yield feedstock to produce biofuels.

Cofiring of Biomass

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Cofiring of biomass involves utilizing existing power generating plants that are fired with fossil fuel (generally coal), and displacing a small proportion of the fossil fuel with renewable biomass fuels. Cofiring of biomass with coal and other fossil fuels can provide a short-term, low-risk, low-cost option for producing renewable energy while simultaneously reducing the use of fossil fuels.

Biomass can typically provide between 3 and 15 percent of the input energy into the power plant. Cofiring of biomass has the major advantage of avoiding the construction of new, dedicated, biomass power plant. An existing power station is modified to accept the biomass resource and utilize it to produce a minor proportion of its electricity.

Cofiring of biomass may be implemented using different types and percentages of biomass in a range of combustion and gasification technologies. Most forms of biomass are suitable for cofiring. These include dedicated energy crops, urban wood waste and agricultural residues such as rice straw and rice husk.

The fuel preparation requirements, issues associated with combustion such as corrosion and fouling of boiler tubes, and characteristics of residual ash dictate the cofiring configuration appropriate for a particular plant and biomass resource. These configurations may be categorized into direct, indirect and parallel firing.

1. Direct Cofiring

This is the most common form of biomass cofiring involving direct cofiring of the biomass fuel and the primary fuel (generally coal) in the combustion chamber of the boiler. The cheapest and simplest form of direct cofiring for a pulverized coal power plant is through mixing prepared biomass and coal in the coal yard or on the coal conveyor belt, before the combined fuel is fed into the power station boiler.

2. Indirect Cofiring

If the biomass fuel has different attributes to the normal fossil fuel, then it may be prudent to partially segregate the biomass fuel rather than risk damage to the complete station.

For indirect cofiring, the ash of the biomass resource and the main fuel are kept separate from one another as the thermal conversion is partially carried out in separate processing plants. As indirect co-firing requires a separate biomass energy conversion plant, it has a relatively high investment cost compared with direct cofiring.

Parallel Firing

For parallel firing, totally separate combustion plants and boilers are used for the biomass resource and the coal-fired power plants. The steam produced is fed into the main power plant where it is upgraded to higher temperatures and pressures, to give resulting higher energy conversion efficiencies. This allows the use of problematic fuels with high alkali and chlorine contents (such as wheat straw) and the separation of the ashes.

Utilization of Date Palm Biomass

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Date palm trees produce huge amount of agricultural wastes in the form of dry leaves, stems, pits, seeds etc. A typical date tree can generate as much as 20 kilograms of dry leaves per annum while date pits account for almost 10 percent of date fruits.

date-wastes

Date palm biomass is found in large quantities across the Middle East

Date palm is considered a renewable natural resource because it can be replaced in a relatively short period of time. It takes 4 to 8 years for date palms to bear fruit after planting, and 7 to 10 years to produce viable yields for commercial harvest. Usually date palm wastes are burned in farms or disposed in landfills which cause environmental pollution in dates-producing nations.

The major constituents of date palm biomass are cellulose, hemicelluloses and lignin. In addition, date palm has high volatile solids content and low moisture content. These factors make date palm residues an excellent biomass resource in date-palm producing nations.

Date palm biomass is an excellent resource for charcoal production in Middle East

A wide range of physico-chemical, thermal and biochemical technologies exists for sustainable utilization of date palm biomass. Apart from charcoal production and energy conversion (using technologies like combustion and gasification), below are few ways for utilization of date palm wastes:

Conversion into fuel pellets or briquettes

Biomass pellets are a popular type of alternative fuel (analogous to coal), generally made from wood wastes and agricultural biomass. The biomass pelletization process consists of multiple steps including pre-treatment, pelletization and post-treatment of biomass wastes. Biomass pellets can be used as a coal replacement in power plant, industries and other application.

Conversion into energy-rich products

Biomass pyrolysis is the thermal decomposition of date palm biomass occurring in the absence of oxygen. The products of biomass pyrolysis include biochar, bio-oil and gases including methane, hydrogen, carbon monoxide, and carbon dioxide.

Depending on the thermal environment and the final temperature, pyrolysis will yield mainly biochar at low temperatures, less than 450 0C, when the heating rate is quite slow, and mainly gases at high temperatures, greater than 800 0C, with rapid heating rates. At an intermediate temperature and under relatively high heating rates, the main product is bio-oil.

Bio-oil can be upgraded to either a special engine fuel or through gasification processes to a syngas which can then be processed into biofuels. Bio-oil is particularly attractive for co-firing because it can be more readily handled and burned than solid fuel and is cheaper to transport and store.

Conversion into biofertilizer

Composting is the most popular method for biological decomposition of organic wastes. Date palm waste has around 80% organic content which makes it very well-suited for the composting process. Commercial-scale composting of date palm wastes can be carried out by using the traditional windrow method or a more advanced method like vermicomposting.

Things You Should Know About Algaculture

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High oil prices, competing demands between foods and other biofuel sources, and the world food crisis, have ignited interest in algaculture (farming of algae) for making vegetable oil, biodiesel, bioethanol, biogasoline, biomethanol, biobutanol and other biofuels, using land that is not suitable for agriculture.

Algae holds enormous potential to provide a non-food, high-yield, non-arable land use source of biodiesel, ethanol and hydrogen fuels. Microalgae are the fastest growing photosynthesizing organism capable of completing an entire growing cycle every few days. Up to 50% of algae’s weight is comprised of oil, compared with, for example, oil palm which yields just about 20% of its weight in oil.

Algaculture (farming of algae) can be a route to making vegetable oils, biodiesel, bioethanol and other biofuels. Microalgae are one-celled, photosynthetic microorganisms that are abundant in fresh water, brackish water, and marine environments everywhere on earth. The potential for commercial algae production is expected to come from growth in translucent tubes or containers called photo bioreactors or open ocean algae bloom harvesting. The other advantages of algal systems include:

  • carbon capture from smokestacks to increase algae growth rates
  • processing of algae biomass through gasification to produce syngas
  • growing carbohydrate rich algae strains for cellulosic ethanol
  • using waste streams from municipalities as water sources

Algae have certain qualities that make the organism an attractive option for biodiesel production. Unlike corn-based biodiesel which competes with food crops for land resources, algae-based production methods, such as algae ponds or photobioreactors, would “complement, rather than compete” with other biomass-based fuels. Unlike corn or other biodiesel crops, algae do not require significant inputs of carbon intensive fertilizers.  Some algae species can even grow in waters that contain a large amount of salt, which means that algae-based fuel production need not place a large burden on freshwater supplies.

Several companies and government agencies are funding efforts to reduce capital and operating costs and make algae fuel production commercially viable. Companies such as Sapphire Energy and Bio Solar Cellsare using genetic engineering to make algae fuel production more efficient. According to Klein Lankhorst of Bio Solar Cells, genetic engineering could vastly improve algae fuel efficiency as algae can be modified to only build short carbon chains instead of long chains of carbohydrates.

Sapphire Energy also uses chemically induced mutations to produce algae suitable for use as a crop. Some commercial interests into large-scale algal-cultivation systems are looking to tie in to existing infrastructures, such as cement factories, coal power plants, or sewage treatment facilities. This approach changes wastes into resources to provide the raw materials, CO2 and nutrients, for the system.