Tag Archives: Biomass

The Importance of Biomass Energy in Energy Mix

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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. Renewable energy supplies around one-fifth of the final energy consumption worldwide, counting traditional biomass, large hydropower, and “new” renewables (small hydro, modern biomass, wind, solar, geothermal, and biofuels).

Traditional biomass, primarily for cooking and heating, represents about 13 percent and is growing slowly or even declining in some regions as biomass is used more efficiently or replaced by alternative energy forms. Some of the recent predictions suggest that biomass energy is likely to make up one third of the total world energy mix by 2050. Infact, biofuel provides around 3% of the world’s fuel for transport.

biomass_feedstock

Biomass energy resources are readily available in rural and urban areas of all countries. Biomass-based industries can foster rural development, provide 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 waste-to-energy technologies which provide solid, liquid and gaseous fuels as well as electricity. Biomass wastes encompass a wide array of materials derived from agricultural, agro-industrial, and timber residues, as well as municipal and industrial wastes.

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.

Advantages of Biomass Energy

Biomass energy systems offer significant possibilities for reducing greenhouse gas emissions due to their immense potential to replace fossil fuels in energy production. Biomass reduces emissions and enhances carbon sequestration since short-rotation crops or forests established on abandoned agricultural land accumulate carbon in the soil.

Bioenergy usually provides an irreversible mitigation effect by reducing carbon dioxide at source, but it may emit more carbon per unit of energy than fossil fuels unless biomass fuels are produced unsustainably.

Biomass can play a major role in reducing the reliance on fossil fuels by making use of thermochemical conversion technologies. In addition, the increased utilization of biomass-based fuels will be instrumental in safeguarding the environment, generation of new job opportunities, sustainable development and health improvements in rural areas.

The development of efficient biomass handling technology, improvement of agro-forestry systems and establishment of small and large-scale biomass-based power plants can play a major role in rural development and sustainable utilization of biomass. Biomass energy could also aid in modernizing the agricultural economy.

Consistent and reliable supply of biomass is crucial for any biomass project

When compared with wind and solar energy, biomass power plants are able to provide crucial, reliable baseload generation. Biomass plants provide fuel diversity, which protects communities from volatile fossil fuels. Since biomass energy uses domestically-produced fuels, biomass power greatly reduces our dependence on foreign energy sources and increases national energy security.

A large amount of energy is expended in the cultivation and processing of crops like sugarcane, coconut, and rice which can met by utilizing energy-rich residues for electricity production.

The integration of biomass-fueled gasifiers in coal-fired power stations would be advantageous in terms of improved flexibility in response to fluctuations in biomass availability and lower investment costs. The growth of the bioenergy industry can also be achieved by laying more stress on green power marketing.

Breaking Down the Process of Biofuel Production

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Biofuels are renewable and sustainable forms of energy. They can reduce greenhouse emissions by almost 30%, which means that although they do release carbon dioxide into the atmosphere, they do so in a very limited manner.

With the aim of building a green new world, and eliminating the need for fossil fuel and other traditional energy sources, people are now turning towards biofuel to meet their daily needs. Thus, we see biofuel being used for transportation in many countries. It’s also being used to generate electricity. The rural areas in many underdeveloped and developing countries will use biofuel for their cooking purposes as well. All in all, this particular fuel has diverse uses.

Biofuel is produced from biomass, which itself is treated as a clean energy source. We can produce biofuel from biomass through a series of steps. These steps can be performed even in our houses if we have the right materials. A quick overview of the whole biofuel production process is described below.

biofuel-production

1. Filtration

The purpose of the filtration process is to get rid of the unnecessary particles from the biomass. In this step, we take the waste vegetable oil and then heat it to a certain degree. Once the liquid has been heated, the waste particles will automatically separate themselves from the main mixture. Afterward, we just have to filter it with a regular filter paper.

2. Water removal

Next, we need to remove water from the residual gangue. If the water is allowed to stay in the mixture, it’ll end up delaying the overall process. By removing all the water, we can make the reaction move a lot faster. The easiest way to remove water from the mixture is by heating it steady at 212 degrees F for some time.

3. Titration

Titration is conducted on the mixture to determine the amount of chemical catalyst (like lye) that will be needed. The catalyst is a key component in any chemical reaction. It pretty much determines how fast and how much of a product we’re going to receive. Thus, this step is very important in the biofuel manufacturing process.

4. Sodium methoxide preparation

In this step, we take methanol (18-20% of the waste vegetable oil) and mix it with sodium hydroxide. This gives us sodium methoxide, which is also used as a catalyst in the reaction. It helps perform synthesis reactions on the reagents and facilitates the overall reaction process. Sodium methoxide is a key ingredient in this manufacturing process. It’s considered to be a standard substance used to accelerate the reaction, and yield better results.

5. Mixing and heating

Next, we heat the residue between 120-130 degrees F. Afterward, we mix it properly. This process aims to evenly distribute the mixture. This will help the mixture to settle down later on, and cool off, after which we can begin the extraction process. In a way, the mixing and heating stage can be seen as the final preparation before extraction.

biofuel-production

6. Setting

Once the mixing is completed, the liquid is allowed to cool and settle down, after which we can extract the final product, i.e. the biofuel.

7. Separation

After the liquid has cooled, the biofuel can be extracted from the top of the mixture. It’ll be found floating on top, like oil in water. To get the biofuel, we’ll have to remove the glycerin underneath it. This can be done by simply draining it out from the bottom, and keeping the fuel afloat. The biofuel is finally ready.

The whole process described above is for a small-scale operation. However, it can be scaled up as needed, given that you have the right tools, ingredients, and setup.

It should also be noted that chemical catalysts (such as lye) are used in the manufacturing process as well. Recently, however, scientists and researchers are looking into the use of ultrasonics as additional catalysts. According to recent observations, a combination of chemicals and ultrasonics can lead to a higher yield of fuel, and reduce the overall processing time. This also leads to better utilization of biomass.

Companies such as Coltraco (https://coltraco.com/) are now using ultrasonic systems and technology in a wide variety of fields, one of which is the renewable energy industry. And while the technology’s use in other fields has gained more traction in recent times, it shouldn’t be long before it’s used in biofuel manufacturing, as well as in other renewable energy sectors, in full swing.

Why Are We Converting Waste Into Energy?

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The world is running out of fossil fuels, and we need to find new ways to generate energy. Converting waste into energy is a clean and efficient way to generate power. It doesn’t produce the same level of pollution as traditional fuel sources, and it helps reduce our dependence on fossil fuels.

We need to find ways to convert waste into energy today in order to address the issue of climate change. By converting our waste into energy, we can reduce our reliance on polluting fuels and help preserve our environment for future generations.

Reasons to convert Waste to Energy

What is waste to energy?

Waste to energy is a process of turning waste into electricity. This is a clean and efficient way to generate power, and it doesn’t produce the same level of pollution as traditional fuel sources. Converting our waste into energy can help reduce our reliance on polluting fuels and preserve our environment for future generations.

Can all types of waste be used?

The different types of waste that can be used in waste to energy are municipal solid waste, agricultural waste, and industrial waste. Municipal solid waste is the most common type of waste that is used in this process. It includes everyday items like paper, plastic, and metal. Agricultural waste includes things like manure, straw, and wood chips. Industrial waste includes things like slag, ash, and boiler dust. Municipal solid waste is the most common type of waste that is used in waste to energy.

Is Waste to Energy the same as Biomass?

The similarities between waste to energy and biomass are that they are both renewable resources, and they can both be used to create energy. The main difference between them is that waste to energy uses organic material that would otherwise be thrown away (like food waste), while biomass uses plants specifically grown for the purpose of creating fuel.

WTE plant

Waste to Energy – Frequently Asked Questions

Is waste to energy effective?

Yes, waste to energy is an effective way to generate power. It doesn’t produce the same level of pollution as traditional fuel sources, and it helps reduce our dependence on fossil fuels. Converting our waste into energy can help preserve our environment for future generations.

There are many reasons to believe that waste to energy is a more efficient renewable energy source than other types of renewables. First, waste to energy facilities can be located near population centers, which reduces the amount of energy lost in transmission. Second, waste to energy plants tend to have higher capacity factors than other types of renewable energy sources, meaning that they produce more electricity per unit of capacity.

Finally, waste to energy plants can use a variety of feedstocks, including municipal solid waste, construction and demolition debris, and sewage sludge. This flexibility gives waste-to-energy plants a significant advantage over other renewable energy sources that are limited to a single feedstock.

Is waste to energy sustainable?

The short answer is yes – waste to energy (WtE) is a sustainable solution for managing municipal solid waste (MSW). But it’s important to consider the whole picture when making decisions about sustainability. That means taking into account factors like greenhouse gas emissions, financial costs, and other renewable energy options like solar and wind.

When it comes to conserving energy, there are many things that people can do to help out, both big and small. Saving energy at home can help reduce the amount of waste going to energy plants, and it can also save homeowners money on their monthly energy bills.

WtE plants use MSW to generate electricity, and they can actually help reduce greenhouse gas emissions. That’s because when MSW is incinerated, it doesn’t release methane, a powerful greenhouse gas that’s produced when MSW breaks down in landfills. In fact, WtE plants are so efficient at reducing methane emissions that they’re actually considered carbon-neutral.

WtE plants are also cost-effective, and the technology is constantly improving. In the past, WtE plants were criticized for being too expensive to build and operate. But new plants are much more efficient, and the costs have come down significantly.

What are the advantages and disadvantages of waste to energy?

The advantages of waste to energy are that it is a sustainable solution for managing MSW, it reduces greenhouse gas emissions, and it is cost-effective. The disadvantages of waste to energy are that it requires high initial investment, and it produces some air pollution. Overall, waste to energy is a good option for communities looking for a sustainable and cost-effective solution for managing MSW.

What are the alternatives to waste to energy?

The main alternative to waste to energy is landfill gas-to-energy, which captures methane gas produced by decomposing MSW in landfills and uses it to generate electricity. Landfill gas-to-energy is less expensive than waste to energy, but it has a higher greenhouse gas emissions footprint.

Other renewable energy options include solar and wind power. Solar and wind power are both carbon-neutral, but they are more expensive than waste to energy. Waste to energy is a good option for communities looking for a sustainable and cost-effective solution for managing MSW. It has some disadvantages, but overall it is a good option for communities looking to reduce their environmental impact.

Why are we converting Waste to Energy?

We need to convert waste to energy today because the world is running out of fossil fuels. The use of coal, oil, and natural gas has created an unprecedented level of pollution, which is damaging our environment and contributing to climate change. In order to reduce our dependence on these polluting fuels and address the issue of climate change, we need to find ways to convert waste into energy.

Sysav–WTE-plant-Sweden

Sweden is one of the best proponents of waste-to-energy in the world

In recent years, waste to energy (WtE) has become increasingly popular as a means of generating electricity. However, not everyone is convinced that WtE is the best option for the environment. Some critics argue that WtE actually damages the environment and is not worth the investment.

One of the major criticisms of WtE is that it emits pollutants into the air. When waste is burned, it releases harmful chemicals and particulates into the atmosphere. These pollutants can have a negative impact on human health, as well as the environment. In addition, WtE plants are often located in close proximity to populated areas, which means that the pollution they emit can affect a large number of people.

Food waste and waste to energy are two important topics that we should be thinking about more. With the right infrastructure in place, food waste can be used to create energy, which can help to power our homes and businesses. In addition, by reducing food waste, we can also help to reduce greenhouse gas emissions.

Another criticism of WtE is that it is actually less efficient than other means of generating electricity. WtE plants typically have lower efficiency rates than coal-fired power plants, for example. This means that more waste needs to be burned in order to generate the same amount of electricity. This can lead to more pollution and more damage to the environment.

Critics also argue that WtE plants are expensive to build and operate. The initial investment can be significant, and the operating costs can be high. This means that WtE may not be the most cost-effective option for generating electricity.

Despite these criticisms, some experts believe that WtE can be a valuable tool for generating electricity. WtE plants can help to reduce the amount of waste that is sent to landfill, and they can provide a source of renewable energy. In addition, WtE plants can create jobs and boost the economy.

Ultimately, the decision of whether or not to use WtE should be based on a careful consideration of all the pros and cons. WtE may not be right for everyone, but it could be the best option for some.

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.

Role of Biogas in Rural Development

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Anaerobic digestion has proven to be a beneficial technology in various spheres for rural development. Biogas produced is a green replacement of unprocessed fuels (like fuel wood, dung cakes, crop residues). It is a cost effective replacement for dung cakes and conventional domestic fuels like LPG or kerosene. Biogas technology has the potential to meet the energy requirements in rural areas, and also counter the effects of reckless burning of biomass resources.

Biogas has the potential to rejuvenate India’s agricultural sector

An additional benefit is that the quantity of digested slurry is the same as that of the feedstock fed in a biogas plant. This slurry can be dried and sold as high quality compost. The nitrogen-rich compost indirectly reduces the costs associated with use of fertilizers. It enriches the soil, improves its porosity, buffering capacity and ion exchange capacity and prevents nutrient depletion thus improving the crop quality. This means increased income for the farmer.

Further, being relatively-clean cooking fuel, biogas reduces the health risks associated with conventional chulhas. Thinking regionally, decreased residue burning brings down the seasonal high pollutant levels in air, ensuring a better environmental quality. Anaerobic digestion thus proves to be more efficient in utilization of crop residues. The social benefits associated with biomethanation, along with its capacity to generate income for the rural households make it a viable alternative for conventional methods.

The Way Forward

The federal and stage governments needs to be more proactive in providing easy access to these technologies to the poor farmers. The policies and support of the government are decisive in persuading the farmers to adopt such technologies and to make a transition from wasteful traditional approaches to efficient resource utilization. The farmers are largely unaware of the possible ways in which farm and cattle wastes could be efficiently utilised. The government agencies and NGOs are major stakeholders in creating awareness in this respect.

Moreover, many farmers find it difficult to bear the construction and operational costs of setting up the digester. This again requires the government to introduce incentives (like soft loans) and subsidies to enhance the approachability of the technology and thus increase its market diffusion.