BIOMASS ENERGYBY

SIENG LY & JOHN DEBUQUE

ADVANTAGES OF BIOMASS

Biomass used as a fuel reduces need for fossil fuels for the production of heat, steam, and electricity for residential, industrial and agricultural use.

The crops used to produce biofuels can be grown almost anywhere.

Help most countries reduce their dependence on imported oil.

Can make use of agricultural, timber and urban waste.

The rate of harvesting and conversion of these plants to biofuels does not exceed the rate at which they are replenished by new plant grow and there is no net increase in Carbon Dioxide emissions.

Biomass is always available and can be produced as a renewable resource.

Biofuels are available can us existing distribution and gas stations networks and can fuel vehicles available today at little or no additional cost

They are easy to restore and transport

DISADVANTAGES

Land used for energy crops maybe in demand for other purposes, such as faming, conservation, housing, resort or agricultural use.

Expanding the area of land devoted to growing biofuels crops can degrade and decrease the Earth’s biodiversity

There could be growing competition between using land to grow crops for food and for biofuels.

Ethanol, as a biodiesel is terribly inefficient when compared to gasoline, and it often has to be mixed with some gasoline to make it work properly anyway

Not only does it take a lot more fuel to do the same job as using conventional fuels, but it also creates environmental problems of its own. To produce enough lumber to power a nation full of vehicles or even a power plant, companies would have to clear considerable forest area.

Combustion of biomass products require some land where they can easily be burn.

CONSUMPTIO AND USAGE

CONSUMPTION AND USAGE

Biomass energy consumption in the United States grew more than 60% from 2002 to 2013. This growth is almost entirely due to increased consumption of biomass to produce biofuels, mainly ethanol but also a smaller amount of biodiesel and other biomass-based diesel fuels. In 2013, biomass accounted for about half of all renewable energy consumed and 5% of total U.S. energy consumed.

From 2002 to 2013, biomass energy converted to biofuels grew more than 500% as U.S. production of ethanol and biodiesel grew. On average, 60% of the energy in feed stocks is converted to deliverable biofuels. The remainder becomes energy losses or coproducts, which are measured as energy consumed by the industrial sector. Most biofuels are consumed as blended transportation fuels—ethanol blended with motor gasoline or biodiesel blended with diesel fuel. Some biodiesel is used as heating oil. Consumption of. wood and waste energy increased just 4%.

Biomass covers approximately 10 percent of the global energy supply, of which two-thirds is used in developing countries for cooking and heating. In 2009, about 13 percent of biomass use was consumed for heat and power generation, while the industrial sector consumed 15 percent and transportation 4 percent. Brazil leads the list at 18 percent of the total industrial use globally in 2009. Since the 1970s, Brazil has saved almost $50 billion in imported oil costs due to the production of biomass energy and fuel..

SOURCES Wood pellets

Wood pellets are a type of wood fuel, generally made from compacted sawdust. They are usually produced as a byproduct of sawmilling and other wood transformation activities. High-efficiency wood pellet stoves and boilers have been developed in recent years, offering combustion efficiencies of over 90%.

Biomass briquettesBiomass briquettes are made from agricultural waste and are a replacement for fossil fuels such as oil or coal, and can be used to heat boilers in manufacturing plants, and also have applications in developing countries. Biomass briquettes are a renewable source of energy and avoid adding fossil carbon to the atmosphere.

BiofuelsBiofuel is a bioorganic fuel. This is a scientific name for any plant or animal substance that can burn of two types , (plant and animal). Biofuel is an alternative considered to replace petroleum gas (gasoline) or petrol. Bioethanol, Bio methane and biodiesel are biofuels. Biofuels can be used as transportation fuels liquids and non-transportation for combined heat and power generation.

Industrial residues are solid (as paper, fibers, textile, pulp, etc.) and liquid industrial residues (which could be used for production of biodiesel, ethanol, etc.).

Municipal solid waste (MSW) is a waste that includes predominantly household waste (domestic waste) with sometimes the addition of commercial wastes collected by a municipality within a given area. The term residual waste relates to waste left from household sources containing materials that have not been separated out or sent for reprocessing.

EFFICIENCY AND COST Since biomass energy can be used for producing electricity and heat, it needs to be utilized in the best way

possible. The actual efficiency depends heavily on the source of the biomass and the method of extracting the energy that is being used. For instance, wood is considered to be a source of biomass and it is certainly renewable. In order to make wood like this, a process known as Torre faction needs to be carried out, but this is something that takes time and money.

Moreover, the most common form of biomass energy is extracting ethanol from various sources, but this is also something takes time and resources. Currently the best source for ethanol is corn, but slowly newer sources and cheaper procedures are being created. Some experts also say that a certain amount of biomass will roughly allow only 25% - 30% of the energy that the same amount of coal would allow. In addition, there are several waste products that also arise as a result of harnessing this energy, and this affects the energy costs and the overall efficiency of these energy sources.

Ultimately, its efficiency will depend on the manner in which the biomass is collected. If it is farmed specially for the purpose of creating energy, then this source makes sense. But, simply using biomass because it is around will eventually lead to a depletion of these sources as well, and also cause pollution and leave unwanted residues at the same time. The amount of energy that is derived should be on par with the environmental damage that occurs, and we still need more time to minimize such damage while using biomass energy.

EFFECIENCY AND COST Costs of Biomass Energy

Biomass Energy in general costs around 10-13c/kWh depending on the feedstock used and the type of technology used in energy conversion. It is possible to have costs of 5c/kWh for coffering plants which use existing equipment. Cogeneration is a cheaper option for agricultural industry owners. Sawmill and paper plants owners can generate at very low cost of under 5c/Kwh as their feedstock is virtually free and would be entirely wasted if not used to generate electricity. Sugar plants these days have ethanol production and electricity generation as very important revenue streams.

Cost of a Biomass Power Plant

A Biomass Power Plant like Biomass Energy has a very wide range of costs. Small plants generally have higher costs while larger plants can be built at a lower cost per Megawatt.

Small plants can cost between $1.5-4/watt for building. While co-firing plants can cost as little as 25c/Watt. Note some of the larger biomass plants being built are between  $2-3/watt. Note the important thing to consider when investing in a biomass power plant is to look into the LCOE being generated by biomass electricity. The investment in the biomass plant is only a part of the total costs of bioelectricity.

EQUIPMENT (EXTRACTION) There are two methods of generating energy out of biomass materials; wet and dry process.

Dry processes; Combustion and Pyrolysis. Wet processes; Gasification, fermentation, and anaerobic digestion.

Combustion: The most obvious way of extracting energy from biomass is combustion. Combustion systems come in a wide range of shapes and sizes burning virtually any kind of fuel, manure, to tree trunks, and scarp materials. Its mostly use for cooking and heating industrial buildings. One problem with this method is its very low efficiency. With an open fire most of the heat is wasted and is not used to cook or whatever.

Pyrolysis: Biomass energy can be produced by roasting dry woody matter like straw and woodchips. The process has been used for centuries to produce charcoal. The material is pulverized then fed into a reactor vessel and heated in the absence of air. One of the most useful products is methane, which is a suitable fuel for electricity generation using high-efficiency gas turbines.

Anaerobic digestion: Biogas is produced when wet sewage sludge, animal dung or green plants are allowed to decompose in a sealed tank under anaerobic (oxygen-free) conditions. The residue left after digestion is a potentially valuable fertilizer or compost.

Fermentation: Ethanol is produced by the fermentation of sugar solution by natural yeasts. Suitable feed stocks include crushed sugar beet and fruit. After about 30 hours of fermentation, the brew contains 6-10 per cent alcohol, which can be removed by distillation as a fuel.

Gastification: using wood produces a flammable gas mixture of hydrogen, carbon monoxide, methane and other non flammable by products. This is done by partially burning and heating the biomass (using the heat from the limited burning) in the presence of charcoal (a natural by-product of burning biomass). The gas can be used instead of petrol and reduces the power output of the car by 40%. It is also possible that in the future this fuel could be a major source of energy for power stations

ECOLOGICAL PROBLEMS Environmental Problems

Some of the common ways biomass energy is used and has been used for generations produce a high level of carbon dioxide. This occurs when wood is burned.

It becomes more of the a problem when the wood is cut for the purpose of burning as we create more carbon dioxide while removing a living plant that helps control carbon by its very existence.

Cutting down forests to use wood as a biomass fuel has damaged many third world countries that did not plan for any forest conservation or renewal.

Trees in a forest capture and hold carbon. By cutting live trees and burning the wood, we double the negative affect on the environment. This is now understood and accepted but for some areas the knowledge comes too late.

There are countries where the forest has been clear-cut to burn wood for heat and cooking. The resulting living conditions in a poor country are even worse once the trees are gone as land is open to flooding and erosion.

Pollution of Biomass Energy

Biomass fuels such as ethanol are no less a pollutant than fossil fuels. Combustion of ethanol is incomplete and this produces the black carbon which is known to increase global warming.

Use of ethanol as a gasoline additive is promoted as reducing our reliance on fossil fuels. An entire prosperous industry has grown in recent years around the production and distribution of ethanol.

Though some experts claim ethanol has a damaging effect on automobile engines over time and is not better for the environment, the product continues to be used as the profits are too high to abandon.