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Woody Biomass Resources, posted in Biofuels, Industry.


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Woody Biomass Resources

News » Energy | Biofuels | Environment | Hydrogen | Solar | Transportation | Wind
October 27th, 2008 - View Comments

Woody Biomass Pellets Biomass power is the largest source of renewable energy as well as a vital part of the waste management infrastructure. An increasing global awareness about environmental issues is acting as the driving force behind the use of alternative and renewable sources of energy. A greater emphasis is being laid on the promotion of bioenergy in the industrialized as well as developing world to counter environmental issues.

Biomass may be used for energy production at different scales, including large-scale power generation, CHP, or small-scale thermal heating projects at governmental, educational or other institutions. Biomass comes from both human and natural activities and incorporates by-products from the timber industry, agricultural crops, forestry residues, household wastes, and wood. The resources range from corn kernels to corn stalks, from soybean and canola oils to animal fats, from prairie grasses to hardwoods, and even include algae. The largest source of energy from wood is pulping liquor or black liquor, a waste product from the pulp and paper industry.

Woody biomass is the most important renewable energy source if proper management of vegetation is ensured. The main benefits of woody biomass are as follows:

  • Uniform distribution over the world’s surface, in contrast to finite sources of energy.
  • Less capital-intensive conversion technologies employed for exploiting the energy potential.
  • Attractive opportunity for local, regional and national energy self-sufficiency.
  • Techno-economically viable alternative to fast-depleting fossil fuel reserves.
  • Reduction in GHGs emissions.
  • Provide opportunities to local farmers, entrepreneurs and rural population in making use of its sustainable development potential.

The United States is currently the largest producer of electricity from biomass having more than half of the world’s installed capacity. Biomass represents 1.5% of the total electricity supply compared to 0.1% for wind and solar combined. More than 7800 MW of power is produced in biomass power plants installed at more than 350 locations in the U.S., which represent about 1% of the total electricity generation capacity. According to the International Energy Agency, approximately 11% of the energy is derived from biomass throughout the world.

Biomass Resources

Biomass processing systems constitute a significant portion of the capital investment and operating costs of a biomass conversion facility depending on the type of biomass to be processed as well as the feedstock preparation requirements. Its main constituents are systems for biomass storage, handling, conveying, size reduction, cleaning, drying, and feeding. Harvesting biomass crops, collecting biomass residues, and storing and transporting biomass resources are critical elements in the biomass resource supply chain.

All processing of biomass yields by-products and waste streams collectively called residues, which have significant energy potential. A wide range of biomass resources are available for transformation into energy in natural forests, rural areas and urban centres. Some of the sources have been discussed in the following paragraphs:

Biomass Cycle
A host of natural and human activities contributes to the biomass feedstock

1. Pulp and paper industry residues
The largest source of energy from wood is the waste product from the pulp and paper industry called black liquor. Logging and processing operations generate vast amounts of biomass residues. Wood processing produces sawdust and a collection of bark, branches and leaves/needles. A paper mill, which consumes vast amount of electricity, utilizes the pulp residues to create energy for in-house usage.

2. Forest residues
Forest harvesting is a major source of biomass for energy. Harvesting may occur as thinning in young stands, or cutting in older stands for timber or pulp that also yields tops and branches usable for bioenergy. Harvesting operations usually remove only 25 to 50 percent of the volume, leaving the residues available as biomass for energy. Stands damaged by insects, disease or fire are additional sources of biomass. Forest residues normally have low density and fuel values that keep transport costs high, and so it is economical to reduce the biomass density in the forest itself.

3. Agricultural or crop residues
Agriculture crop residues include corn stover (stalks and leaves), wheat straw, rice straw, nut hulls etc. Corn stover is a major source for bioenergy applications due to the huge areas dedicated to corn cultivation worldwide.

4. Urban wood waste
Such waste consists of lawn and tree trimmings, whole tree trunks, wood pallets and any other construction and demolition wastes made from lumber. The rejected woody material can be collected after a construction or demolition project and turned into mulch, compost or used to fuel bioenergy plants.

5. Energy crops
Dedicated energy crops are another source of woody biomass for energy. These crops are fast-growing plants, trees or other herbaceous biomass which are harvested specifically for energy production. Rapidly-growing, pest-tolerant, site and soil-specific crops have been identified by making use of bioengineering. For example, operational yield in the northern hemisphere is 10-15 tonnes/ha annually. A typical 20 MW steam cycle power station using energy crops would require a land area of around 8,000 ha to supply energy on rotation.

Herbaceous energy crops are harvested annually after taking two to three years to reach full productivity. These include grasses such as switchgrass, elephant grass, bamboo, sweet sorghum, wheatgrass etc.

Short rotation woody crops are fast growing hardwood trees harvested within five to eight years after planting. These include poplar, willow, silver maple, cottonwood, green ash, black walnut, sweetgum, and sycamore.

Industrial crops are grown to produce specific industrial chemicals or materials, e.g. kenaf and straws for fiber, and castor for ricinoleic acid. Agricultural crops include cornstarch and corn oil? soybean oil and meal? wheat starch, other vegetable oils etc. Aquatic resources such as algae, giant kelp, seaweed, and microflora also contribute to bioenergy feedstock.

Woody Biomass and Sustainability

Harvesting practices remove only a small portion of branches and tops leaving sufficient biomass to conserve organic matter and nutrients. Moreover, the ash obtained after combustion of biomass compensates for nutrient losses by fertilizing the soil periodically in natural forests as well as fields. The impact of forest biomass utilization on the ecology and biodiversity has been found to be insignificant. Infact, forest residues are environmentally beneficial because of their potential to replace fossil fuels as an energy source.

Plantation of energy crops on abandoned agricultural land will lead to an increase in species diversity. The creation of structurally and species diverse forests helps in reducing the impacts of insects, diseases and weeds. Similarly the artificial creation of diversity is essential when genetically modified or genetically identical species are being planted. Short-rotation crops give higher yields than forests so smaller tracts are needed to produce biomass which results in the reduction of area under intensive forest management. An intelligent approach in forest management will go a long way in the realization of sustainability goals.

Improvements in agricultural practices promises to increased biomass yields, reductions in cultivation costs, and improved environmental quality. Extensive research in the fields of plant genetics, analytical techniques, remote sensing and geographic information systems (GIS) will immensely help in increasing the energy potential of biomass feedstock.

Bioenergy 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.

Conclusions

Biomass can play a major role in reducing the reliance on fossil fuels by making use of thermo-chemical 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. Biomass energy could also aid in modernizing the agricultural economy. 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.

Written by Salman Zafar, Renewable Energy Expert.

What do you think?

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  • Chris Johnson

    1. Why does the author wish to further deforest our already ailing planet?

    2. How much would topsoil be depleted by collection and consumption of natural grasses rather than leaving them to decompose?

    3. Why do engineers think they’re smarter than the Creator (your choice) who put the tremendously complex, intricately interrelated ecosystems in place? It appears they are interested primarily in profit, not serving as stewards of our bounty.

  • Salman

    Thanks for your kind words, Mr. Johnson
    (1) The author has no wish to cut down forests to produce energy. You should have read the full article before jumping to such a conclusion. The author is talking about biomass residues and the crops that can grown on non-arable land.
    (2) The depletion of the topsoil would be much less than that caused by other human activities, if biomass wastes can be collected and utilized for energy production.
    (3) Engineers, like the author, are not challenging the Creator. Infact, they are are trying to produce energy from different wastes to satiate the ever-increasing energy appetite of the mankind.

    With due respect to you
    Salman

  • Jim Cook

    I have to agree with Salman. Anyone who has followed even the timber industry alone, should realize that it is one of the perfect renewable resources, and one of the reasons why the use of wood and wood products have endured so long. My wise grandfather talked with me about the importance of this 40 years ago, and he was just a poor country farmer that did not even finish high school. The use of vegetative/woody products and other natural energy sources of this planet (and perhaps eventually others), particularly when they are so easily renewable (such as planted forests, algae, and crop by-products) should be the primary focus of a planned, sustainable, renewable, low-impact initiative to reduce dependence of fossil fuels. The use of planted forests and ag by-products in North America is a stellar example of how this could be done on a larger scale than it already is. And a healthier planet will be the result…

  • Salman

    I agree with you, Jim. If agriculture is modernized up to reasonable standards in various regions of the world, several billions of hectares may be available for biomass energy production. This land would comprise degraded and unproductive lands or excess cropland, and preserve the world’s nature areas and quality cropland.
    Biofuels are one way to ensure adequate fuel supplies at a time when yields from existing oil fields are declining and new fields are not yet up and running. Biofuels can do much to help fill the gap between limited fuel supplies and increasing worldwide demand—a gap that is almost sure to widen in the coming years.

  • http://www.energyprofessional.in M.R.Menon

    Dear Salman:

    You wrote an excellent article. I suggest you to please do a study on kitchen waste from 3-5 star hotels and large educational and technical institutions. My friend Mr. B.J.Britto, the MD of Britto Energy Engineers in Mumbai have installed a bio-mass plant at Larsen & Toubro’s canteen in Powai. This plant not only gets rid of the kitchen waste but also produces bio-gas for cooking purposes.

    When the crude oil price hit the roof with US $145 per barrel, I thought renewable energy projects will be given priority. Alas, now the price crashed down to US $62 per barrel and is likely to hit the bottom price of US $45 per barrel very soon. This will make the players in the Clean Development Mechanism more richer.

    With best wishes,

    Solarically yours,
    M.R.Menon
    Sub-Editor, Energy Manager and
    Editor, Sun Power, India

  • Salman

    Dear Menon Saheb
    Many thanks for your kind words. Food residuals from hotels, restaurants, institutions and homes have very good biogas potential due to high percentage of organic matter, As per your wishes, I will write an article soon on this topic.
    CDM has become a tool to outsource pollution to the developing world. There should be an equal responsibility on industrialized and developing world to mitigate climate change.
    Thanks again
    Warm regards
    Salman

  • http://victorygasworks.com Amanda

    Salman and Cook,

    I am a member of VictoryGasworks.com an online community for alternative energy utilizing biomass gasification or wood gasification.

    http://VictoryGasworks.com is a cool social network where we take (like Salman writes) biomass from nonagricultural crops, yard waste, wood waste, any kind of biowaste and convert it into energy through gasification. The site really explores biomass gasification as an alternative energy source and the pros and cons of current gasifiers. People share their findings, thoughts, inventions etc…

    Your article Salman is good and it’s nice to see a good article on biomass and how it can be turned into clean renewable energy.

  • http://www.renewable.com.au Prof. Tenta

    Biomass is an excellent energy source, what with ti being renewable and all!! It is a fantastic way for Australia to use rubbish etc. in a useful way, because if not that rubbish would have added dramatically to the amount of rubbish clogging up our country that we are running out of room to store!!

  • Salman

    I agree with your views, Prof Tenta. Biomass as an energy source can solve our energy problems as well as waste management headaches.
    Thanks for your comments.
    Salman

  • Hipnology

    The use of woody biomass will be a key ingredient in helping managing the health of our forests. Just look a Finland and other European countries. The amount of fiber that could be utilized on a renewable basis is outstanding. Lets just hope the state and federal agencies will buy in to this type of harves. I agree with all.

  • http://www.initsiaator.com Eero

    In North America (US)is company what have begin to retrofit wood pellet burners in to oil boilers. Even price of the oil is now low , there is lot of interest of the wood pellet burner technology. Pellergy LLC VT.

  • bhupendra

    Pl. take a note that biomass gasifier is of great use, but biomass storage, drying and transportation is one of the problem for larger gasifiers.

    Pl. send details for storage of biomass woody biomass for 15 days and drying from 40% moisture to less than 20% and then storage and conveying to gasifier of 1.5 MWe plant. The biomass required 1200 kg/hr, bulk density is 445 kg/m3.

    Awaiting for reply.

  • bill west

    How many tons of biomass is there in a typical acre of woods if you were to utilize everything available in that acre?

  • Bubba

    Biomass – Hmmmmmm

    Back in my day they used to call it something else,…firewood.

    I like wood pellets. Easier to handle than cordwood.

    I’d like to see more pellets made from stuff like grass, goldenrod or hemp. Burning goldenrod will not support foreign terrorists.

  • christopher

    I like your article i am currently a forestry student at HSU and am writing a paper on woody biomass energy and although your article is a good overview i think your estimate of how much energy is produced from woody biomass should include heating energy from wood stoves and other wood burning heat sources which are becoming more popular especially as programs like fuels for schools (http://www.fuelsforschools.info/pdf/business_outlook.pdf) are starting in state’s with timber lands. The main problem with biomass is getting it from where it is grown to a processing faculty because of its bulkiness many times it cant pay its own way out of the woods or field at least not yet.

    PS if anyone has any links to sites that are about the energy potential of woody biomass on a MW per acre terms especially pertaining to CA they would be appreciated

  • http://www.dac.us Jason San Souci, GISP

    Hi Bill,

    The number of bone dry tons (BDT) of biomass available in a single acre of forest varies by region, forest type and density. In the southwest, there are 27 BDT per acre in a medium density mixed conifer forest and upwards of 44 BDT per acre in a high density pinon-juniper woodland. Obviously, not every acre is clear-cut to create hog fuel feedstock, but forest residues as a result of restoring forests and woodlands to healthy stocking levels is a viable source of woody biomass. I hope this helps.

  • 622149

    this is good

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