Plant biomass can be burnt as fuel or fermented to release heat energy or used to make fuels such as ethanol or diesel. Biomass cellulose crops are already being burnt with coal at power stations. USA alone uses > 30% of their maize crop for ethanol production. Brazil uses huge quantity of sugarcane for biofuel production that has significantly reduced the country's dependence on fossil fuels. However, there is reasonable aversion for using food crops such as sugarcane, wheat and maize for fuel and more sustainable solutions are being looked-for. Certain cellulosic/lignocelluloses biomass yielding plant species like Agave can provide very high yields with low water inputs compared with other crops even in hot arid regions. Further, to combat global warming, emission of carbon dioxide must be drastically reduced. In this connection, 'Biochar' involving heating of plant material in absence of air to convert carbon into charcoal has attracted attention in recent times as in this form, carbon cannot readily re-enter the air, and, if added to the soil, can increase fertility. With these options, what are other prospects of tackling pressing issues of energy crisis and global warming and to what extent plants can contribute?
@Selvaraju
and yes, if American's weren't driving around 2-3 metric tons of metal over long distances, biofuel penetration would have occurred earlier. Gasoline is the only thing that has sufficient energy density to satisfy the manifest consumption destiny of America.
On a more seroius note - yes if we drove 1 Metric Ton vehicles then switch grass grown on American and Canadian praries could reach 50% of total consumption without any need for new technology.
http://www.agmrc.org/commodities__products/biomass/switchgrass-profile
is a good synposis
1, Cellulosic ethanal (from feed stocks like swithgrass) is quite promising as an alternative to gasoline. People that live in the past will argue that this has a Negative Net energy gain (which it used to 25 years ago), but many recent field studies now show very positive energy gain (up to 300% in some cases).
2. Burning biomass to make electricity can be done but you do have to worry about the particulate emission as well as CO emission (e.g. carbon monoxide)
3. Sugar cane has the highest available energy density and Brazil can grow a lot of it - so it is a natural source for them. Doesn't scale to the rest of the world however,.
Henry Ford predicted in 1925, “The fuel of the future is going to come from fruit like that sumac out by the road, or from apples, weeds, sawdust – almost anything. There is fuel in every bit of vegetable matter that can be fermented” (Ford Predicts Fuel from Vegetation, N.Y. TIMES, Sept. 20, 1925, p 24)
@Selvaraju
and yes, if American's weren't driving around 2-3 metric tons of metal over long distances, biofuel penetration would have occurred earlier. Gasoline is the only thing that has sufficient energy density to satisfy the manifest consumption destiny of America.
On a more seroius note - yes if we drove 1 Metric Ton vehicles then switch grass grown on American and Canadian praries could reach 50% of total consumption without any need for new technology.
http://www.agmrc.org/commodities__products/biomass/switchgrass-profile
is a good synposis
I think it would not be apt and sensible to utilize food plants for biofuel production I think it would not be apt and sensible to utilize food plants for biofuel production when a large population is still depriving of food security. There are lot of non-edible oil yielding forest seeds and other lignocellulosic biomass including forest wastes, agro-byproducts and biomass derived from commercial plantations that can be utilized if efficient and cost effective technologies are developed and applied for biofuel production.
Hi all
There's another side of the energy saving and CC issue, I guess: sparing fossil fuels used for ecological functions that can be performed by plants - like nitrogen provision to roots by legumes instead of the Carbon-costly ammonium or nitrate fertilisers. This is potentially a huge saving in CO2 emissions if we can use plants to properly close the mineral cycles in agrosystems. Many initiatives are ongoing to do this, like promoting legumes as crops or intercrops, sometimes as species mixtures (remember the age old maize/bean associations of pre-Columbian civilisations), transfering N -fixation ability to cereals and other major crops ( the Bill and Melinda Gates fundation, as well as many public agencies, currently fund large research programmes on this), re-instating mycorrhization activity in crops that lost it through domestication, again like cereals, etc...
Best
Didier
Plant derived biomass is a renewable energy because it contains the energy which comes from the sun. Through the process of photosynthesis, chlorophyll present in plants absorbs the energy from the sun by converting the carbon-dioxide present in air and water from the ground in carbohydrates. So, when these plants are burned they turn back into carbon dioxide and water and release the sun’s energy they contain. In this way, we can say that biomass is renewable source of energy because we can always produce more crops and plants and waste will always exist. As long as biomass is produced this source of renewable energy will last forever. Biomass in itself contains chemical energy. So, when wood which is a biomass fuel is burnt, the chemical energy inside released as heat. It can also be used to produce steam which can further be used to generate electricity. Using biomass for energy can cut back on waste and can also help in reducing the landfill. It may look like that biomass may result in global warming. But, in fact it is other way round. Plants use carbon dioxide and release oxygen. When these plants decay, they are burnt and carbon dioxide is released into the atmosphere. When these crops are again replanted, the new plants use the same CO2 produced by the burned plants. This way biomass does not contribute towards global warming. However, if the plants are not replanted, then biomass may release carbon dioxide (CO2) which will in turn increase global warming. So, crux of the point is biomass energy is renewable as the stored energy i.e. CO2 is release, recycled and reused. It is environment friendly as doesn’t contribute to global warming and can be produced over and over again. Plant/crop biomass is an easily available and inexhaustible fuel source and its use may lessen the dependence on fossil fuels. Though it also emits carbon-dioxide, but carbon-dioxide released by it is largely balanced by the carbon dioxide captured in its own growth.
With respect and in my humble opinion: changing growing/processing/application methods for a few plants can make a slight impact. But the urgency of the decay of air, soil and water quality requires a solution that imitates the original state of plants. That is, canopies of large trees with incrementally smaller structures (shrubs, bushes, smaller trees) and ground cover like moss, grass, and flowering plants that support insect and wildlife. Nations like Israel have successfully done this over the last half a century to regenerate water tables in formerly arid and useless land areas. Of course, this is not an immediate solution and just planting trees here and there is very similar to the aforementioned one plant solution. The establishment of coastal and water aquifers utilizing natural plant life to stabilize soil and therefore retain water in the soil is a method that requires a long-term commitment and implementation process to develop new resources even as supply in many areas grow critical. I do not think the short-term solutions for plant life that consumes CO2 to halt some decay or the use of crops as fuel can be the only solution without the reintroduction of natural plant life on a large scale that builds resources for growing, watering, etc of plants that have been deemed a large part of the solution. Without this reintroduction of nature, if you will, back into the ecosystem, we will further strain resources until they no longer become sustainable due to overuse and abuse. This morning I do not have time to do an exhaustive search, but there are resources on how to use current atmospheric precipitation that are gaining momentum. Of course, there are many other examples but this information may best represent my perspective.
http://www.nwrm.eu/sites/default/files/regional-workshops/West/day%201/4-Heather.pdf
Dear @Yogesh, You have raised two major points. One is energy! This paper Can Biomass as a renewable energy Resource be an answer to our energy crisis? is fine paper about this issue, case study of Pakistan. I find that the impact of biomass to the solution of overall energy problem is not big one!
For example, in Serbia,the goal is to increase the market share of biofuels and other
renewable fuels to at least 2,2% of the total fuel consumption in transport calculated on the basis of energy content. Potential of Biomass in Serbia follows!
http://www.academia.edu/6378211/Can_Biomass_as_a_renewable_energy_Resource_be_an_answer_to_our_energy_crisis_Prepared_for_TABLE_OF_CONTENTS
http://www.drustvo-termicara.com/resources/files/9bae712.pdf
Regarding biomass energy impact on global warming, many studies show the fact that Biomass Energy May Accelerate Global Warming!
http://ecowatch.com/2012/02/14/carbon-from-biomass-energy-may-accelerate-global-warming/
It is an interesting issue to discuss the plants' contribution to dealing with the global energy crisis and global warming. There is a related issue: this will increase the prices of food which hurts the poor people.
The scientific view that the increase in global temperature should be below two degrees Celsius, declared that "we agree that deep cuts in global emissions are required... so as to hold the increase in global temperature below two degrees Celsius." By insisting on two degrees – about 3.6 degrees Fahrenheit – the accord ratified positions taken earlier in 2009 by the G8, and the so-called Major Economies Forum. It was as conventional as conventional wisdom gets. The number first gained prominence, in fact, at a 1995 climate conference chaired by Angela Merkel, then the German minister of the environment and now the center-right chancellor of the nation. So far, we've raised the average temperature of the planet just under 0.8 degrees Celsius, and that has caused far more damage than most scientists expected. (A third of summer sea ice in the Arctic is gone, the oceans are 30 percent more acidic, and since warm air holds more water vapor than cold, the atmosphere over the oceans is a shocking five percent wetter, loading the dice for devastating floods.) Given those impacts, in fact, many scientists have come to think that two degrees is far too lenient a target. "Any number much above one degree involves a gamble," writes Kerry Emanuel of MIT, a leading authority on hurricanes, "and the odds become less and less favorable as the temperature goes up.
http://www.rollingstone.com/politics/news/global-warmings-terrifying-new-math-20120719
Dear Yogesh,
I agree with you that plant biomass can be burnt as fuel or fermented to release heat energy or used to make fuels such as ethanol or diesel. But what negative effects can plant biomass cause to mankind?
1) Biochar is an interesting way to provide local off-grid communities with a form of woodgas (to cook food or power a generator to provide electricity), directly use the heat emitted by the gas generator to heat a greenhouse or even the houses in which people live, and at the same time help to fertilise local arable land. If it is done on large scale, then it costs too much energy to ship the biomass to the large plant, the heat emitted can't be used productively, and the gas needs to be distributed by pipelines...so that it becomes non-sustainable.
2) My preferred liquid biofuel is ethanol produced from carbohydrate plants, because these are far more productive than oil plants per time of cultivation and per surface land occupied, in particular the annual crops (potato, sweet potato) can be rotated with other crops, and we can either eat those plants or use them to make fuel. And ethanol can be used to make polyethylene and polyvinylchloride and is thus far more valuable than just a fuel.
However, I am not convinced that we should do this because of the climate, we should consider this to make our future more sustainable and less dependent on fossil fuels so that we can maintain the way we live since 60 years. 2000 years ago it was about 5 degrees warmer in Europe, the Romans were cultivating vineyards in Yorkshire, and the carbon dioxide levels were lower than now. The climate is controlled by water circulation, water evaporation/condensation pumps heat back to space, water vapor is a greenhouse gas and helps us stay warm, and clouds reflect sunlight back to space during day time and keep the heat in our atmosphere during the night, and these major effects are several orders of magnitude bigger than carbon dioxide so that carbon dioxide doesn't even scratch the background noise in climate fluctuations. Climate models in which water is treated as a constant because it is impossible to include it in models and studies in which carbon dioxide levels are simply calculated as independent variable added on top because it is easy to measure is like "looking for the keys under a lamp post because the light is better".
Forget about the climate, but think about energy and food sustainability. We have enough food, and we can easily make more, but we need even more energy to distribute and preserve the food and do all the other things we like to do which have nothing to do with food, such as building with metals and cement, using electricity etc,.... And if we want to maintain a warm fertile Earth with a stable climate without extremes, we need to rebuild our forests to boost water circulation.
Hi all,
I'm no expert in either the technology or economics of biofuels, but my gut feeling is that plants grown specifically for transformation into biofuel will:
1) severely compete for land and resources with food and feed crops, that we'll need as the world population continues to increase and is now rather far from a satisfactory food status. The land debate is well known - no need to reiterate it here probably. The resource issue is less often dealt with. It is usually taken for granted that 'energy crops' are 'low-input' crops, but this is probably not always the case ('energy oilseed rape' crops are sprayed, as are the food crops), and might not remain so anyway as the quest for yield will increase to supply raw material to biofuel transformation factories without overstretching transportation costs.
2) possibly be detrimental in the long run to overall soil fertility. My understanding of biofuel crops ( especially the most interesting ones, ie the 'third generation' based on fermentation of cellulose and lignin) will use as much of the organic matter produced per land unit for transformation into biofuels, thus contributing to the depletion of organic matter in soil in the medium run. This will be even more marked with semi-perennial crops such as switchgrass or Miscanthus, as no new organic matter will be supplied to the soil as long as the crop is in place ( usually several years.
To make a long issue short, I think there are much better services we should ask plants to provide than just fill the tanks of our cars. I'd rather see them providing food, feed or timber, stocking carbon (an efficient way of decreasing the GES impacts) and increasing soil fertility by fixing nitrogen and contributing to the closing or mineral and water cycles.
Best
Didier
Didier, I agree that wood should be used as building material, natural fibre should be used to make clothing, tissues or composite materials, and high value food crops should not be turned into bio-diesel, because the value of such feedstocks exceeds their caloric value. But there are high starch crops that are so productive that their potential as bio-ethanol feedstock is real, we work towards a yield of 10,000 litres ethanol per hectar high starch potato after 6 months growth, with high quality cellulose pulp for paper production as side fraction, along with yeast extract and mineral fertiliser as added value on top. When locally produced so that the off-heat from the distillation can be used directly to heat a greenhouse on the same farm, nothing is lost and the farm produces several high value products in stead of low value potatoes (the long distance transport of which is a major cost). Just because american corn ethanol was a really bad idea and gave the bio-fuel field such bad publicity shouldn't be used as argument to categorically give up all bio-fuel research. Lignocellulosic ethanol and microalgae are "generation phantasy", but first generation biofuel can be sustainable and economical as long as the best crops are used for that. Sugar cane in Brazil works already, potato and sweet potato would work even better, nut not corn and cereals that should be eaten. If we use less land for animal farming, and grow more starch crops and legumes, we have more food and more energy.
Plants on Energy
Bioenergy carriers range from a simple firewood log to a highly refined gaseous fuel or liquid biofuel. Different biomass products suit different situations and specific objectives for using biomass are affected by the quantity, quality and cost of feedstock available, location of the consumers, type and value of energy services required, and the specific co-products or benefits. Prior to conversion, biomass feedstocks tend to have lower energy density per volume or mass compared with equivalent fossil fuels. This makes collection, transport, storage and handling more costly per unit of energy. These costs can be minimized if the biomass can be sourced from a location where it is already concentrated, such as wood-processing residues or sugar plant.
https://www.ipcc.ch/pdf/assessment-report/ar4/wg3/ar4-wg3-chapter4.pdf
Very good example of transnational organization Legacy Foundation which provides training, technology and media services for biomass fuel briquette production, environmental conservation and income generation throughout the world. Many good resources are available like training materials, case studies...!
http://www.legacyfound.org/?gclid=CPDZ9PuhwMICFarjwgod2E4AdQ
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