Anumakonda Jagadeesh's Comments

October 22, 2014

Turning Humble Seaweed to Biofuel

How about Biofuel from Agave and Opuntia,care - free growth ,regenerative CAM plants. These can be grown millions of hectares of wastelands in developing countries. Also biogas for power generation from these plants. Mexico is pioneer in this. Let India take it up on a massive scale to provide employment and to bring waste land under cultivation.Also biogas can be produced from these plants locally and biogas for cooking can be supplied through pipes just like in China.
Agave is a CAM Plant. Crassulacean acid metabolism, also known as CAM photosynthesis, is a carbon fixation pathway that evolved in some plants as an adaptation to arid conditions in a plant using full CAM, the stomata in the leaves remains shut during the day to reduce evapotranspiration, but open at night to collect carbon dioxide (CO2). The CO2 is stored as the four-carbon acidmalate, and then used during photosynthesis during the day. The pre-collected CO2 is concentrated around the enzyme RuBisCO, increasing photosynthetic efficiency. Agave and Opuntia are the best CAM Plants.
Agave Competitive Advantages
* Thrives on dry land/marginal land. Most efficient use of soil, water and light
* Massive production. Year-around harvesting
* Very high yields with very low or no inputs
* Very high quality biomass and sugars
* Very low cost of production. Not a commodity, so prices are not volatile
* Very versatile: biofuels, byproducts, chemicals
* World-wide geographical distribution
* Enhanced varieties are ready.
Another care-free growth plant is OPUNTIA.
Biogas from Opuntia
A source of renewable gas and fertilizer
Structure of the proposed process
1st step: Production of Biomass (Opuntia)
2nd step: Process of the Biomass into Biogas through Anaerobic Fermentation
3rd step: Process of the Digested Material into Fertilizer
The potential of Opuntia Biomass for energy production in semi-arid areas
100 to 400 tons of biomass/ha/year
1 ton Opuntia biomass = 50-60 m3 of biogas = 300-360 kWh of gas
30 000 to 140 000 kWh per ha
150 to 400ha necessary for 1MW electrical capacity
High efficiency in water & fertilizer use
Reduced risk for farmers of crop failure due to high drought tolerance. No competition with food crops on arable land as it can grow on degraded land.
Study on renewable biogas energy production from cladodes of Opuntia ficus indica by Elias Jigar, Hameed Sulaiman and Araya Asfaw and Abraham Bairu (ISABB Journal of Food and Agriculture Science Vol. 1(3), pp. 44-48, December 2011) revealed:
Cladodes, which are a plate like section of Opuntia ficus indica, were characterized for their physical properties, total solids (TS) and volatile solides (VS) and they were assessed in five combinations with or without cow dung for their suitability to biogas production in 2.8 L triplicate batch digesters. The highest total biogas yields were obtained from T5 (75% Cow dung: 25% Cladodes combination) as 14.183 L followed by T1 (cow dung alone) as 13.670 L (0 .022 m3/kg) and the lowest was from T2 (Cladodes alone) as 6.176 L. The percentage of methane gas obtained from the experiment for treatments T1, T2, T3 (50% cow dung: 50% cladodes), T4 (25% cow dung: 75% Cladodes) and T5 were 66.33, 53.16, 63.84, 52.1 and 69% respectively. Among all treatments, T5 was found to produce high methane percent of the biogas.
From Biogas, Power generation can be done at local level itself.
Another Option is to utilize Water Hyacinth which has become a menace for Biogas and subsequent power generation. In Indonesia Fine Furniture is made from Water Hyacinth.
Youth Economic Zones(YEZ):
The waste land can be allotted to youth with agricultural background (about 10 acres) on lease and ten such people can form a co-operative. They can grow fast growing care free plants like Agave, Opuntia and Jatropha. Biogas and biofuel can be generated at local level. Biogas power plants from KW size to MW size are available commercially from China. This way unemployment problem can be solved to some extent and the waste land can be brought under use.

Also in Philippines people weave clothes under the trade name DIP DRY. The specialty of these clothes, water won't stick to it. Just rinse the used clothes in soap water weave it and wear. Also Hecogenin a steroid can be got from it. There is cellulose and it can be input for paper making. There is a Paper mill in Brazil with raw material from Agave. Also in Tanzania,Lesotho,Kenya people curt the agave into pieces, dry them and mix them in concrete. Since it has fibrous material there will be binding.
Dr.A.Jagadeesh Nellore(AP),India
Renewable Energy Expert

October 21, 2014

Earth to Cellulosic Biofuels: Good to See You, Buddy, What Took So Long? Part II

Excellent.
Dr.A.Jagadeesh Nellore(AP),India

October 19, 2014

New Software Modeling Tool a Boon for Wind Industry

I hope Indian Wind Turbine Manufacturers and Wind Energy Promoters will look into this.
Dr.A.Jagadeesh Nellore(AP),India
Wind Energy Expert

October 16, 2014

Action in India: Government Announces 15-GW Solar Power Purchase Program

Such ambitious plans are welcome provided the targets are achieved which is known in Energy Sector in India.
Dr.A.Jagadeesh Nellore(AP),India

October 16, 2014

Putin Strengthening China-Russia Ties for Renewable Energy Development

When two giants join there will be explosion of Renewable Energy.
Dr.A.Jagadeesh Nellore(AP),India

October 15, 2014

Offshore Wind Power Can Save US Billions On Electricity, Recent DOE Study Finds

Yes. US can go in for massive offshore wind projects. Already US is leader in onshore wind. Countries like China,Taiwan,Republic of Korea,France have ambitious plans to harness offshore wind energy.
Dr.A.Jagadeesh Nellore(AP),India

October 14, 2014

India Should Move Solar to Fixed Tariffs, Yes Bank Says

Yes. I agree.
Dr.A.Jagadeesh Nellore(AP),India

October 14, 2014

New Report Sheds Light on the Old "Food Vs. Fuel" Bioenergy Debate

Excellent article.
In the debate Food Vs Fuel,fortunately there are alternatives like Agave and Opuntia for Corn and Sugarcane as biofuel.

According to Arturo Velez, Agave Expert:
“On an annualized basis agave produces 3X more distilled ethanol than sugar cane in Brasil; 6X more distilled ethanol than yellow corn in the US; at least 3X more cellulosic ethanol than switchgrass or poplar tree. Producing one gallon of distilled ethanol from agave costs at the most half the cost of one gallon from sugar cane and one fourth of corn's production cost.
One hectare of Agave captures at least 5X more CO2 than one hectare of the fastest growing Eucalyptus on a high density plantation and in one single year agave produces the same cellulose pulp Eucalyptus produces in 5 years”..
CAM species such as Agave show considerable promise as a biofuel crop for the future due to their high water-use efficiency, tolerance to abiotic stress (e.g., drought and high temperatures), and potential for high biomass production on marginal lands .
The optimal use of water to grow a selected feedstock is of critical importance because water scarcity, more than any other factor, determines whether land is suitable for growing food crops. Thus, growing plants with high water-use efficiency on land that is too dry to grow food crops is a potentially powerful strategy for producing biomass feed stocks in large amounts while minimizing competition with the food supply. Additionally, making productive use of semi-arid land can have positive effects on poor rural areas. The water-use efficiency (WUE) value (grams CO2 fixed/kilogram water transpired) varies markedly among plants with different types of photosynthetic metabolism. C3 plants typically have WUE values of 1–3; C4 plants, between 2 and 5; whereas crassulacean acid metabolism (CAM) plants have values between 10 and 40. Therefore, CAM plants can be cultivated in arid or semi-arid land normally unsuitable for the cultivation of most C3 and C4 crops. It is exceedingly unlikely that a C3 or C4 plant could be developed, with or without genetic modification, with water-use efficiency approaching that of CAM plants.Moreover, CAM plants are native to essentially every state in the USA except Alaska, although they are prominent parts of ecosystems only in the Southwest.
In spite of this potential, CAM plants have received much less systematic study or development as energy crops relative to inherently less water-efficient plants such as corn (maize), sugarcane, switch grass Miscanthus, poplar, sugar beets, Jatropha, soy, and canola.
Cellulose content is far more in Agave Americana compared to Deciduous Wood,sugarcane,wheat straw,corn stover and switch grass while lignin content is far less in Agave Americana as compared to the others mentioned.
A group of Mexican researchers believe they've discovered what they call the "missing energy crop," and though it hasn't exactly been missing-it grows abundantly in Mexico and in some southern U.S. and South American locations-these scientists claim agave possesses characteristics superior to other feedstocks currently being examined for biofuel purposes, such as cellulosic ethanol production.
Agave is arguably one of the most significant plants in Mexican culture. It has a rosette of thick fleshy leaves, each of which usually end in a sharp point with a spiny margin, and is commonly mistaken for cacti.

President Barack Obama’s Plan to tackle Climate Change includes,” The US will increase its research and development of bio ethanol as fuel. I believe biomass and ethanol are a part of the solution and belong in the green transition. Yet bio fuels and ethanol are many things. Not all are green and not all are sustainable in the broadest sense. For bio ethanol to belong in the green economy it has to deliver substantial greenhouse gas savings and avoid negative impact on food prices. Only then will it be good business for farmers and good for the climate. The technology is available and ready to be scaled up. Second generation bio ethanol is an emerging market with the potential to reduce 85 pct. of CO2 emission compared to regular fossil fuels in transportation. It is also a local resource increasing energy independence and creating local jobs in agriculture, factories and logistics.”. It is most welcome.

Hitherto Corn and Sugarcane are used in the biofuel production. In the debate on FOOD Vs FUEL, it is necessary to find alternatives.

“Agave has a huge advantage, as it can grow in marginal or desert land, not on arable land,” and therefore would not displace food crops, says Oliver Inderwildi, at the University of Oxford. The majority of ethanol produced in the world is still derived from food crops such as corn and sugarcane. Speculators have argued for years now that using such crops for fuel can drive up the price of food.

Agave, however, can grow on hot dry land with a high-yield and low environmental impact. The researchers proposing the plant’s use have modeled a facility in Jalisco, Mexico, which converts the high sugar content of the plant into ethanol.
The research, published in the journal Energy and Environmental Science, provides the first ever life-cycle analysis of the energy and greenhouse gas balance of producing ethanol with agave. Each megajoule of energy produced from the agave-to-ethanol process resulted in a net emission of 35 grams of carbon dioxide, far below the 85g/MJ estimated for corn ethanol production. Burning gasoline produces roughly 100g/MJ.“The characteristics of the agave suit it well to bioenergy production, but also reveal its potential as a crop that is adaptable to future climate change,” adds University of Oxford plant scientist Andrew Smith. “In a world where arable land and water resources are increasingly scarce, these are key attributes in the food versus fuel argument, which is likely to intensify given the expected large-scale growth in biofuel production.”

Agave already appeared to be an interesting bio ethanol source due to its high sugar content and its swift growth. For the first time Researchers at the universities of Oxford and Sydney have now conducted the first life-cycle analysis of the energy and greenhouse gas (GHG) emissions of agave-derived ethanol and present their promising results in the journal Energy & Environmental Science.

On both life cycle energy and GHG emissions agave scores at least as well as corn, switch grass and sugarcane, while reaching a similar ethanol output. The big advantages agave has over the before mentioned plants is that it can grow in dry areas and on poor soil, thus practically eliminating their competition with food crops and drastically decreasing their pressure on water resources.

Plants which use crassulacean acid metabolism (CAM), which include the cacti and Agaves, are of particular interest since they can survive for many months without water and when water is available they use it with an efficiency that can be more than 10 times that of other plants, such as maize, sorghum, miscanthus and switchgrass. CAM species include no major current or potential food crops; they have however for centuries been cultivated for alcoholic beverages and low-lignin fibres.
They may therefore also be ideal for producing biofuels on land unsuited for food production.

In México, there are active research programs and stakeholders investigating Agave spp. as a bioenergy feedstock. The unique physiology of this genus has been exploited historically for the sake of fibers and alcoholic beverages, and there is a wealth of knowledge in the country of México about the life history, genetics, and cultivation of Agave. The State of Jalisco is the denomination of origin of Agave tequilana Weber var. azul, a cultivar primarily used for the production of tequila that has been widely researched to optimize yields. Other cultivars of Agave tequilana are grown throughout México, along with the Agave fourcroydes Lem., or henequen, which is an important source of fiber that has traditionally been used for making ropes. The high sugar content of Agave tequilana may be valuable for liquid fuel production, while the high lignin content of Agave fourcroydes may be valuable for power generation through combustion.

Along with Agave species described above, some other economically important species include A. salmiana, A. angustiana, A. americana, and A. sisalana. Agave sisalana is not produced in México, but has been an important crop in regions of Africa and Australia. Information collected here could thus be relevant to semi-arid regions around the world.

Agave is a CAM Plant. Crassulacean acid metabolism, also known as CAM photosynthesis, is a carbon fixation pathway that evolved in some plants as an adaptation to arid conditions in a plant using full CAM, the stomata in the leaves remains shut during the day to reduce evapotranspiration, but open at night to collect carbon dioxide (CO2). The CO2 is stored as the four-carbon acidmalate, and then used during photosynthesis during the day. The pre-collected CO2 is concentrated around the enzyme RuBisCO, increasing photosynthetic efficiency. Agave and Opuntia are the best CAM Plants.

Agave Competitive Advantages

* Thrives on dry land/marginal land. Most efficient use of soil, water and light
* Massive production. Year-around harvesting
* Very high yields with very low or no inputs
* Very high quality biomass and sugars
* Very low cost of production. Not a commodity, so prices are not volatile
* Very versatile: biofuels, byproducts, chemicals
* World-wide geographical distribution
* Enhanced varieties are ready.

Agave can be grown in huge areas of waste lands in Developing countries like India. Another route of power production is biogas generation from Agave as well as Opuntia. Biogas power generators are commercially available. This way power can be generated at local level with local resources. Both agave and Opuntia are regenerative plants.
In their research paper SARAH C. DAVIS et al conclude:
"Large areas of the tropics and subtropics are too arid or degraded to support food crops, but Agave species may be suitable for biofuel production in these regions. We review the potential of Agave species as biofuel feedstocks in the context of ecophysiology, agronomy, and land availability for this genus globally. Reported dry biomass yields of Agave spp., when annualized, range from 1 to 34Mg /ha/yr without irrigation, depending on species and location. Some of the most productive species have not yet been evaluated at a commercial scale. Approximately 0.6Mha of land previously used to grow Agave for coarse
?bers have fallen out of production, largely as a result of competition with synthetic ?bers.
Theoretically, this crop area alone could provide 6.1 billion L of ethanol if Agave were reestablished as a bioenergy feedstock without causing indirect land use change. Almost one-?fth of the global land surface is semiarid, suggesting there may be large opportunities for expansion of Agave crops for feedstock, but more ?eld trials are needed to determine tolerance boundaries for different Agave species(The global potential for Agave as a biofuel feedstock, GCB Bioenergy (2011) 3, 68–78, doi: 10.1111/j.1757-1707.2010.01077.x)."
Agave and Opuntia are the best choice to grow in waste and vacant lands in Asia,Africa and Latin America.The advantage with the plants is both are regenerative and thrive under harsh conditions.

Another plant of great use is OPUNTIA for biofuel / biogas production.

The cultivation of nopal((OPUNTIA FICUS-INDICA), a type of cactus, is one of the most important in Mexico. According to Rodrigo Morales, Chilean engineer, Wayland biomass, installed on Mexican soil, “allows you to generate inexhaustible clean energy.” Through the production of biogas, it can serve as a raw material more efficiently, by example and by comparison with jatropha.
Wayland Morales, head of Elqui Global Energy argues that “an acre of cactus produces 43 200 m3 of biogas or the equivalent in energy terms to 25,000 liters of diesel.” With the same land planted with jatropha, he says, it will produce 3,000 liters of biodiesel.
Another of the peculiarities of the nopal is biogas which is the same molecule of natural gas, but its production does not require machines or devices of high complexity. Also, unlike natural gas, contains primarily methane (75%), carbon dioxide (24%) and other minor gases (1%), “so it has advantages from the technical point of view since it has the same capacity heat but is cleaner, “he says, and as sum datum its calorific value is 7,000 kcal/m3.
Javier Snchez et al in their extensive study on Opuntia as potential input for bioethanol concluded:
“Prickly pear is a widely-known crop in the SE of Spain, where it is currently used for forage, fodder and fruit. Now it is being considered as a potential crop for bioethanol production from its whole biomass. In order to estimate the potential bioethanol production in the province of Almeria (SE-Spain) and the optimal location of bioethanol processing plants, a GIS analysis involving a predictive yield model of prickly
pear biomass was undertaken following specific restriction criteria. According to this analysis, the total potential bioethanol production in Almeria would be up to 502,927.8 t dm•year–1 from 100,616 ha maximum that could be cultivated with prickly pear, with a calculated yield ranging between 4.2 and 9.4 t dm•ha–1•year–1. An exclusive suitability analysis and a preferable suitability analysis based on the
Analytic Hierarchy Process were performed in order to estimate the optimal location of the subsequent processing plants within Almeria’s road network by a discrete location-allocation model.”(Javier Snchez , Francisco Snchez , Mara Dolores Curt & Jess Fernndez (2012) Assessment of the bioethanol potential of prickly pear (Opuntia ficus-indica (L.) Mill.) biomass obtained from regular crops in the province of Almeria (SE Spain), Israel Journal of Plant Sciences, 60:3, 301-318).
In the developing countries like India which has vast waste land Opuntia can be grown along with Agave for Biofuel/Biogas and subsequent power generation.
Corn ethanol, for example, has an energy balance ratio of 1.3 and produces approximately 300-400 gallons of ethanol per acre. Soybean bio diesel with an energy balance of 2.5, typically can yield 60 gallons of bio diesel per acre while an acre of sugar cane can produce 600-800 gallons of ethanol with an energy balance of 8.0. An acre of poplar trees can yield more than 1,500 gallons of cellulosic ethanol with an energy balance of 12.0, according to a National Geographic study published in October 2007.

Dr.A.Jagadeesh Nellore(AP),India
E-mail: anumakonda.jagadeesh@gmail.com

October 14, 2014

Renewables to Drive Power Generation Growth in Africa, IEA Says

Renewables are best option as decentralised power in Africa.
Dr.A.Jagadeesh Nellore(AP),India

October 14, 2014

Earth to Cellulosic Ethanol: Glad You’re Here, Buddy, What Took so Long? Part I

Outstanding article.
Cellulosic ethanol is a biofuel produced from wood, grasses, or the inedible parts of plants.
It is a type of biofuel produced from lignocellulose, a structural material that comprises much of the mass of plants. Lignocellulose is composed mainly of cellulose,hemicellulose and lignin. Corn stover, Panicum virgatum (switchgrass), Miscanthus grass species, wood chips and the byproducts of lawn and tree maintenance are some of the more popular cellulosic materials for ethanol production. Production of ethanol from lignocellulose has the advantage of abundant and diverse raw material compared to sources such as corn and cane sugars, but requires a greater amount of processing to make the sugar monomers available to the microorganisms typically used to produce ethanol by fermentation.
Switchgrass and Miscanthus are the major biomass materials being studied today, due to their high productivity per acre. Cellulose, however, is contained in nearly every natural, free-growing plant, tree, and bush, in meadows, forests, and fields all over the world without agricultural effort or cost needed to make it grow.
According to Michael Wang of Argonne National Laboratory, one of the benefits of cellulosic ethanol is it reduces greenhouse gas emissions (GHG) by 85% over reformulated gasoline. By contrast, starch ethanol (e.g., from corn), which most frequently uses natural gas to provide energy for the process, may not reduce GHG emissions at all depending on how the starch-based feedstock is produced. According to the National Academy of Sciences in 2011, there is no commercially viable bio-refinery in existence to convert lignocellulosic biomass to fuel. Absence of production of cellulosic ethanol in the quantities required by the regulation was the basis of a United States Court of Appeals for the District of Columbia decision announced January 25, 2013, voiding a requirement imposed on car and truck fuel producers in the United States by the Environmental Protection Agency requiring addition of cellulosic biofuels to their products. These issues, along with many other difficult production challenges, led George Washington University policy researchers to state that "in the short term, [cellulosic] ethanol cannot meet the energy security and environmental goals of a gasoline alternative."

The French chemist, Henri Braconnot, was the first to discover that cellulose could be hydrolyzed into sugars by treatment with sulfuric acid in 1819. The hydrolyzed sugar could then be processed to form ethanol through fermentation. The first commercialized ethanol production began in Germany in 1898, where acid was used to hydrolyze cellulose. In the United States, the Standard Alcohol Company opened the first cellulosic ethanol production plant in South Carolina in 1910 during WWI. Later a second plant was opened in Louisiana. However, both plants were closed after WWI due to economic reasons.
The first attempt at commercializing a process for ethanol from wood was done in Germany in 1898. It involved the use of dilute acid to hydrolyze the cellulose to glucose, and was able to produce 7.6 liters of ethanol per 100 kg of wood waste (18 US gal (68 L) per ton). The Germans soon developed an industrial process optimized for yields of around 50 US gallons (190 L) per ton of biomass. This process soon found its way to the US, culminating in two commercial plants operating in the southeast during WWI. These plants used what was called "the American Process" — a one-stage dilute sulfuric acid hydrolysis. Though the yields were half that of the original German process (25 US gallons (95 L) of ethanol per ton versus 50), the throughput of the American process was much higher. A drop in lumber production forced the plants to close shortly after the end of WWI. In the meantime, a small but steady amount of research on dilute acid hydrolysis continued at theUSFS's Forest Products Laboratory. During World War II, the US again turned to cellulosic ethanol, this time for conversion to butadiene to produce synthetic rubber. The Vulcan Copper and Supply Company was contracted to construct and operate a plant to convert sawdust into ethanol. The plant was based on modifications to the original German Scholler process as developed by the Forest Products Laboratory. This plant achieved an ethanol yield of 50 US gal (190 L) per dry ton, but was still not profitable and was closed after the war.
With the rapid development of enzyme technologies in the last two decades, the acid hydrolysis process has gradually been replaced by enzymatic hydrolysis. Chemical pretreatment of the feedstock is required to prehydrolyze (separate) hemicellulose, so it can be more effectively converted into sugars. The dilute acid pretreatment is developed based on the early work on acid hydrolysis of wood at the USFS's Forest Products Laboratory. Recently, the Forest Products Laboratory together with the University of Wisconsin–Madison developed a sulfite pretreatment to overcome the recalcitrance of lignocelluloses for robust enzymatic hydrolysis of wood cellulose.
US President George W. Bush, in his State of the Union address delivered January 31, 2006, proposed to expand the use of cellulosic ethanol. In his State of the Union Address on January 23, 2007, President Bush announced a proposed mandate for 35 billion US gallons (130,000,000 m3) of ethanol by 2017. It is widely recognized that the maximum production of ethanol from corn starch is 15 billion US gallons (57,000,000 m3) per year, implying a proposed mandate for production of some 20 billion US gallons (76,000,000 m3) more per year of cellulosic ethanol by 2017. Bush's proposed plan includes $2 billion funding (from 2007 to 2017?) for cellulosic ethanol plants, with an additional $1.6 billion (from 2007 to 2017?) announced by the USDA on January 27, 2007.
In March 2007, the US government awarded $385 million in grants aimed at jump-starting ethanol production from nontraditional sources like wood chips, switchgrass and citrus peels. Half of the six projects chosen will use thermochemical methods and half will use cellulosic ethanol methods.
The American company Range Fuels announced in July 2007 that it was awarded a construction permit from the state of Georgia to build the first commercial-scale 100-million-US-gallon (380,000 m3)-per-year cellulosic ethanol plant in the US. Construction began in November, 2007. The Range Fuels plant was built in Soperton, GA, but was shut down in January 2011, without ever having produced any ethanol. It had received a $76 million grant from the US Dept of Energy, plus $6 million from the State of Georgia, plus an $80 million loan guaranteed by the U.S. Biorefinery Assistance Program.

Cellulolysis (biological approach)
The stages to produce ethanol using a biological approach are:
1. A "pretreatment" phase, to make the lignocellulosic material such as wood or straw amenable to hydrolysis
2. Cellulose hydrolysis (cellulolysis), to break down the molecules into sugars
3. Separation of the sugar solution from the residual materials, notably lignin
4. Microbial fermentation of the sugar solution
5. Distillation to produce roughly 95% pure alcohol
6. Dehydration by molecular sieves to bring the ethanol concentration to over 99.5%
In 2010, a genetically engineered yeast strain was developed to produce its own cellulose-digesting enzymes. Assuming this technology can be scaled to industrial levels, it would eliminate one or more steps of cellulolysis, reducing both the time required and costs of production.
Pretreatment
Although lignocellulose is the most abundant plant material resource, its usability is curtailed by its rigid structure. As the result, an effective pretreatment is needed to liberate the cellulose from the lignin seal and its crystalline structure so as to render it accessible for a subsequent hydrolysis step. By far, most pretreatments are done through physical or chemical means. To achieve higher efficiency, both physical and chemical pretreatments are required. Physical pretreatment is often called size reduction to reduce biomass physical size. Chemical pretreatment is to remove chemical barriers so the enzymes can have access to cellulose for microbial destruction.
The cellulose molecules are composed of long chains of sugar molecules. In the hydrolysis process, these chains are broken down to free the sugar before it is fermented for alcohol production.
There are two major cellulose hydrolysis (cellulolysis) processes: a chemical reaction using acids, or an enzymatic reaction(Source: Wikipedia)
Agave can be an excellent option for cellulosic ethanol since it is care free growth,CAM and regenerative. It can be grown in vast track of waste lands in developing countries.
Here is an excellent analysis by Anna Austin:
“As the pursuit for the perfect cellulosic ethanol feedstock continues, new light is being shed on plants traditionally used for different purposes. A group of Mexican researchers believe they've discovered what they call the "missing energy crop," and though it hasn't exactly been missing-it grows abundantly in Mexico and in some southern U.S. and South American locations-these scientists claim agave possesses characteristics superior to other feedstocks currently being examined for biofuel purposes, such as cellulosic ethanol production.

Researcher Arturo Velez Jimenez is a developer of the Agave Project, designed to explore and promote the potential of the plant, which began four years ago when he was the national administrative coordinator at the National Confederation of Forestry Producers in Mexico. Now developing the project separately from the agency, Jimenez says the research currently extends into all 17 agave regions of Jalisco State (central-western Mexico) and will soon become a nationwide project. Local Congressman Jose Luis Ortega, Juan Frias of Bioenergy Solutions, Professor Juan Villalvazo at the University of Guadalajara, the Mexican Agavaceas Net and the State Council of Agave Tequilana Producers are also participating in the project, he adds.

The core of the project is based on the research of Remigio Madrigal Lugo, a professor at the University of Chicago, who developed enhanced varieties of agave tequilana weber, agave angustifolia and agave fourcroides, according to Jimenez.

Now convinced that agave is the missing energy crop, he tells Biomass Magazine that the high-quality feedstock is reliable, abundant, easy to handle, and possesses an interesting history.
Agave is arguably one of the most significant plants in Mexican culture. It has a rosette of thick fleshy leaves, each of which usually end in a sharp point with a spiny margin, and is commonly mistaken for cacti.

According to Jimenez, more than 100 uses for the crop have been documented. "It was used as a food 9,000 years ago and probably was the main source of carbohydrates in ancient Mexico, before corn," he says. "When I was a kid, men walked the streets selling toasted agave, a candy with a very soft taste of alcohol. Nowadays, nobody makes this candy and agave isn't used as a food. Sometimes during drought, the leaves are fed to cattle, and some people collect agave worms, which are toasted and used in mescal bottles."
Lugo has been working to develop enhanced strains of different varieties of agave, including agave tequilana, angustiflio and fourcrocides, which Jimenez says have even higher sugar content and the plants are several times larger than typical agave strains. "His agave tequilana variety, for instance, produces six to 10 times more tequila than common agave," he says.

Lugo's initial agave research began in 1979, when the first agave plantation was established in Yucatan, Mexico, using an in vitro propagation protocol. In the following years, work continued with different strains of agave being developed with respective protocols for propagation in vitro. Since then, all propagation has had to be done from immature plants, since mature plants didn't allow this type of propagation, Jimenez adds. "But immature plants don't have well-defined characteristics. Thus the seedlings could be large and productive or small and unproductive, resulting in very diverse plantation. The possibility to propagate mature plants, with well-defined characteristics allows the industry to select only the best plants to propagate."

In agave characterization, among other qualities of production importance is the weight of the plant head, which determines sugar content-the heavier the head the higher the sugar content, according to the research. Lugo and Jimenez say some agave strains can possess three times more sugar than sugarcane in Brazil, four times more cellulose than the fastest-growing eucalyptus, and five times the amount of dry biomass than the genetically modified poplar tree; one hectare (2.47 acres) of agave usually produces more than 500 metric tons (551 tons) of biomass.”( Avant-Garde Agave,BIOMASS Magazine)
Dr.A.Jagadeesh Nellore(AP),India
Renewable Energy Expert
E-mail: anumakonda.jagadeesh@gmail.com

October 10, 2014

Lessons from the Cell Phone Phenomenon: How Microgrids Can Power Developing Countries

Excellent article on Microgrids.
Microgrids are gaining importance amongst researchers and practitioners alike.
Primarily these microgrids will operate connected with the national power grid, at the same time they have the potential to completely isolate themselves from the power grid and function as a stand alone grid to increase efficiency and local reliability. Microgrids are gaining importance amongst researchers and practitioners alike. Primarily these microgrids will operate connected with the national power grid, at the same time they have
the potential to completely isolate themselves from the power grid and function as a stand alone grid to increase efficiency and local reliability.
Dr.A.Jagadeesh Nellore(AP),India

Anumakonda Jagadeesh

Anumakonda Jagadeesh

Dr. Anumakonda Jagadeesh obtained his Bachelors and Masters degrees in Physics from Sri Venkateswara University, Tirupati, Andhra Pradesh, India, and his Doctorate degree in Wind Energy from the prestigious University of Roorkee {now the...

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