By Martin Lidegaard, Guest Blogger on Jun 26, 2013 at 4:13 pm
President Obama’s Climate Action Plan is promising. Curbing global warming will demand serious action from all of us. Needless to say, US leadership makes a great difference. Denmark is a mouse compared to the US elephant, but our experience proves that the President’s Plan is indeed possible and can be profitable. Over the past 30 years, the Danish economy has grown steadily, while energy efficiency has kept our energy consumption at the same level in absolute terms.
Lower Greenhouse Gases In The Coal Sector
The US will impose regulations for new and existing coal-fired power plants. That is good news and absolutely critical if the world is to stay below a 2 degree Celsius rise in global temperature, according to the International Energy Agency (IEA). IEA proposes limitations on inefficient coal-fired power plants. In Denmark we will phase out coal completely and move towards a fossil-free power and heating system by 2035. This means that no new coal plants will be built and existing capacity is being retrofitted to biomass and other sources.
More Renewable Energy In The Mix
The US will use federal lands for renewable energy aiming for an additional 10,000 MW by 2020. That is good news as well. Denmark has long had wind as a major part of the power mix and with the recent national Energy Agreement half of our electricity consumption will be supplied by wind in 2020 while we still have electricity prices – excl. VAT and energy tax but incl. Public Service Obligations (PSO) for supporting renewables – below the European average. Wind power is a good long term investment because the marginal price pr kWh is next to nothing once the turbines are up and the blades are spinning. With a free power market wind is actually driving down power prices. And renewable energy delivers local jobs and economic growth.
Create Green Infrastructure
The US will streamline electric grid transmission projects across the country. For a market-based solution to work, that is absolutely critical. In Denmark we have the Nordic Electricity Market, Nordpool. Nordpool has shown the importance of good interconnections to neighbouring countries by bringing our energy prices down. Recently we launched a Smart Grid strategy that will integrate renewable energy and consumption in a way that will recharge your batteries when the wind is blowing or the sun is shining bringing down consumer prices further. The European Union expects the market for such technology to grow from € 5 billion in 2011 to 56 billion in 2020. China and the US are also expected to invest three-figure billions in Smart Grid technology towards 2020.
Comment by Anumakonda Jagadeesh
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, switchgrass 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.
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.
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.
No comments:
Post a Comment