India ranks seventh in the world in terms of coal resources, and 10th in CBM resources. India has a good resource base for CBM with an estimated resource of 2,000 billion cubic meters (bcm) in 2,000 square kilometres out of which recoverable reserves are about 800 bcm,with a gas production potential of 105 million cubic meters a day over 20 years. 

Methane was once regarded by miners as a hazard rather than a resource and many miners died in methane explosions before the introduction of high-capacity ventilation to dilute gasses. However, if  methane is not recaptured it is not only lost as a resource but contributes to global warming. Even though the volume of methane contributing to greenhouse gasses is three times smaller than carbon dioxide, its greenhouse potential is 21 times higher. Coal mining is estimated to cause about 9 per cent of global methane emissions.

Methane captured during coal mining could be a significant, ecologically friendly source of energy, producing no particulates and only about half the CO2 associated with coal combustion. Depending on quality methane from mines could be sold to gas companies, used to generate electricity, used to run vehicles, used as feedstock for fertilizer or methanol production, used in blast furnace operators at steelworks; sold to other industrial, domestic or commercial enterprises; or used on-site to dry coal. In the USA today coal bed methane (CBM) represents between two and three per cent of all gas production.

Methane and coal are formed together during coalification, a process in which plant biomass is converted by biological and geological forces into coal. Methane is stored in coal seams and the surrounding strata and released during coal mining. Deeper coal seams contain much larger amounts of methane than shallow seams. Small amounts of methane are also released during the processing, transport, and storage of coal.

Coalbed methane (CBM) is a natural gas formed by geological, or biological, processes in coal seams. CBM consists predominantly of methane. Lower concentrations of higher alkanes and non combustible gases are also often present.

CBM was primarily formed in coal seams as a result of the chemical reactions taking place as the coal was buried at depth. The greater the temperature and duration of burial, the higher the coal maturity (rank) and hence the greater the amount of gas produced. Much more gas was produced during the “coalification” process than is now found in the seams. The lost gas has been emitted at ancient land surfaces, dissipated into the pores of surrounding rocks, removed in solution, and some will have migrated into reservoir structures forming natural gas deposits.

CBM tends to remains firmly locked in the coal at the prevailing pore fluid pressure until released as a result of mining disturbance or by specific gas production activities conducted in boreholes.

If effectively recovered, coal bed methane associated with coal reserves and emitted during coal mining could be a significant potential source of energy.

CBM is the generic name applied to the naturally occurring gas found in coal seams. It is recovered from coal seams as:

Virgin coal bed methane (VCBM)   from unmined coal using surface boreholes;Coal Bed Methane (CBM) and Virgin Coal Bed Methane (VCBM) are terms conventionally used for methane drained and captured directly from the coal seams. CBM is generally reserved (in addition to its use as a generic term for all coal seam gas) to describe the gas produced from surface boreholes ahead of mining for coal mine safety and coal production reasons. VCBM is produced by a similar process but completely independently of mining activity. Methane concentrations in VCBM are generally very high, around 99%, and can be used as a replacement for natural gas supplies.

Abandoned mine methane (AMM) from disused coal mines;

When an active coal mine is closed and abandoned, methane continues to be emitted from all the coal seams disturbed by mining, decaying gradually over time unless arrested by flooding due to groundwater recovery. Depending on the methane concentrations, local regulations and the geology it may be possible, or required for public safety reasons to continue draining or venting this Abandoned Mine Methane (AMM). AMM extraction and utilisation schemes aim to recover the gas left behind in unmined coal above and below goaf (worked-out) areas formed by longwall mining methods. The gas can either be transported by pipeline to a nearby user consumer for combustion in boilers or used on-site to generate electricity for local use or sale to the grid. AMM reservoirs consist of groups of coal seams that have been de-stressed, and therefore of enhanced permeability, but only partially degassed by longwall working. Favourable project sites are those where a market for the gas exists, the AMM reservoir is of substantial size and not affected by flooding and the gas can be extracted at reasonably high purity. A number of schemes are in place in countries such as the UK and Germany.

Coal mine methane (CMM) which is captured in working coal mines to allow safe working.- Methane is released as a result of mining activity when a coal seam is mined out and if not controlled to prevent the accumulation of flammable mixtures of methane in air (5-15%) it presents a serious hazard. Gas drainage techniques are used to enable planned coal production rates to be achieved safely by reducing gas emissions into longwall mining districts to a flow that can be satisfactory diluted by the available fresh air. In some instances gas drainage is also needed to reduce the risk of sudden, uncontrolled emissions of gas into working districts. In well managed mines, in favourable geological and mining conditions, the methane concentrations in drained CMM can reach 70% or more. CMM of such quality may be utilised. However, poorly drained mines will only achieve methane concentrations that are much lower, and may be too low for conventional utilization purposes.

Methane capture and its utilisation from coal mines is generally not practiced in India as current levels of coal production in gassy mines are generally achievable using ventilation controls but even where there may be some safety benefit there is some resistance to introducing gas drainage due to a lack of technology, expertise and experience. Additionally, there is the perception that CMM utilisation is not commercially viable.

In addition, very dilute gas mixed with ventilation air, known as ventilation air methane (VAM), is emitted from coal mines.

Ventilation Air Methane (VAM)

Methane released from coal seams into the ventilation air of the active coal mine is called Ventilation Air Methane (VAM). Concentrations of methane in the ventilation air is generally limited by law, for safety reasons, at 0.5 to 2% in different parts of a mine with variations depending on the country.

Concentrations can be controlled by the volume of ventilation air circulated (dilution) or through special drainage (CMM). The concentration of methane in VAM is typically 0.8% or less and is too low for conventional utilisation purposes. However, technologies are being developed to remove the methane, and where additional gas is available to generate electricity using the thermal energy recovered. 

There are near about 300 varieties of non-edible oil seed bearing trees in India. Many of the foresters were of the view that the Honge Tree is God’s gift to India. It is very versatile tree that grows in land as well as in coastal area and all these without much care. Growing these trees enhances the maintenance of environment of the surrounding and offers employment opportunities. Honge oil is extracted from the seed of Honge tree, whose Latin name is Pongammia Pinnata and whose international name is Pongammia Pinnata Perry. Honge oil can be produced on a commercial scale provided the right strategies are followed.

The performance of the engine with Honge oil is found to be satisfactory. The viscosity of Honge oil has to be corrected by preheating the oil. The output of the engine remains almost the same though the calorific value is slightly lower. Taken into account the sale value of cake which is a good fertilizer, Honge oil works out to be cheaper (i.e. Rs 13 per kg) compared to current price of diesel. The high viscosity of Honge oil interferes with injection process and leads to poor fuel atomization. The high viscosity has to be overcome by using methyl ester honge oil. The  transformation of Honge oil to its methyl ester reduces molecular weight to one third, reduces viscosity to one eighth and increases the diesel index.

Bio Diesel is source of energy, supplement for Petroleum products. Bio Diesel is manufactured by using different edible and non-edible oils but edible oils use is not economical and no surplus production for costing purposes. So other sources are non-edible oils, such as Karanj oil, Neem oil, Mahua Oil, Jatropha oil, and Karanj oil. In compression ignition and spark ignition engines for different utilities Since India can not affroad the use of edible vegetable oils as power sources because of short supply, Researcher and planner suggested the use of non edible vegetable oils as alternatives fuels like Pongamia, Jatropha and Neem etc .As India consists of 40% of waste land .It is develop all theses lands by growing non edible oil plants which not only gives the oil but also enriches the environment by adding the green forest cover for Ecological balance.

According to Indian climate and Research Government of India decided to undertake plantation of Karanj and Jatropha plants in barren, waste and unfertile soil from North to South and East to West, Government of India decided two Non Edible oils from Karanj and Jatropha plants are suitable for Biodiesel manufacturing.

So it is better to use the available plants, which produce the non-edible oil seeds to cater the needs at rural level for self-sustainability. Though there are more than 300 different species of trees which produces oil bearing seeds, pongamia and jatropha are the drought resistant plants, which grow with limited water which has enough potential to meet the fossil fuel demand at rural level. Hence these plants can well be utilized to produce the Biodiesel at rural and industrial level. Karanj plant is known by different names as per local level. Pongamia pinnata is botanical name from leguminosea family. It has different uses, medicinal as well as Ayurvedic. Karanj has long life from 60 to 80 years. It has tendency to stay in drought condition, no need of irrigation. Karanj plant is resistant to diseases and insects free. They also used as road shading tree because it is green in summer also. So it helps to increase the natural beauty and decrease the soil erosion. Karanj cake and leaves also helpful in organic manure accordingly it helps to increase the economy of Indian farmers.

Now a days agriculture forestry Dept. worked on different varieties of Karanj plant for high yielding and high oil percentage. Some institutions like SUTRA, Dept. of Mechanical Engg., Indian Institute of Science, Bangalore has developed the hybrid variety by grafting which is high yielding and oil percentages. Planting methods, fertilizers and new techniques also developed. Stump technique is method in which plants are grown for one year in nursery and transfer in the field after one year by making stump shape by removing leaves and branches which is more convenient for transportation. It saves the money and nursery accessories. Other technique is tissue culture, helps to produce good quality seed plant in short time.

Jatropha curcus is plant belongs to Euphorbiaceae family known by Mogali Erand, Ratan jyot, Ratna jyot in Telagu Nepalam and Yellamunaka, in Kannada Kadalabudu.etc. in different regions of India . Jatropha plant is used by local and Adivasi people for different purpose. All parts of plants are used by local people. It has medicinal value. Its roots are used against Aatisaar, stem used for dental problem an4 tooth cleaning, leaf extract also useful in cattle problem.

Benefits of Karnj and Jatropha cultivation: -

• Cultivation of Karanj and Jatropha plants prevents soil erosion and makes the soil fertile.

• Cost of cultivation is low as compare to other plants.

• Low requirement of water and also stay in low ground water level.

• Seasonal and regional acceptance.

• Often cheated by unfavorable monsoon.

• Lack of insurance coverage.

• Long life plant

• Low insect and disease damage.

• It increases rural employment.

• Pollution control.

Bio-Diesel Plantation Requirement

PRESENT CONSUMPTION OF DIESEL 3 CRORES 70 LAKH TON

IF 20% BIODIESEL USED WITH DIESEL REQUIRED 70 TO 80 LAKH TON BIODIESEL OIL

80 LAKH TON OIL REQUIRED

FOR 80 LAKH TON OIL REQUIRED 

1 CRORE HECTRE LAND FOR PLANTATION

In India most of the trials were done using bio diesel from Karanj and Jatropha.

Indian Railway Conducted a successful trial run of an Express Passenger train on the Delhi-Amritsar route using 5% of biodiesel as fuel. Indian Oil Corporation began in January 2007 field trials of running buses on diesel doped with 5% biodiesel. Hariyana Roadway buses used of Biodiesel. Automobile manufacturers like Mahindra and Mahindra, Ashok Leyland etc. have already tried biodiesel mix as a fuel for their vehicles. Harbinsons Biotech Pvt. Ltd. has set up pilot plant at Gurgaon. IIT Delhi, IIT Chennai, have already set up a biodiesel products facility of 60 kg/day at Faridabad. Mahindra and Mahindra Ltd. has a pilot plant using Karanj for Biodiesel production in Mumbai.

What are biofuels

 Renewable fuels from biosources includes : -

1. Ethanol

2. Biodiesel

3. Biogas

Why Biofuels

• Pollution threat

• Reduction of green house gas emission

• Regional development

• Social structure & Agriculture

• Security of supply.

Importance of Biodiesel

• Environment friendly

• Clean burning

• Renewable fuel

• No engine modification

• Increase in Engine life

• Biodegradable & non toxic

• Easy to handle and store.

The economy of a country mainly depends upon its energy source. Energy source is the main contribution factor for the development and growth of the developing countries. Among the various sources identified for alternate fuel Non-edible oils were considered to be ideal in view of compatible properties with respect to diesel. This Biodiesel concept is been adopted with Jatropha and Karanj oils in our country.

India has vast tract of degraded lands, mostly in areas with adverse Agro – Climatic condition, where hardy tree bone oil seed Species like jatropha, Karanj, etc. can be grown easily. Even 30 million Hectares planted for Biodiesel can completely replace the current use of Fossil fuel. Our oil bill is presently $ 6 Million a Year and the Waste Land Development would required only about 1000 Crores per Year for 20 Years to make India self sufficient forever in oil. Developing A strong market for Biodiesel would have Treatmendous economic Benefits. Investment in Biodiesel will have great

Future.

India is the sixth country in the world with a billion population. Our country faces problems in regard to the fuel requirement for increased transportation demand and now imports about 70 % of its petroleum requirement .The petroleum import bill is about 14 billion dollars. The current yearly consumption of diesel oil in India is approximately 40 million tones forming 40 % of the total petroleum products consumption. The potential demand for Biodiesel at 20% blend is estimated at 13.38 million tones per annum by 2012. In the present problematic traditional cultivation, raising of energy plantation to produce Biodiesel, farmers can develop and utilize waste lands and improve incomes, rural labour will have more employment opportunities and soil fertility and condition will improve. Any vegetable oil can be converted in to Biodiesel; however, in India there is no surplus production of edible oil. Therefore, the oil that can be used as Biodiesel has to be non-edible oil.

Produced in abundance and with stand harsh climate, as they would be taken up in wastelands, the most suitable species in this regard are Jatropha and Pongamia. These plants could be grown on wasteland about 80 million hectares of which is available in India. The oil extracted from the seed is used in place of diesel after simple filtration. After further processing this can be used in four wheelers. The seed cake after extraction of oil will be very good organic manure as it contain high nitrogen content. This cake can also be utilized for biogas production. The pruned leaves are used as green leaf manure.

The world today is behind two resources – energy and water. Over the years man has utilized positively or negatively various conventional resources to satisfy his needs and greed. Thus, limited storage of resources have been depleting steadily. Hence the propagation of non-conventional energy sources and their utilization is imperative today.

Why Bio-gas?

Bio gas generated from locally available waste material seems to be one of the answers to the energy problem in most rural areas of developing countries. Gas generation consumes about one fourth of the dung but available heat of gas is about 20% more than that of obtained by burning the entire amount of dung directly. This is mainly due to very high efficiency (60 %) of utilization compared to poor efficiency (11%) of burning dung cakes directly. The technology thus seeded and spawned is populist technology based on ‘Nature’s income and not on nature’s capital’ so being an agricultural country use of bio-gas as a fuel for cooking or lighting purpose can be the best solution for all Indian farmer families.

Potential for Bio-gas energy

The potential of renewable energy in India is estimated as 1,00,000 MW while for bio-gas and bio-mass it is 19,500 MW. So there is need to bring about change in mind to focus on renewable sources of energy. No matter whether you get the power from Thermal Power station , Hydro Power Plant or from Bio-gas Plant, the end product is energy and power.

Bio-gas technology – General Description

Bio-gas or gober-gas is clear, odorless combustible gas which is produced when organic matter content in animal excrements like dung, human night soil, parts of a tender plants or residues like leaves, stems and straws are anaerobically fermented with the help of methenological bacteria in air and water tight containers called bio-gas digester.

Chemically, a useful gas is just a methane gas. It’s chemical composition consist of one part of carbon (C) and four parts of Hydrogen molecule. It’s chemical formula is CH4 .Bio-gas burns with clear blue flame without giving any smoke. It’s flame temperature is up to 800 oC and it has calorific value of 5650 KCAL/ m3

Technical aspects

Bio-gas is a mixture of :

Methane (CH4 ) : 50 to 70 %

Carbon-dioxide (CO2) : 30 to 40 %

Hydrogen (H2 ) : 5 to 10 %

Nitrogen (N2 ) : 1 to 2 %

Hydrogen Sulphide (H2 S) : Small quantity

Bio-gas is generated when bacteria degrade biological material in absence of oxygen process known as anaerobic digestion. This process produces less temperature hence valuable in terms of energy conservation.

Advantages

One cubic meter of biogas is equivalent to –

3.47 Kg of wood

0.63 liter of kerosene oil

0.61 liter of diesel oil

1.5 Kg Of coal

1.25 KWh of electricity

0.45 Kg of LPG

13 Kg of fuel dung

0.5 Kg of butane.

It is non polluting

It gives cheap and easily available energy.

It uses waste like animal and human excreta and plant residues, which can otherwise create undesirable conditions. So it can give hygienic, clean and safe atmosphere around populated areas.

Its slurry could be used as a nutrient rich manure in farms and could tremendously improved agriculture production.

It can substitute firewood for cooking, heating, fuel and kerosene for lighting so saving in foreign currency normally spent in fuel and fertilizers.

Socially it can save a lot of time and labour in activities such as cleaning, washing and cooking, which they can use for other income generating /saving activities to care more for their children and to learn.Environmentally information technology can save wood and through that help to save vulnerable forest, soil, water and clean of the environment.

Aside from the generation of electricity, it has been proposed that OTEC plants could assist ocean based industries, such as aquaculture, refrigeration and air conditioning, desalinated water crop irrigation and consumption as well as mineral extraction through the use of the fresh and chilled water byproducts

OTEC has important benefits other than power production.

1) Air conditioning

Air conditioning can be a byproduct. Spent cold seawater from an OTEC plant can chill fresh water in a heat exchanger or flow directly into a cooling system. Chilled-

2) Soil agriculture

OTEC technology also supports chilled-soil agriculture. When cold seawater flows through underground pipes, it chills the surrounding soil. The temperature difference between plant roots in the cool soil and plant leaves in the warm air allows many plants that evolved in temperate climates to be grown in the subtropics.

3) Desalination

An OTEC plant that generates 2-MW of net electricity could produce about 4,300 cubic meters (14,118.3 cubic feet) of desalinated water each day.

4) Mineral extraction

An OTEC plant that generates 2-MW of net electricity could produce about 4,300 cubic meters (14,118.3 cubic feet) of desalinated water each day.

Some Major Otec Power Plants in World

India possess excellent thermal gradients and some of the best sites in the world for harnessing OTEC power India has a potential of exploiting 80,000 MW of OTEC based power. Some of the coastal regions of Tamil Nadu and Andhra Pradesh provide excellent sites for OTEC plants. Although the theoretical efficiency of OTEC is small (~2%), there are vast quantities of sea water available for use in power generation. It has been estimated that there could be as much as 10⁷ MW power available worldwide.

OTEC’s economic benefits:

· Helps produce fuels such as hydrogen, ammonia, and methanol

· Produces base load electrical energy

· Produces desalinated water for industrial, agricultural, and residential uses

· Is a resource for on-shore and near-shore mariculture operations

· Provides air-conditioning for buildings

· Provides moderate-temperature refrigeration

· Has significant potential to provide clean, cost-effective electricity for the future.

OTEC’s non economic benefits

· Promotes competitiveness and international trade

· Enhances energy independence and energy security

· Promotes international sociopolitical stability

· Has potential to mitigate greenhouse gas emissions resulting from burning fossil

  fuels.

Energy is a crucial input in the process of economical, social and industrial development. High energy consumption has traditionally been associated with higher quality of life, which in turn is related to the Gross National Product (GNP). Variation in magnitude of energy resources , differing mix of energy resource profiles , lack of adequate resources of fossil fuels in many nations, dispersed geographical location of energy resources within nations and in the world are some of the complexities that characterize the global energy scene.Sources that are replenished more rapidly are termed as ‘renewable’.These include solar,wind and ocean which are inexhaustible.

Significance of Ocean Energy

Oceans cover more than 70% of earth’s surface, making them the world’s largest solar collectors. The sun’s heat warms the surface of water a lot more than the deep ocean water and this temperature difference creates thermal energy.Just a small portion of the heat trapped in the ocean could power the world.

Ocean can produce two types of energy: thermal energy from the sun’s heat and mechanical energy from the tides and waves. Ocean thermal energy is used for many applications including electricity generation. There are three types of electricity conversion systems: closed cycle, open cycle and hybrid. Ocean mechanical energy is quite different from ocean thermal energy. Even though the sun affects all ocean activities, tides are driven primarily by the gravitational pull of the moon and waves are driven primarily by the winds. As a result, tides and waves are intermittent sources of energy while ocean thermal energy is fairly constant. Also, unlike thermal energy, the electricity conversion of both tidal and wave energy usually involves mechanical devices.

OCEAN THERMAL ENERGY CONVERSION

Ocean Thermal Energy Conversion (OTEC) utilises the temperature difference between the warm surface sea water and cold deep ocean water to generate electricity. For OTEC to produce a net output of energy, the temperature difference between the surface water and water at a depth of 1000m needs to be about 20oC.

Temperature difference between surface and sub surface (1000m) sea water

The concept of OTEC is envisioned by Jacque’s D’Arsonval in 1881. However, D’Arsonval did not live to see his idea to fruition, and the task was completed by his student Georges Claude in 1930. Although the theoretical efficiency of OTEC is small (~2%), there are vast quantities of sea water available for use in power generation. It has been estimated that there could be as much as 10⁷ MW power available worldwide.

Otec Systems are Classified into Three Categories

Closed Cycle Otec

D’Arsonval’s original concept used a working fluid with a low boiling point, such as ammonia, which is vapourised using the heat extracted from the warm surface water. The heated working fluid is used to turn a turbine to produce electricity. Cold deep sea water is used to condense the working fluid in a second heat exchanger prior to being recirculated to the first heat exchanger.

Open Cycle Otec

Open cycle OTEC is very similar to the closed cycle one. The only difference is that an open cycle OTEC does not use intermediate fluid with low boiling point but uses the sea water as working fluid that drives the turbine. The warm sea water on the ocean surface is turned into low pressure vapour under a partly vacuumed environment.The steam is then condensed either by a second heat exchanger, as in the closed cycle, or by mixing with the deep cold water.

Hybrid Otec System

Hybrid Cycle OTEC is a theoretical method of maximizing the use of ocean thermal energy.

There are two concepts. The first one is to use a closed cycle OTEC to generate electricity to create the necessary low-pressure environment for the open cycle OTEC. The second concept is to integrate two open cycle OTEC (one is used to create the vacuumed environment) so that there will be twice the amount of the original desalinated water.

Wave energy is moving off shore. Although a number of successful devices have been installed at shoreline locations, the true potential of wave energy can only be realized in the offshore environment where large developments are conceivable. In terms of power potential, offshore locations offer more than shoreline locations. The negative side is that devices in offshore locations have more difficult conditions to contend with. Shore line technologies have the benefit of easy access for maintenance purposes, whereas offshore technologies are, in most cases more difficult to access. Improving reliability and accessibility are, therefore important in commercialization of wave energy harnessing.

Shoreline wave energy is limited by fewer potential sites & high installation cost whereas a 50 MW wave farm is conceivable on offshore locations. No shoreline wave energy converter is able to offer such potential for deployment in this way. Deployment costs for shoreline wave energy devices are high because they are individual projects and economics of scale are, therefore, largely inapplicable. Shoreline devices only account for 8% of forecast capacity between 2004-2008. Offshore represents the most significant wave energy sector, with 58% of all forecast capacity. Offshore is so dominant because devices are typically of a larger capacity than their nearshore compatriots.

Ocean Power Delivery Pelamis

In the present time OPD is viewed as market leader which has developed ‘pelamis’ concept. The ‘pelamis’ is made up of five cylindrical segments connected by hinged joints. The wave induced motion on these sections is resisted by hydraulic rams which pump high pressure fluid through hydraulic motors via smoothing accumulators to drive electric generators. The power is fed through a cable to a junction on the sea floor where a single cable carries the electricity to the shore. The

first full-size pelamis has a rated capacity of 750 KW.

Wave Dragon A/S – Wave Oragon.

Wave Dragon is the first operational grid connected offshore wave energy device, installed in Denmark. The prototype wave dragon has an output of 20 KW. The device is under study to gain more knowledge & experience. The different models of 7MW, 4 MW & 11 MW capacity are proposed for the different levels of wave resource.

Wavegen – Limpet

Wavegen is one of the market leaders in wave energy, having installed their Limpet shoreline devices in Scotland in 2000. It is also developing technology which generates power from wave energy, whilest also acting as an artificial reef. The device which rests on the sea bed, could in some cases and coastal protection. The technology is of particular benefit to island communities.

 Environmental Impacts

Small-scale wave energy plants are likely to have minimal environmental impacts. However some of the very large-scale projects that have been proposed have the potential of harming the ocean ecosystems covering very large areas of the surface of the oceans with wave energy devices would harm marine life and could have more wide-spread effects. Changes in waves and currents would most directly impact species that spend their lives nearer to the surfaces. The dampening of waves may reduce erosion on the shoreline and may have damaging ecologies effects, that need to be scientifically proved.Wave energy is promising holds huge potential to reduce reliance on fossil fuels. Carefully choosing sites that can withstand the alterations to the environment caused by power plants will be crucial to effectively develop these technologies without harming the ocean.