BiogasAs an alternate fuel option

Environmental ManagementPragya GuptaB.V.P.D.U.C.O.A

Biogas what is

Biogas typically refers to a gas produced by the breakdown of organic matter in the absence of oxygen. It is a renewable energy source, like solar and wind energy. Furthermore, biogas can be produced from regionally available raw materials such as recycled waste and is environmentally friendly.

Biogas production of

Biogas is produced by anaerobic digestion with anaerobic bacteria or fermentation of biodegradable materials such as manure, sewage, municipal waste, green waste, plant material, and crops.

Biogas production of

Bio gas is practically produced as landfill gas (LFG) or digested gas. A bio gas plant is the name often given to an anaerobic digester that treats farm wastes or energy crops. Bio gas can be produced using anaerobic digesters. These plants can be fed with energy crops such as maize silage or biodegradable wastes including sewage sludge and food waste. During the process, an air-tight tank transforms biomass waste into methane producing renewable energy.

Biogas production of

Biogas sources of

Biogas sources of

Biogas comes from four main sources:

Sewage treatment plants: Many sewage treatment plants produce methane rich gases in the sludge fermentation stage. Utilisation of methane from sewage plants is used on a large scale in many countries. Optimised process conditions can enhance the production and collection of these gases. Landfills: All landfills produce methane rich gases. Collection and utilisation of the gases is applied quite widely. Improved collection, processing and utilisation of landfill gases will be an important tool to increase the importance of landfill gas.

Biogas sources of

Cleaning of organic industrial waste streams: Anaerobic digestion processes are often successfully applied to clean the waste streams of agricultural processing industry.The methane rich gases are mainly utilised to produce electricity and heat in local co-generation plants. Mesophilic and thermophilic digestion of organic waste: Compact installations convert organic waste to methane rich gases at higher temperatures. The main difference between the two methods is the digestion temperature (35°C in the mesophilic process and 55°C in the thermophilic process).

Biogassources of

Biogas sources of

Biogas benefits of

Can be used to produce electricity thus reducing the strain on waning supplies of fossil fuels

Can be used for cooking, heating, lighting etc. which reduces the need for firewood and oil.

Can be used as a fuel for Vehicles (if it is purified and compressed)

Biogas reduces emissions by preventing methane release in the atmosphere. Methane is 21 times stronger than carbon dioxide as a greenhouse gas.

Producing biogas through anaerobic digestion reduces landfill waste and odors, produces nutrient-rich liquid fertilizer, and requires less land than aerobic composting

Biogas benefits of

Eunomia (2010) analysed a range of different uses for biogas and found that using biogas to power vehicles had the lowest carbon footprint. When the carbon impacts of treating one tonne of organic material were analysed, the following carbon savings could be made: • Using biogas as a vehicle fuel has a carbon saving of 97kgCO2 equivalent. • Using biogas for on-site has a carbon saving of 86kgCO2 equivalent. • Pumping biogas straight to the grid has a carbon saving of 85kgCO2 equivalent. • Using biogas to produce electricity has a carbon saving of 62kgCO2 equivalent.

Biogas benefits of

The use of biogas as a transportation fuel can contribute towards sustainable development in the following ways; Decreased fossil fuel extraction, transportation and use. Reduced reliance on foreign fossil fuel supplies. Reduced emissions from transport.

1. Reduced carbon emissions. 2. NOx and Particulates.

Reduced sound emissions. Gas vehicles are quieter than diesel vehicles. Noise reductions average around 10 decibels, the equivalent of halving the noise level (Chive Fuels website, 2006).

Biogas benefits of

Reduced odour. Reduced emissions from transport in towns and cities, and more biowastes receiving treatment. Increased safety. Biomethane/CNG is safer than petrol in a crash situation (Cenex, 2009). Reasons for this are that the ignition temperature is higher than that of petrol, and if the storage tank is punctured all the gas immediately escapes to the atmosphere. Reduced emissions from fertilizer production. Recycling of nutrients in digestate to land (depending on quality). Long term benefits to soil. Recycling of organic material in digestate to land.

Biogas benefits of

Biogas disadvantages of

Both electricity generation and compression of gas (for storage or use in vehicles) use large amounts of energy for a small output of useful energy.

The methane contained within biogas is 21 times more potent a greenhouse gas than carbon dioxide. Therefore, uncontained landfill gas, which escapes into the atmosphere may significantly contribute to the effects of global warming

Biogas upgrade

Raw biogas produced from digestion is roughly 60% methane and 29% CO2 with trace elements of Hydrogen Sulphide, and is not high quality enough to be used as fuel gas for machinery.The corrosive nature of Hydrogen Sulphide alone is enough to destroy an engine.The solution is the use of biogas upgrading or purification processes whereby contaminants in the raw biogas stream are absorbed or scrubbed, leaving more methane per unit volume of gas.Methane within biogas can be concentrated via a biogas upgrader to the same standards as fossil natural gas.

Biogas upgrade

There are four main methods of biogas upgrading, these include water washing, pressure swing absorption, selexol absorption, and amine gas treating.

The most prevalent method is water washing where high pressure gas flows into a column where the carbon dioxide and other trace elements are scrubbed by cascading water running counter-flow to the gas. This arrangement could deliver 98% methane with manufacturers guaranteeing maximum 2% methane loss in the system. It takes roughly between 3-6% of the total energy output in gas to run a biogas upgrading system.

Biogas around the world

EUROPE - The level of development varies greatly in Europe. While countries such as Germany, Austria and Sweden are fairly advanced in their usage of biogas, there is still a vast potential for this renewable energy source in the rest of the continent, especially in Eastern Europe. In February 2009, the European Biogas Association (EBA) was founded in Brussels as a non-profit organisation to promote the deployment of sustainable biogas production and use in Europe. EBA's strategy defines three priorities: establish biogas as an important part of Europe’s energy mix, promote source separation of household waste to increase the gas potential and support the production of biomethane as vehicle fuel. In July 2013, it had 60 members from 24 countries across Europe.

Biogas around the world

U.K. – There are currently around 60 non-sewage biogas plants in the UK, most are on-farm, but some larger facilities exist off-farm, which are taking food and consumer wastes.

GERMANY - It is Europe's biggest biogas producer as it is the market leader in biogas technology. In 2010 there were 5,905 biogas plants operating throughout the whole country. Most of these plants are employed as power plants. The total installed electrical capacity of these power plants was 2,291 MW.

Biogas around the world

USA - In 2003, the United States consumed 147 trillion BTU of energy from "landfill gas", about 0.6% of the total U.S. natural gas consumption. Methane biogas has been tested to prove that it can reduce 99 million metric tons of greenhouse gas emissions or about 4% of the greenhouse gases produced by the United States.

CHINA - The Chinese had experimented the applications of biogas since 1958. Around 1970, China had installed 6,000,000 digesters in an effort to make agriculture more efficient. During the last years the technology has met high growth rates. This seems to be the earliest developments in generating biogas from agricultural waste.

Biogas around the world

Biogas in India

In India, biogas produced from the anaerobic digestion of manure in small-scale digestion facilities is called gobar gas; it is estimated that such facilities exist in over two million households in India.

The Deenabandhu Model is a new biogas-production model popular in India. The unit usually has a capacity of 2 to 3 cubic metres. It is constructed using bricks or by a ferrocement mixture. In India, the brick model costs slightly more than the ferrocement model; however, India's Ministry of New and Renewable Energy offers some subsidy per model constructed.

Biogas in India

Deenabandhu Gas Plant

Biogas in India

In order to create awareness and associate the people interested in biogas, an association "Indian Biogas Association" (www.biogas-India.com) was formed. The “Indian Biogas Association” aspires to be a unique blend of; nationwide operators, manufacturers and planners of biogas plants, and representatives from science and research. The association was founded in 2010 and is now ready to start mushrooming. The sole motto of the association is “propagating Biogas in a sustainable way”.

Biogas in Vehicles

Biogas has been used as vehicle fuel in larger scale since 1996 when the first biogas bus project started in Trollhättan in the west of Sweden.The development of biogas as vehicle fuel started in countries with low electricity prices and a growing market for natural gas vehicles.Many countries and cities were in the 90’s focussed on reducing the pollution in civic centres and a predominant source of pollution was the urban transport system.An easy measure to reduce both local and global emissions was to change from diesel buses to natural gas buses and this happened in many countries in Europe and in Asia.

Biogas in Vehicles

Some examples of biogas use in Europe include:

Austrian drivers can fill up their CNG cars using biogas made from grass.Denmark has more than 50 biogas plants in operation.The Netherlands is generating biogas from sewage treatment plants and feeding it into the gas grid and to fuel cars.Sweden is producing biogas from wastewater treatment plants and using it to generate power and to fuel buses and trains.Germany is producing biogas from maize and using it in combined-heat-and-power plants (the French have developed a giant maize variety specifically for biogas production).

Biogas in Vehicles

The German government is considering feeding biogas into the country's natural gas network (ironically, the main obstacle to this has been that biogas is too good for the network - exceeding Germany's upper limit on gas heating value, something the German Greens and farming lobby are trying to have fixed). 

According to the government, locally produced biogas could supply up to 10 percent of Germany's total gas consumption by 2030. Germany is the largest producer of biogas in Europe, and biogas is Germany's fastest growing renewable energy sector.

Biogas in Vehicles

India is one of the leading countries in the market development and the implementation of natural gas buses and taxis in India has led to dramatic improvements of air quality in large cities such as Mumbai and New Dehli.

Both India and China have shown an increasing interest in using biogas as vehicle fuel.

Biogas in Vehicles

Biogas in Vehicles

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Biogas in Vehicles

Limited market due to a hesitant vehicle industry. Car manufacturers are more used to liquid fuels and thus reluctant to invest heavily in development of gas vehicles.

Limited distribution possibilities. Vehicle fuel is normally distributed via the large oil companies and those have to be convinced that there is a market also for gaseous fuels. Also the gas distribution companies have hesitated in being involved in the biogas business.

Limited production. Biogas is produced mainly from organic waste material and the availability of such material is limited. A promising possibility is to utilise energy crops and also to produce methane from gasified forest residues and wood waste.

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BiogasCase Study on

LINKÖPING, SWEDENThe Linköping Biogas plant in Sweden was started in1997 in order to treat organic waste from the agriculturalsector in southeastern Sweden.The plant has an annual treatment capacity of 100,000 tonnesand produces 4.7 million m3 of upgraded biogas(97% CH4) that is used in 64 buses and a number ofheavy and light duty vehicles. Since 2002 there are onlybiogas buses in the urban transport fleet and the CO2-emissions have been reduced by more than 9,000 tonnesper year.

BiogasCase Study on

LINKÖPING, SWEDENFACTS– Treatment of slaughter house waste and industrialorganic waste– Start of operation: 1996– Total biogas production: 7.7 million m3/year– Digester volume: 2 * 3700 m3– Upgraded biogas delivered to vehicles(97% methane): 4.7 million Nm3/year (2005)– Total investment : 14 million EUR– 64 biogas buses– 12 public biogas filling stations (2005)

BiogasCase Study on

In Linkoping, each bus running on biogas fuel contributes to reducing NOx emissions by 1.2 tonnes and CO2 by 90 tonnes per year.

BiogasCase Study on

Cost Analysis for Bus Service in Finland

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BiogasCase Study on

Cost Analysis for Bus Service in Finland

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BiogasCase Study on

Biomethane production costs to reach the diesel cost: Cost reduction may be achieved by substrate and technology selection, cost efficient upgradation, substrate and digestate handling etc.National incentives (investment support, 202020 targets)

Economical profitability depends on the biogas plant capacity the dependency is less significant when production capacity exceeds 1 000 Nm3/h.

Investment and maintenance costs of gas buses to meet the

costs of diesel buses. National subsidies for renewable energies

Development of engine technologiesEconomy of scaleCost associated with EURO VI certification (diesel buses) does not level of the cost differences between biogas and diesel

High greenhouse gas emission savings achieved when using manure and waste as a substrate for biogas

Biogas PMPML

ABOUTPune Mahanagar Parivahan Mahamandal Ltd (PMPML), is the public transport service provider for the city of Pune and Pune Metropolitan region, which includes areas surrounding Pune and Pimpri-Chinchwad.

At present, the PMPML has a fleet of 1000 buses, transporting about 800 thousand commuters daily.

Biogas PMPML

COSTS OF IMPLEMENTATION The cost for Retrofitting a bus running on conventional diesel fuel to CNG or CBG (compressed bio gas) is about Rs. 600,000 per bus.

There are also costs with regard to the up gradation of facilities at the PMPML depots to support the refueling and maintenance work on these new systems.

The maintenance staff has to be re trained for servicing the buses that are running on the gas.Cost of contracts with suppliers of bio gas or setting up a biogas plant themselves.

Biogas PMPML

COSTS OF IMPLEMENTATION

PMC Generates 328500 tpy. The case study data indicates that 1 million tones of MSW can yield a saving of 5.5 million liter of petrol and diesel.The biogas has a potential to annually replace 15 million lof petrol and diesel.The UK generates some 30 million dry tonnes of this waste material a year, capable of producing some 6.3 million tonnes of oil equivalent of methane gas.

Biogas PMPML

COSTS OF IMPLEMENTATION

The Fuel efficiency of Vehicle              Fuel Type/ Mileage            Mileage with CNGBus                   Diesel/ 3.5 Km/ Litre        3.5 Km/ KgCar                    Petrol/ 15 Km/ Litre          21 Km/ KgThree wheeler  Petrol/ 25 Km/ Litre          35 Km/ Kg

Biogas PMPML

ADVANTAGESThe Considerable Fuel bills that the corporation faces are sure to fall as buses running on CNG and CBG are more fuel efficient compared to Diesel powered buses.

The maintenance cost of buses goes down because the gaseous fuel does not contaminate the fluids in the engines. Burning CNG/CBG emits significantly less pollutants such as carbon dioxide (CO2), unburned hydrocarbons (UHC), carbon monoxide (CO), nitrogen oxides (NOx), sulfur oxides (SOx) and particulate matter (PM), Increasing the air quality of the city.

Biogas PMPML

CONCLUSIONBio gas as a fuel has been implemented sparingly but efficiently in countries like Sweden, UK and some other parts of Europe. The potential is high and benefits range from economical savings to being a major coefficient for increased air quality.

With india investing heavily in public transport systems, including more efficient but investment intensive systems such as monorail, this cost is clearly justified.

However lack of awareness and initiative is a major deterrent.

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