Indian sugar mills to produce 'bio-CNG' from cane biomass with European aid

In a very interesting development - a possibility Biopact hinted at long ago - three sugar factories from Maharashtra, India, have decided to produce 'bio-CNG' from sugarcane biomass as a transport fuel. The projects will be set up with finance from the German Investment and Development Company (DEG), one of Europe's largest international development banks, which has earmarked €15 million for lending to the factories. German firm Biogas Nord and Enersearch - a European research institute engaging in renewable energy solutions - will provide technical know-how.

In India, compressed natural gas (CNG) has been the fuel of choice in large metropolitan areas and major auto makers now offer CNG models (earlier post). With this new project, a bio-based alternative made from agricultural waste will make it available in rural areas. This represents an interesting case of energy 'leapfrogging' - rural communities jumping into a cleaner and renewable future, beyond what is already the cleanest alternative currently in use in the rapidly modernizing megacities. What is more, with oil approaching $100 and natural gas prices up as well, the bio-CNG makes commercial sense as well. Experts from the Indian Institute of Technology (IIT) predict it could become the cheapest of all transport fuels in India.

Biogas can be produced efficiently from any type of biomass via anaerobic digestion. The renewable gas contains around 60 to 70 percent methane (CH4) with the remainder being CO2 with minor amounts of contaminants and trace gases. For it to be used as a transport fuel in vehicles as a replacement for CNG, it has to be upgraded, with the CO2 scrubbed out. The fuel then becomes 'bio-CNG', a very clean, renewable gaseous energy source. The fuel is already being used on a relatively large scale in Europe, most notably in Sweden, Austria and Germany.

Greenhouse gas emissions and air pollutants from CNG/bio-CNG are considerably lower than those from liquid fossil fuels (previous post). Prices tend to be lower as well, which is why a switch to gaseous fuels for transport is encouraged in major metropolitan areas across the (developing) world. Several countries in the Global South - most notably Argentina, Pakistan, and India - have succeeded in converting large proportions of the public and private transport fleets to CNG. In India, demand for the fuel is now even outstripping [*.cache] that of traditional liquid fossil fuels by a factor of four.

Sugarcane and its main processing residues - distillery sludge, bagasse and spent wash - make for an excellent biogas feedstock. In fact, if sugarcane as a whole crop were to be converted into biogas instead of ethanol, around 35 percent more energy could be obtained per hectare, because anaerobic digestion is a more efficient bioconversion process. Researchers have found that when the energy from sugarcane bagasse, which is used as energy for ethanol distillation, is included in the calculations, the energy output for sugarcane biogas could be up to to 130 percent higher than the figure for ethanol.

The three cooperatives in Maharastra will be producing bio-CNG at a competitive 22-24 rupiah (€0.38-0.41/$0.55-0.61) per kilogram. This compares favorably to current CNG prices in India, which range between 20 and 25 rupiah. On an energy equivalent basis, the bio-CNG would be 30 to 50% less expensive than diesel, the cheapest liquid fuel:
energy :: sustainability :: biomass :: bioenergy :: biofuels :: sugarcane :: biogas :: biomethane :: CNG :: India ::

In the first phase, Warna sugar factory in Kolhapur, Jaywantrao Patil sugar factory in Nanded and Kisan Veer sugar factory in Satara would introduce the technology. About Rs 40 crore (€6.9/$10.2 million) would be required for commissioning the conversion systems at the three sugar factories.

Press mud and spent wash, by-products of sugarcane processing, would be used for producing biogas. The biogas would be further treated to produce bio-CNG. It is unclear which gas cleaning technology will be utilized, but several options are available: water adsorption, pressure swing adsorption or chemical absorption.

India has the world's second largest sugar industry, producing some 14 million tonnes per year grown on 3.6 million hectares of land. A total of 165 sugar mills are located in Maharashtra alone, more than half of all large facilities in India (maps, click to enlarge).

German firms Enersearch and Biogas Nord would be providing the technical know-how and machinery for the projects. Shubhada Jahagirdar, director at Enersearch, told reporters that German companies and financial institutions were keen on providing the know-how and support for the sugar companies as the technology and fuel production path has a large and attractive commercial potential.

Biogas Nord is already active in the biogas sector in India. Recently it acquired an order to build a biogas facility at a sugar factory in Maharastra (previous post).

In India, CNG has been a fuel of the cities, especially for vehicles. Now, with CNG being extracted from agricultural waste, it would be available for the larger rural population.

Ms Jahagirdar said that the bio-CNG technology was still at a pilot stage in Maharashtra and it could receive monetary support from the Sugar Technology Fund of the Union Government. The bio-CNG would be less costly than diesel, the most widely used liquid fossil fuel in the country. German financial institutions would extend project finance only to those sugar mills that have a healthy balance sheet.

Dr Virendra K. Vijay of the Indian Institute of Technology (Delhi), a biogas research expert, said that with crude oil close to $100 a barrel, bio-CNG could be an attractive alternative fuel. Its production cost could come down to 15 rupiah per kg - becoming the cheapest transport fuel in India (CNG currently costs between 20 and 25 rupiah per kg) -, if produced on a large scale.


Background
When biomethane is produced from dedicated energy crops, it can yield more energy than any other current type of biofuel. The green gas can be made from a very wide range of biomass crops as well as from abundant crop residues. Scientists have found [*.pdf] that for temperate grass species, one hectare can yield between 2,900–5,400 cubic meters of methane per year, enough to fuel a passenger car for 40,000 to 60,000 kilometers (one acre of crops can power a car for 10,000 to 15,000 miles).

A recent 'Biogas Barometer' report, published by a consortium of renewable energy groups led by France's Observ'ER, cites a 13.6% increase growth in biogas use for primary energy production between 2005 and 2006 in the EU (earlier post).

The total energy potential for biogas in the EU has been the subject of several projections and scenarios, with the most optimistic showing that it can replace all European natural gas imports from Russia by 2020 (more here). Germany recently started looking at opening its main natural gas pipelines to feed in the renewable green gas. And an EU project is assessing the technical feasibility of doing the same on a Europe-wide scale (previous post).

Biogas as a transport fuel offers particularly interesting prospects for the developing world, where oil infrastructures are not yet developed extensively. By relying on locally produced biomethane used in CNG cars, these countries could leapfrog into a clean, secure and green post-oil future.

For comprehensive overviews of the latest developments in biogas research, development and applications, please search the Biopact website.

References:
Hindu Business Line: Maharashtra sugar mills plan bio-CNG from cane biomass - November 8, 2007.

Colen, F., Pasqual, A., "Sugar cane (Saccharum sp.) juice energetic potential as substrate in UASB reactor", Energia na Agricultura, 2003, Vol. 18, No. 4, pp. 58-71

NVG Global - country reports: Thailand and Asia – Natural Gas Vehicle Market Review. Part One, Part Two - March 21, 2007.

Natural Gas Vehicle Network: CNG Growth Outstrips Traditional Fuels in India.

Biopact: Biogas Nord to make biomethane from bagasse in India - June 17, 2007

Biopact: German biogas company to make gas from sugarcane residues in India - March 20, 2007

Biopact: India's TVS Motor to roll out CNG-fueled motorbikes, allows leapfrogging with biogas - September 04, 2007

Biopact: Report: carbon-negative biomethane cleanest and most efficient biofuel for cars - August 29, 2007

Biopact: Experts see 2007 as the year of biogas; biomethane as a transport fuel - January 09, 2007

Biopact: Pre-combustion CO2 capture from biogas - the way forward? - March 31, 2007

Biopact: Hydrogen out, compressed biogas in - October 01, 2006