Perhaps the most important impact of India’s recent rapid biomass gasification development is socioeconomic, in its capacity to bring power to rural areas that have never had it.
In the past few years, the biomass gasification industry in India has ballooned, growing from plants with kilowatt capacity peppered throughout the country, to development of systems between 1 and 10 megawatts (MW) sprouting up regularly, according to Kam Patel, director of equipment provider Global Energy Collaborations.
Development has increased on residential, community and industrial scales, but different technologies seem more practical in certain applications than others. Residential development has latched onto biomethanation, where a biochemical is used to generate methane gas, according to Surya Chandak, a senior program officer with the United Nations Environment Programme’s International Environmental Technology Centre in Japan. And the most common form of gasification, which Chandak calls thermal gasification, has taken root in community and industrial installations, he says.
In India, biomass feedstocks have been converted to energy for decades, specifically bagasse. Back then, however, it was directly combusted in boilers for steam and power. In the late ’80s, Chandak pioneered a combustion boiler that would burn rice husks on an industrial scale. “I was working in energy and had contact with boiler manufacturers,” he explains. “They all laughed at me, ‘Ha, ha, using rice husks, what nonsense.’” At that time, farmers would pay collectors to take the rice husks and save them from securing disposal, so the plan was viable and innovative for its time, although Chandak jokes that he feels a mixture of pride and shame when thinking about his technology. “The first industrial boiler designed by me was a primitive design,” he laughs.
Winds of Change
Direct combustion seemed to be a no-brainer, especially since bagasse and rice husks are easily burned with little ash. “If you can use a fuel directly as such, why would you want to gasify it?” Chandak says, launching immediately into a multifaceted, yet concise answer. First, converting a boiler to burn solid biomass fuels is extremely difficult and expensive, whereas modifying one to burn syngas is much simpler. Second, boilers are crucial pieces of equipment, and fuel without favorable combustion characteristics can be harmful to them. “To subject your key equipment to such difficult material would mean that you are compromising on the reliability of your equipment,” Chandak says.
Instead, shift the material problem away from the boiler. “You don’t expose your boiler to difficult fuels. You expose a gasifier to a difficult fuel.” Last, different types of biomass are available at different times of the year and they all possess varying characteristics. “If you use it directly, you’ve got to adjust your main equipment very often,” he says. “Whereas if you use an intermediary gasifier, then you’ll get normalized fuel for the boiler and all the variations will be taken care of by the gasifier.”
So after years of almost-exclusive direct firing of bagasse and rice husks, India is in the midst of a shift to wider gasification use, Chandak says. “What people realized is yes, you can direct burn biomass, but we will probably have more flexibility in operations if we use gasifiers.” While fluidization in fluidized bed boilers mandates a minimum size requirement, gasifiers can be built in small, multiple units and can be adjusted to suit a wide variety of purposes, Chandak adds. “That is where the use of gasification is increasing.”
Nearly 500 million tons of biomass is generated every year in India from bagasse, ag residue and forest sources, according to Global Energy Collaborations. In 2006, India was first in the world in biomass gasification, producing almost 70 MW, according to the Energy and Resources Institute in New Delhi, India. India’s Ministry of Agriculture and Ministry of Non Conventional Energy Sources have teamed up with a goal of increasing biomass power generation from 200 MW to an astonishing 19,000 MW, according to Global Energy Collaborations.
To reach such lofty goals, the government has meaningful incentives in place to spur development. They have been effective and a major factor in the successful growth of the biomass gasification industry, Patel says.
The National Biomass Gasifier Programme provides capital subsidies for thermal and electric biomass gasifier applications, based on the output of the system in kilowatts. The program has been wildly successful, assisting in the development of 1,074 gasifiers all around India, together aggregating 34.36 MW in various applications including mechanical, electrical, thermal and cooking, according to Global Energy Collaborations. “They don’t have anything in mind to stop it for the next three or four years,” Patel adds.
Besides the program and others like it, inherent benefits to biomass gasification serve as development drivers, too. Patel says an 80 percent depreciation in the first year can be claimed for certain cogeneration systems and comes in handy if the operator is taking profit from somewhere else. “So where can you go wrong?” he questions. Costs of production also go down with industrial installation of a biomass gasifier, as it allows power production instead of purchase. It also provides a secure supply of power, and in areas where power is scarce, that benefit is good for business, Patel says. Last, the gasifiers can be eligible for carbon credits.
The widespread development driven by such benefits has led to an almost equally widespread and diverse feedstock pool. “What I have seen is that alternative uses of biomass are so widely different from country to country and even within a country from region to region,” Chandak says. “What crops are being grown and what the current use of the residues is would determine what resource is viable.”
In general, though, he lists rice straw, cotton straw and coconut husks, reiterating that bagasse and rice husks are already used to produce energy almost to their full extent. Patel adds bamboo waste to the list and says there is no concern of a feedstock shortage in the midst of the development boom, but prices for those materials have increased.
One energy resource Chandak laments as being unexplored in India is municipal solid waste. “To my mind, if we can have a system for sorting of this waste, this would be a very excellent source of energy.” But comingled waste is hard to handle and unfortunately, everything in India is comingled, he says.
In the U.S., development of any type of biomass power plant, no matter the feedstock, can be met with intense, albeit sparse, opposition. Patel balks at the question of whether biomass developers in India deal with the same hurdles. “No. No. No,” he assures. “Nothing of that sort has come up.” India is the largest democracy in the world, with the U.S. a close second, he says, but there’s one major difference. “India is just a democracy,” he begins. “U.S. has democracy refined and polished and multiplied by five so everybody has got super democratic feelings. Everyone will oppose everything.”
So a lack of fierce local opposition could be one reason biomass gasification is catching on more quickly in India than in the U.S., making way for substantial development. Clenergen has announced it will install by the end of this year a 4 MW per hour (MW/h) gasifier in Bangladore, Karnataka, India, for hydraulic manufacturer Yuken India Ltd. The company will use about 2.5 MW/h, with the rest sold to the state of Karnataka, according to Clenergen.
Global Energy Collaborations cites two projects in the South India state of Hayana with a combined output of 17.55 MW. A 12 MW power plant will be set up in the city of Ambala that will use rice straw, rice husk, wheat straw, bagasse and cotton stalks, and a 5.5 MW plant is being established in Karnal that will generate power using cotton stalks, wheat straw, rice straw and rice husk.
Chandak says the food processing industry in India also makes a great candidate for biomass gasification, as residues need to be disposed of. “If that can be converted into energy, you solve two problems at the same time,” he says. In addition, some locations in Northern India have difficulty securing commercial fuels, such as the Punjab region, which is a textile hub. Fuel such as oil or gas is transported from between 1,000 and 2,000 kilometers. “They are dependent very much on the supply of their fuel,” Chandak says. “If these industries can double up on an energy supply system which uses a locally available, renewable, perennial fuel like waste biomass, they would be ... happy.” These are the things that would drive industrial biomass gasification, he adds.
But the potential for village-level biomass gasification is easily one of the most exciting aspects of the gasification push. Thus far, many small, remote villages have lived without electricity, but the realization that it’s necessary is setting in as economic development reaches down to rural levels, Chandak says, adding that it’s not feasible to extend the transportation grid to all areas. “Any alternative means by which they can get power is very welcome,” he says. And the increased development of biomass gasification has brought hope and a viable solution.
Right now, small kilowatt capacity systems are being developed at villages in Gahar, and Chandak hopes that in due course, those systems will lead to larger ones for larger distribution areas. “Probably in the future, the sizes will increase,” he says.
While the larger systems have a significant impact on the overall national energy demand, the small village systems don’t, Chandak says. But they certainly have a very large impact on socioeconomic development in areas that have been left out of such development. Chandak is convinced it would have a significant ripple effect and cites as an example the fact that children will be able to read at night, thus improving education. “That impact, in my mind, would be much more important to highlight than just a mere impact on the national energy demand.”
Bolstered by government incentives and social benefits, energy from biomass gasification is expected to continue growing in India, providing local resources for commercial and industrial applications that save money, and bringing rural villages out of the dark. “I think gasification offers a very good alternative for enhancing access to energy and simultaneously ensuring you have secured an energy supply from your own resources,” Chandak says. “This need would propel the use of locally adaptable power systems and gasification seems to be a viable route for that.”
Author: Lisa Gibson
Associate Editor Biomass Power & Thermal