Bamboo as a bioenergy source

Climate change is adversely affecting our planet by causing extreme weather events like heat waves, tropical storms, forest fires, bringing alterations in crop production etc.

Use of conventional fuels is one of the leading sources of CO2 and other green house gas emissions. Since the emission of GHGs stands as the major perpetrator that gives rise to global warming, thus causing climate change, it becomes necessary to find alternatives to combat these emissions to the utmost possible levels. 

Our country, India has been quite successful in integrating biofuels to its fuel economy. Biofuels in India are being produced using various substrates such as agrowastes, potatoes, canes, corns etc. In this respect, bamboo, a renewable and non-food biomass is seen to be potentially viable to be used in production of energy. 

Bamboos, a group of large woody grasses, are generally found in warm and humid environment. Their distributions are mainly concentrated in the tropics, but they can also be found in natural conditions in subtropical and temperate regions.

Local Availability

Although Madhya Pradesh holds the largest area under bamboo forests followed by Maharashtra and Arunachal Pradesh, bamboo in India grows in almost all parts, naturally, except in Kashmir. Bamboo is cultivated in 13.96 million hectares in India, with more than 136 distinct species and occupies almost 13% of the total forest area. The total annual bamboo production in India is around 5Mt. 

Fuel Characteristics

Bamboo holds a number of fuel characteristics as in low ash content and alkali index. The moisture content in bamboo is comparatively low (8-23%) to other agri biomasses and has high heat value (near about 33M/J) than majority of the agricultural residues. Growth rate in bamboo is high and hence it prevents deforestation. Methane procured from bamboo is a far more efficient process when compared to other gaseous and liquid biofuels. 

For bioenergy production and environment management

Next to China, India is the second largest bamboo producer nation in the world. In India bamboo is generally produced in the Western Ghats and in the North eastern parts.  Bamboo covers around 13% of the overall forest area in India. According to a report released by Indian State of Forest Report (ISFR) in 2017, the bamboo cultivation area showed an increase of around 3229 km2, which was approximately 1,60,037 km2 in 2017. The gross carbon reserve in forests from bamboo is expected to be 7124.6 Mt, which shows an increase in the nation’s forest carbon stock by 42.6 Mt as in 2017. 

Bamboo is projected to give around 40 tonnes of biomass per hectare which shows its potentiality in the generation of bioenergy and environment mitigation.

The world’s developed countries make use of woody biomasses as their primary source of energy. As a data report provided by Food and Agriculture Organization, around 13% of the world’s primary energy is provided by the woody biomass. Woody bamboos possess a very high growth rate and can hence annually generate around 50Mt of biomass per acre. This biomass could be converted into a wide variety of energy products such as charcoal, biogas and biofuels.

Developing feedstock for biofuels is a tedious task for any nation, as the biofuels production competes with food and land resources. Bamboo species have an annual growth that estimates around 22-44 Mt per hectare that is more than pine and almost equivalent to eucalyptus forests which again makes it viable for energy production.

In a similar pattern as applied with other bioenergy crops, energy from bamboo can be recovered using three different ways: thermal conversion, thermo chemical conversion and biochemical conversion. Thermal conversion involves direct combustion in the presence of oxygen and is the most common method used for the conversion of solid biomass to energy. 

The thermo chemical method involves the process of pyrolysis for generating energy from biomass. Pyrolysis is the process in which biomass is thermally degraded in presence of moderate to high temperature, but in the absence of oxygen. This process can be used to convert bamboo biomass to solid fuels such as charcoal, liquid fuels and syngas.

The biochemical conversion process involves the involvement of various microorganisms that bring out the transformation of biomass to biofuels. This process basically involves the fermentation of sugars and its further conversion into biofuels. 

Thus, bamboo biomass can be utilized in a number of ways to generate energy. 

Potential challenges

Needless to say, bamboo is a potential feedstock for energy production. However, there are many challenges in its cultivating process and management. Bamboo may possess severe threat to invasive species, if the plantations are not managed properly, since its high growth rate can displace the surrounding vegetation.   In addition, even though no or very less pesticides and chemical fertilizers are required for bamboo cultivation, its intensive management requires chemicals that could be harmful for the land and water thus polluting them. 

Conclusion 

Bamboo could be a wonder material and turn out as a miracle plant in mitigating global warming as it caters to effective carbon recycling. With proper planning, management and harvesting, bamboo could turn out to be a potential feedstock for biofuels production in India. Bamboo is available abundantly in India, familiar to the local population, has high growth rate and can store and sequester carbon. It does not require very fertile land for its growth i.e. could grow on degraded lands and has high fuel characteristics for bioenergy production. This multi-purpose ability of bamboo could be integrated into energy production to achieve renewable energy targets in India.