Multi-pronged approach to biogas technology

Biogas as a triple benefit option for Sri Lanka:

By Indeewara Thilakarathne

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The inaugural session of the Lanka Biogas Association was held last Thursday with the launch of its official website (www.lankabiogas.org).

Although one may argue that it is another organization added to the plethora of alternative-energy organizations in the county, Lanka Biogas Association, among other things, will bring biogas practitioners scattered across the country under an umbrella.

It also provides much “needed organizational framework which would connect Sri Lankan biogas practitioners with their counterparts in the region and with international organization engaged in the application of biogas technology in solid waste management and acidic waste water treatment while generating energy and highly fertiled organic manure as a by-product of the process.

With the advancement of biogas technology, biogas can be produced from wide range of materials such as from biomass, waste water and solid waste.

It is currently estimated that entire electricity requirement of the country can even be met by efficient application of biogas technology.

Indigenous technology

Although the early use of biogas in Sri Lanka was marked by the adaptation of foreign technology for the construction of bio-digesters like those of Chinese and Indian models, subsequently Sri Lankan scientists were able to invent the Sri Lankan Dry Batch Biogas System. In terms of efficiency, it has proved that as effective as Chinese and Indian models and won an international award.

By now, through the continuo training programmes, Sri Lanka has produced considerable body of biogas practitioners as well as biogas service providers such as masons who are specialized in the construction of biogas plants. The technology has been effectively used in major scale production of biogas solving seemingly intractable issues such as solid waste management and acidic water treatment.

For instance, Kirulapona Market Garbage Digestion Project and large-scale biogas plants set up at Muthurajawela demonstrate in no uncertain terms the multiple benefits accrued from the application of biogas technology.

Polonnaruwa Garbage disposal project which is to be commissioned soon, bears testimony to application of advanced biogas technology in solid waste management. It has been pointed out that garbage dump in Polonnaruwa in addition to polluting the environment, has posed a serious threat to diminishing elephant population.

Elephants used to eat toxic garbage and the issue was taken up by environmentalists and animal lovers around the world. The plant will solve the garbage problem in the area, producing rich bio-fertilizer.

Biogas technology has also been used in waste water treatment. Waste water is produced by factories and coconut mills and distilleries. These waste water has higher degree of acidity and pollutants which will, in the long run, pollutes surface as well as ground water.

Waste Water treatments plants set up at distilleries, farms and hotels proved that in addition to effectively treating the waste water, biogas produced can be used for thermal purposes.

For instance, biogas can be used to heat up boilers and for cooking and generating electricity. Technology has been applied in Maxis Farm in Seeduwa and Waste Water treatment plant at Air Link Hotel in Seeduwa.

Against the rising cost of petroleum products such as LP gas which has now been used widely in diverse parts of the country for domestic and industrial purposes, cost effective innovative solution to rising fuel bill is to apply biogas technology at domestic level.

Biogas produced from waste generated in household is sufficient for cooking purposes and bio-fertilizer which is a by product of the process, can be used for home gardening. Technical assistant for the construction of such domestic plants can be obtained from National Engineering Research and Development (NERD) Centre of Sri Lanka.

Apart from using fossil fuel for transportation, LP gas which is a by product of crude oil refinery, has been widely used for cooking in Sri Lankan households. Since the staple in Sri Lanka is rice, rice cooking will consume considerable energy irrespective of whether the household use LT gas or electricity for cooking.

NERD has come out with an innovative solution to this much energy consuming exercise, with biomass rice cooker. The biomass rice cooker is designed to cook 1kg of rice, at a time, using a shell of a one coconut which is usually discarded or under-utilized by any coconut consuming family in Sri Lanka .

The biomass rice cooker which is, at present, available in market, can also used to boil up to three liters of water and keep cooked food warm for seven hours without adding any more fuel. Rice can be cooked in 45 minutes.

As advanced technology has been used in the production of the cooker, the Rice pan will not gather any shoot as usual in cooking with firewood. A host of benefits can be accrued from the application of advanced biotechnology in solid waste management, solid water treatment and in generation electricity for out-of the grid villages.

At present, rural electrification projects using biomass have been effectively implemented in several out-of-the grid villages. Another potential area of using biotechnology is to harness biodiesel from not edible seeds and plants which can be directly used for vehicles without causing any damages to mechanical parts.

The need of the hour is to adapt a national policy on Energy which will explore the imminence potentials of using biogas technology for economic development.

Corner stone of such a policy is to recognize science and technology as the engine of economic growth.