Biomass and Electricity from the Sugar Industry

After the sun, biomass is probably the second oldest energy source used by human beings. With the discovery of fire, biomass became to occupy an important place in the lives of early humans, and was used for heat, to cook food, in religious rituals, and as a defense mechanism.

The Cuban sugar industry shows the greatest possibilities in using biomass from sugarcane waste, taking advantage, among other things, of the vast experience of farmers.

The production of sugarcane biomass has been gradually decreasing from 2002 when a restructuring of the sugar industry led to the closure of dozens of mills. In 2008, the production of biomass in the industry increased 13 percent in relation to 2007, while power generation from this source increased 28 percent, showing an increase in efficiency when using this raw material. This is also in keeping with an upturn in sugar production during the last period.

The infrastructure of the sugar industry provides a good avenue for the whole scale treatment of waste materials, turning them into useful by-products. Currently, biogas, electricity and fertilizers are obtained from sugarcane waste materials. What the sugar industry now needs is a policy focusing on generating power for the National Power Grid so as to wean its oil dependency.

In Cuba, power generation by cogeneration promises several benefits and could provide a boost to a declining industry, generate profits through the sale of electricity, lead to growth in other industries, reduce the costs of power production, guarantee a greater amount of energy for the industry and the country, increase the installed capacity, reduce the dependence on imported oil, and have a positive impact on the trade balance.

For example, a sugar mill that grinds 4,000 tons of sugar a day, using boilers and condensation turbo generators with regulated extraction, could meet all its energy demands by burning the resulting bagasse, while providing 12 megawatts to the National Power Grid (more than 44 gigawatts/hour during the sugarcane harvest). This could result in a savings of between 8,800 and 17,600 tons of diesel oil, an import savings of US $4.3 to 8.6 million (at US$ 62 per barrel).

Two of the most serious problems that the sugar industry faces today are inefficiency or technological lag, and the fact that energy production is not included in their mandate.

An example of this is the fact that in 1992, 12 percent of the power generated in the country was produced in the sugar industry; however, a study by the United Nations Organization for Agriculture and Food (FAO) in 1996 states that in 1995 power production in the sugar industry had a deficit of 544 gigawatts/hour.

The study proposes, during a first stage, the possibility of reducing that deficit by 200 gigawatts/hour by increasing the efficiency of the existing facilities and implementing energy saving measures.

In a second stage, it shows that the industry could contribute up to 300 gigawatts/hour to the National Power Grid.

The study reports that from 1989 to 1990, the industry produced 21 million tons of bagasse (each ton of ground sugar equals roughly 0.35 tons of bagasse), while waste reached 35.2 million tons. The latter represents almost two times the equivalent oil used to generate electricity in 1989.

In addition, Cuba has made significant advances in the development of a variety of sugarcane with high fiber content and thus a superior energy producer. Crop performances under ideal conditions can surpass 100 tons per hectare, and harvest waste produces up to 20 percent more combustible material.

Sugarcane Isn’t the Only Source

However, sugarcane is not the only source of biomass. There are other sources of organic material, such as firewood, rice and coconut husk, forest debris and coffee waste, which are not currently being used to their full potential.

Moreover, the country has obtained power from solid organic material, by using bio-digesters, which rot the organic components to obtain biogas used to cook or to generate power, and fertilizers. In Cuba, there are around 700 plants of this type, although only 50 percent of them are used to this end.

The Palmira Pork Production Facility, in the province of Cienfuegos, is a good example of the use of this type of plant. The facility has a bio-digester to process the waste of 35,000 pigs. The City of Havana also has a bio-digester at one of their municipal waste centers (100th Street and Boyeros Ave.) that processes between 15 and 20 tons of organic waste per day, generating between 60 to 70 kilowatts/hour.

Projects like this one and others to exploit renewable and environmentally clean energy sources will help Cuba reduce its dependence on fossil fuels, while lowering its energy vulnerability. The main limitation facing this area is financing.

To fund these projects the country currently relies on credits within the framework of the Bolivarian Alternative for the Americas (ALBA), Petrocaribe or other energy alliances, and foreign investment, as well as reinvesting savings obtained from successfully implementing these policies.


Source:havanatimes