Tuesday August 19^th – Day 9

            We drove to our tour at RENUKA, a sugarcane ethanol plant.  The plant we visited was in Vale do Ivai and began sugar production in 1993.  In 2010 it was bought by Shree Renuka Sugars, a company started in India in 1998.  At the plant we had to opportunity to chew on some sugarcane, which was very sweet and delicious!  Sugarcane is broken down, washed twice, and crushed by going through 5 or 6 mills.  A sweet juice is produced which can go through a fermentation process for ethanol generation or crystallization process that results in raw sugar.  The waste from the sugarcane, called bagasse, is burnt as fuel to create steam and power the generator for the plant.  The plant generates 18 megawatts of power and consumes 7 megawatts to operate so the company is looking into ways of selling the excess energy, though currently the company is not selling any power.  The plant cannot operate during rain and it runs from March to November or December.  When the plant is running at full sugar capacity it generates 75% sugar and 25% ethanol as opposed to if the plant was running at full ethanol capacity, only 45% ethanol could be produced.  The soil at this location in Brazil is some of the best in the world.  It is possible to harvest without replanting for 7 years, where most sugarcane farms must be replanted every 4 years. 

            This entire process of self-power generation through bagasse, creating ethanol as a side product from sugar which will always have a demand, and ending up with excess power after the cycle is great but there are also some downsides as with all energy sources.  Unfortunately 6 to 7 million liters of water is used daily.  The company tests for heat exchange and releases the water back into rivers when the temperature is acceptable again.  Waste water is also used on the farms.  The process releases carbon dioxide and other gases into the atmosphere.  Departments within the company monitor the gas emissions and deal with the management of solid waste.  The visit was very enlightening and I believe that the concept of taking advantage of the resulting product (ethanol) from a staple on such high demand (sugar) is a smart investment and idea.