bagasse

This article may need to be rewritten entirely to comply with Wikipedia's quality standards. You can help. The discussion page may contain suggestions. (April 2009)

Bagasse is the fibrous residue remaining after sugarcane or sorghum stalks are crushed to extract their juice ^[1] and is currently used as a renewable resource in the manufacture of pulp and paper products and building materials.

Agave bagasse is a similar material which consists of the tissue of the blue agave after extraction of the sap.

Sugarcane being crushed in Engenho da Calheta, Madeira. The bagasse falls down a chute and is removed on a conveyor belt below.

Production

For each 10 tonnes of sugarcane crushed, a sugar factory produces nearly 3 tonnes of wet bagasse.

Medical problems

Workplace exposure to dusts from the processing of Bagasse can cause the chronic lung condition pulmonary fibrosis.

The Chest Journal, an official publication of the American College of Chest Physicians published an article on bagasse and its effects on the lungs.^[2] Called Bagasse Disease of the Lungs.

Factory conditions

Historically bagasse factories have had harsh working environments due to the process of milling the pulp. Factory workers have reported bleeding hands and arms. Workers are also required to wear masks to prevent breathing in pulp fibers.

Use

Heaps of bagasse, covered with blue plastic, outside of a sugar mill in Proserpine, Queensland

Many research efforts have attempted to use bagasse as a renewable feedstock for power generation and for the production of bio-based materials.

Fuel

Bagasse is often used as a primary fuel source for sugar mills; when burned in quantity, it produces sufficient heat energy to supply all the needs of a typical sugar mill, with energy to spare. To this end, a secondary use for this waste product is in cogeneration, the use of a fuel source to provide both heat energy, used in the mill, and electricity, which is typically sold on to the consumer electricity grid. Sugar cane Bagasse has recently been used as the primary ingredient in 'Soex' brand Herbal Shisha. The shisha is sold as 100% tobacco, nicotine and tar free. The health effects of smoking Sugar cane Bagasse have not been looked into.

The resulting CO₂ emissions are equal to the amount of CO₂ that the sugarcane plant absorbed from the atmosphere during its growing phase, which makes the process of cogeneration greenhouse gas-neutral. Florida Crystals Corporation, one of America's largest sugar companies, owns and operates the largest biomass power plant in North America. The 140 MW facility uses bagasse and urban wood waste as fuel to generate enough energy to power its large milling and refining operations as well as supply enough renewable electricity for nearly 60,000 homes. The facility reduces dependence on oil by more than one million barrels per year.

Ethanol produced from the sugar in sugarcane is a popular fuel in Brazil. The cellulose rich bagasse is now being tested for production of commercial quantities of cellulosic ethanol. Verenium Corporation (VRNM) is currently building a cellulosic ethanol plant based on cellulosic by-products like bagasse in Jennings, Louisiana. They are using a biotech approach to improve ethanol production above and beyond the midwest corn based ethanol production method. This will allow regional cellulosic ethanol production getting around the problem of ethanol transportation. The Verenium approach will get ethanol and E85 fuel to the important markets in California and the Northeast.

Paper

Around 5%-10% of paper production worldwide is produced from agricultural crops, valuing agricultural paper production at between $5 billion and $10 billion^[3]. The most notable of these agricultural crops are wheat straw and bagasse. Paper production is the second largest revenue stream from bagasse after electricity cogeneration; higher than ethanol. Using agriculatural crops rather than wood has the advantage of reducing deforestation. Bagasse has the added advantage in that it requires fewer greenhouse gases to collect, compared to harvesting of wood chips, as the fibre has already been transported to the factory for extracting the sugar. Due to the ease with which bagasse can be chemically pulped, bagasse requires less bleaching chemicals than wood pulp to achieve a bright, white sheet of paper. The fibers vary in length depending on the country and cane variety but are typically about 1.3mm to 1.7 mm long. Bagasse fibers are well suited for tissue, corrugating medium, newsprint, and writing paper^[4][5].

Bagasse pulp and paper mills tend to be smaller than wood based mills although many world-scale factories exist, notably TNPL (Tamil Nadu, India) Century Pulp and Paper (India) and Ledesma Paper (Argentina).

Most chemical bagasse pulp mills concentrate the spent reaction chemicals and combust them to power the paper mills and to recover the reaction chemicals.

Food containers

Bagasse is used to make insulated disposable food containers, replacing materials such as styrofoam, which are increasingly regarded as environmentally unacceptable (see styrofoam bans). Insulated disposable food containers made of bagasse are commercially available.

See also

• Biofuel

References

External links

• The Potential of Bagasse-Based Cogeneration in the US, Kevin Ho, Columbia University, 2006.

Alternatives

Vegetable starch based products