Can Puerto Rico become a power source production country? Can this deliver

[Leticia_g]

Can Puerto Rico become a power source production country? Can this deliver us the Independence?

Sugarcane Residual Fuels - a Viable Substitute for Fossil Fuels in the
Tanzanian Sugar Industry
by Muhammad Gabra, Luleå University of Technology
Before harvesting cane fields, cane wastes with an energy equivalent
of up to four barrels of oil per acre are usually burnt. In many developing
countries, this energy could be used to reduce dependence on fossil fuels as
well as reduce the negative effects of global warming. A study at the
Tanganyika Planting Company (TPC) sugar mill in Tanzania illustrates the
possibilities of increasing power generation in a manner that is both
economically and environmentally advantageous.
Sugarcane has some of the most advantageous properties of biomass. Apart
from being used to produce sugar and molasses, sugarcane grows faster and
produces more biomass than most energy crops. There are two types of
residual fuels available at cane sugar processing factories, bagasse and
cane trash. Bagasse is the cane residue which is left over after the
extraction of sugar. Cane trash is the leaves and tops of the cane plant,
which are usually burnt before harvesting. There are agricultural benefits
of burning and leaving cane trash in the field after harvesting. However,
these benefits can be obtained by leaving only a fraction of the total
volume. Studies in Puerto Rico, Jamaica, Hawaii and Thailand found that 50%
of cane trash can be removed without any negative effect on field
productivity. By utilization of 50% of the cane trash and all the available
bagasse, the amount of residual fuels available at a sugar mill would double
from 2.5 GJ/ton cane to about 5.2 GJ/ton cane, i.e. the cane trash
represents a fuel resource of the same magnitude as the bagasse.
Today, the electricity generation capacity in most sugar mills is designed
to cover the requirements of the mill only. Generation is often restricted
to the milling period, which varies between six and 10 months, though could
continue during the off-season. The efficiency of electricity generation in
many sugar mills is poor due to low steam pressure and temperature. In some
cases, the electricity generation may be as low as 15-25 kWh/ton cane.
Although some increase in electric power output can be obtained in old sugar
mills by use of a more advanced steam process, further increase in power
generation requires employment of a combined gas/turbine process and maximum
utilization of residual fuels.
In this pilot study, the TPC sugar mill in Tanzania was selected for
investigation. At present, a turbo-alternator, rated at 2.5 MW(e), generates
an average of 1.9 MW(e), which is sufficient for the internal power
requirements of the sugar mill during the milling season. On average, about
76% of TPC's electric energy consumption is purchased from the Tanzania
Electricity Supply Company (TANESCO). The purchase of oil is a significant
financial burden, amounting to about 30% of operating cost for the steam
plant.
Today, all the bagasse and some supplementary fuels are used to generate
electricity and process steam. Generation of energy for irrigation and
possible sale to the national grid would require increased process
efficiency or the use of an additional fuel such as cane trash.
Four options to increase electricity generation at the TPC sugar factory
have been studied, including:
* use of cane trash at the existing factory during the off-season;
* a new system with a more advanced steam process;
* a combined cycle consisting of a gas turbine and back-pressure steam
turbine using bagasse and cane trash; and
* a combined cycle consisting of a gas turbine and condensing,
extraction turbine, also using bagasse and cane trash as fuel.
Greatly increased output
Analysis of these options found that increasing the steam pressure to about
40 bar and steam temperature to about 520oC, the specific electricity can be
increased to about 130 kWh/ton cane. Equipping the power plant with a
low-pressure turbine installed with a condenser would increase electricity
generation to 330 kWh/ton cane. Further, to increase electricity generation
even more, a combined gas/steam turbine process can be used. This technology
is still being developed, but estimates on performance, using CO-generation
of electricity and heat, show that electricity generation can be increased
to 430 kWh/ton of cane.
Financial evaluation of the different processing options indicate that the
more advanced, CO-generation processes are the most profitable. With an
assumed sales price of US$0.06/kWh(e), the annual profit would range from
US$3.5 million for the advanced steam process, to US$4.7 million for the
combined gas/steam turbine process. The payback periods for these options
range from 6.5 to 6.8 years.
The combined gas/steam turbine process, which gives the largest profit,
still has a number of technical uncertainties. Problems that remain to be
solved are ways of avoiding erosion, deposits and corrosion in the gas
turbine caused by mineral matter in the solid fuel. Gas turbines are
designed to run on very clean fuels such as natural gas or light petroleum.
Solid fuels have a relatively high ash content that can produce gas with a
high dust content. Some elements in the ash, in particular sodium (Na),
potassium (K), and vanadium (Va), form corrosive compounds with low melting
points and may deposit inside the turbine. As it may take time to develop a
combined gas/steam turbine with bagasse as fuel, it is better to install a
steam plant with the possibility of back-fitting once the new technology has
matured.
Positive environmental impact
These options for increasing electricity generation and financial profit of
cane sugar factories also have a positive environmental impact. The cane
sugar industry may contribute to the reduction of green house gas emissions
by replacing fossil fueled thermal power plants with biomass powered
plants. Compared to oil and coal fuels, biomass has a much lower sulfur
content. This reduces SO2 emissions and lowers the risk of soil and water
acidification. The ash content in biomass is lower than in coal, meaning
less problems with ash disposal and leakage of heavy metals. Replacement of
old boilers with more modern ones can be expected to reduce emissions,
despite the fact that fuel throughput will be almost doubled.
Conclusion
The study at the TPC sugar mill in Tanzania has shown that further research
on methods to increase electric power generation at sugar mills needs to
focus on:
* use of cane trash and bagasse as fuel in combined gas/steam turbine
cycles;
* combustion of bagasse and cane trash by use of a gas turbine
combustion chamber designed for wood powder;
* gasification of bagasse and cane trash;
* technologies for and the cost of: collection of cane trash, drying
of bagasse and cane trash and densification for minimization of storage
volume; and
* The percentage of cane trash that should be left in the fields to
maintain sufficient organic content and nutrient balance of the soil.

[Virgil]

Leticia,

Antes de que me largara de la isla (a peticion de los separatistas),yo siempre habia entendido que la UTIER y la UITICE son los dueños de la AEE. Digame como usted va a lidiar con estos elementos, si a todo plan que conlleve cambios en la estructura de la agencia, estos tipos tienen toda clase de objecion?

Mi compadre es uno de ese clan y el tipo se gana como 25 dolares la hora y no es celador de linea!!!

Yo a la verdad que no los comprendo a ustedes cuando vienen y presentan este chorro de ideas muy buenas pero sin un plan real de implementacion a la isla. Es mas, todos estas grandes ideas siempre son de en casa'el carajo, de paises que no se parecen en nada a Puerto Rico (socialmente y geograficamente) Hay muchas cosas que ustedes dejan a "la fe de nuestra gente".

Y eso a mi me suena como el tipo que se acerca y te dice si quieres un carro nuevo, dame un cheque firmado que como yo soy tan bueno en los negocios, te voy a conseguir un Lexus del año por $2,000.

Si pepe.

EXITO

[conciencia]

Yellow belly...

Te dire hermano que esta idea esta sido estudiada para injectarlo en Puerto Rico. Todo el mundo sabe que puerto rico fue una potencia economica y agricola en los siglos pasados. Todo el mundo sabe que la Cana de azucar sale en PR sin tener ni que sembrarla. En fin casi todo sale en PR con tan solo tirarla en el piso. Inclusivo en PR se pierde tanta comida y frutas que parece mentira.

Me acuerdo una vez que estaba en North Carolina y tenia un gran ansia de comer mango, cuando fui a varios sitios en contre un mango que ya estaba casi podrido lo compre porque no me quedaba espacio... pero pague $2.00 por un mango que en PR se encuentran en las calles revuelto por mimes.

Un poryecto asi puede traer muchas concecuencia positivas para PR, claro cualqueir forma de energia alterna, trae protestas, ya que son consideradas..interrupt energy sources...osea que interrumpen el flujo de una economia o industria....pero si esta otra forma de energia trae mas empleos, dejamos de depender de EEUU, abrimos un mercado nuevo, el Boricua se puede echar mas dinero en el borcillo y lanza el camino hacia la Independencia con una conciencia de superioridad en vez de inferioridad...lo respaldo un 100%.

[El_Jibaro]

[i]Cuba produces 10 times more sugar cane than PR, yet they need "free oil" from its vassal Venezuela like crazy.

You can even see the local American farming consortiums peddling the idea of getting ethanol from corn to be the sole source of US fuel, but that is always WISHFUL THINKING.

Not that those things couldn't provide some tiny portion of our fuel requirements both in the USA and Puerto Rico, and thereby affect indirectly the prices of oil (5% less oil imports to the USA and PR means that OPEC will have to cheapen its product to sell more and make up the lost revenue).

By the way, the "moral" of all this WISHFUL THINKING story is that we should pay 20 dollars for every gallon of ethanol we use in our cars and for every watt of electricity we produce with sugar cane refuse. If we have money to burn (that is, if we can afford to pay 50% or more of our income in energy costs from farm products), then we should go ahead with these grand schemes. However, why not go back to horse and buggy times like the Amish and just forget about having a comfortable modern lifestyle ... Just think of being taken to the hospital on a cardiac emergency in a horse-drawn ambulance...[b]

[conciencia]

How in the world did you came up with the $20.00 a galon none sense?

Do you think PR will have all the "bureaucracy", "red tapes", and stupidity USA uses? Come on Jibaro...What is it? It seems you are in LALA land lately!

[Leticia_g]

This article is not a fallacy of the independent movement. This was actually on a special shown in Television. It was shown as a positive avenue and a sign of progress for our Island. We are capable of doing a lot for ourselves. Many like yourself think we can't. That is very sad, because if we all think like you, many things in this world would not have occurred. Many progresses would not have been achieved.

We have to stop crippling ourselves. Whether statehood or independence comes about for our Island, time will tell. What we should focus is on many other things that we can do to improve our economic limbo. Nothing to fear but fear itself!


Much regards and respect to you both!

[Madbrunette]

You have to love arguments like El Jibaro's. I mean, the hilarity of it is he most likely believes he's being supremely rational. The problem is that his kind of rationality is so limited to immediate short term effects and ignore larger institutional reasons why things are the way they are in the first place. Now, if one of those rich, white, greedy bastards (think Dick Cheney) in the energy industry had found a way to make a butt load of money off of alternative energy sources while producing them at bare minimum cost, we'd be loading our cars with steam and corn as we speak. The problem is they're too busy filling their ham-fists with cash because of our insatiable lust for petrol as it is, there is no need for them to seek out the solutions for alternative energy sources. Let's say we get alternative sources, and they do cost more than gas...what is the problem? How do those extra cents compare to the cost of a plundered and deeply scarred earth? It's in those corporations' best interest to keep people like El Jibaro going on and on about progress, but how rational is it to keep on exhausting our resources till we hit a major crisis? You can bet the cost will be passed onto the average joe when it does come. That's rationalism and progress for you.