OK, I realize I have been completely remiss in my obligations to post at least somewhat regularly. So I apologize to all of my loyal readers who have been anxiously awaiting my next entry.
Ha!
I'm the only one who ever reads this thing.
At any rate, I have a good excuse, I have been so damn busy with school work that I barely have time for anything.
But never fear. Within the next two weeks I will be completing the first major deliverable for my plasma-gasification project. It is the business case and it will be around 12 pages long and I will post it. Probably won't do anything on the blog until then though.
Thursday, March 6, 2008
Tuesday, January 29, 2008
Getting Organized
OK,
So I realize that my blog is a bit unwieldy so far, too much text, not enough graphics, and I am rambling in general.
I am working on some technical solutions to index my collection of documents about gasification. I have at least 1 GB of .pdf files, a lot of which are federal government reports on coal and biomass gasification. By indexing these documents I will be able to search them more easily and hopefully improve my writing by being more succinct and to the point.
Ideally I would expand this whole effort into a website and host all the doc's on the site and have a public accessible library. But one thing at a time. I barely can find the time to blog, much less build an entire site right now.
So I realize that my blog is a bit unwieldy so far, too much text, not enough graphics, and I am rambling in general.
I am working on some technical solutions to index my collection of documents about gasification. I have at least 1 GB of .pdf files, a lot of which are federal government reports on coal and biomass gasification. By indexing these documents I will be able to search them more easily and hopefully improve my writing by being more succinct and to the point.
Ideally I would expand this whole effort into a website and host all the doc's on the site and have a public accessible library. But one thing at a time. I barely can find the time to blog, much less build an entire site right now.
Friday, January 25, 2008
Plasma-Arc Gasification
Plasma-Arc Gasification is a unique form of gasification that utilizes plasma torches to generate the highest temperatures of any type of gasifier. Plasma is an ionized gas that forms from high currents of electricity passing through the air across two electrodes. Plasma is sometimes called "the fourth state of matter" after solid, liquid, and gas. We see plasma in nature in the form of lightning bolts and also on the surface of the sun. The fundamental advantage of utilizing plasma is that it generates much higher temperatures than other technologies, and since it is electrically powered it can be fired up at the flip of a switch (a pretty big switch!) and attain operating temps almost immediately, and be shut down just as quickly. Plasma torches can generate heat up to 10,000 degrees.
Plasma gasification utilizes two primary techniques, the transferred torch and the non-transferred torch. The non-transferred torch has the electrodes inside the torch body and on the outside of the gasification reactor, air is blown through the torch across the plasma arc and into the gasifier. This it the type of system developed by Westinghouse-Plasma Corp which is the world leader today in gasifying MSW. I will detail the Westinghouse technology quite a bit in my blog.
A transferred torch places the electrodes inside the reactor and the arc is made inside the reactor. Proponents of this technique claim better heat transfer and electrical power efficiency, the downside may be greater wear on the torch because of the corrosive nature of the gases. Transferred torches are used in electric arc furnaces in the steel making industry. Heat also needs to be balanced between making sure there is enough to effectively break down all of your feed and the resulting tars while at the same time protecting the interior of your reactor and its refractory lining. Uncontrolled heats will damage the reactor.
Plasma torches have been used for many years to dispose of hazardous wastes and to melt foundry wastes and incinerator ashes. The military has also used the technology to destroy chemical weapons.
Plasma gasification utilizes two primary techniques, the transferred torch and the non-transferred torch. The non-transferred torch has the electrodes inside the torch body and on the outside of the gasification reactor, air is blown through the torch across the plasma arc and into the gasifier. This it the type of system developed by Westinghouse-Plasma Corp which is the world leader today in gasifying MSW. I will detail the Westinghouse technology quite a bit in my blog.
A transferred torch places the electrodes inside the reactor and the arc is made inside the reactor. Proponents of this technique claim better heat transfer and electrical power efficiency, the downside may be greater wear on the torch because of the corrosive nature of the gases. Transferred torches are used in electric arc furnaces in the steel making industry. Heat also needs to be balanced between making sure there is enough to effectively break down all of your feed and the resulting tars while at the same time protecting the interior of your reactor and its refractory lining. Uncontrolled heats will damage the reactor.
Plasma torches have been used for many years to dispose of hazardous wastes and to melt foundry wastes and incinerator ashes. The military has also used the technology to destroy chemical weapons.
high temperature and slag
There are endless varieties of gasifiers that have been produced over the years. Gasification is very much an art and the equipment is tailored to the feedstocks that are put into it. Most gasifiers have been used for either coal or biomass and have been optimized for those purposes. Generally speaking coal gasification is done in very large industrial facilities while biomass gasification is done on a much smaller scale, and is often done by hobbyists and tinkerers in their garage as well as in developing world countries.
I intend to do a review of gasification technologies at some point.
The challenge in gasifying garbage (municipal solid waste or MSW) is the heterogeneous nature of the materials. MSW by its nature is composed of a huge variety of materials ranging from plastics and papers to metals, glass, construction debris, and many others in varying sizes and moisture contents. Traditional gasifiers cannot handle such mixed waste. In order to reliably process MSW the gasifier needs to operate at much higher temperatures and throughputs. Basically the temperature needs to be high enough that it can reliably melt all the metals and glass that go in. Gasifiers that melt metals and ashes are called "slagging" gasifiers because the melted materials from glass, mineral, stone, and metal becomes molten fluid in the gasifier and will pour out a tap hole and be cooled. Once cooled the molt is called slag and it forms vitrified glass. The slag is very stable and in the USA must pass EPA TCLP leachability tests which test for a variety of potential toxins that may potentially leach out. Slag from high temperature gasifiers is remarakbly stable and clean. The high temperatures break down organic hazards and the glass itself seals up many other dangers such as volatile metals like mercury, lead and cadmium.
Insert details on TCLP tests.
Insert characteristics of Slag. Review New York harbor sludge.
I intend to do a review of gasification technologies at some point.
The challenge in gasifying garbage (municipal solid waste or MSW) is the heterogeneous nature of the materials. MSW by its nature is composed of a huge variety of materials ranging from plastics and papers to metals, glass, construction debris, and many others in varying sizes and moisture contents. Traditional gasifiers cannot handle such mixed waste. In order to reliably process MSW the gasifier needs to operate at much higher temperatures and throughputs. Basically the temperature needs to be high enough that it can reliably melt all the metals and glass that go in. Gasifiers that melt metals and ashes are called "slagging" gasifiers because the melted materials from glass, mineral, stone, and metal becomes molten fluid in the gasifier and will pour out a tap hole and be cooled. Once cooled the molt is called slag and it forms vitrified glass. The slag is very stable and in the USA must pass EPA TCLP leachability tests which test for a variety of potential toxins that may potentially leach out. Slag from high temperature gasifiers is remarakbly stable and clean. The high temperatures break down organic hazards and the glass itself seals up many other dangers such as volatile metals like mercury, lead and cadmium.
Insert details on TCLP tests.
Insert characteristics of Slag. Review New York harbor sludge.
Thursday, January 24, 2008
Great slideshow on gasification history
http://www.slideshare.net/ncenergy/operating-engines
-on-woodgas-by-bill-olsen/
(get the link on one line!)
Hoping to get permission to post the whole file, but in the meantime take a look at the link. Fascinating stuff, especially once you get to pictures of all the woodgas cars. Don't think too many of those would pass inspection here in the US!
-on-woodgas-by-bill-olsen/
(get the link on one line!)
Hoping to get permission to post the whole file, but in the meantime take a look at the link. Fascinating stuff, especially once you get to pictures of all the woodgas cars. Don't think too many of those would pass inspection here in the US!
Coal gasification process
http://www.gasification.org/gasproc.htm
This graphic comes from the Gasification Technologies Council.
They are an industry association focused primarily on coal gasification. Their site has a ton of info if you are interested.
http://www.gasification.org/index.htm
Gasification
First we need to explain gasification. Gasification is a very old industrial practice that has been with us throughout the industrial revolution and used continuously in various forms. Gasification is a thermal process where heat (and sometimes pressure) is applied to carbon based materials, usually coal or biomass, in an air reduced container. The materials are not allowed to burn but instead are broken down into tars, char, and gas. Gasification is closely related to combustion but distinctly different. Low temperature or poorly engineered gasification will produce lots of tar which is bad for our purposes, the goal of high temperature gasification is to achieve a complete breakdown of the tars into gases.
The output gas is called Syngas, which is short for synthesis gas, and it is primarily a blend of carbon monoxide and hydrogen. The higher the ratio of hydrogen, the more potent the fuel. Pure syngas is a green fuel with a very clean combustion profile. It is about as clean a fuel that exists for burning, and can be used in steam boilers or electrical turbines, but syngas can be used for far more than simply burning. Syngas is an excellent feedstock for a variety of purposes, it can be made into liquid fuels such as ethanol, methanol, diesel, or jet fuel (kerosene). Syngas can be used to make chemicals and plastics, including biodegradable plastics. Adding methane to syngas produces Synthetic Natural Gas. Syngas can also be broken apart to separate the H2 from CO, and can be a major source of hydrogen for a potential hydrogen economy as well enabling carbon sequestering. All of these outputs are worthy of a discussion of their own and my goal will be to get to each one in turn and present the business perspective on them.
Gasification, primarily of coal, has been used for a very long time. Here in the US the first municipal power systems utilized "town gas" from coal gasification to light street lamps in the late 1800's. Chemical industries have utilized coal gasification to produce chemicals since the 1950s. Overseas countries under embargo have utilized coal gasification to produce liquid fuels for decades. The Germans used coal to liquids in WWII and in South Africa the energy firm Sasol has done coal to liquids for decades and continues to be a world leader in the technology. After WWII woodgas powered automobiles were popular in Europe when gasoline was in short supply and home-built wood gasifiers allowed people to go 1 mile per pound of wood. There is some real fascinating history to gasification and hopefully I will can get permission to post some of the materials I have collected that go into detail.
The fundamental premise and promise of gasification, is the ability to take a wide variety of raw materials, many of which are considered waste, and reduce them to a common gas. The gas in turn can be used for a variety of outputs, and do so in a manner that is green.
Raw materials can include unconventional fossil fuels such as high sulphur coal, oil shale, tar sands, pet coke, or municipal waste, plastics, chemicals, agricultural waste whether plant matter or manure, and also sewage sludge.
The ultra high temperature processes, above 1200 F will melt metals and glass in the feedstock and will destroy organic hazards such as poisons and infectious matter. At high temperatures a process called "molecular disassociation" occurs where materials are disintegrated and torn apart at a molecular level destroying their toxic nature. So these gasifiers can serve as hazardous waste disposal sites as well, but more about that later.
Enough for now, as you can probably see there is enough to talk about here to fill a bunch of books, my challenge is to maintain a coherent thread.
The output gas is called Syngas, which is short for synthesis gas, and it is primarily a blend of carbon monoxide and hydrogen. The higher the ratio of hydrogen, the more potent the fuel. Pure syngas is a green fuel with a very clean combustion profile. It is about as clean a fuel that exists for burning, and can be used in steam boilers or electrical turbines, but syngas can be used for far more than simply burning. Syngas is an excellent feedstock for a variety of purposes, it can be made into liquid fuels such as ethanol, methanol, diesel, or jet fuel (kerosene). Syngas can be used to make chemicals and plastics, including biodegradable plastics. Adding methane to syngas produces Synthetic Natural Gas. Syngas can also be broken apart to separate the H2 from CO, and can be a major source of hydrogen for a potential hydrogen economy as well enabling carbon sequestering. All of these outputs are worthy of a discussion of their own and my goal will be to get to each one in turn and present the business perspective on them.
Gasification, primarily of coal, has been used for a very long time. Here in the US the first municipal power systems utilized "town gas" from coal gasification to light street lamps in the late 1800's. Chemical industries have utilized coal gasification to produce chemicals since the 1950s. Overseas countries under embargo have utilized coal gasification to produce liquid fuels for decades. The Germans used coal to liquids in WWII and in South Africa the energy firm Sasol has done coal to liquids for decades and continues to be a world leader in the technology. After WWII woodgas powered automobiles were popular in Europe when gasoline was in short supply and home-built wood gasifiers allowed people to go 1 mile per pound of wood. There is some real fascinating history to gasification and hopefully I will can get permission to post some of the materials I have collected that go into detail.
The fundamental premise and promise of gasification, is the ability to take a wide variety of raw materials, many of which are considered waste, and reduce them to a common gas. The gas in turn can be used for a variety of outputs, and do so in a manner that is green.
Raw materials can include unconventional fossil fuels such as high sulphur coal, oil shale, tar sands, pet coke, or municipal waste, plastics, chemicals, agricultural waste whether plant matter or manure, and also sewage sludge.
The ultra high temperature processes, above 1200 F will melt metals and glass in the feedstock and will destroy organic hazards such as poisons and infectious matter. At high temperatures a process called "molecular disassociation" occurs where materials are disintegrated and torn apart at a molecular level destroying their toxic nature. So these gasifiers can serve as hazardous waste disposal sites as well, but more about that later.
Enough for now, as you can probably see there is enough to talk about here to fill a bunch of books, my challenge is to maintain a coherent thread.
Getting Started
So I am just getting started here.
This blog is meant to serve a purpose, at least for me, if not for anyone else.
So I am an MBA student at the Johnson School of Management at Cornell University. I am working on a big project on Waste to Fuel, specifically, using ultra-high temperature gasification from plasma torches to vaporize garbage and landfill wastes to produce green fuels and clean the environment at the same time. My project is supposed to be a business plan. This whole area of research is incredibly fascinating to me. I am convinced that the technology does/can work, but it is an art as much as a science, and it is a large industrial process requiring substantial amounts of money. I have done a ton of research and have so much material that I have been finding it to be very challenging to reduce it down to a coherent business plan. I am planning on using this blog as a method to work through my material and get it into a presentable form. And maybe if anyone actually reads it I may even get some feedback.
So the theme of this blog is going to be me presenting the things I have been learning. I am not an expert presenting expert knowledge, merely a student striving to develop some expertise. In that spirit I may present things that may prove to be completely wrong or technically off the mark, but I will try to present theories as theories and hypotheses as hypotheses, and give credit where ever credit is due with regards to the information I come up and the people it came from. I will also strive to correct my mistakes!
This blog is meant to serve a purpose, at least for me, if not for anyone else.
So I am an MBA student at the Johnson School of Management at Cornell University. I am working on a big project on Waste to Fuel, specifically, using ultra-high temperature gasification from plasma torches to vaporize garbage and landfill wastes to produce green fuels and clean the environment at the same time. My project is supposed to be a business plan. This whole area of research is incredibly fascinating to me. I am convinced that the technology does/can work, but it is an art as much as a science, and it is a large industrial process requiring substantial amounts of money. I have done a ton of research and have so much material that I have been finding it to be very challenging to reduce it down to a coherent business plan. I am planning on using this blog as a method to work through my material and get it into a presentable form. And maybe if anyone actually reads it I may even get some feedback.
So the theme of this blog is going to be me presenting the things I have been learning. I am not an expert presenting expert knowledge, merely a student striving to develop some expertise. In that spirit I may present things that may prove to be completely wrong or technically off the mark, but I will try to present theories as theories and hypotheses as hypotheses, and give credit where ever credit is due with regards to the information I come up and the people it came from. I will also strive to correct my mistakes!
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