It’s everywhere. It’s produced all the time, virtually anywhere there is water, some heat and some decaying organic matter. There are huge pockets of it all around the earth. Occasionally, we humans produce our own little supply. Not to mention cows. Natural gas or methane is the subject of this month’s column.
Natural gas is the best choice among fossil fuels. Is natural gas itself a fossil fuel? In some cases yes but in others no. On a hot summer day at a murky pond in the woods you may see bubbles rising out of the pond. Most likely that is methane. However, if you are in a desert and have an oil well with methane coming out then that is fossil derived. ExxonMobil is doing a lot of research on algae and methane gas and other biofuels. Biofuels are distinct from natural gas in that they encompass a large array of sources, from algae to animal fat, but it also includes natural gas. I am leaving out biomass in this article due to its diverse nature and space constraints. Natural gas has many benefits. It burns clean, has a very low carbon footprint, is cheap and is available domestically. It can run virtually all combustion engines save for diesel. Yes, there are conversion kits for diesel but it has very limited applications. Natural gas is far more efficient as a fuel for generating electricity because it does not need an intermediary medium to transfer its heat energy. Coal, oil and nuclear require large amounts of water that must be heated and converted to steam, which expands to drive the turbines which drive the generators to produce electricity. In a gas turbine the natural gas is burned and its exhaust expands rapidly to drive the turbine. This makes it highly efficient. Gas turbine generating plants produce power within a matter of seconds on a large scale. When local systems are facing “brownouts” producers rely on “peaker” plants. These are predominately gas turbine plants that can fill in the gap for power demand say on hot days when everyone is using air conditioners simultaneously. These plants, which are predominately run on natural gas, are essentially jet engines sitting on reinforced pedestals. The carbon footprint of natural gas as a fuel is approximately one-fifth the output of gasoline and diesel fuel. Yes, we could have had natural gas vehicles a long time ago when Jimmy Carter proposed the multi-fuel agenda, which was to mandate that all vehicles were to be multi-fuel accessible. The Reagan administration defunded this and most of Mr. Carter’s energy proposals. Mr. Reagan was an actor and Jimmy Carter was a nuclear engineer. One of the most amazing mainstream energy conversion devices today is the “Bloom Box.” This is a fuel cell that runs on natural gas. The natural gas, a hydrogen rich substance, is converted to hydrogen. Fuel cells run on hydrogen. The Bloom Box is now rated at a whopping 60 percent efficiency. It has a near neutral carbon footprint as it has a carbon to hydrogen ratio of 1-to-4, which is much higher than oil or coal. I would like to give a Reader’s Digest version of fuel cells but not today. However, fuel cells are definitely the future for energy, especially transportation. Presently, it is not quite cost effective, but give it time. I contritely ask the reader to look up www.bloomenergy.com In the United States we use hydrofracking, which has been around for 60 years. For 50 of those years it was vertical drilling. This required much less water and less chemical lubricants as well as less potent ones, but as time wore on, so did the vertical pockets of natural gas. There was still plenty of natural gas except you had to make a left or right turn 3,000 feet (give or take a few thousand) down. So the drilling now took a different turn, which got natural gas out by drilling horizontally. This process required much more water and chemicals. The voids left by the removal of the methane were filled in with water, which in turn would cause the soil to weaken that would exacerbate any fluctuation in the earth, often causing or enlarging an earthquake. So once again a cost benefit analysis needs to be implemented and we need to find better ways to obtain natural gas, which is in worldwide abundance. If I had space I would opine about the issue of global warming on the permafrost areas, especially those methane rich areas of Alaska, the northwest territories of Canada and eastern Siberia. It is a very serious issue indeed and is seldom talked about though it has truly catastrophic consequences if these large fields were thawed at the same time, which could happen. What it means is that we would have to burn or store all this gas at once or risk an unprecedented global warming as methane is 32 times more heat retentive than carbon dioxide.
0 Comments
|
AuthorJames Bobreski is a process control engineer who has been in the field of electric power production for 43 years. His “Alternate Energy” column runs monthly. Archives
June 2020
Categories |