Gasification Archive for November 2002

   Within this next century, certainly within the lifetime of our small children, we will run out of gas and oil. Coal may last a century of two. The life of all of these fuels depends very much on the rate they are used. I would not be surprised to see a shortage of gas within the next few years. It really doesn't matter how soon shortages develop because we can spend only so much Sustainability money per year and since it will take a lot of money, we must start now.
   Presently the USA is using about 100 quadrillion btus (quads) of energy each year. Of this about 40 quads comes from oil, 24 quads gas, 24 quads coal, 8 quads nuclear, 4 quads hydroelectric, and less than 1 quad renewables. The large percentage of oil shows clearly the folly of trying to replace oil with either coal or gas. These resources would also be quickly depleted. It is likely that shortages will develop by 2010. The situation will be so bad that both emergency and long range measures will have to be taken. We can expect a diminishing input from fossil fuels that will last forever. How fast the plunge will be is hard to determine. The effects of the catastrophe will be reduced if we start taking countermeasures such as high energy taxes immediately. If we assume an average of 10 quads oil over the next century, 10 quads gas, 10 quads biomass, 10 quads wind, 20 quads coal, 10 quads nuclear, and 10 quads solar, we can get through this century with an energy average of 80 quads. That would keep us from starving. However the century after that will be far worse and any moral society would attempt to cut the consumption to below 80 quads both for scarcity and Global Warming reasons.
    The first thought will be to greatly expand nuclear. This is a mistake because we can't guarantee enough fossil fuel to store nuclear waste and we have no right to be leaving our grandchildren a mess that they can't clean up. Furthermore our supplies of Uranium are finite so we need to save fuel for later generations. What we should do is slowly expand and improve our nuclear plants and increase our output to about 10 quads instead of the seven we are getting now. This limited expansion may give us new ideas for greatly improved plants.
     Obviously from our present position it much easier to save energy than it is to make more energy. That is easy to demonstrate from the fact that the Chinese consumption per capita is only 10% of ours. I am sure that they are cold in winter. However, by changing our society to be more energy efficient we can probably get by on 30% of what we are consuming now for several centuries. Of course we want enough to eat and to be warm in winter but we will have to give up individual houses and cars. We will also have to give up luxuries such as casino gambling, golf courses, and ski resorts. All of these use too much energy not only in their buildings but also in the transportation necessary to get there. I am happy that things like listening to classical music, playing bridge, and nature walks will always be possible. The big reason that we must conserve rather than produce is Global Warming. There is no possibility of our producing ourselves out of that problem.
     We can add perhaps 10 quads to our energy supply by planting enormous quantities of trees. I have seen estimates as high as 60 quads possible but I don't believe them. We can also add considerable amounts of food by planting fruit trees. There probably would be enough bad apples to make considerable amounts of ethanol or feed a lot of deer. Liquid fuels for plowing will be precious so anything available will be used.
     In coming up with a strategy for meeting this energy problem we must start with a living module that can be demonstrated in a small area and then repeated across the USA. Solar energy and food production both are measured by the acre in the US. What we are taking here is how many people per acre we can support. We can call this a model town. A square mile, 640 acres, is a standard measurement and probably would be an ideal size. However because of the huge investment costs, early models would probably be much smaller than that. It is inherent in the design that as much of our food, energy, and recreation as possible would be derived from the home area. In other words transportation requirements must be minimized.
     Every step available that would reduce the heating of buildings must be taken. The first step is to stop building houses and build only Ecomindiums. An Ecomindium is a large building that has apartments on the upper floors and work places on the first floor and basements. The dwellers farm in the summer and manufacture in winter inside the building. This arrangement has many advantages. First larger buildings are easier to heat because of their reduced surface area per unit volume. In comparison to a house with the same space as one apartment, the wall area per apartment of a two story, eight unit building that has four units on each floor arranged in a square is only half as much. This geometrical advantage can be improved if better windows and insulation are used. In their ability to save energy each Ecomindium is the equivalent of a miniature oil or gas well. Whether their construction energy is too high to make them practical is a question. However they could easily last a 1000 years and that is the longest lasting energy investment we could make.
     Cogeneration is a term for Combined Heat and Power or CHP whereby the waste heat from the generation of electricity is used to heat a building. It is possible also to use a similar term, comanufacturing, to mean using the waste heat from manufacturing to heat the building. In other words you put the factory inside the building and use it only in winter. Between comanufacturing and cogeneration you can heat the building with no other heat input. Note that comanufacturing is a concept of great importance because it not only provides winter space heating but it also eliminates commuting. Suppose you have only the wood on your property to use for heating. With comanufacturing you can use it twice. The manufacturing can be almost anything from simply making charcoal to full scale manufacturing. Obviously safety and noise will be continual problems. There are many other energy economies that can be obtained by cooperative action within the group. Ecomindiums have the potential to cut energy use by 90%.
     Most of our fertilizer is taken from mines, phosphorous in Florida and Potassium in Canada. Nitrogen is made from air using natural gas as energy. This fertilizer will not last forever because the mines and the natural gas will be exhausted. Therefore it is essential that we recycle fertilizer to the fullest. Nitrogen can be made from almost natural methods by recycling sewage in a biodigester that consists of some large tanks. The result of biodigestion is a burnable biogas plus residual liquids that are rich in nitrogen and the other elements of sewage. Soft biomass such as leaves, paper, or straw be mixed with this to purify it and get more gas. If a leguminous plant such as hay is mixed with this, again you get more gas and more nitrogen in the liquids and solids left after being biodigested. These can be spread directly on the fields.
     Another type of fertilizer can be made from fuel ashes of various kinds, probably principally wood. These ashes will contain potassium and phosphorous but probably not much nitrogen. The heating process will drive it off. This recycling of fertilizer must take place religiously. Otherwise the land would quickly be depleted. It may be possible to keep fertilizer on land by putting rings of trees around farm fields. These rings would trap the fertilizer and convert it back into biomass. The ashes then return the nutrients to the fields.
     Since wood and crop residues may be the principal winter manufacturing and heating source it is imperative that such resources be husbanded to the utmost. One method of producing gaseous fuel mentioned previously is that of making biogas from sewage and biomass. This produces a gas that has about 50% of the strength of natural gas at about 50% efficiency and also makes fertilizer. If the waste heat from any process can be used for space heating then that process can be made nearly 100% efficient. Another type of gas can be produced by the partial combustion of wood. The fuel components of this gas are called producer gas and consist of carbon monoxide (poisonous) and hydrogen. Like the output from the biodigester the output can run an engine and produce electricity. However these gases might be too dilute to be compressed and used to run a tractor
     Liquid fuels will be precious but still may be used for farm operations. It is possible to make methanol from producer gas. However, that process is said to be practical only in very large, very well funded facilities. Further research might make an Ecomindium size operation feasible. It would certainly be more efficient because of the waste heat use for space heating.
     A calculation on my own personal energy usage shows about 150 million btus for my gas, electricity, and gasoline. However, since the per capita consumption in the US is 360 million btus, there are a lot of expenditures coming from factories and businesses that the individual has no control over. This suggests that in combating an energy shortage we must close out many recreational industries and convert many commercial buildings into apartments. Furthermore we must figure out how to tear down houses so that the materials can be reused in Ecomindiums.
     Various energy devices must be worked on to both generate and save energy. One of the better devices in summer would be the steered solar mirror, boiler, and steam engine system. Hopefully this would generate enough power in summer for air conditioning and utilities in the daytime. Having lights in the summer would depend on expensive batteries that might not be affordable or on fossil or nuclear fuel. People might have to sit around in the dark and talk for recreation.
     In the winter, the carefully saved wood and agricultural wastes, would be used for manufacturing and power generation. The waste heat from these processes would probably heat the building. If more heat is needed then solar heating panels might be used. If still insufficient, Then heat pumps driven by coal or nuclear generated electricity would be possible for perhaps a century. This extra energy from coal and nuclear could also be used for summer lighting. A wind farm with transmitted electricity is also a source for summer lighting.
     In many areas there is insufficient wind to pay for the cost of the mill. Nevertheless wind must be experimented with. Each batch of energy from a high wind would be welcome. Pumping water or sewage might be useful. The mill could also be used to charge batteries. One way to increase usefulness would be to increase blade diameter for expected output and then use protective measures against high wind breakage.
      My conclusions are that the road to Sustainability will require many sacrifices from the public. The key words here are Modular Development, Ecomindium, Farm in summer manufacture in winter, wood gasification, biodigestion, tree planting program, Cogeneration, Comanufacturing, solar mirrors.

GAS-L: Principles of Sustainability