Tuesday, November 26, 2013
Biofuels – Truth or Consequences
Proper evaluation of biofuels is long overdue. Many politicians are infatuated with ethanol and bio-diesel. They give little thought to the consequences. For the past 15 years or more, environmentalists have mesmerized these politicians with plaudits about secure, clean and cheap biofuels. It turns out most are unreliable, expensive and environmentally destructive. Moreover, even with the government’s outlandish subsidies and tax credits they are not cheap.
Environmental junkies shout out about the merits of ethanol usage. They seem to be unable to cope with the truth - biomass fuel sources produce large amounts of CO2. Let’s find out why. It takes 1.635 gallons of ethanol to equal the energy contained in one gallon of gasoline. One gallon of gasoline emits 19.56 pounds of CO2, while the equivalent amount of energy from ethanol emits 20.55 pounds. This being so, then, which pollutes the most and delivers less energy.
It is possible that some forms of biofuel will supplement our energy mix as petroleum resources deplete. Nevertheless, it is even more important to understand that larger and larger quantities biomass fuels processed from agricultural crops dramatically lower food crop production, thereby increasing food prices, and at the same time causing destruction of forests. As forests disappear and crop lands swell, land erosion will wrack havoc with the remaining crop lands as well as the land surface in general. Wouldn’t these agricultural crops help feed the populations of underdeveloped countries? Are the consequences apparent?
How about corn as a source for ethanol? Let’s not forget that it swallows huge government tax subsidies, raises food prices, and fails to decrease atmospheric CO2.
ExxonMobil Research labs report that an acre of corn yields 250 gallons of ethanol per annum. Dr. David Pimental, professor emeritus at Cornell University, a highly qualified agricultural expert, estimates 328 gallons per acre for corn ethanol yields. America’s annual average gasoline consumption is around 140 billion gallons, or 382 million gallons per day. How many square miles of agricultural lands must be planted in corn to satisfy domestic gasoline consumption for a year? Answer: 1.2 million square miles based on Dr. Pimental’s 328 gallons of ethanol per acre per annum. This happens to be about 30% of the total land and water area of the U.S. Problem - there are only 900,000 square miles of arable land. Using the ExxonMobil yields the land requirements would be even greater. By the way, how many corn crops can a farmer raise in one year? Commonsense tells you that corn can best be used as a food source.
Corn farmers argue their crops are ready to meet government fuel regulations - NOW. They claim their biofuel plants can also produce corn oil and animal feed while sorghum plants cannot. Sorghum biofuel plants burn the plant stalks for boiler fuel, generate heat for distillation, steam for electricity. All this said, producing biofuel is easier said than done. Plant equipment is very expensive and remains idle much of the year; and in the case of sorghum, the juice spoils quickly. It must be processed almost immediately. In spite of these obvious drawbacks, huge subsidies and large tax credits are still pumped into so-called “green energy” projects. Oh, let’s not forget the cost of diesel fuel used to harvest and haul any crop to the processing plant. How about the transportation to refineries for blending with gasoline? Interest in the use of sorghum as a biofuel source crop remains in university laboratories. So far, farmers have not been persuaded.
Agriculturally produced biofuels are a complete economic FLOP. They are big environmental negatives. The EROI for ethanol from corn is about 1.1:1, while to be economically viable the ratio should be a minimum of 5:1.
In the author’s opinion, likely the only method of eventually obtaining economically feasible biofuels will come from biomass, i.e., algae. Three thousand species of algae have been identified. However, only 300 appear to be suitable for cultivation to produce ethanol, biodiesel, and jet fuel. Microalgal technologies have shown that algae hold far more potential than corn, soybeans, rapeseed, palm, and sugar cane. Why? Algals have the highest oil content of any other biological form. Their rapid growth makes harvesting cycles of one to ten days a reality (from 40 to as many as 300 harvests per annum), plus their cultivation does not require arable lands.
Large-scale cultivation of algae in salt water may also become practical. In fact, it might even be more effective in their growth. For example, while most terrestrial crops yield from 60 to a high of 700 gallons of ethanol per acre per year. On the other hand, algal forms may yield around 4,000 gallons (100 barrels) per acre per year of algal oil under full-scale commercial production. Some researchers believe that within the several decades, algal biofuel production might be capable of replacing a portion of American imported oil volumes. However, it will not replace will not replace oil.
Unlike the first-generation feedstocks such as corn, soybean, palm, sugarcane, and others, the price and supply of algae will be stable. Once a location for cultivation and processing has been selected, production and product quality can be controlled much like any chemical plant. Importantly, algal biofuels have molecular structures that are very similar to the petroleum and refined products in use today. Environmentally, they will have an insignificant CO2 footprint.
NASA scientists are proposing an ingenious and remarkably resourceful process that could produce large quantities of biofuels. The process would also clean waste water, remove CO2 from the atmosphere, and at the same time retain nutrients. Additionally, it does not require the use of agricultural land or fresh water resources. The similarity of the chemical components in algae to petroleum is understandable, since originally a large part of the formation of petroleum came from algal material.
NASA plans to grow and harvest algae in an ocean environment. Huge semi-permeable plastic bags filled with sewage will be deployed offshore. These enclosures will not only grow the algae, but clean up the sewage. The semi-permeable bags will allow the fresh water to flow out into the sea, while retaining the algae and nutrients. The membrane prevents the salt water from entering the enclosure, but allows the fresh water to flow out into the sea.
These inexpensive bags will collect solar energy as the algae inside the bag produces oxygen by photosynthesis. Algae feeds on nutrients in the sewage, growing rich, fatty cells. Through osmosis, the bag absorbs CO2 from the atmosphere, releases oxygen and fresh water. The temperature will be controlled by the heat capacity of the ocean, while the ocean’s waves will keep the system mixed and active. The whole process is environmentally beautifully simple. Biofuel stocks can grow and process sewage. No longer will harmful sewage be dumped into the ocean. Processing the algal feedstock can add large amounts of petroleum type products, as well as other commercial products from the residue.
So far, it appears that a wet extraction process on low-nitrogen grown algae may give the best positive energy balance. Ninety percent of the energy consumed in the dry extraction process comes during lipid extraction. This compares to just 70% using a wet extraction process – a 20% decrease in energy. After extraction of the lipids is completed only about one-third of the biomass raw material can be used for production of petroleum type products.
In the production of biodiesel, the oil (lipid) part of the algae biomass amounts to only about 25-30% of the product potential. The remaining 70% includes nutrients, pharmaceuticals, animal feed, and other biomass products. We must accept the fact; algal applications are still in a fundamental research stage. Don’t be too quick to accept the notion that algal biofuels are just over the horizon – they are not. However, their potential is better than the failed attempts to replace fossil fuel with agriculturally produced fuels. Just be aware of the fact that there are no quick solutions, petroleum is going to remain the main transportation fuel for decades in the future.
There are dozens of algal research and development projects underway, but so far few are close to commercial production. The production of biofuel from algae is still very expensive, about $30 per gallon. However, the author believes it may have the greatest potential as a supplemental fuel for transportation. Shell Oil, BP Oil, Exxon, and other oil companies seem to agree that algae may offer the best economic outcome of any other source for the development of large scale biomass production facilities.
While the use of algae for biofuel production appears to have the best possibility for manufacturing commercial quantities of biodiesel fuel, the author remains skeptical. Dr. John Benemann, speaking at an Algal Biomass Organization conference recently said, “Don’t count your algae until you actually have them. It may take longer than you expect. Everything takes longer than we expect.” While he is a believer in the development of biofuel from algae, he is a realist. Answering a question about algal biofuel production, he said, “First of all, I think that one of the real fundamental problems here is that the algae is not the Great Green Hope, to put it politically correctly. It is one of the many things that we have to do, and one of the many things that requires continuous research and development. At this point, I believe it requires more research than development, but these things are overlapping of course.”
 Dr. John Benemann – PhD Biochemistry (Georgia Tech). Recognized as one of the foremost researches on algae development for fuel and wastewater applications.