Frontiers of Science: Plants to the Rescue!

Plants to the Rescue!

Where do we get the gasoline to drive our cars? Why, from the service station, of course. But where do the service stations get it? Usually, they are supplied by large companies that obtain gas from deep wells, both on land and over the coastal waters of oceans. Originally all petroleum products come from ancient plant life that once flourished upon the earth. So it is perhaps not surprising that scientists today are looking at living plants as new sources of this valuable but dwindling resource.

Petroleum plantations? It smacks of science fiction, but the not-too-distant future may well see us growing our own gas. Already the Brazilian government has an immediate goal of supplying one-fifth of its total fuel needs with substances obtained from sugar cane. Perhaps the most promising future source of gasoline, however, will not be such a well-known crop, but rather some of the humble shrubs that grow on many of the world’s dry, rocky soils unsuitable for any other farming purposes.

One of the shrubs that scientists have high hopes for is the common milk bush of Brazil that is often grown as a hedge. It produces a material that one Nobel Prize-winning scientist says makes it an excellent candidate for a “gasoline tree.” He estimates that under the proper conditions oil yields of 40 barrels per acre could be obtained from large-scale plantings of the shrub and that a planted area the size of Arizona could meet current requirements of the United States for gasoline.

Some other plants with similar potentials for producing petroleum products are the gopher plant of California and the common milkweed that grows the world over. In Puerto Rico there is also a tree from whose bark, when cut, flows a milklike sap that can be converted into gasoline. Most regions of the globe have a similar ability to produce petroleum from living plants, many of which can be grown where there is too little rainfall for normal agriculture.

Another plant that has scientists quite excited is the jojoba (pronounced ho-ho-ba), a 3-to-15-foot-tall evergreen shrub that grows wild in portions of Southern California, Arizona, and Sonora, Mexico. The excitement arises from the fact that it is apparently the only plant in the world that produces a special kind of high-quality liquid wax in its seeds. This liquid wax is almost identical to the valuable sperm whale oil used for lubricating machinery that operates under extremely high temperatures and pressures. Previously, the sperm whale was the only known source of this oil. The whale was hunted mercilessly for many years, to the point where it is now an endangered species (an animal close to becoming extinct). Hopefully, the discovery of the important properties of jojoba seeds will relieve some of the pressure to kill the sperm whales and save them from extinction.

In addition to serving as a lubricant, jojoba wax is used in the making of rubber, varnish, linoleum, carbon paper, candles, soap, shampoo, and even chewing gum. And the list seems to grow daily.

Besides exploring new uses for plants such as the jojoba and the gasoline tree, scientists are searching for ways to grow them faster and better. As they work toward this goal, we can expect to see some dramatic changes in things we never before thought of as being related to plants. Who, for instance, would have supposed that the magnificent sperm whale that navigates the great expanses of the world’s oceans would one day owe its life to an insignificant little shrub, rooted to the dry soil of the desert? Or who would have guessed just a few years ago that plants would play a major role in meeting the challenge of the world energy crisis? We can be thankful that some farsighted scientists did. Hats off to them and to the amazing plants our Heavenly Father has placed here for our use!

[illustrations] Illustrated by Dick Brown

[photo] Milkweeds like these, which grow from Michigan to California and from Puerto Rico to Brazil, are a source of raw materials for petroleum products. They can be harvested like sugar cane or tapped like rubber trees. (Photo courtesy of the Lawrence Berkeley Laboratory, University of California.)

[photo] Tree-size bushes that produce a milky substance that can be converted to gasoline are being grown on experimental “petroleum plantations.” This example comes from Brazil, where such plants are very common. (Photo courtesy of the Lawrence Berkeley Laboratory, University of California.)

[photo] On the dry coastal shoreline of Puerto Rico, this cactuslike tree produces a latex sap that can be tapped and collected just like maple syrup and rubber. The sap can be refined to produce gasoline and other petrochemicals. (Photo courtesy of the Lawrence Berkeley Laboratory, University of California.)

[photos] Seeds high in valuable liquid wax hang from a jojoba branch, while a scientist displays a portion of the plant’s harvest. (USDA photos.)