The price of guar gum, produced from the seeds of the guar plant, has been skyrocketing recently. While it has long been used in the food industry as a texture-modifying agent, it is its use in “fracking” that has dramatically increased its value.
Fracking is the process of unlocking previously untapped oil and gas deposits by pumping water into underground layers of rock called shale. The high-pressure water creates cracks in the rock which release trapped gas and oil that can then be pumped to the surface. The injection of “proppants,” such as sand or ceramic beads, keeps fractures open once they’ve formed. More viscous fluids can carry proppants in greater concentration, making fracking more efficient. Guar gum is an ideal thickener because it can be broken down by the addition of enzymes to prevent the proppant being pulled out of the rock as excess water returns to the surface.
About 80 per cent of the world’s guar beans are grown in India where the crop was originally introduced as an economical source of cattle feed. Prices began to rise in the middle of the last century when the food industry discovered that guar gum was an excellent viscosity modifier for use in foods such as yogurt, processed cheeses, salad dressings and sauces. It is also useful in allowing flours made from whole grains to rise just like white flour when leavened. Otherwise, the texture of whole grain flours allows the carbon dioxide produced by yeast to escape. It’s used to prevent the growth of ice crystals in ice cream that result from the freeze-thaw cycle that happens every time it leaves the freezer. The personal care products industry uses guar gum as a thickener in toothpaste and conditioner.
One of the most attractive features of the substance is that it poses no health risk. Chemically, guar gum is very similar to starch but instead of being composed of chains of glucose units it is made up of a backbone of mannose with some side-branches of galactose. Mannose and galactose, like glucose, are simple sugars that the body is accustomed to handling.
Guar gum prices have hit new heights with the expansion of fracking, obviously a boon to farmers in India and Pakistan. But given that a typical well consumes some 4,000 kilograms of guar gum, expense is becoming a problem for the oil companies: just one more thing to add to the list of challenges that surround fracking, including significant concerns about the impact of the practice on human health and the environment.
Many of these concerns arise from the more than 600 chemicals that are used in fracking. These include friction reducers (polyacrylamide), corrosion inhibitors (glutaraldehyde, quaternary ammonium chloride), freezing point depressors (ethylene glycol, methanol), clay swelling inhibitors (choline chloride), metal oxide precipitation inhibitors (citric acid), scale formation inhibitors (sodium polycarboxylate) and pH modifiers (sodium hydroxide). Since the specific composition of fracking fluid used by fracking companies is proprietary information, it is difficult to determine which chemicals may find their way into the environment from fracking’s wastewater.
As with everything else, there is a quid pro quo. If we want cheap energy, we have to pay. And not only financially.
Joe Schwarcz is the director of McGill University’s Office for Science and Society. Read his blog at chemicallyspeaking.com.