The market
The global chlorine market in 2010 was estimated at $24 billion, based on a global production capacity of 80 million tons. While the United States saw a decrease of 1.3 million tons in production, reaching 13.8 million tons that same year, Europe gained 500,000 tons, reaching just over 9 million tons. China added massive production capacity, reaching 25 million tons in 2010, representing approximately one-third of the global market. With global demand projected to grow at an annual rate of 4.4% between 2011 and 2015, China was expected to increase its capacity by an additional 2 million tons in 2011. Chlorine is produced by subjecting ordinary salt to an electric current. Because chlorine is highly reactive with water, mercury was used to neutralize the process. The U.S. chlorine industry still consumes 79 tons of mercury for approximately 14 million tons of chlorine. The European industry has committed to phasing out all mercury by 2020, but still admits to releasing 0.93 grams of mercury per ton of chlorine. Chlorine was invented in Sweden by Karl Scheele over two centuries ago. The city of Pittsburgh was—exactly a century ago—the first to mix sodium hypochlorite (or chlorine) into its public drinking water to control bacteria. This led to a dramatic increase in demand and a significant reduction in disease outbreaks. Chlorine dissolved in water reacts with iron and manganese, and then with bacteria, effectively controlling the spread of disease. However, cyst-forming protozoa (Cryptosporidium) cannot be eliminated even at high concentrations. The American Wisconsin State Hospital has determined that 80% of residual free chlorine enters the human body through skin absorption. Although it has been the most effective public health treatment for decades, chlorine causes allergies and has been linked to cancer, arteriosclerosis, and anemia. Chronic buildup damages proteins, leading to dry hair and rashes, and creates a large number of free radicals that accelerate aging.
Innovation
Since the U.S. Environmental Protection Agency (EPA) advised municipalities to reduce and limit the amount of chlorine in drinking water, there has been a widespread search for alternatives. However, its use is mandated by laws and ordinances. Public health officials are hesitant to replace chlorine or try other chemicals like the potent triclosan (polychlorophenoxyphenol), which, over time, may cause even more unforeseen consequences. The advantage of chlorine is that its harmful effects are well-known. The option has been to continue applying chlorine to drinking water systems but to have it removed before consumption. The use of filtration based on activated carbon, minerals, or even ion exchangers has given rise to a new and rapidly growing industry with hundreds of suppliers. However, the filters are wasted and end up in landfills where they continue to contaminate and often require more energy than was needed to produce chlorine in the first place. Hu Bor Yu, Liu Chen Panc, and Liang Teh Ming, researchers at the Industrial Technology Research Institute (ITRI) in Taiwan, observed that the flow of (chlorinated) water contains kinetic energy, which their colleagues successfully harnessed to generate electricity. This electrical energy, generated by the flow of the tube, increases its laminar flow by applying a simple geometric change: the tube becomes smaller. The electricity thus produced is applied to the anode, and the resulting electrolyzer eliminates the chemical potential of residual chlorine in situ. The process requires no external energy, consumes no materials, reacts instantly to the water flow, is sustainable, inexpensive to install, and requires no maintenance. Performance improves as the flow rate and water temperature increase. The potential applications extend beyond chlorine. The same process can destroy perchloric acid (HClO4), sodium sulfite (NaSO3), and other water impurities harmful to our health. This creates an innovative approach to water purification where chemicals and filters have traditionally dominated the market. It implies that "something is substituted by nothing," or that chemistry has been (partially) replaced by physics—two fundamental characteristics of the Blue Economy.
The first cash flow
The ITRI research team quickly concluded that this technology is widely used in homes where the harmful effects of (excessive) chlorine use are well documented. Installing this self-powered dechlorination unit, combined with self-powered sensors that generate lights indicating water temperature, offers another set of innovations that make the home safer. And as the water temperature rises, the chlorine removal efficiency improves. These units are inexpensive, and since no additional wiring is required, they provide a platform for many enthusiastic entrepreneurs ready to enter the market.
The opportunity
While domestic use is an obvious first market entry, its application can be combined with many other innovations, such as vortexing in ice production, where the presence of chlorine requires more energy to freeze the water, thus adding another element of energy saving without requiring expensive equipment. And, since generating power from water flow has been proven in large-volume systems, generating only a minimal reduction in flow while producing 50 watts of electricity to power powerful LED lights, the system is ready for industrial applications such as producing ultra-clean water for the food and beverage industries, which rely on expensive filters that need to be replaced monthly and sometimes weekly. Although it's impossible to hide a preference for the complete elimination of chlorine use, we cannot take the perfect position that opposes both good and best. Since the use of chlorine in drinking water is often regulated, the option offered by the self-powered dechlorination unit allows us to operate in this world of transition. It also anticipates a period of introducing substitutes, moving beyond the stigmatization of chlorine, to clean up pollution sources in a materially and energy-efficient way. This is a job-creating entrepreneurial platform, one of the priorities of the Blue Economy.
