SBIR-STTR Award

A team of EP Purification and the University of Illinois engineers and chemists is pursuing the commercialization of low-cost microchannel plasma modules capable of efficiently producing ozone for water treatment. The conservation of water resources for human consumption is a growing national priority. Contamination of ground municipal water by animal manure, fertilizer and pharmaceuticals, for example, is posing an increasing hazard for human health. Ozone is a unique purification agent as it is the strongest oxidant and disinfect available commercially. It is known to be extremely effective for neutralizing pathogens (bacteria, viruses, cysts) and some pesticides, making it ideal for the disinfection of water, grain and vegetables. Another benefit of using ozone is that minimal disinfection byproducts or residues are produced during its use, as compared with chlorination. Also, ozonation is generally regarded as being superior to traditional disinfection through chlorination because the latter requires hazardous chemicals, produces carcinogenic byproducts when reacting with hydrocarbons in water, and leaves much to be desired from an environmental perspective. The primary drawback of ozonation for utility and consumer applications is cost and power consumption. This Phase I proposal leverages technology developed at the University of Illinois and EP Purification to realize low cost and yet robust ozone generators based on massively parallel plasmachemical processing of O2/N2 mixtures in large arrays of microcavity plasmas. Modules producing ozone at concentrations higher than 5 weight percent on efficiency of at least 180 g/kWh will be designed in Phase I, and Phase II will demonstrate and characterize a 100 g/hour ozone generator for treating water in small/medium system applications that is superior to existing technology in cost (capital and operating), efficiency and size. The microplasma technology proposed here has several advantages over conventional large-scale corona discharge systems that are currently used for municipal water treatment. Based on microchannels fabricated inexpensively in alumina (Al2O3), this technology has already been shown to be efficient (>180 g/kWh at .3 wt.% O3) and robust but at much lower system weight and cost for equivalent production. With respect to the latter, lifetimes beyond 1600 hours of continuous operation in an accelerated aging test have already been demonstrated. Our design philosophy is to produce robust, inexpensive and fully recyclable modules, comprising 200 to 300 microchannels, as the ”building block” for O3 production, allowing the ozone production rate (kg/h) to be readily scaled to the value demanded by an application. Supplemental

Keywords:
Water Disinfection and Remediation, Ozonation, Microplasma, Microchannel

A team at EP Purification has performed research for the development and commercialization of low-cost microchannel plasma reactor modules capable of efficiently producing ozone for water treatment and other environmental applications in a slim form factor and size. The conservation of water resources for human consumption is a growing national priority. Ozone is a unique purification agent as it is the strongest oxidant and disinfectant available commercially. It is known to be extremely effective for neutralizing pathogens and the dissociation of toxic organic chemicals, making it ideal for the disinfection of water. Also, ozonation is generally regarded as being superior to traditional disinfection or cleaning methodologies (through a combination of chemical and thermal treatment processes) because the latter requires significant energy consumption to be effective (for heating water), and leaves a number of byproducts and chemical wastes after the process. The primary drawback of ozonation for utility and consumer applications at present is high cost (capital and operating), size and power consumption. In Phase I, EP Purification has developed and demonstrated a series of low cost and yet robust ozone generators based on massively-parallel plasmachemical processing of air or oxygen gases in large arrays of microchannel plasmas. Prototype modules have been realized that produce ozone at a rate of 10 g/hour and with an efficiency comparable to, or higher than, commercially available ozone generators. Furthermore, the size of the module is, at least a factor of 3 smaller than conventional units, and the reduction in production costs is expected be as much as a factor of two. EP Purification designed and fabricated basic modules (in the range of 10 g/h), including the pulse-power supply optimized for this unit, and modules can be combined to obtain the desired ozone production capacity. Currently, for example a ~100 g/hr ozone generation system has been designed by “stacking” basic modules. Additionally, an optimized power supply design was built and is being evaluated in field tests. In Phase II, EP Purification will develop and commercialize a system capable of ozone production at a rate higher than 100 g/hour. Designed for treating water in small/medium system applications, this system will be considerably smaller, more efficient, and more cost effective from both capital and operating perspectives than existing technologies. Also, EP Purification has identified immediate markets of this technology and intends to commercialize this product in point-of-use applications, such as commercial laundries and food preservation during this Phase II program. Supplemental

Keywords:
water treatment, disinfection, ozonation, microplasma, microchannel