Lithium silicate is seen as a milepost toward the development of lighter, cheaper ceramic materials offering faster absorption rates, while its room-temperature absorption CO2 opens the way to a wide range of practical applications in reducing CO2 emissions. Details of lithium silicate will announced at the American Ceramic Society, which will be held from April 22 to 25 in Indianapolis, Indiana.
Toshiba’s advances in CO2-absorbing ceramics include the April 1998 breakthrough development of a lithium zirconate ceramic material that absorbs 400 times its own volume of CO2–a level surpassing previous CO2 absorbers by a factor of ten.
Lithium silicate, which Toshiba co-developed with Toshiba Ceramics, absorbs CO2 at a rate 30-times faster than lithium zirconate and lithium transition metal oxide predecessors. In a 20% CO2 gaseous environment at 500, 1g of lithium silicate absorbs 62mg of CO2 in a minute, while its predecessors can manage only 1.8mg a minute.
Lithium silicate offers a light, low cost solution that widens the range of practical applications. Zirconium, the main material in earlier CO2-absorbing ceramics, is expensive and comparatively heavy. Silicion, the main material of lithium silicate, costs only 15% the price of zirconium and is 70% lighter in weight. Its ability to absorb CO2 will extend use of lithium silicate into consumer products, such as air cleaners.
Toshiba’s development of lithium zirconate and lithium transition metal oxide demonstrated a simplified absorption-discharge cycle that is temperature-triggered and does not require any complicated chemical reaction. Absorption occurs between 450 to 700 and discharge occurs by heating to a temperature exceeding 700. With the new material the same simplified cycle commences absorption at room temperature, while retaining same high discharge temperature.
CO2 has long been identified as a major contributor to global warming. International concern over CO2 emission levels is growing and lower levels are a must in order to combat global warming. In addition to energy saving measures, there is another route to reduction: to collect and fix the gas before it is released into the atmosphere.
The successful development of practical CO2-absorbing materials is one of the Toshiba Group’s wide ranging environmental protection activities, including improved power generation, energy-saving products and technologies for combating pollution.
Toshiba Ceramics, a specialist in industrial ceramics, made a major contribution to the development of lithium silicate. We are delighted to have contributed to development of this breakthrough ceramic material that holds out great promise for fighting CO2 emissions and contributing to environmental protection, said Mr. Hideo Uemoto, Deputy Manager at Toshiba Ceramics’ Research & Development Center We now look forward to developing a variety of practical applications and to bringing them to market at an early date.
The development of new material confirms the highly promising direction of Toshiba Group’s research. We have made great progress since we first announced CO2 absorbing ceramics in 1998 by developing a more effective, low cost, CO2 absorber that functions at room temperature, said Dr. Masahiro Kato, Research Scientist at Toshiba’s Power Supply Materials & Devices Laboratory in Research & Development Center. This achievement will contribute to combating global warming in the near future and enhance Toshiba’s group-wide contribution for environmental protection activities.
Commercial versions of the new ceramic material could play a central role in emission reduction. For example, drivers could exchange full CO2 absorbing ceramic cartridges for new ones at gas stations. A similar service could be introduced at power plants and industrial facilities. Collected CO2 could be recycled. In commercial agriculture, it could be used to promote photosynthesis and plant growth in greenhouses; or it could be reacted with hydrogen to produce methanol. Some researchers envisage an environment-friendly fuel cycle in which carbon dioxide from methanol-burning power plants is converted back into methanol, by natural energy such as sunlight, holding out the promise of a long-term solution to the problem of climatic change.
Toshiba and Toshiba Ceramics plan to launch the prototype of small-size industrial use CO2 collection devices by the end of year, followed by large-size devices used to combat global warming in 2003. Toshiba and Toshiba Ceramics will together propose a wide range of uses for the lithium silicate to interested parties.
