Journal of Advanced Chemical Engineering

Chemical looping combustion and gasification technologies for production of heat and valuable commodities

2^nd International Conference on Advances in Chemical Engineering and Technology

November 16-17, 2017 | Paris, France

Ranjani Siriwardane

U.S. Department of Energy, USA

Scientific Tracks Abstracts: J Adv Chem Eng

Abstract:

Chemical-looping combustion (CLC) is a promising combustion technology that uses an oxygen carrier, such as metal oxide, to transport oxygen to the fuel without exposing it to air. The significant advantage of CLC over conventional combustion is that CLC can produce a sequestration-ready carbon dioxide (CO2) stream undiluted by nitrogen (N2) without expending the major energy required for the separation of CO2. Large-scale application of CLC is dependent on the availability of a suitable oxygen carrier. An ideal oxygen carrier should meet a number of requirements, including high reactivity, low fragmentation and attrition, low tendency for agglomeration, low cost, and stability under repeated reduction/oxidation cycles at high temperature. The carrier should also be environmentally benign. NETL researchers have developed and patented various oxygen carriers containing copper oxide, iron oxide, and manganese oxide, all of which have shown promising performance. Successful commercial-scale preparations and pilot-scale tests have been performed with these NETL-developed oxygen carriers. Beside the combustion reaction, chemical looping concepts have been proposed to produce hydrogen or synthesis gas from coal and methane. Chemical looping gasification of coal using oxygen carriers will produce a concentrated syngas stream undiluted with nitrogen. Chemical looping coal gasification will not require an air separation unit�a major advantage over traditional coal gasification, which uses air. However, development of oxygen carriers for gasification has been a challenge because most oxygen carriers combust fuels. NETL researchers have developed oxygen carriers containing calcium ferrite and barium ferrite for chemical looping coal gasification to produce syngas. These unique oxygen carriers selectively react with coal to produce syngas but do not combust the syngas. Chemical looping technologies for heat generation and production of syngas, which is a precursor for production of valuable commodities, will be discussed.

Biography :

Dr. Ranjani Siriwardane is a research scientist at the U.S. Department of Energy’s (DOE) National Energy Technology Laboratory (NETL). She leads the oxygen carrier development research work in both chemical looping combustion and chemical looping gasification at NETL. Dr. Siriwardane has also conducted research on development of sorbents for CO2 removal and hydrogen sulfide and hydrogen chloride removal from coal gasification gas streams. She is a co-inventor of 19 U.S. patents, 7 U.S. patent applications, and has co-authored 80 peer-reviewed publications. She has won three R&D 100 awards. She has designed sorbents/ oxygen carriers from lab-scale to pilot-scale operations and has licensed her patents to three U.S. companies.