Environmentally Benign Synthesis Of Sodium Hydroxide Without Chlorine Using Ion Exchange FibersEPA Grant Number: R831433
Title: Environmentally Benign Synthesis Of Sodium Hydroxide Without Chlorine Using Ion Exchange Fibers
Investigators: Sengupta, Arup K. , Munley, Vincent G. , Sengupta, Sukalyan , Warner, Steven B.
Institution: Lehigh University , University of Massachusetts - Dartmouth
EPA Project Officer: Richards, April
Project Period: October 15, 2003 through December 4, 2007
Project Amount: $319,998
RFA: Technology for a Sustainable Environment (2003) RFA Text | Recipients Lists
Research Category: Nanotechnology , Pollution Prevention/Sustainable Development , Sustainability
Currently, the production of sodium hydroxide (NaOH) and chlorine (Cl2) are closely linked and they are produced universally as co-products of electrolysis processes. As long as chlorine production remains coupled with the production of NaOH, it will be nearly impossible to promulgate regulations banning or reducing productions of various chlorinated compounds and enforcing them globally. The general objective of the project is to synthesize sodium hydroxide without co-production of chlorine through an ecologically clean route. Specific objectives include identifying and determining important process design parameters for the proposed process.
Our laboratory experiments will involve use of Ion Exchange (IX) fibers in fixed-bed processes to convert inexpensive lime and seawater into sodium hydroxide without requiring or producing any regulated chemicals. Harvested snowmelt/rainwater and carbon dioxide will be used as regenerant chemicals. In particular, we will evaluate how specific process variables such as IX fiber capacity, fiber diameter, calcium-sodium selectivity, etc., will influence the purity and productivity of NaOH per unit mass of IX fibers. The long-term economic viability of the process will also be duly addressed.
Once completed, the experimental results and analyses of the data are likely to confirm that 5-10% mass/volume sodium hydroxide with minimum impurity can be synthesized in an operationally simple process without using any regulated chemicals and without co-production of chlorine.
Improvement in Risk Management: From a holistic viewpoint, the production of sodium hydroxide needs to be decoupled from the production of chlorine which is the primary feedstock for producing chlorinated solvents, vinyl chloride, chlorofluorocarbons and other toxic synthetic organic compounds with adverse impacts on the environment. Only then it will be possible to promulgate regulations banning or reducing productions of various chlorinated compounds and enforcing them globally. The project attempts to achieve that goal through synthesis of sodium hydroxide without chlorine in an environmentally benign way. The other accompanying benefit of the process is that it may utilize flue gas rich in carbon dioxide for efficient regeneration of IX fibers, thus providing a new route to sequester carbon dioxide, a green house gas, before its emission to the atmosphere.