(BAT) Reference Document for the Production of Chlor-alkali ...

Chapter 5
The BAT-associated consumption levels for steam from the caustic evaporation
process for new caustic concentrators in membrane cell plants are:
Number of effects/stages in evaporator
Steam consumption in t/t NaOH
2 3
produced as yearly average values on
the basis of 100 % NaOH
Q 710 Q 480
NB: Figures refer to a feed temperature of 80 °C and for
caustic concentration from 32 wt-% to 50 wt-%.
[This BAT conclusion is based on information given in Section 4.3.2.3.8.]
8. In order to reduce energy consumption, BAT is to use the co-produced hydrogen from the
electrolysis as a chemical reagent or fuel.
Description
Hydrogen can be used in chemical reactions (e.g. production of ammonia, hydrogen
peroxide, hydrochloric acid, and methanol; reduction of organic compounds;
hydrodesulphurisation of petroleum; hydrogenation of oils and greases; chain
termination in polyolefin production) or as a fuel in a combustion process to produce
steam and electricity.
For the use of hydrogen as a chemical reagent or fuel, the BAT-associated
environmental performance level is to use, as a yearly average, 90 – 100 % of the
co-produced hydrogen.
The higher end of the range is achieved by plants on sites with a high demand for
hydrogen.
[This BAT conclusion is based on information given in Section 4.3.2.3.9]
WORKING DRAFT IN PROGRESS
278 December 2011 TB/EIPPCB/CAK_Draft_1