The electrosynthesis of p-hydroxybenzaldehyde (PHB) from sodium p-hydroxyma
ndelate (SPHM) was investigated and good synthesis conditions were obtained
. The electrochemical reactor was a divided filter-press with carbon felt e
lectrodes (anode and cathode). Two different anolytes were used depending o
n the membrane employed. Thus, a 0.6 M SPHM 2.71 M NaOH solution was used i
n conjunction with a cationic Nafion(R) 117 membrane while a 0.6 M SPHM in
1.8 M NaOH solution was employed with an anionic Ionac(R) MA-3475 membrane.
The electrolysis was carried out at a constant current density of 100 mA c
m(-2). A material yield of approximately 90% was obtained at an energy cost
of 1.4-1.5 kWh kg(-1) PHB and a production of 49 kg PHB m(-2) day(-1).