PERANAN KATALIS K3-xHxPW12O40 PADA KATALISIS SELEKTIF SINTESIS METILAMINA DARI METANOL DAN AMONIAK

Abstract

Role of K3-xHxPW12O40 as a Catalyst in Selective Catalysis of Methylamine Synthesis from Ammonia andMethanol. Synthesize of methylamine from methanol and ammonia was studied in this research work using a partiallypotassium heteropoly salt (K3-xHxPW12O40 abbreviated as KPW) as a catalyst. KPW was prepared from heteropoly saltand potassium carbonate by using ion exchange method. The reaction was conducted at 600 ~ 800K and at theatmospheric pressure. Reactor used was a continue flow reactor with W/F=0,1~0,9g-kat.mnt./cc.Concentration ofreactants and products were analyzed by gas chromathography while catalyst structure was observed by XRD (X-raydiffraction). Isothermal adsorption method was used for determining catalyst pore size. The result showed that ionexchange between H ion in zeolit with K ion produced potassium heteropoly salt that caused the change of interstitialspace. The change of interstitial space was observed by the change of the lattice constant of the catalyst crystal.Trimethylamine(TMA) has molecule size smaller than catalyst pore size but bigger than molecular size ofDimethylamine (DMA) and Monimethylamine (MMA). This phenomenon caused the suppression of TMA formation.KPW has a rigid crystal structure and stabil during reaction. On the other hand, crystal structure of a non selectivecatalyst (NH4)3PW12O40 was not rigid and its pore size is easy to change depending on the product molecule size.Keywords : methylamina, shape selective, heteropoly aci