Pemodelan Kinetika Reaksi Standar Selective Catalytic Reduction (SCR) NOx dengan Amonia Menggunakan Katalis Zeolit Cu-BEA

CATUR RINI WIDYASTUTI, Prof. Ir. I Made Bendiyasa, M.Sc., Ph.D.

2015 | Tesis | S2 Teknik Kimia

Peraturan terkait jumlah emisi yang dihasilkan oleh mesin diesel semakin ketat sehingga penelitian tentang pengurangan emisi NOx menjadi semakin menarik untuk dikaji. Salah satu teknologi terbaru yang digunakan untuk mengurangi emisi NOx dari mesin diesel adalah dengan menerapkan SCR dengan amonia sebagai reduktor menggunakan katalis Cu-BEA. Berbagai penelitian tentang topik ini telah dilakukan, namun mekanisme yang dapat menjelaskan reaksi reduksi NOx dalam sistem NH3-SCR belum dikaji. Penelitian ini difokuskan pada pemodelan kinetika untuk memahami mekanisme reaksi selective catalytic reduction NOx dengan amonia. Dua model dikembangkan, yaitu model reaksi Eley-Rideal (E-R) dan Langmuir-Hinshelwood (L-H). Model E-R memberikan nilai SSE yang lebih kecil dibandingkan nilai SSE model L-H. Selanjutnya model E-R digunakan untuk mengevaluasi parameter-parameter yang muncul dalam model, yaitu nilai konstanta laju reaksi (k1), konstanta keseimbangan adsorpsi-desorpsi (KNO, KNH3, and KO2), faktor frekuensi (A1, ANO, ANH3, and AO2), dan energi aktivasi (E1, CENO, CENH3, and CEO2). Selain itu juga dievaluasi nilai perubahan entalpi, CH, dan perubahan entropi, CS, dari sistem.

As the rule regarding the total emission of heavy duty diesel engines is getting stringent, consequently a research about NOx abatement becomes more interesting recently. One of the latest technology used to reduce the emission of NOx from diesel engines is by implementing SCR with ammonia as a reducing agent over the Cu-BEA catalyst. Various research regarding that topic has been conducted, however the mechanism which is able to explain the reaction of NOx reduction in the NH3-SCR system has yet to be explored. This work was focused on the kinetic modelling to understand the mechanism of NOx reduction with ammonia. Two models were developed, those were Eley-Rideal (E-R) and Langmuir- Hinshelwood (L-H) model. The E-R model gives SSE less than that of the L-H model. Subsequently the E-R model was used to evaluate parameters that come up in the model of constant of reaction rate (k1), constants of adsorption-desorption equilibrium (KNO, KNH3, and KO2), pre-exponential factor (A1, ANO, ANH3, and AO2), and activation energy (E1, CENO, CENH3, and CEO2). In addition, it was also evaluated the enthalpy change, CH, and entropy change, CS, for the system.

Kata Kunci : katalis Cu-BEA, DeNOx, NH3-SCR, model kinetika