Path: TopS2-ThesesChemical Engineering-FTI2018

PENGARUH KEASAMAN KATALIS FISCHER-TROPSCH BERBASIS Co/γ-Al2O3 TERHADAP AKTIVITAS DAN SELEKTIVITAS KATALIS: PENAMBAHAN PROMOTOR KALIUM DAN MANGAN

THE CATALYST ACIDITY EFFECT TOWARD ACTIVITY AND SELECTIVITY OF Co/γ-Al2O3 BASED FISCHER-TROPSCH CATALYST: POTASSIUM AND MANGANESE LOADING

Master Theses from JBPTITBPP / 2018-01-12 15:13:53
Oleh : AHLUL HAFIZAN RESHA - NIM: 23015035 , S2 - Chemical Engineering-FTI
Dibuat : 2018-01-12, dengan 1 file

Keyword : Fischer-Tropsch, katalis Co/γ-Al2O3, promotor Mn, promotor K, keasaman, reaktor unggun tetap

Setiap tahun konsumsi bahan bakar minyak (BBM) meningkat 4% sedangkan produksinya menurun 2,7% sehingga menyebabkan Indonesia harus mengimpor 33.565,89 tons oil equivalent (toe) minyak bumi. Di sisi lain, Indonesia mempunyai kelebihan produksi relatif terhadap konsumsi gas alam dan batubara, masingmasing sebanyak 31.779,38 toe dan 160.734,12 toe setiap tahun. Oleh karena itu, dibutuhkan teknologi untuk mengonversi kelebihan gas alam dan batubara tersebut menjadi bahan bakar minyak, yaitu sintesis Fischer-Tropsch.

Sintesis Fischer-Tropsch (SFT) mengonversi syngas (gas H2 dan CO) yang dapat diperoleh dari gas alam dan batubara menjadi senyawa hidrokarbon melalui proses katalitik. Salah satu katalis yang digunakan pada SFT adalah Co/γ-Al2O3, tetapi katalis tersebut masih memiliki aktivitas dan selektivitas yang rendah. Penambahan promotor elektronik, seperti mangan (Mn) dan kalium (K), diketahui meningkatkan kinerja katalis Co. Modifikasi tersebut dievaluasi melalui perubahan keasaman katalis. Mn berperan sebagai promotor asam, sedangkan K sebagai promotor basa. Oleh karena itu, penambahan K dan Mn sebagai promotor tunggal maupun ganda dapat digunakan untuk memperbaiki kinerja katalis Co/γ-Al2O3.

Katalis Co-K/γ-Al2O3, Co-Mn/γ-Al2O3, dan Co-K-Mn/γ-Al2O3 disintesis dengan metode impregnasi kering. Variasi pembebanan pada katalis berpromotor tunggal K atau Mn sebesar 0,5%, 1%, dan 1,5% berat katalis. Kadar K dan Mn katalis CoK1.5-Mn0.5 dipilih berdasarkan α terbesar, sedangkan pada Co-K1.2-Mn0.8 berdasarkan perolehan C5+ terbesar. Hasil XRD menunjukkan ukuran kristal Co berada pada rentang 8,01-10,22 nm. Penambahan Mn memperkecil ukuran Co. Hasil analisis dengan metode BET dan BJH menunjukkan proses impregnasi mengurangi luas dan volume pori katalis. Ukuran pori seluruh katalis adalah 6,72±0,06 nm. Hasil TPD menunjukkan penambahan K menurunkan keasaman dan kekuatan asam katalis, sedangkan penambahan Mn hanya meningkatkan keasaman katalis. Uji aktivitas katalis diselenggarakan pada reaktor unggun tetap dengan kondisi operasi 250°C, 20 bar, dan laju alir syngas 1500 mL/jam. Perolehan C5+ katalis Co-K1.2-Mn0.8 adalah 0,199 g/(gkat.jam).

Deskripsi Alternatif :

Indonesian fuel consumption has increased 4% while production has fallen down 2.7% which forced Indonesia to import 33,565.89 tons of oil equivalent (toe) of petroleum every year. On the other hand, Indonesia’s annual production excesses relative to consumption of natural gas and coal, 31,779.38 toe and 160,734.12 toe respectively. Therefore, a technology should be performed to convert excessed natural gas and coal into fuel, namely Fischer-Tropsch synthesis (FTS).

Fischer-Tropsch synthesis converts syngas (H2 and CO), which can be generated from natural gas and coal, into hydrocarbons through catalytic process. An invented catalyst for FTS is Co/γ-Al2O3, but it has to be enhanced to get higher conversion and selectivity. The addition of electronic promoters, such as manganese (Mn) and potassium (K), enhances the performance of cobalt catalysts. This modification can be evaluated by alteration of the catalyst acidity. Mn is an acidic promoter, whereas K is an alkaline promoter. Therefore, the addition of Mn and K as single and double promoters can be applied to enhance Co/γ-Al2O3 catalyst performance.

Co-K/γ-Al2O3, Co-Mn/γ-Al2O3 and Co-K-Mn/γ-Al2O3 were prepared by incipient wetness impregnation. K or Mn loading for single promoted catalysts were varied into 0.5%, 1% and 1.5% w/w. The loaded amount of K and Mn on Co-K1.5-Mn0.5 catalyst were referred to the largest α respectively, while at Co-K1.2-Mn0.8 was based on the largest C5+ yield. The XRD results showed the crystallites size of Co is in the range of 8.01-10.22 nm. Mn addition decreased Co crystallites size. BET and BJH method exhibited the impregnation process reduced surface area and pore volume. Pore size of the entire catalysts was 6.72 ± 0.06 nm. TPD results confirmed K decreased the total amount and strength of acid sites of the catalyst, whereas the addition of Mn only increased the acidity of the catalyst. Activity test has been performed at fixed-bed reactor on 250°C, 20 bar and syngas flow rate 1500 mL/h. The C5+ yield of Co-K1.2-Mn0.8 catalyst was 0.199 g/(gcat.h).


Copyrights : Copyright (c) 2001 by Perpustakaan Digital ITB. Verbatim copying and distribution of this entire article is permitted by author in any medium, provided this notice is preserved.

Beri Komentar ?#(0) | Bookmark

PropertiNilai Properti
ID PublisherJBPTITBPP
OrganisasiS2 - Chemical Engineering-FTI
Nama KontakUPT Perpustakaan ITB
AlamatJl. Ganesha 10
KotaBandung
DaerahJawa Barat
NegaraIndonesia
Telepon62-22-2509118, 2500089
Fax62-22-2500089
E-mail Administratordigilib@lib.itb.ac.id
E-mail CKOinfo@lib.itb.ac.id

Print ...

Kontributor...

  • Prof. Subagjo

    Dr. Melia Laniwati, Editor: Irwan Sofiyan

File PDF...