A comparative study of fixed-bed and dispersed catalytic upgrading of heavy crude oil using-CAPRI

Abarasi Hart,Malcolm Greaves,Joseph Wood

doi:10.1016/j.cej.2015.01.101

Abarasi Hart, Malcolm Greaves + Show 1 more

Open Access

https://doi.org/10.1016/j.cej.2015.01.101

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Abstract

CAtalytic upgrading PRocess In-situ (CAPRI) incorporated with Toe-to-Heel Air Injection (THAI) for heavy oil and bitumen recovery and upgrading was studied for fixed-bed and dispersed catalysts. The extent of upgrading was evaluated in terms of API gravity, viscosity reduction, impurity removal, and true boiling point (TBP) distribution. The test was carried out using Co-Mo/Al2O3 at temperature of 425°C, pressure 20bar, and residence time of 10min. The dispersed catalyst was tested in a batch reactor. However, the residence time, catalyst-to-oil (CTO) ratios as well as the Reynolds numbers of both contacting patterns were kept the same to ensure dynamic similitude. It was found that the produced oil from dispersed ultrafine Co-Mo/Al2O3 catalyst (dp=2.6μm) exhibited superior light oil characteristics and quality than that produced with the fixed-bed of pelleted Co-Mo/Al2O3 (1.2mm diameter×2–5mm length). The API gravity of the feed oil was 13.8° and the produced oil showed an increase of 5.6° in the fixed bed and 8.7° with the dispersed catalyst. Unlike the fixed-bed of pelleted Co-Mo/Al2O3 which may suffer from diffusion limitations, rapid deactivation, and channelling effect, the ultrafine particles presented high surface area to volume ratio, reducing the chances of pore plugging, have more accessible reaction sites per unit mass, and lead to enhanced cracking of macromolecules. Moreover, the reduction of sulphur of 38.6% and (Ni+V) content of 85.2% in the produced oil show greater heteroatom removal compared to 29% (sulphur) and 45.6% (Ni+V) observed in the product from the fixed-bed.

Highlights

The quantitative and qualitative data showing the extent of upgrading of the heavy oil after thermal cracking, fixed-bed and dispersed ultrafine particles experiments are presented and discussed
The pelleted and ultrafine Co-Mo/Al2O3 catalyst samples with the same chemical composition were analysed by the nitrogen sorption technique according to ASTM C1274 method, and the results are presented in Fig. 1 and Table 3, respectively
The challenges confronting the to-Heel Air Injection (THAI)–CAtalytic upgrading PRocess In-situ (CAPRI) process involving the use of a fixed-bed of pelleted catalyst surrounding the horizontal production well has led to the investigation of an alternative contacting pattern using dispersed ultrafine catalyst

Summary

Introduction

Over the past 12 years, the THAI process research and subsequent field studies have been carried out in conjunction with the CAtalytic upgrading PRocess In-situ (CAPRI) in which a pelleted refinery catalyst is incorporated with the horizontal production well to aid in-situ catalytic upgrading as the hot mobilised oil flows across the layer of pelleted catalyst [3,4,5,6] This technology offers the advantage of using in-situ generated energy from the in situ combustion reactions to mobilise the oil and catalytically upgrade it in the reservoir, thereby offering great potential cost advantages compared to SAGD and CSS which incur the cost of natural gas, steam generation and post water treatment.

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