Abstract

Japan National Oil Corporation ("JNOC") has been developing natural gas to liquids ("GTL") conversion technology since 1998. This work was conducted in collaboration with five private companies, namely: JAPEX, CYD, COC, NSC and INPEX. The research aimed to establish a technology to enable the economic exploitation of stranded gas reserves.

The JNOC GTL process jointly developed by our collaboration ("JNOC GTL process") has the following particularities, comparing it with the other GTL processes (hereafter referred to as the "conventional GTL process"):

1. The synthesis gas generation section ("Syngas") of JNOC GTL process uses a steam/CO₂ reforming technology rather than the Autothermal Reforming ("ATR") or Non-catalytic Partial Oxidation ("POX") technology used in the conventional GTL process, and

2. The Fischer-Tropsche synthesis section ("FT") of JNOC GTL process employs a slurry reactor with noble metal or non-noble metal catalysts, as compared with Co or Fe catalysts used in the conventional GTL process.

The JNOC GTL process is particularly effective when it is applied to natural gas feedstock containing a relatively high concentration of CO₂, as it can utilize any CO₂ contained in the natural gas feedstock. It has a particularity that it does not require the following three high cost items; i.e. (1) an oxygen supply plant, (2) a CO₂ separation unit, and (3) a H₂ conditioning unit. The reduction of three facilities, which are indispensable to the conventional GTL process, generally results in less CAPEX and OPEX.

The JNOC GTL process is optimal at a plant scale of 15,000 bpd in GTL production rate, and where the natural gas feedstock has CO₂ content in the range of 20 to 40 vol%. Economic evaluation indicates that it is more economical than the conventional processes at these conditions.

This paper covers the fundamental principles of the JNOC GTL process, highlights the leading features of the process, and presents the results of performance tests for the Syngas catalyst and FT catalyst. It also outlines a joint feasibility study with Pertamina, in the pursuance of the applicability of the JNOC GTL process into Pertamina's gas fields in Indonesia.