Go to the contents of this page.

By technology classification

Osaka Gas believes that technologies serve as the foundation of corporate competitiveness, and considers R&D to be one of the most important elements in the strategy to make a difference.
For this reason, Osaka Gas works actively on R&D and commercialization of new technologies, as presented below.

Compact synthesis gas production process for saving CO2 emissions, AATG process


Environmentally-friendly natural gas is receiving international attention as alternative energy to oil. However, natural gas from small- and medium-sized gas fields, which accounts for a large part of global natural gas reserves, and associated gas from oilfields remain unutilized due to unassured business viability. There is an urgent need for development of gas-to-liquids (GTL) conversion as a key technology to promoting the utilization of such natural gas.
In the GTL process, natural gas is first converted into a synthetic gas which consists primarily of hydrogen and carbon monoxide, from which liquids are produced, such as diesel oil, kerosene, methanol and dimethyl ether (DME).
There are various reasons for the interest in GTL products. They can be transported and stored at normal temperatures using the existing infrastructure. In addition, GTL products are cleaner than petroleum-based fuels, since the exhaust gas contains significantly lower levels of particulate matter (PM) and NOx, and no SOx.
Osaka Gas is working on developing2 a new gas synthesizing process (AATG process) using the Company's years of experience in catalyst technology applied to on-site hydrogen production systems, fuel cell hydrogen production systems and so on.
We have conducted a demonstration test on a pilot plant scale (plant capacity: approx. 2,000 Nm3/h), which revealed that the AATG process produces synthetic gas safely and stably. Moreover, engineering data we obtained indicates that the AATG process is superior to conventional methods in terms of construction cost and CO2 emissions from production processes. To produce GTL products from associated gas at an offshore oilfield, it is necessary to synthesize gases on a floating production, storage and offloading (FPSO) system or other offshore facilities. Since high-purity oxygen gas may not be available as oxidant for such facilities, we commenced a demonstration AATG process test in fiscal 2008 using low-purity oxygen gas and air. The test results obtained so far are favorable.
The AATG process is suited not only to synthesis gas production process for GTL systems, but also to synthesis gas production process used for ammonia, methanol and DME production. Osaka Gas is promoting the implementation of the process in gas synthesis systems for commercial use at chemical plants in Japan.

■Awards Osaka Gas received for AATG

  • FY 2009 Special Engineering Promotion Award from the Engineering Advancement Association of Japan.
  • FY 2011 Advance of Technology Award (Technical Department) from the Japan Institute of Energy.


  1. 1. The AATG1 process, designed to produce a synthetic gas (CO and H2 gas mixture) from natural gas via catalytic partial oxidation, is suitable for GTL production and other various applications where synthetic gases are used as a raw material to produce methanol, ammonia and the like.
  2. 2. Reduces construction cost and installation space since it is simplified process and consist of compact facilities.
  3. 3. Reduces CO2 emitted from production processes since it operates with a smaller number of fired heaters.
  4. 4. Is suitable for gas synthesis facilities used in offshore GTL production from associated gas, since the process requires only simple and compact facilities and reduced fired heaters.
  5. 5. Enables CO2 emission reductions and efficient energy use by using associated gas that was fired and wasted until now, for GTL production.

Application to synthesis gas production process for GTL production plants

The AATG process is a synthesis gas production process in which high-performance desulphurization developed by Osaka Gas and catalytic partial oxidation are combined. In comparison with the conventional process that combines steam reforming and autothermal reforming (ATR) using burner, the AATG process has the following features.

  1. 1. The conventional process requires a pre-reformer for steam reforming, a fired heater to provide necessary heat for steam reforming and a reformer with a burner. In contrast, the AATG process is a very simple process that produces synthetic gas in only one fixed bed catalytic reactor without using a burner.
  2. 2. The reactor size can be significantly smaller because the AATG process operates at a higher space velocity (SV: 1/h) than in the conventional process. Osaka Gas developed an high-performance desulfurization catalyst. This catalyst enables desulferizing at a ppb level far better than conventional ppm levels, thereby protecting the catalyst in the AATG reactor from sulfur poisoning and maintaining the performance of the catalyst filled in the AATG reactor for a long period of time.
  3. 3. The simple process and compact reactor translate to a reduced system construction cost, as compared with the conventional process.
  4. 4. Absence of fired heaters results in reduced CO2 emissions from gas synthesis process, as compared with the conventional process.
  5. 5. The AATG reactor uses a catalyst that initiates stable oxidation even at a reactor inlet temperature of 300ºC or below and enables using a lower peak temperature inside the catalyst bed due to high activity of endothermic steam reforming.
  6. 6. The AATG process produces no soot because oxidation and steam reforming occur simultaneously in the catalyst bed, while in the conventional process, it is a major problem to minimize soot produced in the burner-equipped reactor.

Alternative technology to associated gas flaring/Associated gas utilization technology

If an oilfield is close to an energy consuming area, there are some ways to use associated gas from the oilfield. The associated gas can be transported via a pipeline and consumed as city gas. Alternatively, a power plant can be built near the oilfield with electricity transmitted via a electrical power transmission line. If the oilfield is in a remote place from energy consuming areas and it is not possible to reinject into the oil well, the associated gas must be flared. A total of some 150 billion m3 a year (accounting for approximately 5% of the world's annual LNG production) of associated gas is flared on the globe, without being used as an energy source, yet releasing carbon dioxide into the atmosphere.
In recent years, offshore oilfields far distant from energy consuming areas are increasing in number, posing the challenge of how to use associated gas efficiently. One solution is GTL production using associated gas as raw material. Compared with flaring, this solution will bring about some 50% reduction in carbon dioxide emissions and, additionally, GTL products for efficient energy use.
The AATG process is simple and compact and enables reducing fired heaters. These features make the process suitable for synthesis gas production process for use in offshore GTL plants that use associated gas as raw material, since in such applications installation spaces are limited.

Application to synthesis gas production process for domestic chemical industry

Osaka Gas is promoting the implementation of commercial systems within the extent that the technology is effective, as proven with the pilot plant.

Pilot plant

AATG is a registered trade name of Osaka Gas Co., Ltd. and JGC Corporation.