ENTERPRISE FUTURE
Biogas Upgrading System Commercialization Project in Thailand

Biogas Utilization Project to Open Up a New Field

Biomethane refueling station and natural gas truck

Biomethane refueling station and natural gas truck

Approximately 800 km south of Bangkok, the capital of Thailand, lies Nakhon Si Thammarat Province. Drive just outside the urban district, and you will see greenery all around you. Palm plantations and wetland stretch before your eyes, and palm oil factories are dotted here and there. One of them belongs to Agriculture of Basin Company Limited (ABC). In a corner of this factory, a new attempt to open up future possibilities has begun—to obtain high-purity biomethane from wastewater discharged in the palm oil production process and to utilize the biomethane as automotive biogas fuel (CBG: compressed biogas). The leader of this attempt is Osaka Gas, which has developed its unique biogas upgrading technology.

Palm waste discharged from palm oil factories

Palm waste discharged from palm oil factories

Biogas is expected to be utilized as a carbon-neutral renewable energy. Biogas is generated when organic waste, garbage and activated sludge in sewage plants ferment. Thailand has a rich source of material for biogas and has been active in the spread of CBG. Although CBG usage in the country is limited at the moment, the Thai government has set a goal of increasing it to 4,800 t per day in 2036. This ambitious dissemination goal is unmatched in the world and suggests the government's keen enthusiasm and great expectations for the utilization of biogas.

Meanwhile, Osaka Gas has had its eye on biogas, which is regarded as the most promising renewable energy in the gas industry. The company has thought about promoting the use of biogas as an effective measure against global warming by developing unique, competitive technologies.

And now, across borders, Osaka Gas's biogas upgrading technology, which is appreciated for its high usefulness, is going to bloom in Thailand. Follow the progress of this biogas utilization project that opens up a new field.

Methane Gas Recovery Rate Raised to 99%,
Halving Methane Gas Diffusion into the Air

Bench-scale test equipment at Torishima Test Field

Bench-scale test equipment at Torishima Test Field

Hiroshi Tanaka, who was responsible for developing this biogas upgrading technology, started in 2013 to form the basic concept at Torishima Test Field, owned by Osaka Gas Co., Ltd.He was tasked with establishing a technology for separating and removing CO2 from biogas. Biogas consists of methane (approximately 60%), CO2 (approximately 40%), and a trace of impurities. To use biogas as automotive biogas fuel (CBG), you need to upgrade it to biomethane by removing CO2 and the impurities. Methane has a global warming potential 25 times as high as CO2. If diffused into the air without being used effectively, methane has a significant impact on global warming. Therefore, the new technology had to combine high-efficiency, low-cost CO2 removal and a high methane recovery rate.

Tanaka took a hybrid approach that combined two technologies: PSA (pressure swing adsorption) and membrane separation. PSA uses adsorbent to separate gas. CO2 can be removed by the use of adsorbent that adsorbs CO2. In fact, Osaka Gas had already used PSA as a gas upgrading technology. A separation membrane separates CO2 from methane by selectively letting CO2 through it. Both technologies are widely known, and each of them had been separately used by competitors to upgrade biogas, but not in combination. Tanaka sought possibilities in the hybrid upgrading technology, which passes off-gas, discharged from the PSA process, through separation membrane, allowing even a small amount of methane in the off-gas to be recovered.

He pursued a goal of boosting the biomethane recovery rate to 99%. Competitors had already achieved up to 98% with technologies such as PSA and separation membrane. In other words, Tanaka's attempt was to raise the rate by another 1%. A rise by 1% sounds like a small change, but it would halve the amount of methane gas diffusion into the air. It would make a big difference.

the biomethane recovery rate to 99%

Tanaka wasted no time in building a hybrid system and started experiments, but the recovery rate would not go beyond 95.6%. The reason for the low recovery rate was the inherently unstable properties of biogas, the source of biomethane. Biogas is something like a living creature. It is subject to the biological process of fermentation. Considerable fluctuations in composition make it hard to control the flow rate of the gas to pass through the system.Tanaka started afresh with the establishment of a concept of flow rate control by considering which parameters he should focus on. Then he rewrote the program, made other adjustments, and successfully managed to reach the target: a recovery rate of 99%.

Pilot Testing Partner Finally Found after a Search across Thailand

The project members have much to discuss in order to achieve success in this big, cross-border project.

The project members have much to discuss in order to achieve success in this big, cross-border project.

While Tanaka was spending all his time doing experiments at Torishima Test Field, Nishida, another member of the project team, was pursuing market research in anticipation of successful development of the technology. Nishida's strategy targeted overseas markets from the beginning because Japan had a limited supply of biogas to upgrade. Among others, he set his eyes on Thailand, which world ranked third in palm oil production and second in cassava production. Nishida considered that this country had a rich source of agricultural residue from which biogas could be obtained. Another advantage of Thailand was the widespread use of natural gas vehicles, which could use CBG as a fuel. He also guessed that the government-led promotion of the use of CBG, as mentioned above, must be a favorable factor.

Nishida began his market research in Thailand by listing palm oil and cassava factories as biogas sources and visited them door to door. His visits had two purposes: to determine if local factories had the ability to supply materials for biogas and to ask promising factories for their cooperation in a local pilot test. Osaka Gas (Thailand) Co., Ltd., a Daigas Group company there, helped Nishida with the research. In a foreign land where he did not know how to get around and sometimes could not communicate in English, he felt encouraged to have the support of the staff of the local subsidiary. However, things did not go smoothly. Most of the factories were hard to access. Sometimes a five-hour drive for a factory visit turned out to be a complete waste of time. Still, Nishida continued his visit around the country, believing that somewhere there was a factory that would be sympathetic to this project. And he finally found one—ABC, a palm oil manufacturer.

ABC had been actively working on using energy more effectively, including power generation with biogas from its factory wastewater and selling the electricity to local power companies. In those days, ABC was planning to expand its factory, but it had no chance of selling more electricity to the power companies. ABC was facing the problem of how to deal with excess biogas as a result its factory expansion. Osaka Gas's proposal was a very timely offer to ABC. Discussions between the two went very smoothly. They agreed to build a pilot biogas upgrading facility on the premises of ABC's factory and conduct a one-year pilot testing program there.

It was great to have secured a pilot testing partner, but the process of building the pilot testing facility was an even tougher task. The test equipment Tanaka had developed at Torishima Test Field was only small in scale. A pilot testing facility to be operated for a long period was another story. The world had never seen such a facility. Project team members had never built one, and they were trying to make it happen in a foreign country. This was an unprecedented project for Osaka Gas. Tanaka started off by looking for a local manufacturer to which he could subcontract the fabrication. Under heavy pressure to complete this overseas project he could not afford to fail, Tanaka took charge of the entire process from facility design to construction management, and successfully managed to get the facility completed by the starting day of the pilot testing.

Construction site of the pilot testing facility

Construction site of the pilot testing facility

In November 2017, Osaka Gas posted a press release: "Pilot Project Launched in Thailand to Explore Biogas Refining and Vehicle Natural Gas Fuel Supply for Future Commercial Usage. "In Thailand, an opening ceremony for the pilot testing facility was held with Thai government officials invited as guests, and the event was shown on TV in the country. At the ceremony, Tanaka and Nishida reflected on the hectic days they had spent leading to the opening of the facility, and renewed their strong determination to make the coming pilot testing a success.

Valuable Innovative Technology that Paved the Way for Widespread Use of Biogas

Truck being refueled at a refueling station Natural gas truck with gas cylinders mounted between the driver's seat and the platform

Truck being refueled at a refueling station

Natural gas truck with gas cylinders mounted between the driver's seat and the platform

The pilot testing started. This is how the system works. Wastewater from ABC's palm oil factory is fermented to produce biogas, which is fed to the Osaka Gas-made pilot biogas upgrading facility to become high-purity biomethane, which is then sent to an adjacent biomethane refueling station. Natural gas trucks are filled with CBG. Several issues came up at the beginning of the pilot testing, but it generally got off to a steady start. The upgraded biomethane met the CBG regulations established by the Thai government, and permission was granted for it to be supplied to trucks. The pilot testing facility kept working stably with operation by local staff. In March 2019, the pilot testing came to an end after achieving stable operation for over 6,000 hours and refueling over 6,000 natural gas vehicles in total. This first attempt in Thailand of making CBG by upgrading biogas from palm oil factory wastewater brilliantly marked the first step of practical use.

The biogas upgrading facility installed at ABC has moved to a commercial phase and is now being operated by Osaka Gas (Thailand). Meanwhile, the project team started another activity for the next step. The next issue to tackle was to expand the size of the facility. To undertake full-fledged commercial activities, the team needed a facility approximately four times as large as the pilot testing facility. Toyokazu Tanaka, newly assigned to this project, started to look for a subcontractor to which construction of a plant of this size could be entrusted.

One issue was how to combine high quality and low cost. It seemed tough to convince the subcontractor to build a facility of the required quality at low cost, but Tanaka drew on his own experience. In his previous department, as a sales representative of hydrogen production plants, Tanaka used to scout for plant and device manufacturers and handle customer's cost reduction requests. Making full use of this experience and know-how, Tanaka examined plant construction companies in Thailand, from large- to small-sized, and visited promising candidates himself to ascertain whether they had adequate building capabilities or not. He also made the best combination of tangible (facility construction) and intangible (facility management) factors, thereby achieving both high quality and low cost and seeing the light at the end of the tunnel for facility construction. A remaining issue is customer acquisition. Osaka Gas (Thailand) is now striving to find potential users of the biogas upgrading system.

The project members never slacken their pace toward the next step.

The project members never slacken their pace toward the next step.

High costs and a low recovery rate have prevented conventional biogas upgrading systems from growing popular. Unlike them, Osaka Gas's new hybrid biogas upgrading system combines low cost and a high recovery rate, having opened up new avenues for the widespread use of biogas. Depending on future developments, biogas can raise expectations as the next promising renewable energy. With such developments in mind, the project members, including Tanaka, will steadily promote the spread of the system, first in Thailand and then in other Southeast Asian countries. Their project, in which many people are investing their hopes and dreams, has only just begun.

Profile
  • Hiroshi Tanaka
    Process Engineering Team, Engineering Dept.
    Hiroshi Tanaka
  • Toyokazu Tanaka
    Process Engineering Team, Engineering Dept.
    Toyokazu Tanaka
  • Harunobu Nishida
    Technology Planning Team, Innovation Dept.
    Harunobu Nishida
Latest articles