Regulation, certification and the two borders
The binding regulatory problem is not an unpublished tariff but the absence of any third-party access regime on the segment the project depends on.
On the Thai side the position is worse than an unpublished tariff, and this is the most important regulatory finding in the case.
A molecule leaving a Thai mill for a Singapore burner tip crosses two national borders and at least three regulatory regimes.
PTT has established a Third Party Access Code for its onshore gas transmission system, under the Energy Industry Act, which obliges a network licensee to allow others to connect (Lexology). That Code governs PTT's own onshore system. It is not the asset this project would use. The only physical link from the Songkhla corridor to the Malaysian network is the Trans Thai-Malaysia line, which runs from the offshore Joint Development Area to the gas separation plant at Chana in Songkhla and on to the Malaysian system. That line is owned by a 50/50 project company of PTT and PETRONAS, and it provides transportation services to those two shareholders and to nobody else (Trans Thai-Malaysia).
So the gap is not a number nobody has published. It is that no third-party access regime is established on the segment the project depends on, and the two parties who would have to grant one are the incumbent sellers of the fossil gas this project would displace. Their incentive is to refuse or to price it at the value of what it displaces, and neither of those is a tariff question. We searched for the Code by name and for a rate schedule, and obtained the framework's existence and structure but not the tariff itself. Salerno's own Malaysia office records the wheeling arrangement over the mills-to-border segment as a regulatory scheme still to be confirmed. We therefore carry the Thai leg at an estimated $0.50/MMBtu and compute below what value would change the answer.
On the Malaysian side the position is documented. PETRONAS Gas Berhad publishes third-party access tariffs for the Peninsular Gas Utilisation system, with a 2026 allowed tariff of RM 1.204/GJ/day for transportation and RM 1.592/GJ/day for compression of high-pressure gas to Singapore (PETRONAS Gas). The system is 2,623 km, carries up to 3,500 mmscfd, and lists four entry points of which one is Thailand (PETRONAS Gas). Salerno's own slide quotes RM 1.262 and RM 1.698 per MMBtu per day, which are those same base tariffs correctly converted, so that part of the client's work checks out.
What is not established is whether biomethane specifically may enter that system from Thailand. PETRONAS Gas's published third-party access material does not address biomethane injection or disclose entry-point specifications. Salerno's own transcribed slide records the PETRONAS biomethane injection station as under development pending engineering, procurement and construction. Gas Malaysia's biomethane entry stations at Sedenak and Coronation and its Kluang injection station are on the distribution network rather than the transmission system. So the physical interconnection exists, the tariff exists, biomethane injection exists in Malaysia, and the combination of all three across the Thai border does not yet exist as a precedent we could find.
On the Singapore side, four term LNG importers are licensed and a state entity aggregates gas procurement for the power sector. The sandbox allocates to generators. The EMA release announcing the sandbox states no carbon-intensity threshold and no certification requirement, and we did not find those criteria published elsewhere; the brief asserts that Thai POME biomethane must meet a carbon-intensity and certification bar, and the bar's location is open rather than known.
On certification, POME sits in Annex IX Part A of the EU Renewable Energy Directive and double-counts in EU transport (ISCC), and ISCC is the scheme Gas Malaysia uses at Kluang. That is the practical route. It carries a reputational cost: an estimated 1.8 million tonnes of fraudulently certified POME entered the EU in 2023 (Advanced Biofuels USA), which any Thai POME exporter now inherits as a diligence burden.
On carbon, Singapore and Thailand signed an Article 6.2 implementation agreement on 19 August 2025 and published an eligibility list on 18 November 2025, and authorized credits can offset up to 5% of a Singapore company's taxable emissions (MTI).
This memo books no carbon revenue against gas sold to Singapore, because the brief states the green attribute is embedded in the bundled price and the buyer claims it. Booking both would count the same attribute twice.
That argument does not reach the roughly 40% of Southern mills with no digester, and there it matters. At those mills the methane is currently vented from an open lagoon. Capturing it is a different intervention from displacing a fossil molecule, against a different counterfactual, and methane capture from palm oil mill effluent is among the most widely approved crediting methodologies under the international mechanisms. The brief itself prices Singapore's carbon tax at S$45/tCO2e against up to 5% of a payer's taxable emissions. This memo separately establishes that somebody must fund digesters at those mills before there is any gas to buy, and that the client's model carries zero for that capital. Those two facts belong together: the instrument that could fund the digesters is the one the case set aside.
Sizing it needs an additionality and eligibility test that has not been done, and the answer turns on whether a mill that would have installed a digester anyway can claim the credit. It is named here rather than left out because a funding gap reported as unfunded, beside a funding mechanism the brief handed over, is a gap of the memo's own making.