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The order to investigate for a fired boiler (biomass such as rice husk, or LPG): first a flue-gas economizer, second as much clean, hot condensate back to T-1 as possible, third the heat pump HP-1 where the press return has enough heat and the combined heating and cooling economics justify it. - Diagram: new ECON-1 (option, fired boilers only) between the feed pumps and the boiler manifold, with a bypass for an electric bank and the flue-gas path from the boilers; feed in 90 to 95 C, outlet and stack temperature are vendor figures. HP-1 is now drawn as an option and labelled the third measure. AT conductivity on the condensate return to T-1; off-spec condensate goes to the warm tank. - Found in Newbilt's offer 240620-04: steam and cooling water share the mould channels, with one steam/water outlet valve and steam trap per mould, so the condensate is only as clean as the cooling loop. Noted in the T-1 detail, sustainability.md and as a Newbilt RFQ question. - With most condensate returned (about 15 % flashes at atmospheric pressure, estimate) the feed tank needs only a fraction of the ~70 kW that heating all make-up takes, so HP-1 may not pay. - RFQ: economizer outlet feed and stack temperature, corrosion limit, pressure drop; rice husk ash is high in silica and abrasive, so fouling, cleaning, wear protection and a bypass. - sustainability.md: the order, before the exclusions. biomass.md: new "Recovering heat at the boiler". Checked headless (scripts/pw_sc_check.py): 33 boxes, 20 tags, no overlap or overflow, no unstyled pipes, no card or page overflow at 1600, 1258 and 390 px in all four cases, every box opens its detail, no errors.
175 lines
10 KiB
Markdown
175 lines
10 KiB
Markdown
# Biomass Fuel Strategy
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If the steam boiler goes the biomass route (see the options in
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[sustainability](sustainability.md) and the Getabec candidate in the
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[utilities CSV](finance/utilities-investment.csv)), the fuel comes from two
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sources: the team's own 60 rai of currently unused land, and northern
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Thailand's agricultural waste market. Figures below are planning estimates,
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plus or minus a wide margin, to be refined against the actual boiler choice
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and duty cycle.
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## Demand: what the boiler would burn
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The five-press fleet draws 750 to 900 kg/h of steam at full demand, ~510
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to 610 kW thermal, from a proposed bank of two 500 kg/h boilers
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([steam and cooling](steam-cooling.html)). Fuel follows records pressed,
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not presses installed. With the heat recovery architecture trimming the
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load and realistic duty cycles:
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- Mature plant (two shifts, ~300 days/yr, about 1.0 to 1.1 million
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records): roughly **350 to 400 tonnes of air-dry wood per year** (at
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~80% boiler efficiency and ~4 kWh/kg air-dry wood); the start fleet at
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its full ~1.5 million records needs up to **~550 t/yr**
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- Early operations (one press line, single shift): roughly a quarter of
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that, **~90 to 100 t/yr**
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- Bought as fresh wood chips (~45 % moisture, ~2.6 kWh/kg) the same heat
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is **~540 to 620 t/yr**, up to ~840 t/yr at 1.5 million records, which
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is what the fuel store and the monsoon
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stock have to be sized for (estimate)
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### Recovering heat at the boiler
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A fired boiler loses heat up its stack, so an economizer that preheats the
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boiler feedwater with the flue gas is the first heat-recovery measure to
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investigate, ahead of condensate return and the feedwater heat pump
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([sustainability](sustainability.md#energy-efficiency-architecture-recover-before-generating)).
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How far the flue gas can be cooled is the vendor's figure: it depends on
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the flue-gas temperature, the corrosion limit and the fuel. Rice husk ash
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is high in silica and abrasive, so the RFQ asks for fouling and cleaning
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provisions, wear protection and a bypass rather than a clean-gas
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economizer ([steam and cooling](steam-cooling.html)).
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## The 60 rai: own-grown fuelwood
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60 rai is 9.6 hectares. Managed as short-rotation coppice (planted once,
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harvested on a 2 to 4 year cycle, regrowing from the stump), fast species
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proven in Thailand (eucalyptus, acacia, leucaena, bamboo) yield roughly 8 to
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14 air-dry tonnes per hectare per year. So the land can sustainably supply
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about **80 to 135 t/yr**:
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- Enough to cover **most or all of early operations**
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- About **a fifth to a third of mature two-shift demand** at ~1.0 million
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records, a seventh to a quarter at the start fleet's full 1.5 million
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That makes the land a meaningful supplement and a strong brand story
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("records pressed with steam from our own trees"), not a complete fuel
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supply. At the market prices below, 80 to 135 t of air-dry wood is worth
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only ~0.1M to 0.25M THB a year (estimate): the land's value is supply
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security and the story, not the fuel bill.
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### The classification check comes first
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The land is currently classified as forestry, and in Thailand that carries
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legal weight. Before a single tree enters the fuel plan:
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- Verify the parcel's actual status: clean Chanote title vs Sor Por Kor vs
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National Forest Reserve. Planting, harvesting, and transporting trees,
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even self-planted ones, can be restricted depending on classification,
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and some species are restricted regardless.
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- If eligible, register the plantation under the forest plantation
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framework, which legalizes grow-and-harvest cycles and the transport
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paperwork.
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- If the parcel carries actual standing forest, it should not be harvested
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for fuel: that would undercut the sustainability commitments the plant is
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built on. Coppice belongs on the degraded or empty portions.
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## Filling the gap: the northern biomass market
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The region fills the remainder easily and cheaply:
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- **Longan orchard prunings**: Lamphun is Thailand's longan heartland and
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prunings are an established traded fuel
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- **Sawmill and wood-processing residues**
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- **Corn cobs and rice husk**: abundant regional crop wastes; a
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Getabec-class solid-fuel boiler is designed for exactly this fuel mix
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- Buying from local farmers also strengthens the local-sourcing story that
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already runs through packaging and PVC
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## Fuel prices (market check, October 2026)
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There is no public price index for biomass fuel in northern Thailand. DEDE
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publishes lists of buyers and sellers (February 2026: 42 registered buyers
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wanting 2.09M t a year), not prices, so the figures below are reported
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market prices from bank research, a government industry unit and the
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press, all checked 7 October 2026. None is a quote to this plant.
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| Fuel | Reported price | Source | Heat cost (estimate) |
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| Wood chips, fresh (45 to 50 % moisture) | 1,350 to 1,800 THB/t delivered | [LH Bank Research, wood pellet outlook](finance/biomass/LHBank_Wood_Pellets_Industry_Outlook_2026-03.pdf), 9 March 2026: 1,700 to 1,800 THB per fresh tonne for export; a power-plant chip quota in Nakhon Ratchasima at 1,350 THB/t, at most 45 % moisture (undated trader post) | ~0.65 to 0.85 THB/kWh |
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| Firewood and rubberwood offcuts, air-dry | over 1 THB/kg at the farm gate, up from 0.55 to 0.70 before late 2025 | [OIE Rubber Intelligence Unit](https://rubber.oie.go.th/Article.aspx?id=66365), 2026; southern rubber belt, so chipping and haulage to Lamphun come on top | ~0.3 to 0.5 THB/kWh before chipping and haulage |
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| Corn cobs and stalk residue | 2 THB/kg, bought from farmers in Mae Chaem (Chiang Mai) | Sunsweet's "no burning, we buy" programme, [Prachachat](https://www.prachachat.net/economic/local-economy/news-1498508), February 2024; an incentive price set to stop field burning | ~0.6 THB/kWh |
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| Rice husk | ~1.5 THB/kg at past demand peaks | [FTI renewable energy group](https://re-fti.org/%E0%B9%84%E0%B8%9F%E0%B8%9F%E0%B9%89%E0%B8%B2%E0%B8%8A%E0%B8%B5%E0%B8%A7%E0%B8%A1%E0%B8%A7%E0%B8%A5%E0%B8%A3%E0%B8%B0%E0%B8%AA%E0%B9%88%E0%B8%B3%E0%B8%A3%E0%B8%B2%E0%B8%84%E0%B8%B2%E0%B9%81%E0%B8%81%E0%B8%A5%E0%B8%9A%E0%B8%9E%E0%B8%B8%E0%B9%88%E0%B8%87/) (undated); power plants compete for it and northern milling volumes are small | ~0.5 THB/kWh |
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| Wood pellets, domestic | 3,000 to 5,000 THB/t | LH Bank Research, March 2026; export FOB averaged 4,482 THB/t in 2025 | ~0.75 to 1.25 THB/kWh |
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Heat cost assumes an 80 % boiler (85 % on pellets) and ~2.6 kWh/kg for
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fresh chips, ~4 for air-dry wood, ~4.2 for corn cobs, ~3.75 for rice husk
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and ~4.7 for pellets (estimates).
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What it means for the plan:
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- **Planning price: 1.35 to 2 THB/kg delivered**, which is ~0.5 to 0.9 THB
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per kWh of heat. The earlier assumption of 1 to 2 THB/kg of air-dry wood
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(~0.3 to 0.6 THB/kWh) was too low at the bottom: the cheap end is
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farm-gate wood, not chipped fuel at the plant gate. At maturity the fuel
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bill is **~0.6M to 1.2M THB a year** (~0.15M to 0.3M early), still a
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quarter to a tenth of electric steam (see
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[grid tariff](sustainability.md#grid-tariff-pea-and-what-it-decides))
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- **Prices are rising and follow diesel.** With diesel near 40 THB/L in
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2026, chip traders feeding power plants parked trucks and cut purchases
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([Thai Post](https://www.thaipost.net/district-news/971839/), 30 March
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2026), and rubberwood firewood roughly doubled since late 2025. Haulage
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is a large share of a delivered tonne, so source within ~50 km and write
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a diesel clause into the fuel contract rather than a fixed price
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- **Supply is not the constraint.** Lamphun alone produces more than
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900,000 t of farm residues a year (Maejo University, via
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[ThaiPublica](https://thaipublica.org/2026/08/lamphun-reduce-pm2-5-agricultural-waste-biomass-fuel/),
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August 2026) against the plant's ~600 t. Buying them also counts against
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the burning season, which is part of the story
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- **The local price-setter is in Mueang Lamphun.** Ratch Pathana's
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[biomass buying centre](https://www.ratchpathana.com/th/our-businesses/related-and-other-businesses/biomass-business)
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at Pa Sak, Mueang Lamphun, buys wood waste, sawdust and corn cobs from
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farmers for Saha Cogen Green's 9.6 MW, 25 t/h steam cogeneration plant
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in the Saha Group Lamphun industrial park. It is the reference price to
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ask for and the main competitor for the same fuel. Further out, Clover
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Power at Wang Chin (Phrae) buys chips, corn husks and cobs, and bamboo
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([DEDE buyer list](finance/biomass/DEDE_biomass_buyers_2026-02.pdf),
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February 2026)
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- **Next step:** written quotes from the Pa Sak centre and two or three
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chip suppliers within 50 km, priced by moisture content (an oven-dry
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tonne carries roughly twice the heat of a fresh one), before the boiler
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decision
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## Logistics on site
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To reflect in the facility planning: a fuel storage shed (biomass
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must be kept dry; monsoon-season storage sizing matters more than dry
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season), chipping for coppice wood, ash handling, and the emissions stack
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that comes with solid fuel. These are the capex/opex adders that the
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biomass premium in the utilities CSV (roughly 4M to 7M THB for the boiler
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package vs 2.5M to 4M electric/gas) partially reflects; fuel handling and
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storage are additional.
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## Decision framing
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- Biomass makes the steam genuinely renewable and pairs with cheap northern
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fuel, at the cost of higher capex, fuel logistics, ash, and an emissions
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point
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- The 60 rai tilts the economics and the story further toward biomass, but
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only after the land-title check clears
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- The electric boiler remains the alternative: cleanest permitting, no fuel
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logistics, but effectively grid-powered steam at a ~520 to 625 kW draw
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for the five presses. On PEA's time-of-use tariff that costs ~5.2M to
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6.0M THB a year at mature load against ~0.6M to 1.2M of fuel for
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biomass, and ~1.6M to 1.8M (one 500 kg/h module) against ~0.15M to 0.3M at early load, because the demand charge follows
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the boiler's full-power draw (estimates; see the
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[grid tariff](sustainability.md#grid-tariff-pea-and-what-it-decides)).
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The electric boiler is the more efficient machine; biomass is the far
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cheaper heat
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- A staged path is possible: start electric (fast, clean permitting), plant
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the coppice now (first harvest in 2 to 4 years), and add the biomass
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boiler at the automated-line expansion when demand and the fuel supply
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have both matured. At the tariff above that is a permitting and logistics
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choice, not a cost one: every year on electric steam costs roughly 1.4M
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to 5.4M THB more than biomass, so the switch should come as soon as the
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permit and a fuel contract are in place
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