cnx_vinyl/docs/sustainability.md

Sustainability

Two commitments are fixed design requirements for this plant, not aspirations to be traded away during engineering: run on as much renewable energy as possible, and discharge no contaminated water. Both are decisions we can actually make, because the two biggest utility systems (steam and cooling) are explicitly excluded from the Newbilt scope and will be sourced and installed locally in Thailand. That gives us a free hand to spec them green from day one.

Renewable energy: large solar installation

The pressing machinery itself is a modest electrical load: 32 kVA connected, ~21 kW average for a full Duplex line. The real energy demand sits in the utilities around it, above all the steam generator (400 kg/h saturated steam at 10 bar / 180 °C) and the 250 kW cooling system.

• A large rooftop/ground PV installation is planned. Northern Thailand's solar irradiance is favorable, and daytime-heavy production shifts align well with PV output.
• The chosen hardware direction: multiple large Deye three-phase hybrid inverters (30 to 80 kW class, parallelable up to 10 units) paired with a Gobel Power high-voltage LiFePO4 battery stack at 271 kWh (15 stacked 18 kWh packs, LFP 314 Ah cells, rated 8000+ cycles). Deye is an officially supported protocol on the Gobel BMS, and Deye has established Thai distribution. Two engineering checks are open: matching the battery rack's DC voltage window to the specific Deye model (a full 15-pack rack can exceed the 800 V window of the smaller Deye series), and obtaining Gobel's safety certifications (not published) for a Thai commercial install. At 271 kWh the stack is a peak-shaving and ride-through buffer, not full off-grid autonomy, against loads like the 250 kW cooling system.
• The machine load and cooling system are straightforward PV targets.
• Steam is the open engineering question. Options under evaluation include an electric boiler (maximizes the solar share), a biomass boiler (locally abundant fuel), and solar-thermal pre-heating of boiler feedwater. No technology choice has been made yet; it will be driven by honest numbers on load profiles, storage, and grid backup, not by what sounds greenest.
• Whole-factory HVAC (continuous temperature, humidity, and PM control, see facility systems) adds a major tropical-climate load on top of process cooling and must be part of the PV and battery sizing.
• System sizing (kWp, storage, grid-connection model) is open until the site is chosen.

Energy efficiency architecture: recover before generating

The deepest efficiency in this plant comes from its own thermodynamics: the steam's job is to heat the molds, and the cooling water's job is to remove that same heat again, so roughly 98% of the 250 kW cooling load is heat leaving the press molds, put there almost entirely by the steam, and the press cooling return exits at ~60 °C. That warm return is a premium heat source, and the architecture is built around reusing it before generating anything new:

• Feedwater heat recovery: a water-to-water heat pump lifts the 60 °C press cooling return into boiler feedwater at 90 to 95 °C. Each kWh it consumes does double duty: it cuts the boiler's work and removes load from the chiller at the same time. Together with condensate return, this saves roughly 10 to 15% of steam energy while shrinking the cooling system.
• Waste heat for low-grade consumers: the label dry oven and HVAC dehumidification reheat (the 35 to 60% RH spec means air is cooled below dew point and reheated continuously) run on recovered press heat instead of fresh electricity.
• Solar thermal feedwater preheat: flat-plate or evacuated-tube collectors reach 60 to 90 °C trivially in the Thai sun; cheap, proven, and stackable with the heat pump recovery.
• Steam accumulator: the presses draw steam in bursts, so an accumulator (already a Newbilt option) lets a smaller boiler ride the peaks.
• The boiler only does the final lift: whichever technology is chosen (electric, LPG, or biomass), it supplies just the last step to 180 °C / 10 bar from already-hot feedwater.

Two honest exclusions, checked and ruled out:

• Heat pumps cannot make the final steam: commercial steam-generating heat pumps top out around 120 to 165 °C at lower pressures than the fixed Newbilt spec of 10 bar / 180 °C; hybrid heat-pump-plus-compression systems exist as industrial pilots, but core utility reliability is the wrong place to pioneer.
• Ground-source (earth temperature) does not work in tropical Thailand: the ground sits at 28 to 30 °C year-round, far too cold to be process heat and warmer than the 20 to 25 °C cooling loop wants, so boreholes help neither side. That budget is better spent on PV panels.

Fuel-side context for the boiler choice: there is no natural gas pipeline in northern Thailand, so gas firing means an on-site bulk LPG tank (roughly 2.5 to 5 tonnes, with hazardous-storage separation distances and licensing), and diesel means a fuel tank with price exposure. The electric and biomass paths avoid a fossil tank on the property entirely, which matters for both the sustainability commitments and the BOI story.

Zero contaminated water

The reference process schematic shows a conventional open "dirty water" cooling loop. We will not build it that way.

• Cooling (up to 250 kW, 220 l/min peak, roughly 98% of it mold cooling) will run as a closed loop with a cooling tower/chiller, so process water is recirculated rather than discharged.
• Steam condensate will be recovered and returned to the treated feedwater cycle instead of being dumped.
• The planned in-house galvanics line (silvering and stamper electroforming) involves plating chemistry: silver solutions and nickel baths. This is the hardest part of the zero-discharge commitment. Rinse water will need closed-loop treatment and metal recovery, designed in from the start rather than retrofitted.
• Solvent handling (flagged in the site requirements) will be contained and disposed of as controlled waste, never via wastewater.
• Target: no process-water discharge to the local environment. Detailed water balance and treatment design are pending site selection.

Materials

The plant design already includes a PVC recycling loop: an in-house grinder returns trimmings and rejects to the extruder, with the standard feed mix at 80% virgin / 20% recycled compound. Record scrap becomes feedstock, not landfill.

For the virgin compound itself, the preference is local (Thai/regional) PVC sourcing if the quality meets vinyl-record specifications. The current supplier list (2021) is almost entirely European, with one US option; qualifying a local compound would cut shipping distance, cost, and the carbon footprint of the feedstock. European suppliers remain the fallback where quality demands it.