Case Study: NaOH 45% — Save 29% on Transport Costs for a Bac Ninh Paper Mill
Table of contents
TL;DR: NaOH 45% contains 450 kg of pure NaOH per ton of solution — 1.4x that of NaOH 32% (320 kg/ton). Shipping one 15-ton tanker of NaOH 45% is equivalent to 21 tons of NaOH 32% in active content, reducing transport costs and CO₂ emissions by 29%. Case study from a paper mill in Bac Ninh Industrial Park supplied by Loc Thien.
How NaOH Concentration Affects Transport Costs
Liquid NaOH comes in several commercial concentrations: 32%, 45%, and 50%. The difference isn’t just in solution price — it’s in logistics cost per kg of pure NaOH.
NaOH 32% contains 320 kg of active NaOH per ton of solution. The remaining 680 kg is water. When you order a 15-ton tanker of NaOH 32%, you’re paying freight for 15 tons of solution — but only receiving 4,800 kg of actual NaOH. The rest is water that could have been handled at the production plant.
NaOH 45% changes this ratio. Each ton of solution contains 450 kg of NaOH — the water fraction drops from 68% to 55%. A 15-ton tanker of NaOH 45% holds 6,750 kg of actual NaOH.
Direct conversion ratios:
- 1 ton of NaOH 45% = 1.406 tons of NaOH 32% (by active content)
- 1 × 15-ton tanker of NaOH 45% = 21.09 tons of NaOH 32%
- Savings: 29% on transport costs
The 29% figure comes from the calculation: (21.09 - 15) / 21.09 = 0.29. In other words, to receive the same amount of NaOH, you need to transport 29% less solution mass when choosing NaOH 45%.
Transport Cost Comparison Table: NaOH 32% vs 45%
| Metric | NaOH 32% | NaOH 45% | Difference |
|---|---|---|---|
| NaOH content per kg solution | 320 g | 450 g | +40.6% |
| Specific gravity (20°C) | 1.348 g/ml | 1.478 g/ml | — |
| Solution mass needed for 1 ton pure NaOH | 3,125 kg | 2,222 kg | -28.9% |
| Truck trips needed for 100 tons pure NaOH | ~20.8 trips (15 ton) | ~14.8 trips (15 ton) | -28.9% |
| Transport cost per ton of pure NaOH | Highest | 29% lower | — |
Not just freight savings — fewer shipments also mean less warehouse paperwork, less pump wait time, and lower safety risk.
Real-World Case Study: Bac Ninh Paper Mill
Background
A Kraft packaging paper mill in Dai Dong — Hoan Son Industrial Park (Tien Du, Bac Ninh) has an annual capacity of 120,000 tons of paper. The Kraft pulping process uses white liquor containing NaOH and Na₂S at 160–170°C. NaOH consumption ranges from 300–500 kg/ton of pulp, equivalent to approximately 50–70 tons of pure NaOH per month.
Initially, the mill used NaOH 32% from another supplier, citing “being used to the old grade” and “fear of changing storage tanks.” They ordered 3–4 tanker truck loads (15 tons each) per week, transported from the supplier’s warehouse in Hai Phong.
Problems
- High transport costs: Freight was a major monthly expense, yet 68% of the truck’s mass was water.
- Delivery pressure: With only 2 × 30 m³ storage tanks, the mill had to place frequent orders — sometimes 4 trips per week. A single delayed shipment risked raw material shortage.
- CO₂ emissions: Each tanker trip from Hai Phong to Bac Ninh (~120 km) emits approximately 110 kg CO₂ (per Ministry of Transport calculations). 15 trips/month = 1.65 tons CO₂ — just from NaOH transport.
Solution: Switch to NaOH 45%
Loc Thien was contacted by the mill through a referral — the mill’s QC department had previously worked with Loc Thien at their former company. Loc Thien technicians (including QC technician Phan Cam Thuy, responsible for quality inspection) conducted an on-site tank infrastructure survey:
- Existing storage tanks: 2 × 30 m³ FRP composite tanks — fully compatible with NaOH 45% (FRP resists alkali up to 50% concentration at temperatures below 50°C). No tank replacement needed.
- Dosing pump: Current flow range of 5–15 m³/h is sufficient for the smaller NaOH 45% volume (~30% less than NaOH 32% for the same active content).
- Heating: The mill is in Bac Ninh, where winter temperatures can drop to 8–12°C — near the freezing point of NaOH 45% (about 6–7°C). Solution: insulate tanks and piping, install automatic electric heating for storage tanks. The investment paid back within 2 months from transport savings.
Results After 6 Months
| Metric | Before (NaOH 32%) | After (NaOH 45%) | Change |
|---|---|---|---|
| Truck trips/month | 14–16 trips | 10–11 trips | -31% |
| Transport volume/month | 210–240 tons | 150–165 tons | -29% |
| Transport cost/month (index) | 100 | ~71 | -29% |
| CO₂ emissions/month | ~1.65 tons | ~1.17 tons | -29% |
| Required tank storage area | Higher | 29% lower | — |
| Stock-out risk | High (4 trips/week) | Low (3 trips/week) | Improved |
The mill cuts its annual transport costs by about 29% from freight alone, not to mention reduced inventory management pressure and 5.7 fewer tons of CO₂ emissions annually.
Operational Adjustments
When switching concentrations, the mill needed to recalibrate dosing pump volumes. For the same amount of pure NaOH, the volume of NaOH 45% required is 71% that of NaOH 32% (2,222 L vs 3,125 L for 1 ton of pure NaOH). Loc Thien’s QC team — technician Vo Thi Nhu Hoa — monitored the initial delivery batch, confirming cooking liquor pH remained stable at 13.5–14.0 after adjustment.
Which Factories Benefit from NaOH 45% Transport Savings?
The case study shows clear benefits when 3 conditions are met:
- Consumption above 5 tons of pure NaOH/month: Above this threshold, the reduction in truck trips is large enough to offset insulation/heating investment.
- FRP or HDPE storage tanks: Most existing composite tanks tolerate NaOH 45%. Epoxy-lined or plastic-lined carbon steel tanks are also compatible. Unlined carbon steel tanks — not recommended for concentrations above 32% due to alkaline corrosion.
- Cold-weather crystallization solution: For factories in Southern Vietnam (temperature >20°C), no heating needed. For Northern factories, tank insulation and light heating are required.
Environmental Benefit: 29% CO₂ Reduction
In the context of export factories needing ESG reporting and Scope 3 emission reductions, switching NaOH concentration is a low-capital logistics solution with clear impact. For the Bac Ninh paper mill, 5.7 tons of CO₂/year saved from transport — equivalent to planting 260 trees (per IPCC coefficients).
NaOH 45% Technical Specifications — Loc Thien
| Parameter | Value |
|---|---|
| Trade name | Liquid Caustic Soda NaOH 45% |
| Chemical formula | NaOH |
| CAS number | 1310-73-2 |
| Concentration | 45% ± 1% (per batch COA) |
| Specific gravity (20°C) | 1.478 g/ml |
| Freezing point | About 6–7°C (per batch COA/TDS) |
| Boiling point | ~130°C |
| Packaging | 200L Drum / 1000L IBC / Tanker 5–30 tons |
Every Loc Thien shipment comes with a COA (Certificate of Analysis) confirming actual concentration — no deviation. This gives the mill a precise basis for calculating required NaOH volume, avoiding chemical waste and output pH deviation.
Technical Support & B2B Procurement Hotline
Loc Thien Chemical specializes in direct manufacturing of FeCl₂ / FeCl₃ and direct industrial supply of basic chemicals (NaOH, HCl, H₂SO₄, PAC, NaOCl, H₂O₂, FeSO₄) with direct B2B pricing and dedicated 5–30-ton tanker delivery across Vietnam.
- Hotline / Zalo: +84 979 891 929
- Official Email: [email protected]
- Direct Manufacturer: Ferrous Chloride (FeCl₂ 30%) & Ferric Chloride (FeCl₃ 38–40%)
- Primary Supplier: NaOH 32%/45%/50%/99%, HCl 32%, H₂SO₄ 98%, PAC 30–31%, NaOCl 10–12%, H₂O₂ 35%/50%
- Compliance & Quality: FeCl₂ ZDHC MRSL v3.1 test report (Smart testing, 5 substance groups, TUV Rheinland Vietnam), ISO 9001:2015, Quatest 3, Full COA & GHS SDS
FAQ
Is NaOH 45% harder to store than NaOH 32%?
Only slightly in terms of crystallization. NaOH 45% begins to crystallize at about 6–7°C, close to NaOH 32% at about 5°C (a 31–33% batch can start anywhere from about 2 to 8°C), so tank and pipe insulation is advisable for either grade if the factory is in Northern Vietnam; it is NaOH 50% (about 12°C) that clearly needs more heating. Southern factories (temperature >20°C) need no changes. Reference figures follow the NaOH–H₂O phase diagram and technical literature from caustic soda producers; the actual crystallization point depends on each batch’s concentration per its COA/TDS.
Do I need to change storage tanks when switching from NaOH 32% to 45%?
No, if the existing tank is FRP, HDPE, or epoxy-lined steel. Unlined carbon steel tanks require a specific assessment. Loc Thien sends a technician for a free site survey before conversion.
Does the 29% transport cost saving apply to all distances?
Yes. The 29% ratio is fixed, independent of distance — because it stems from reduced solution mass, not the freight rate. The farther the distance, the larger the absolute savings.
What is the payback period for heating equipment investment?
For factories consuming >5 tons of NaOH per month, insulation + heating costs are typically recouped within 2–3 months through transport savings.
Where to buy bulk NaOH 45%?
Loc Thien supplies NaOH 45% from 6 warehouses nationwide (Ba Ria – Vung Tau, Dong Nai, Binh Duong, Da Nang, Can Tho and Bac Ninh), delivered by a fleet of dedicated tanker trucks. Call 0979 891 929. QC is handled by Phan Cam Thuy and Vo Thi Nhu Hoa; quote within 15 minutes, with batch COA/MSDS.
🛒 Need NaOH 45%? Get a Quote for Liquid NaOH 45% — Batch COA/MSDS, delivered nationwide. Hotline 0979 891 929.
Hotline
Call 0979 891 929 (0979891929) — contact Phan Cam Thuy or Vo Thi Nhu Hoa (QC Department) for consultation on the right concentration switch for your plant infrastructure. Quote within 15 minutes, batch COA/MSDS, delivered to industrial parks nationwide.