A pyrolysis oil transfer and metering system is designed from samples and laboratory analysis of the oil the plant will actually handle, not from a single typical product definition. Oil sold under the same name can come from biomass, end-of-life tires or plastic waste and from very different process conditions, so viscosity, water content, solids, acidity and odor vary from one plant to the next. Every decision on pumps, filters, meters and materials follows from that variability.
Why there is no single pyrolysis oil
Bio-oil from fast pyrolysis of biomass is the most thoroughly documented type. According to IEA Bioenergy, it typically contains 20–30 wt% water, has a pH of 2–3 and a viscosity of about 15–35 cSt at 40 °C, against 3.0–7.5 cSt quoted for fuel oil in the same source. It is corrosive, does not mix with petroleum oils and ages over time as its viscosity rises. Corrosion studies also note that total acid numbers of 90–100 are common in biomass pyrolysis oils.
Existing product specifications (ASTM D7544 and EN 16900) cover biomass-derived pyrolysis liquids only. No verified product specification for tire- or plastic-derived pyrolysis oils was identified in this work. For those oils the design inputs rest entirely on analysis of the product itself, and feedstock-related impurities such as sulfur, chlorine and metals should be considered for the analysis program.
Design inputs come from the laboratory
Analysis parameter | Why it matters | Effect on design |
Viscosity and its temperature dependence | Sets pumpability and pressure drop across the meter | Pump type, line size, heating need |
Water content and phase behavior | A separate phase can form in storage | Tank draw-off point, sampling, metering approach |
Solids | Cause wear and plugging in pumps and narrow passages; sludge can build up in tank bottoms | Filtration stages, meter selection, cleaning access |
Acidity (pH, total acid number) | Accelerates corrosion, especially at elevated temperature | Wetted-part and gasket materials |
Density | Links mass and volume | Metering basis and meter technology |
Thermal stability | Overheating can permanently degrade the product | Heating method and upper temperature limit |
Flash point and volatiles | Feed hazardous-area and vapor management decisions | Protection method for electrical equipment, ventilation and odor control |
The biomass pyrolysis liquid specification tests heat of combustion, water, solids, kinematic viscosity, density, sulfur, ash, pH, flash point and pour point. That list is a useful starting point for an analysis plan even for oils from other feedstocks. Where and how the sample is taken matters as much as the result itself; EN 16900 treats sampling and materials compatibility in a separate annex.
Heating: needed, but limited
Like heavy oil, pyrolysis oil can be made more fluid by heating, but not with the same freedom. IEA Bioenergy notes that biomass bio-oil heated to 100 °C or more reacts rapidly and eventually leaves a solid residue of about half the original liquid by weight. The heating method and upper temperature limit are therefore set from the product's thermal stability data; heating habits from heavy oil and fuel oil plants do not carry over directly.
Transfer and metering points in the plant
· Truck loading: Filtration, product homogeneity and odor control as product leaves the site.
· Truck unloading: Acceptance sampling, stratification in the truck and unloading pump selection.
· Metering skid: Meter technology for a product of variable composition and use of density data.
· Heated transfer: Defining the heating window and line heating architecture.
· Batch metering: Batch-based sampling, records and traceability to the buyer.
· Tank-to-tank transfer: Transfer between intermediate and settling tanks and level reconciliation.
TLY Enerji's approach
Depending on project scope, TLY Enerji can support engineering review of product analyses, selection of metering technology and materials, supply of measurement and control equipment, valves and pumps, integration, installation and commissioning. For pyrolysis oil plants, the supply boundary and design inputs are agreed together on the basis of the product data shared by the operator.
Pyrolysis oil solutions
· Pyrolysis oil truck loading systems: Managing variable product properties on the loading line.
· Pyrolysis oil truck unloading systems: Checks at receipt and unloading arrangement.
· Pyrolysis oil metering skids: A reliable metering approach for oil of variable composition.
· Heated transfer systems for pyrolysis oil: How much and how to heat.
· Batch metering systems for pyrolysis oil: Batch-based measurement and traceability.
· Tank-to-tank transfer skids for pyrolysis oil: Setting up in-plant transfers between tanks.
· Heavy oil and fuel oil facilities: Temperature management and equipment for viscous products, and how pyrolysis oil differs.
Frequently asked questions
Can pyrolysis oil be handled with fuel oil equipment?
That should not be assumed. Biomass pyrolysis oil is acidic and corrosive, does not mix with petroleum oils and can degrade permanently if overheated. Carbon steel wetted parts, gaskets and heating arrangements chosen for fuel oil may therefore be unsuitable. For tire- or plastic-derived oils, suitability is likewise decided through product analysis and a materials compatibility review.
Which analyses should we request for design?
At minimum: viscosity versus temperature, water content, solids, density, acidity (pH and total acid number), flash point, pour point and thermal stability. For tire- and plastic-derived products, feedstock-related impurities are added to the program. Basing the analysis on several samples that reflect normal production variation, rather than on a single sample, makes the design more robust.
Can biomass specifications be used for tire pyrolysis oil?
ASTM D7544 and EN 16900 cover only pyrolysis liquids made from biomass; they do not define tire- or plastic-derived oils. Their test parameters can guide an analysis plan, but their limit values should not be applied to products from other feedstocks. For those oils, design rests on the product's own analysis results and on the contract terms agreed with the buyer.