Light hydrocarbon analysis and sales conditions

Introduction to Light Hydrocarbons

As mentioned in the article “What is a Light Hydrocarbon,” light hydrocarbons are those that contain 5 to 12 carbon atoms in their carbon chain. These hydrocarbons are derived from various sources and are not exclusively extracted from crude oil. In addition to crude oil, natural gas, gas condensates, and even biomass are among the sources that can produce light hydrocarbons. These compounds play a crucial role in various refining and petrochemical processes, contributing to the production of light fuels, solvents, and petrochemical feedstocks.

Light Hydrocarbon Analysis

Light hydrocarbon analysis is a process through which the various compounds present in a sample, including the percentage of different hydrocarbons and other substances affecting fuel quality, such as mercaptans (sulfur compounds) and density, are examined and identified. This analysis helps producers and specialists determine the quality of the hydrocarbons and their suitable applications.

Key Indicators of Light Hydrocarbon Analysis

Flash Point

The flash point is the temperature at which a liquid, such as hydrocarbons, produces enough vapor to ignite. At this temperature, if a spark or flame comes close to the liquid, it will catch fire. Simply put, the flash point indicates the temperature at which a liquid can ignite. The flash point is a crucial factor in assessing the hazard level of the hydrocarbon in question and helps determine the necessary safety guidelines for transportation, storage, and usage. Understanding these characteristics can prevent accidents such as fires and explosions.

One of the recognized standards for measuring the flash point is ASTM D93. This standard uses the closed cup method, where the liquid sample is heated in a sealed chamber, and the temperature at which the vapor ignites when a spark is introduced is recorded.

Density

Density is one of the key physical characteristics in the analysis of both light and heavy hydrocarbons, referring to the mass of a substance relative to its volume. The density of light hydrocarbons is usually expressed in grams per cubic centimeter (g/cm³) or kilograms per cubic meter (kg/m³). It helps classify petroleum products like gasoline, diesel, and crude oil, and plays an essential role in determining the energy content per unit volume of fuel. Additionally, density is crucial for accurate calculations in transportation and storage, aiding in the conversion between weight and volume. Furthermore, it assists in evaluating the flammability risks of materials and setting safety conditions for their transport and storage.

The density of hydrocarbons and petroleum liquids is commonly measured using standards such as ASTM D1298 (hydrometer method) or ASTM D4052 (digital density meter method).

Mercaptan Content

Mercaptan is a sulfur compound with a very strong odor. A high level of mercaptans in light hydrocarbon analysis indicates lower product quality. Additionally, elevated mercaptan content can lead to problems such as equipment corrosion, reduced fuel efficiency, and increased emissions of environmental pollutants, including sulfur dioxide.

To determine the mercaptan content in petroleum products, ASTM D3227 is used. This standard outlines the potentiometric titration method for measuring the amount of mercaptans in light hydrocarbons and other petroleum products.

Sulfur

Sulfur naturally occurs in crude oil, natural gas, and many hydrocarbon products. The combustion of sulfur leads to the production of sulfur dioxide, a pollutant gas. Additionally, sulfur compounds have corrosive properties and can damage refinery equipment and pipelines. Reducing sulfur content in fuels is crucial not only from an environmental standpoint but also for increasing equipment lifespan and improving vehicle engine performance.
Various standards exist for measuring sulfur content. ASTM D4294 uses the X-ray fluorescence method, ASTM D5453 employs combustion with UV fluorescence, and ASTM D2622 utilizes high-resolution X-ray fluorescence.

Aromatics

In light hydrocarbon analysis, aromatics refer to hydrocarbons that contain benzene rings or structures similar to benzene. Aromatics increase the octane number of fuel, which enhances fuel performance in gasoline engines. However, due to their carcinogenic properties and the production of harmful pollutants during combustion, many national and international standards have set limits on the amount of aromatics in fuel to mitigate their negative effects on health and the environment.
To determine the amount of aromatic compounds, ASTM D1319 and ASTM D5186 are commonly used.

Distillation Range

The distillation range refers to the temperature at which different components of a hydrocarbon mixture, such as crude oil or fuel, begin to evaporate and separate. This range spans from the lowest to the highest distillation temperature. The distillation range should neither be too high nor too low. For light fuels like gasoline, the distillation range should be balanced and appropriate to ensure proper evaporation and optimal combustion. For heavier fuels, a broader distillation range is more suitable to allow the fuel to perform better at higher temperatures. Compliance with fuel standards is also essential in determining the appropriate distillation range.

The ASTM D86 standard is used to determine the distillation range. In this method, the liquid sample is gradually heated so that its different components evaporate and distill at varying temperatures. The temperatures at which 10%, 50%, and 90% of the sample distill are key points used to assess fuel quality and determine the distillation range.

Light Hydrocarbon Sales Procedure

• Prepayment Deposit: The buyer must deposit 10% of the total transaction value as a prepayment no later than one hour before the start of the offering.
• Exchange Rate for Prepayment: The exchange rate for the prepayment is determined based on the average purchase and sale rate of the US dollar in the Currency Monitoring System (SANA), owned by the Central Bank of the Islamic Republic of Iran, two business days prior to the offering.
• Exchange Rate for the Transaction: The exchange rate used to calculate fees and the provisional value of the transaction will be the average purchase and sale rate of the US dollar in the SANA system on the business day before the transaction.
• Prepayment Refund: After the final settlement and deduction of legal fees, the prepayment amount will be refunded to the account designated by the buyer.
• Settlement Time: The settlement is conducted through off-exchange documents in accordance with the rules and regulations of the Clearing House and the executive instructions of the export ring of the Iran Energy Exchange. The declaration and issuance of the goods will be in the name of the buyer, under their responsibility.
• Declaration of Export Destination: The buyer must declare the export destination. Exports are only allowed through authorized customs borders.
• Goods Delivery: The goods will be delivered at the factory, and after delivery, the seller bears no responsibility for transportation or how the product is used.
• Customs Permits: The buyer is responsible for obtaining customs permits at the destination, while the customs declaration remains the seller’s responsibility.
• Non-transfer of Delivery Rights: The buyer does not have the right to transfer delivery rights to another party and must be personally present, or send the designated carrier, to the delivery site.
• Goods Pickup Deadline: The buyer must collect the goods within 30 calendar days of the transaction date. Failure to collect the goods on time allows the seller to cancel the remaining quantity and charge a penalty of 5.2% of its value.
• Tanker Weighing: Tankers must undergo initial and secondary weighing at the scale according to Iranian customs regulations and obtain the necessary permits for loading.
• Product Complaints: Any complaints about the delivered product must be raised in accordance with the Energy Exchange’s guidelines.

Kian Petroleum is not a producer of light hydrocarbons, but if you intend to purchase this commodity from the export ring of the Energy Exchange, Kian Petroleum offers comprehensive services, including specialized consultation, facilitation of administrative and legal procedures, continuous support, and provision of market reports and analysis for the purchase of light hydrocarbons from the international ring of the Energy Exchange.