Process Calorimeter applications: Wobbe Index, LHV – Lower Heating Value, CARI

Process Calorimeter applications have been a TECNOVA HT hallmark since 1994, thanks to successful partnerships with major players in the steel and power generation industries. This analytical system primarily serves three major sectors:

• Optimization of gas turbines powered by raw gas or tail gas
• Steel plants recovering process gases such as COG (Coke Oven Gas) and mixing them with makeup gas to be burned as fuel gas
• Gas production and pressurized gas cylinder filling plants

The goal in all cases is to achieve energy savings and consumption reduction, contributing to greater industrial energy efficiency.

To operate correctly, all these applications require the installation of an analytical instrument capable of measuring:

• LHV (Lower Heating Value)
• Wobbe Index
• Relative Density of the gas
• CARI (Combustion Air Requirement Index)

The Wobbe Index provides insight into the interchangeability of gases, ensuring a consistent energy content regardless of changes in composition.
The CARI index tells us the air volume needed for complete (stoichiometric) combustion – when the feed gas is fully oxidized or burned.

What are the advantages of the Process Calorimeter over conventional Gas Chromatographs (GC) used in the field?

• Faster response time – just a few seconds compared to minutes for a GC, making it ideal for gas turbines
• Complete sample combustion – providing full analysis, not just the main components as GCs typically do
• Thermal measurement principle – no catalyst degradation or column deterioration over time, hence less drift

Process Calorimeter solutions are customizable based on:

• Plant requirements (hazardous area or not)
• Environmental conditions (need for heated or airconditioned enclosure)
• Geographic destination (CE, FM, ATEX or UL certified items)

You’ll find:

• Standalone Process Calorimeters with air fans in case of no dedicated air network
• Integrated Process Calorimeters in airconditioned enclosures
• Process Calorimeters for Hazardous Areas in pressurized EEX p cabinets certified for ATEX or NEC depending on the destination

Applications Without Integration – Steel Industry

In this context, dirty and sticky gases like COG or BFG (Blast Furnace Gas) must be handled, so engineering focuses on sample conditioning and treatment to avoid fouling. This schematic shows how the calorimeter feedback to the air valve to always produce fuel gas for furnaces to spec. Cleaner gases like LPG can also be used for this purpose.

Wobbe Index Applications – Steel Sector

These setups are customized for engineering companies and clients in the steel industry – even in China, India, and Vietnam. For example, a doubledoor cabinet, convenient for maintenance, fully airconditioned, installed in a steel mill in Southeast Asia. Commissioning, startup, and training are always handled by our Service Division.

Oil & Gas and Turbogas Sector

Applications here focus on optimizing lowBTU raw gas extracted from fields. This gas is mixed with richer, more valuable gas before combustion in turbines. If not monitored quickly and accurately, two major problems can arise:

• A too lean mix could slow down the turbine and reduce power generation
• A too rich mix might cause a turbine trip due to overspeed

As shown below, the two gas streams are first analyzed individually for their LHV values. Then, the mixed gas is analyzed to confirm if the resulting LHV is within specification before preheating and turbine feed.

PFD Example – Continuous Wobbe Index Analysis in BTU

This process diagram illustrates realtime monitoring of the Wobbe Index in BTU.

Hazardous Area Installations

For Oil & Gas, we provide hazardous area shelters certified EEX p, and based on the final destination: ATEX, IECEx, or NEC standards. Some installations include:

• QAFCO – Qatar
• Sakhalin – Russia
• Gorgon – Australia
• Porto Marghera – Italy
• LNG Plant – Qatar
• Cove Point Dominion – USA

From FAT to SAT and subsequent training, our Service Division is available 24/7/365 for international field operations.

In both the steel and oil & gas sectors, our solutions deliver substantial energy savings and consumption reduction, boosting overall industrial energy efficiency.

Process Calorimeter applications – Tecnova HT Service Division

Call us for more informations about Process Calorimeter applications and you will discover the strength of those who make facts their creed. At your service. Follow us also on Linkedin.