Linde Engineering Dresden Breathes New Life into Carbo-V Technology

We’ve discussed in previous blog posts how the broad definition of ‘gasification’ covers many diverse processes with different end goals.  These various processes can have different benefits and costs, but the distinction is ultimately at the chemical level. The sophisticated manipulation of the chemical process used in the Carbo-V Technology has particularly held our interest since Linde Engineering Dresden announced it was licensing the technology for use in a Biomass-to-Liquid (BtL) plant last week.

Courtesy: Linde Engineering Dresden; Biomass Energy.

Carbo-V Technolog is described as a multi-stage gasification processes that was originally developed by CHOREN Industries, and acquired by Linde in February 2012 after CHOREN went bankrupt. The subsidiary of The Linde Group announced it was licensing the technology to Finnish Forest BtL for use in a 480 MW plant to be built in Kemi, Northern Finland and is expected to be operational by the end of 2016.

 The Carbo-V Technology claims to have overcome the tar and methane obstacles that frequently prohibit syngas from being used in Fischer-Tropsch applications for the production of synthetic fuel. The multi-stage process appears to use a sophisticated form of partial oxidation while borrowing elements from steam reformation and re-injecting carbon into the gas cleanup cycle.

Feedstocks suitable for the Carbo-V Technology include rice husks, wood chips, lumber and other wood residues. Process heat is used to dry the feedstock to 15 percent water content before passing it through a low-temperature gasifier (400-500 degrees Celsius), where the biomass is thermally broken down into volatile gases and solid bio-coke or char. At the same time, a mixture of O2/CO2 and steam is injected into the chamber.

A drawing of the Carbo-V Process by CHOREN. 

In the next stage, the partially deconstructed biomass is sent through a partial-oxidation combustion chamber that reaches 1400 degrees Celsius to continue breaking down the tar and long chain C-H molecules. The char that has resulted from the first stage is ground to powder and blown into the hot exit gases below the combustion chamber in a chemical endothermal quenching process that reduces the gas temperature almost instantaneously to approximately 900 degrees Celsius. This elimates unnecessary temperature cycling of the char and improves Carbo-V’s cold gas efficiency.

The resulting syngas is fed through a Fischer-Tropsch process to convert the carbon monoxide and hydrogen into hydrocarbons. CHOREN’s white paper says that the syngas may contain small traces of contaminants that could be harmful to sensitive Fischer-Tropsch catalysts and says they do use scrubbers before compressing the syngas for the Fischer-Tropsch reactor they used when producing SunFuel, before declaring bankruptcy in 2011.

BETTER BTU TAKE: The Carbo-V Technology is a unique manipulation of the traditional partial-oxidation process. In this tricky economic environment, companies may falter, but a good technology will ultimately survive and it looks like Linde Engineering Dresden is breathing new life into this technology with its announcement of the licensing agreement with Finnish Forest BtL. Our only concern is that a 480 MW plant will require 1.5 million tons of wood to produce its projected 130,000 tons of biodiesel and naptha. The project is being funded by the European Union’s NER300 for innovative, low-carbon technologies and we’ll continue to monitor the project and bring you updates on our project blog.

Recommended Reading:

Linde and Forest BtL Sign Licensing Agreement for Carbo-V Techonolgy – The Linde Group (Jan. 24, 2013)

Linde Buys CHOREN’s Carbo-V Technology – Renewables International, The Magazine (Feb. 15, 2012)

Sustainable SunFuel from CHOREN’s Carbo-V Process – By Tom Blades, Matthias Rudloff and Olaf Schulze, CHOREN Industries (Sept. 2005)project blog