Biomass to Liquids (BtL)

View SPM4 Presentation by Ingvar Landälv on status of selected thermochemcial demonstration projects (740 Kb PDF 14-11-09)

Introduction

The term BtL is applied to synthetic fuels made from biomass through a thermo chemical route. The objective is to produce fuel components that are similar to those of current fossil-derived petrol (gasoline) and diesel fuels and hence can be used in existing fuel distribution systems and with standard engines. They are also known as synfuels.

Although the processes for production of BtL are well known and have been applied using fossil-feedstocks, such as methane (GtL) or coal, commercial biofuels based on these technolgies are not currently widely available in the market place. However, BtL R&D&D in Europe is gathering momentum.

UPM announces world's first biorefinery for production of biodiesel from wood

On 1 February 2012, UPM announced it is to invest in a biorefinery producing biofuels from crude tall oil in Lappeenranta, Finland. The industrial scale investment is the first of its kind globally. The biorefinery will produce annually approximately 100,000 tonnes of advanced biodiesel. Construction of the biorefinery will begin in the summer of 2012 at UPM’s Kaukas mill site and be completed in 2014. UPM’s total investment will amount to approximately EUR 150 million. UPM has not applied for a public investment grant for the project.

UPM’s advanced biodiesel, UPM BioVerno, will decrease greenhouse gas emissions of transport up to 80% in comparison to fossil fuels. The product’s characteristics correspond to those of the traditional oil-based fuels and highly complement today’s vehicles and fuel distribution systems.The construction of the biorefinery will offer work for nearly 200 people for approximately two years. When production commences, the biorefinery will directly employ nearly 50 people and indirectly about 150 people. [Source: UPM].

Choren industrial-scale BtL plant

Previously, the world's first commercial BtL Plant was under construction in Frieberg Saxony, utilising the Choren Carbo-V ® Process. Choren Industries filed for insolvency in July 2011. A new investor for Choren Components was announced in October 2011. Investors are now being sought to take forward two other businesses within the group.

The Choren Carbo-V ® Process

The Carbo-V® Process is a three-stage gasification process resulting in the production of syngas:

low temperature gasification,
high temperature gasification and
endothermic entrained bed gasification.

The Fischer-Tropsch (FT) process is then used to convert the synthesis gas into an automotive fuel SunDiesel®. The waxes formed during the FT synthesis are further processed using hydrocracking.

Choren BTL plant - reactor being delievered

The Choren website lists a number of advantages for SunDiesel®:

High cetane number and therefore much better ignition performance than conventional diesel fuel,
No aromatics or sulfur and significantly reduces pollutants from exhaust emissions,
Can be used without any adjustment to existing infrastructure or engine systems,
Largely CO₂-neutral.

SunDiesel® demonstration fuel station at Choren BTL plant

Presentation on Choren BtL plant from EBTP SPM2

The BioTfuel BtL demonstration project

BioTfueL is a joint project launched by five French partners and Uhde. BioTfueL aims to integrate all the stages of the BTL process chain and bring them to market. This involves the drying and crushing of the biomass, torrefaction, gasification, purification of the synthesis gas and its ultimate conversion to second generation biofuels using Fischer-Tropsch synthesis.

The project will use Uhde's proprietary PRENFLOTM™ gasification process with direct quench (PDQ). The procees can utilise a wide range of feedstocks, allows high energy efficiency and enables very pure synthesis gas to be produced.

The overall budget for the BioTfueL project is 112.7 million euro. The project includes the construction and operation of two pilot plants in France to produce biodiesel and biokerosene based on biomass gasification.The plants are scheduled to go into operation in 2012 [Source: Uhde GmbH].

CEA Bure Saudron Pilot Plant

In December 2009, CEA (Atomic and Alternative Energy Commission) France announced the construction of a pilot BTL plant in Bure Saudron. The plant will use 75000 tonnes per foresty and agricultural residues to produce ~23000 tonnes/year of biofuel (diesel, kerosene and naptha). The Bure Saudron project will add hydrogen during the synthesis stage to optimise the ratio with carbon monoxide [Source CEA].

NSE Biofuels Demonstration Plant

NSE Biofuels Oy - a joint venture between Neste Oil and Stora Enso has opened a BtL demonstration plant at Stora Enso’s Varkaus Mill in Finland. The output is 656 t/a from a 12 MW gasifier. As well as providing test data and operating experience, the plant will also reduce greenhouse gas emissions as wood-based gas from the plant will replace oil in the pulp mill’s lime kiln, making the Varkaus integrate virtually fossil fuel free. NSE Biofuels (in partnership with Foster Wheeler and VTT) is planning to develop a commercial production plant at one of Stora Enso’s mills with a projected output capacity of 100000 t/a and a potential launch date of 2016.

Presentation on the Neste Oil Stora Enso joint venture from EBTP SMP2

Stora Enso Neste Oil BTL demonstration plant

Bioliq Pilot Plant at Karlsrhue

Forschungszentrum Karlsruhe GmbH in partnership with LURGI GmbH is constructing a pilot plant (due 2016) for production of BtL and "gasoline type fuels". The three-stage process consists of flash pyrolysis, entrained-flow gasification, and synfuel production.

The Dutch Biorefinery Initiative (DBI)

In 2009, a demonstration facility will be initiated in the Port of Rotterdam by WUR and ECN with support from the Netherlands government. This will include a 10 MWth entrained-flow gasification based syngas production platform for heat and power, base chemicals and BtL. Information on this project is included in the IEA Bioenergy Task 42 publication on Biorefineries

BtL Facts and Figures

BtL fuels may be produced from almost any type of low-moisture biomass, residues or organic wastes such as short rotation trees, perennial grasses, straw, forest thinnings, bark from paper-pulp production, bagasse, waste paper or reclaimed wood or fibre based-composites.

It is estimated that over 4m³ of BtL-fuels can be produced per hectare of land per annum. Hence, in future if 4-6 million hectares of land were used to grow energy crops, one could replace 20-25 % of the liquid transport fuel currently used.

The advantage of the BtL route to liquid transport fuels lies in the ability to use almost any type of biomass, with little pre-treatment other than moisture control. This is because the feedstock is gasified in the first stage of the process. The gas produced is then treated further to clean it, remove tars, particulates and gaseous contaminants, and to adjust the ratio of the required gases (hydrogen and carbon monoxide) to that required. The result is a balanced syngas that can be used in the second, catalytic, stage. Syngas may also be obtained by pyrolysis to form charcoal. The hot charcoal is then reacted with steam to produce watergas.

The two main catalytic processes for BtL production are Fisher-Tropsch and the Mobil Process

Fisher-Tropsch

The Fischer-Tropsch process is a catalyzed chemical reaction in which carbon monoxide and hydrogen are converted into liquid hydrocarbons of various forms. Generally the catalysts used, for the following reaction, are based on iron and cobalt.

(2n+1)H₂ + n(CO) -> C_nH_2n+2 + nH₂O

The FT process is an established technology and is already applied on a large scale from coal or natural gas. Developed in the 1920s in Germany, it was used by both Germany and Japan during World War II and later by South Africa and to a lesser extent in the United States.

One problem is the high capital cost of the multistage process. This may be greater when biomass is used as feedstock, since the scale of operation may be limited by the distance over which biomass can be transported to the factory at an economic price. Hence, the economy of scale is decreased compared to a large coal or gas-based operation. Running and maintenance costs are also comparatively high.

Mobil Process

This is a two stage catalytic process. In the first stage LINK methanol is produced. The methanol is then used as feedstock to generate hydrocarbons of varying chain length, using a zeolite catalyst. In the conversion, a number of reactions take place in the gas phase. The conversion is initiated by the removal of water to produce dimethyl ether:

2CH₃OH(g) -> CH₃OCH₃(g) + H₂O(g)

This is followed by various other reactions in which further molecules of water are removed resulting in gradual increase in chain length.

These reactions include the following.

2CH₃OCH₃(g) + 2CH₃OH(g) -> C₆H₁₂(g) + 4H₂O(g)

3CH₃OCH₃(g) -> C₆H₁₂(g) + 3H₂O(g)

As a result of other dehydration reactions occuring in parallel a mixture of hydrocarons is produced of which about 80% is suitable for petrol production. The mixture contains (w/w) around 50% highly branched alkanes, 12% highly branched alkenes, 7% cycloalkanes and 30% aromatics. This process has been commercialised by Methanex in New Zealand using methanol produced from natural gas.