American steam exploded wood pellets, black pellets, replace coal for heat and power in Paris.
/inbio.biz/Lennart ljungblom/2016-08-30/ The steam exploded pellets, branded black pellets, are produced in Selma Alabama and shipped from Mobile to Port of Rouen and transported by train to the coal power plant Saint-Ouen in the north of Paris. In Paris will the main district heating operator, CPCU replace half of the coal for the production of heat and power. In spring the company inaugurated the logistic terminal that will handle the pellets. The producer Zilkha Biomass Energy has got a five year contract for 140 000 t/y.
The centre is located close to an existing combined heat and power, CHP, coal plant. Soon they expect to have 60 percent of the coal to be replaced by wood pellets. The start up mix is 50/50. In the end the goal is to take away all of the coal. Most central parts of Paris have district heating. The plant is operated by CPCU, a subsidiary of Engie Group, earlier named GDF Suez, with the city of Paris. The Paris heating network is France’s largest and will now be supplied with 50pc renewable energy. CPSU use waste, gas and coal and now also woodpellets.
The black wood pellets are produced from timber and sawmill residues in a converted traditional wood pellet plant, earlier owned by bankrupted Dixie Pellets. Zilkha Biomass Energy bought the facility a few years ago and has rebuilt it for the production of black pellets. It was opened for production in the autumn 2015. The plant capacity is 275 000 t/y.
The production of black pellets is the same as for ordinary wood pellets with one exemption, an added fibre conditioning step. As in all pellets plant the incoming fibre raw material are crushed and then cleaned from eventually impurities. In the Black coal process, the fibres are then treated under pressure with steam and when suddenly the pressure is cut, the fibres explode and separates into cellulose, hemicellulose and lignin. In the following pelletizing step the free lignine helps the pellets to form to a stable, water resistant, high energy rich pellets with a hard solid black or dark brown surface.
The Black Pellet has a higher energy content and is more simple to handle. They can be unloaded from a ship in heavy rain as an example. Something that can save a lot of money for the trader. This is not possible with traditional wood pellets. The black pellets are also bricle and are even more easy to handle and transport than ordinary wood pellets. If the energy plant use powder burners, the black pellets are very easy milled and mixed with coal powder. The bad side of the coin is that the cost for production increases and may not be balanced with cheap enough handling costs and and the higher energy content.
In Port of Rouen Sea Invest, handle the logistics of this new high quality energy product.
Last September, Sea Invest received the first black pellets ship from Mobile (Alabama). The 187 meter long bulk carrier Mandarin then delivered 25,000 tons of wood pellets. In Rouen, Sea Invest expects an annual traffic of 145,000 / 150,000 tons.
”Sea Invest will in Rouen unload, store and ship cargoes to the Parisian customer by train and secondarily by river convoys,” Robert Goudon said.
The CHP plant is as well as Rouen located by the Seine river but as CPCU have invested in an advanced train handling system train, not barges will be the priority transport.
It´s amazing it can be stored on-ground … like coal! ” says Robert Goudon.
”Our handling of the black pellets follows our logistics of coal, and are therefore without extra investment for our company ”.
”Halving the use of coal, the arrival of this new facility will avoid a discharge of 300,000 tons of CO2 into the atmosphere each year”, says the president of CPCU, Frédéric Martin.
The pellet shipment arrives in Saint-Ouen by train and are automatically unloaded in the receiving house. It takes two daily trains to supply the need of 1 300 tonnes per day for the boilers. Inside the building, the wagons are opened to fill the tanks located in the basement. A hopper then carries the pellets to five silos capable to hold 15,000 tons of fuel.
A one km long conveyor then link the silos to the biomass boiler. Finally, only a few meters before the infeed to the boiler, coal and pellets are mixed.
The energy plant in Saint-Ouen is located close to Stade de France, the French national football arena. Located beside is also an ecological garden and on an empty adjacent area the community now plans to build 4 000 apartments.
It is therefore of most importance that new energy projects do not disturb and are environmental friendly. The five silos built has been hidden behind a wall looking like an office building. So if you don’t know what is behind you would have no idea. The use of pellets instead of coal also creates substantially lower emissions and reduces emissions of carbon dioxide with 300 000 t/y.
CPCU do frequently get the question why it is necessary to import pellets from the United States. There is a large and growing pellet industry also in France.
”The French timber industry could not respond positively for our tender. In France we could not get more than 40 000 tonnes/year and this with a 30 percent higher price”, explains Marc Barrier, CEO of CPCU.
”Most French pellet producers focus on the household market and the French pellet industry is simply not organised to supply the need for a large customer like CPCU. ”
”We will launch a new tender in April 2017 for the need after 2019, and we hope that the French industry then will be able to compete.”
The potential of the pellet industry is big and the demand of pellets is rapidly increasing, Europe is the largest market and pellets are used in all sizes of boilers. From small stoves with a yearly consumption of 1-2 ton up to the large UK based Drax power, a company with the capacity to use 7 million ton in a year.
The future for Black pellets – Green coal
The future market share for black pellets are however still uncertain, because the product is new to the market.
There are three main production methods for reasonable similar products of water resistant and higher energy wood pellets on the market.
- Torrefaction, a heat treatment process that so far has not reached a market penetration, even though there are a number of companies offering the technology and production capacity.
- Hydro THermal Carbonization (HTC) method is torrefaction in liquid phase and takes place in pressurised reactor.
- In Steam explosion the biomass is heated with steam in a pressure vessel and the blown to atmospheric pressure breaking the material structure.
Steam exploded fibre have three front running companies. Norwegian Arbaflame AS with a contract to supply pellets for OPG, the main power company in Oregon, Canada, the US based company Zilkha Biomass Energy and Finnish Valmet. Zilkha and Valmet also work together even though they have different process lines for sale.
Arbaflame is owned by Norwegian energy group Pemco AS and has produced more than 100 000 ton black pellets in their demonstration plant in Kongsvinger, Norway and is now preparing to build a full scale, 200 000 t/y production plant together with the forest group Traeklyngen in the south of Norway.
Zilkha Biomass Energy, already having a commercial 275 000 t/y unit up and running in Alabama and have recently announced that they now close their earlier demo plant in Crocket, Texas.
Valmet has a pilot plant in Sundsvall, Sweden. They have constructed a continuous flow reactor, a difference from the Zilkha batch process. Valmet and Zilkha do have a 5 year cooperation contract for further developing and international marketing of the steam explosion technology