The wood based panel industry consumes energy on a large scale and in various forms. For instance, the MDF production line consumes saturated steam to pre-steam wood chips in the cooker and in the refiner, while hot gas is required to dry the wet fibres, and thermal oil is used to heat the fibre mix in the press.
The energy plant is another of the core pieces of any production facility, requiring reliable high-end technological solutions and maximum availability,says Vyncke’s senior sales manager, Lieven Tarras.
For its thermal energy, the wood based panel industry is generally self-sufficient since its own production waste is used for fuel, giving threefold benefits: elimination of waste; savings on fuel cost; and a cleaner environment.
Each energy plant has its own features, mainly depending on the type of raw material and board being produced. This implies that each panel production line needs a tailor-made energy plant which takes into account the different fuel specifications and ratio of energy output.
Vyncke Clean Energy Technology, based in Flanders, Belgium, has supplied custom-made energy plants throughout the world for almost 100 years. Now with over 3,500 references worldwide, Vyncke claims it is the best-known supplier of biomass-to-energy solutions for the board industry. In fact it says a trip around the world is necessary to describe the activities of its ‘Vynckeneers’.
“We are the market leader for large wood based panel energy plants in China, starting up eight energy plants in the 45-70MW range for the leading Chinese MDF producers in 2004,says Mr Tarras, adding: “Several repeat orders from satisfied customers such as Asia Dekor and the Dare Global Group followed.”
In 2004 Vyncke’s China office moved from Beijing to Shanghai to be closer to its customers for service and assistance.
All the company’s energy plants in China are equipped with the Dynamic Watercooled Stepgrate. The table on the following page gives a list of all energy plants commissioned within the last year in China by Vyncke, except the ones for Guodong (MDF) in Shengdu and Decade Woods (particleboard), which are scheduled for commissioning in 2005.
Most commentators anticipate an increase in particleboard plants in China and Vyncke says it is already in the design stage of two energy plants for that sector.
For Decade Woods in China, it will install a 29.5MW energy plant, while for SPB Panel in Thailand, the company was selected to supply and install an energy plant fuelled with waste from palm oil plantations – the first of its kind in the world.
As fuel availability is rather limited in the particleboard industry, more biomass needs to be sourced from outside.
Vyncke’s Dynamic Water-cooled Stepgrate, as a multi-fuel step grate, can take other types of biomass.
Vyncke energy plants for Metro Particle Board and Rayong (both in Thailand) came on stream in 2004 and are producing thermal oil and hot gas. The Vyncke service centre in Bangkok serves Thai customers in close cooperation with the offices in Kuala Lumpur and in Shanghai.
Turning to other parts of the world, Mr Tarras feels that eastern Europe is a market with significant potential – in 2004 the group Fazerles (Bulgaria) started up a Vyncke steam boiler. In western Europe the investment climate was rather slow in 2004, he admits, but at Spanolux in Belgium, Vyncke designed and built a thermal oil heater to provide high availability and reliability.
Energy plants for OSB are similar to those for particleboard. Even though investments in OSB lines will not happen to the same extent as MDF and particleboard, Vyncke – already having references in OSB – says it anticipates new orders.
Water cooling of combustion grates
“Reliability of energy plants is a prime concern, since, just like other key equipment, they are a vital link in the production chain and frequent shut-downs would disturb the entire production line,points out Mr Tarras. “A major weakness of typical aircooled step grates is that they too frequently need to be repaired and maintained. In order to optimise the availability and also minimise maintenance cost, water-cooling is essential for any combustion grate for the wood based panel industry.”
Mr Tarras says that water cooling in step grates maintains a stable temperature on the combustion grate, which has advantages. “For instance, there will be less expansion and therefore less friction and wear, ash trough fall is reduced to an absolute minimum, maintenance costs are significantly lower and the lifetime significantly higher.”
A major added advantage, he claims, is that the combustion air serves no cooling function and can therefore be optimally controlled, resulting in remarkably good combustion and so extremely low emissions.
“As a result of the fuel flexibility and low emissions, Vyncke combustion systems have been selected for several ‘green energy’ (CHP plants) projects in Europe using emolition timber as fuel to produce steam and power,says the sales manager.
Vyncke says it operates on the forefront where innovation is an ongoing process. In the field of combustion technology, the company has developed the Hybrid Stepgrate, in addition to the well-known Dynamic Watercooled Stepgrate (DWS). This is claimed to have the advantages of the DWS with an additional feature: the post-combustion zone.
It is said to be better for very wet fuels. The main combustion area, as well as the side collectors, are water cooled. The post-combustion area is air cooled to ensure complete burn-out.
Cogeneration and heating
“Power shortages and increasing interest in green electricity have made electricity plants and cogeneration (steam and electricity) very viable options,points out Mr Tarras.We recently commissioned a cogeneration plant for Balcas (11.5MWth + 2.7MWe) in Northern Ireland. The tail-end type steam boiler is a unique innovation in the field of biomass. Several wood and biomass fired power plants, mainly in Europe, are under construction.An example is Holz Dammers Moers, from Germany, which selected a small cogeneration project from Vyncke.
The wood processing industry, such as flooring and furniture, is also profiting from wood fired heaters. For this sector the company developed a thermal oil heater, suited to combustion of sanding dust, although the combustion of larger wood particles and other types of biomass is also possible.
Dare Global, Asia Dekor and Vöhringer, all leading producers of flooring in China, installed several thermal oil heaters, using sanding dust as fuel. “The savings on conventional energy sources, such as fuel oil, are enormous,says Mr Tarras. “It also combines the best of all worlds; whereas the design is 100% European, we source globally to guarantee competitive prices to our customers. To ensure reliability of the system, all critical components originate from well-known European manufacturers.”
Biomass is a clean form of energy and contributes to reducing greenhouse gas emissions. International organisations and governments recognise this fact and offer various forms of incentives.