CORDIS Archive

General Information

• CELULOSA DE LEVANTE, S.A. (ES) Manufacturing pulp for high quality papers
• CLEXTRAL (FR) Manufacturing BIVIS Machine · EGOTEC (ES) Engineering

• Bi-Vis Machine CLEXTRAL -FR-42702 FIRMINY
• Dewatering table and press GOROSTIDI
• Conveyor PROCOME
• Metal detection DYPSA
• Repulper T. BARD

Aim of the Project

In order to improve the production process, reduce the energy bill, abate pollution and increase competitiveness, the company decided to install two innovative technologies:

• BIVIS twin screw press machine for multifunctional pulp treatment including continuous cleaning of the pulp (such as flax, hemp, sisal,...) of inorganic parts to separate the black liquor.

• a new system for black liquor concentration to enable incineration and to generate steam.

By implementing the above mentioned two technologies, the project aims at achieving the following:

• Reduction of power consumption: The BIVIS twin screw press machine uses less power than the "Hollander Beater" system. Total fresh water required for washing per MT of pulp is substantially reduced.
• Energy saving: the organics from the dissolved raw material in the cooking process remain in the black liquor as dissolved solids. This residue will be used to generate live steam. The caustic soda used as reactant in cooking is dissolved in the black liquor together with the organics. About 90 % of it is recovered and reused.
• Pollution abatement. The substantial reduction in fresh water consumption implies a higher content of dissolved solids in the black liquor effluent and therefore a more effective treatment of this latter.
• shorter production cycle. The time of processing pulp is now shorter when compared to traditional plants

Project description

• The project concerns a plant with a production capacity of 45 tons of pulp per day. It was divided in 2 phases:

  Phase 1: Cleaning the pulp to separate the black liquor. The main equipment involved is a dewatering table and press, continuous weighing belt and conveyor, metal detection, BIVIS twin screw machine, repulper and stock store.

  Phase 2: Treatment of the black liquor The main equipment involved is a multiple effect evaporator, furnace, or a liquid oxidation combustion system, caustizers reactors, mud and rotary vacuum washing filter.

  The most innovative piece of equipment involved in phase 1 of the project is the CLEXTRAL BIVIS MACHINE. The use of non-wood fibres often poses special operation problems which cannot be solved efficiently with conventional technologies.

  The new BIVIS system which replaced an existing "Hollander" beater system, consists of two identical intermeshing screws rotating in the same direction inside a barrel. The screws are made in four individual sections and fitted onto a splined shaft. The modular design allows for rapid changes in the screw configuration according to process needs. The barrel can be cooled or heated locally for different applications.

  The BIVIS system enables in one machine the following functions: Transport; Mixing; Compression; kneading or Shearing; expansion and Fluid Injection or Extraction. The machine cuts the long fibres, micronites the uncooked, washes the pulp and filters the black liquor, giving an effluent of high solids content. Another advantage is the capability for continuous processing. A system for the recovery of chemical reactants is added. It aims at 90 % recovery of the caustic soda.

  The process is controlled by a Distributed control system (DCS), a best available technology.

  The project IN 058/92 ended with the implementation of phase 1 of the project only and did not include phase 2.

  For phase 2 Celulosa de Levante Submitted in 1996 a new proposal for a Thermie project. The proposal was accepted and the project took the n° IN/0128/96/ES. This new phase consists in a new system for black liquor concentration to enable its incineration and this generating steam.

  The process includes the following main components:

• A multieffect evaporator where the heat of the steam produced by the combustion of the high concentrated black liquor is transferred to the diluted black liquor, coming from the process of the pulp production, to eliminate its water content;
• a combustion system. for the combustion of the black liquor coming from the evaporator . Such system has not been decided yet and could either be a combustion furnace with a heat recovery boiler or a "liquid oxidation combustion system";
• A recausticizing unit which allows the transformation of sodium carbonate in NaOH to be reused in the non wood pulp cooking.

Project Results

• Specific water consumption reduced from 90 to 50 l/kg pulp (45%)
• Specific electricity consumption reduced from 1.1 to 0.8 kWh/kg (27%).
• Fibre loss improved from 3% to 1%
• More uniform pulp which is also cleaner and easier to bleach. Further improvements are expected for water consumption.

Financing

ECU

%

950,000

21.5

3,467,517

78.5

4,417,517

100

Environmental impact

• Reduction in emissions due to the reduction in power consumption
• Reduction in water consumption

Potential for further installations and dissemination of results

On the other hand, substantial research is carried out in the EU and including the main pulp producing countries, to increase and improve the use of non-wood virgin fibres from various sources like hemp, straw, rice, miscanthus, sorghum, etc. This RTD is done in the course of development for a sustainable paper production and also to create alternative agricultural products.

As a consequence, the market potential of the demonstrated technology at present is still modest and mainly in small and medium pulp plants. Potential for further installations in Europe are presently: few plants in UK, several in France, Spain and Italy; outside Europe the most important markets are India and China. For the future, with a clearly growing importance of non-wood fibres and growing demand in third countries, the market potential of the technology will increase because of it's advanced technical features. The Bi-Vis technology is the most advanced on the market for non-wood fibre treatment.

Besides this market potential in the paper pulp sector, after additional modifications the Bi-Vis machine concept with great benefit can be transferred to other sectors and especially to the agrofood sector, e. g. for beet pulp production in the sugar industry. Tests for this latter application have already successfully been carried out and a first demonstration is currently under way.