NL1044066B1 - Production of biopellets for wood pellet boilers/installations from prunings and/or comparable woody biomass - Google Patents

Abstract

System for the production of biopellets from prunings from landscape maintenance and/or comparable woody biomass, 5 comprising a thermal oil boiler (1) for heating thermal oil (3) by burning biomass fuel (2). Furthermore, the system comprises a steam dryer (4) for drying wet wood chips (5) into dry wood chips (6) by the heat of the hot thermal oil supplied by the oil boiler to the steam dryer (3a). The system further comprises a CO2 capture module (7) which converts the CO2 present in the combustion gases (8) of the oil boiler into liquid CO2 (10) with the aid of steam (9, 9a) released from the steam dryer. Steam (11) discharged from the steam dryer 15 and from the CO2 capture module is fed to an external heating system (12). The dry wood chips produced by the steam dryer are successively cleaned, reduced in size and pelletised. (FIG. 1) 20 1044066

Description

i Short designation: Production of biopellets for wood pellet boilers/installations from prunings and/or comparable woody biomass

DESCRIPTION iQ The invention relates to a method resp. sve tem for the production of bicpellets for {application in) wood pellet boilers and/or (other) installations, as well as pruning wood and/or comparable woody biomass.

It is an object of the present invention to provide a Lie process with a substantially negative CO; footprint ("carbon footprint", for this term see for example hrtps:/ien wikipedia org/wiki/Carbon footpoint).

To this end: according to the invention, a method is provided for the production of high-quality, certified biopellets for wood pellet boilers/installations from ash-rich wood from landscape maintenance and/or from comparable woody biomass, which method includes: in particular wood, to a thermal oil bubbler, arranged for heating thermal oil by combustion of the biomass fuel fed in; 3 - drying wet wood chips into dry wood chips by means of a steam dryer fed by the oil produced by the oil boiler hot thermal oil,

while the cooled return oil is fed back to the oil boiler; — supplying combustion gases from the oil boiler to a CO; capture module, equipped to convert CO: present in the combustion gases into liquid CO; with the aid of steam released from the steam dryer or at least the heat therefrom.

The method according to the invention preferably further comprises supplying steam released from the steam dryer, or at least the heat therefrom, and/or steam originating as a residual product from the CO2 capture module, or at least the heat therefrom, to an external heating system. Dry wood chips produced in a steam dryer are successively cleaned, reduced in size and pelletized.

In addition to the method presented above, the present invention Levens comprises a system for the production of high quality, certified biopellets for wood pellet boilers/plants from ash-rich prunings from landscape maintenance and/or from comparable woody biomass, comprising: — a thermal oil boiler designed for heating thermal oil by burning biomass fuel, in particular wood; - a steam dryer arranged for drying wet wood chips into dry wood chips by exposing the wet wood chips to heat given off by the hot thermal oil supplied to the steam dryer by the oil boiler, the oil boiler is returned;

— a CO; capture module adapted to convert the CO: present in the combustion gases of the oil boiler into liquid CQ; with the aid of steam released from the steam dryer or at least the heat therefrom.

The system according to the invention is preferably designed for supplying steam released from the steam dryer, or at least the heat therefrom, and/or as residual product from the CO; capture module steam, or at least the heat therefrom, to an external heating system, The system according to the invention furthermore comprises means which are adapted to successively clean, reduce and pelletize dry wood chips produced by the steam dryer. using the figure description below.

Figure 1 schematically shows an exemplary embodiment of a system according to the invention, in which the method can be carried out; Figure 2 shows a further detail of a getconde CO: processing module shown in Figure 1 .

Figure 1 schematically shows an exemplary embodiment of a system according to the invention, equipped: for the production of high-quality, certified biopellets for wood pellet boilers/installations from ash-rich prunings from landscape maintenance and/or from comparable woody biomessa. The system collapses

- a thermal oil boiler 1 adapted for heating thermal oil in an oil circuit 3 by burning biomass fuel 2, in particular wood; - a. steam dryer 4 arranged for drying wet wood chips 5 into dry wood chips 6 by exposing the wet wood chips 5 to heat given off by (withdrawn from) the hot thermal oil which, via the oil circuit 3, passes through the oil boiler 1 is fed to the steam dryer 4 {3a)}, while the cooled return oil is returned to the oil boiler via the oil circuit 3 (3b); — a CO2 capture module 7 which is designed to convert the CO: present in the combustion gases 8 of the oil boiler 1 into liquid CO: 10 using a fraction 8a 13 (e.g. approx. 70%) from the steam dryer 4 released (superheated) steam 2 or at least the heat therefrom. The system according to the invention shown in figure 1 is furthermore adapted to supply a fraction of 89h (for instance approx. 30%) of the steam 9 released from the steam dryer 4 or at least the heat therefrom, and/or the steam 11 originating as a residual product from the CO2 capture module, or at least the heat therefrom, to an external heating system 12 for, for example, district heating 13.

The system according to the invention shown in figure 1 furthermore comprises means which are adapted to successively clean and post-reduce (14) the dry hour chips 6 produced by the steam-dryer 4 and to pelletize them into, for example, pellets with a size of, for example, 6 mm (15), obtained from the clean fraction, plus pellets with a size of, for example, 8 mm (16), obtained from the waste fraction. To achieve the intended negative carbon footprint, it is important that practically all material flows are used, including the waste stream (waste fraction). This concerns approximately 10 - 12% of the input of the dry chips that are processed into § mm industrial pellets. Figure 2 shows a further detail of a CQ, processing module shown in figure 1, of which a short English description of the operation is given below: The CO: capture module/system works like this: The precleaned (ready to exhaust to the surroundings if net used for CO: capture) combustion gases are lead into the CO: capture system, The first step is to precool the flue gases; this is done in a quenching/scrubber tank. After cooling and pre-washing the flue gases are led into an absorber vessel, This vessel contains mass-transfer equipment facilitating the transfer of the CO: from the flue gas into the absorption liguid. The absorption liquid (e.g. GALLOXOL®) is an aqueous liquid which contains a salt amine which dissolved in the water can react with the CO; in the air via gas/ligound contact.

The salt amine CO; reaction is reversible and very selective towards Cs. . The mixture content is guaranteed as a risk free and miner: already based mixture with no harmful components.

After the absorption the flue gases are exhausted through the chimney without COs.

The CO; rich absorption liquid flows into the regenerator.

The mizture is heated with waste heat from the drying process.

The heating of the mixture releases the CO: as a CO:/water vapor mixture,

The CO,/water vapor misture is cooled and condensed free water removed.

The heat produced from the cooling process are reused in the process or used for another heat demand-ing process,

The pure still slightly wet CO: is then dried and further purified in the dryer unit up to high technical quality.

The CO; gas undergoes a cleaning process to ensure food grade quality by compressed in a liguefying process and stored to make the CO, portable in trucks.

It is noted that the electrical energy required for carrying out the method according to the invention is

naturally preferably consists of sustainably generated 'green energy'. Thus, the present invention provides a production process with a substantially negative CO: footprint, the-

none can be substantiated by a meanwhile conducted and published study: hrtps://www.stichtingbeon.nl/houtpellets-jalo-biopellets-score-positief-op-sustainability/ and https: //www.stichtingbeon.nl/wp-

content/uploads/2020/05/Jalo-study-DHVHaskoning. pdf

Claims (6)

CONCLUSIONS 1. Method for the production of high-quality biopellets for wood pellet boilers/vinztallations from prunings from landscape maintenance and/or from comparable woody bi-DMASEA, which method comprises: heating thermal oil by combustion of the supplied biomass fuel; — drying wet wood chips to dry hovt chips by means of a steam dryer fed by the hot thermal oil produced by the oil boiler, while the cooled reflux is returned to the oil boiler; “ supplying combustion gases, originating from the oil boiler, to a sen Ch capture module, equipped: to convert CO present in the combustion gases into liquid CO; with the help of sludge released from the steam dryer or at least the heat from it, 2. Method as claimed in claim 1, comprising feeding steam released from the steam dryer, or at least the heat therefrom, and/or steam originating as residual product from the CO2 capture module, or at least the heat from it, to an external heating system, A method according to claim 1 or 2, wherein the dry wood chips produced by the steam dryer are successively cleaned, crushed and pelletized. 4. Bystesm for the production of high-quality biopellets for wood pellet boilers/installations from prunings from landscape maintenance and/or from comparable woody biomass, comprising: — a thermal oil boiler {1} equipped for the combustion of biomass fuel (2), in the special wood, heating of thermal oil {3}; - a steam dryer (4) arranged for drying wet wood chips {5} into dry wood chips {6} by exposing the wet wood chips to heat given off by the hot thermal oil delivered by the oil boiler to the steam dryer word: supplied Za}; a C0: capturing module (7) which is arranged to remove C0 present in the combustion gases {8} of the oil boiler; convert into liquid CO: (10) using steam {2, Sa) released from the steam dryer or at least the heat therefrom, 5. System as claimed in claim 4, adapted for supplying steam {9b} released from the steam dryer, or at least the heat therefrom, and/or steam {11} originating as residual product from the CO: capture module, or at least the heat exchanger. only an external heating system {iz}. 6. System according to Donclusis 4 or 5, comprising means {14,15,16) which are adapted to successively clean, post-reduce and pelletize dry wood chips produced by the steam dryer.