Arba prosessutvikling

The project Arba process development has been performed in 2016 and 2017 and the project has more or less followed the planned activities, only adjusted for internal priorities in time schedule. The results are in line with the expectations, and the most optimistic result are from the work with the condensate/effluent. Results from the project 1) Feedstock preparation . There has been studied mechanismes for downsizing of the logs as a one step process form log to sawdust , i,.e shorter fibres. It has been verified that a one step process will give better particle size distribution than known technologies with 2 step downsizing where the first step is chipping to wood chips ( 30-50 millimeter size) with a following process step with hammer milling. It has been found that optimum solution is increased rotational speed (rpm) and thinner knifes/bits for cutting. The particles will be less and the particle size distribution will be better and the needed electrical energy consumption to get a good and wanted product will be lower. We have developed a cutting concept for the knifes and a prototype machine has been made in Italy with an Italian producer, that has more than 50 years experience with production of wood chippers. The prototype has been used on both soft and hard wood with excellent result and low electrical consumption (less than 40 Kwh/dry ton). A full scale machine is designed for Follum production plant. 2) Condensate University in Bergen has worked with the analyses of the condensate the they have shown interesting concentrations of mainly Furfural but also Methanol and Aceton. NMR has been used in Bergen for the condensate analysis. The analysis work is time consuming and we have made a library for the different element of interest and the total time for analysis of each condensate has been reduced. Both condensate from lab and full-scale operations have been done. A relation between lab scale testing in Sweden and full-scale production at Grasmo plant has been demonstrated and full-scale production gives better results than lab scale. The challenge with the condensate is that it contains Methanol, Aceton and Furfural with different boiling points varying from 63 ? 163 degrees Celsius, and the large number of organic acids, mainly Formic and Acetic acid and then a very low Ph value in the condensate. Evaporation tests have been performed I Finland and Switzerland and techniques has been studied to increase concentrations of chemicals. A closed loop system has been studied. Testing in Switzerland has shown that a system of stripping and evaporation (closed loop) and the concentration of chemicals will be increased and separated from the acids. A Finnish and Swiss company has proposed a design for equipment for «closed loop» and which will reduce emissions to a minimum, and this system will replace previously proposed waste water cleaning system. This system is both cheaper in investment and cheaper to operate than proposed waste water system. With a mass loss of 10-12 % it has been shown that the amount of furfural gives an increased income of 7-10% of total revenue for the production unit. Remaining challenges are separation of furfural to needed quality (98%) and how to increase the yield of furfural during steam treatment. 3) Reactor technology The reactor size and systems for feedstock feeding has been studied. Especially feedings systems are import and the main objective is to have low feeding time without increasing in diameter of the inlet ( important for the lifetime and operation of the high pressure valves). The result of the study is that the reactor size has been increased we have adapted a pneumatic feeding system together with a Canadian supplier. This system meets the requirements to both filling time and diameter needed. A Norwegian company has in cooperation with a Swedish company designed a complete system for the reactors and heat recovery and condensate collection. A complete reactor system can be built in modules in Norway, which will give easier transportation and faster assembly. Studies performed showed that that it was not wanted to go more in detail in the direction of continuous system. Especially the condensate solution and production of green chemicals indicated very low interest to change the excisting batch operation of the reactors.

Prosjektet eies og drives av Arbaflame. Treklyngen blir samarbeidspartner basert på erfaringer med første oppskalering og generell treforedlingsteknologi. Universitetet i Bergen blir forskningspartner på produktutvikling fra kondensat og utvikling av reaktorteknologien. 1) Krav til partikkelstørrelsefordeling i råstoffet: Arba Follum vil benytte en leverandør som har utviklet en maskin for å produsere egnet sagspon fra tømmer i ett trinn. Det mangler imidlertid kommersielt tilgjengelig utstyr for reduksjon av flis (10-30 mm) til akseptable råstoffkvalitet. Et selskap som prøver å kopiere Arbaflame, har med utgangspunkt i flis, ikke lykkes med produktkvalitet. Dette stemmer godt med Arbaflames egne erfaringer. Flis er imidlertid et lett tilgjengelig råstoff, og en betydelig sidestrøm fra sagbruk. Derfor er det strategisk svært viktig for Arbaflame å utvikle metode(r) for råstoffproduksjon fra flis. Dette arbeidet vil gjøres i samarbeid med utvalgte teknologimiljøer. 2) Foredling av kondensat: Energigjenvinning fra prosessen tar vare på 85% av benyttet varme og gjenbruker det i prosessen. Dette genererer et svært konsentrert kondensat som inneholder ca 10% av anvendt trevirke. Arba Follum har valgt en "konvensjonell" anaerob renseprosess med metan som "biprodukt". Dette krever betydelig utspeding og derav betydelige investeringer. Kondensatet som i hovedsak inneholder hemicellulosekomponenter og terpentiner, kan gi grunnlag for større verdiskapning gjennom alternativ prosessering. Forskning på dette fagfeltet foregår med Kjemisk institutt i Bergen som vil engasjeres i dette utviklingsarbeidet. 3) Utvikling av reaktorteknologien: Dagens batchteknologi med relativt små reaktorer møter både praktiske og økonomiske begrensninger ved storskala produksjon. For større anlegg en Arba Follum (200't), må enten matesystemet benytte annen høykapasitetsteknologi, eller kontinuerlige reaktorer utvikles. UiB og relevante teknologimiljører vil bidra i dette arbeidet