<TITLE: Bleached Hardwood Pulps by the Soda/AQ and MAQ Processes
ACADEMIC DOMAIN: technology
DISCIPLINE: forest products chemistry
EVENT TYPE: lecture
FILE ID: ULEC080
NOTES: lecture interspersed with questions

RECORDING DURATION: 56 min 00 sec

RECORDING DATE: 21.6.2005

NUMBER OF PARTICIPANTS: 10

NUMBER OF SPEAKERS: 4

BS1: NATIVE-SPEAKER STATUS: English (Jamaica); ACADEMIC ROLE: senior staff; GENDER: male; AGE: 51-over

S2: NATIVE-SPEAKER STATUS: Finnish; ACADEMIC ROLE: unknown; GENDER: male; AGE: unknown

S3: NATIVE-SPEAKER STATUS: Finnish; ACADEMIC ROLE: unknown; GENDER: male; AGE: unknown

S4: NATIVE-SPEAKER STATUS: Finnish; ACADEMIC ROLE: unknown; GENDER: male; AGE: unknown

SS: several simultaneous speakers>


<BS1> <REFERS TO POWERPOINT SLIDES THROUGHOUT THE PRESENTATION> good afternoon ladies and gentlemen my name is <NAME BS1> and i'm a research associate slash professor at the SUNY college of environmental science and forestry in syracuse new york i'm a professor with the faculty of paper science and engineering and erm also a research associate with the empire state paper research institute the distinction between the faculty of paper science and engineering and the empire state paper research institute is unclear it's we are all in the same building and er er all the activities er there's no clear distinction between the two er what you do as a for the faculty and what you do for the institute i'll be making a presentation entitled bleached hardwood pulp by the soda-AQ and MAQ processes er my co-authors are doctor samar bose my post-doctorial fellow doctor nam H shin from andritz incorporated and andritz are is the fiberline supplier for the soda-AQ mill in kingsport tennessee so we started there's a big mill i think making at least 1,500 tons per day by the soda-AQ process and er i have (xx) into this process trying to help them with some brighten- brightening problems they were having and i'll describe later in this proposal in this presentation er another co-author is doctor omori a permanent member of our staff he's a research support specialist er he maintains our equipment but he's a very good synthetic organic chemist and er one of our technicians senior technician mr hal brown , as i said we started doing this work in conjunction with andritz and it's partially funded by andritz trying to understand why the soda-AQ pulp er bleached to a lower brightness than kraft pulp however as we conti- as we started this project it developed into something i think that is much more significant so i'll just go through some introductory slides and i wrote this one and i said the future and i knew the future and then i corrected it and said probably <SS> [@@] </SS> [but] er the future i think it's the future er pulp mills will steam reform black liquor wood and other biomass to produce an hydrogen rich gas er and i'll tell you why hydrogen gas will you know will be important in the future and there are two pulp mills who are steam reforming their black liquor in the US and getting very good yields of of hydrogen , er steam reforming of organics to hydrogen is one of the most successful areas of research in the rec- recent times there are wide group of research groups who are getting good results in this area and i did put here including in black liquor er including research in bla- black liquor this is some results i took off the web er for the steam reforming and you can this is just this type (xx) yield er for the maximum hydrogen pro- er generation and you can see even for acetic acid this is for catalysed steam reforming they were getting 66 per cent yield for acetone getting eight moles of hydrogen from a mole of acetone they were getting about 80 per cent of theoretical y- yield ethanol they were getting around 70 per cent and this one is quite interesting for phenol getting 14 moles of hydrogen from one mole of phenol they were getting a 100 per cent yield er for for this reaction , er this is some result published by TCI thermochemical incorporated of baltimore they are the one who are building the steam reformers in the fluidised bed steam reformers in the US after steam reforming approximately 70 per cent of the fuel gas was hydrogen and there was 99 per cent carbon conversion to low molecular weight gases so there wasn't a lot of tar or char er in the in the fuel gas and they were getting a very high concentration of hydrogen they are i don't think they have achieve such a high value in commercial practice but i'm aware of one of their installation and they are pretty close <P:05> coal is still abundant and can be oxidised to carbon monoxide in very high yields er there is a trillion ton of coal reserves in the world and er er some people say well why not you know modify the steam reforming to make carbon monoxide from from water from biomass but what i you know my ap- approach at least for now is to make as much hydrogen as possible from from the biomass and we can get the er carbon dioxide quite efficiently from coal and then what do you do with this carbon monoxide and hydrogen you rea- you take your hydrogen mixture and fortify it with carbon monoxide from coal run it over a (xx) catalyst and make gasoline er they are doing this in south africa right now the so-called SASOL process so er where we are going with the soda-AQ pulping is that we have to get some value from the black liquor you know we have to get some value and er if you do a calculation in the US we pay two dollars and 25 cents for 3.8 litres of gasoline you know that's 71 cents per kilogram you know and it's even twice you are paying 1.25 per litre which is only point eight three kilograms you know so you are paying about one and a half euro per kilogram of of of gasoline you know so and we use it by the billions of litres so my approach is a pulp mill you know should make some additional product in addition to pulp and paper and i recommend one gasoline a market that we cannot saturate , er you can also get the same reaction using different catalyst to make methanol er er formaldehyde acetic acid and you have this reaction here to make dimethyl ether which is a substitute for diesel fuel and it's a cleaner burning fuel with a high C2 number that apparently diesel engine can operate on better than actual actual diesel so you can go this way er as well with the carbon monoxide and hydrogen , so we are talking a lot in the US about biorefinery about making products er pre-extracting some of the wood material and making bio-based products and biofuel and er what i propose is (xx) er concentrate your black liquor er grind up additional biomass any biomass it doesn't matter its composition the steam reforming will generate a sizeable amount of h- oxygen from the aromatics or the non-aromatics it will produce a lot of hydrogen from the er carbohydrates as well , so what we are after the proposal is that at a pulp mill the black liquor might be only 25 per cent of the total biomass you are you are gasifying or you are steam reforming er the steam reforming process would be most efficient if they're processing up all the feedstock er black liquor wood (xx) biomass er could be integrated some places in the US we have a lot of wheat straw that we don't know what to do with you know just grind it up and steam reform it , this would require sulphur compounds to be kept at a low level i don't think you want to use the black liquor to contaminate all of your feedstock so such a process is unlikely with the with the kraft the sulphur is just difficult to handle or a large amount of sulphur is just difficult to handle if you use a non-sulphur process you can recover small amount of sulphur by this redox reaction quite easily and it's used in a lot of systems gas systems er you get a you have support ferric oxide er supported f- ferric oxide and it's reduced by the H2S and then you can oxidise the ferric sulphide to give you SO2 and regenerate the ferric oxide and this was done this at a temperature that would correspond to low temperature gasification but there's also some literature that you get the same basic chemistry at even higher at even higher temperatures because some gasification the temperature of gasification is anywhere from 500 to a 1,000 degrees C depending on what system you are using the SO2 would be absorbing caustic and using the bleach plant and most bleach plant use some sodium bisulphite at the end of chlorine dioxide and peroxide stages to to kill the r- the residual oxidant but in this case we'll be talking about probably P-P-M not much SO2 er only the SO2 that only the sulphur that comes in the water the chemicals and the fuel at the kingsport mill for example they don't have to scrub any SO2 out of their recovery system they just clean off the chemicals and the fuel that they were using and the er sulphur that is coming in and is being emitted er is beyond the it's it's so low that that they they can emit it without scrubbing the the flugas so if you don't add sulphur er your sulphur emission can be quite low . now we get to if you want to do all of this it would be good if you could pulp without adding any sulphur and what we are working on is the basic anthraquinone mechanism we are u- and the anthraquinone oxidise the carbohydrate and is reduced to the anthrahydroquinone and the anthrahydroquinone adds to quinone methide and cleave the beta-O4 which i think is the next slide here what you have the an- the anthrahydroquinone is a nucleotide anion and adds here and you have cleaved out this bond and you d- depolymerise er the lignin similar to to the kraft mechanism , okay prior results we have some results that will be published shortly in the journal of wood chemistry and technology and what we wanted to do was to keep the active alkaline same as in the kraft process er normally when you use AQ you have to use a higher active alkaline or effective alkaline because you none of the a- alkalinity comes from sodium sulphide all of it comes from sodium hydroxide you can see when we do that you don't make as low a kappa number with the soda-AQ process but when you use 2-methylanthraquinone you make a pulp that approaches kraft and you are gonna get a significantly higher yield er (xx) yield the higher yield the higher there's more pulp that you make will pay for the cost of the 2-methylhydroquinone so and we got these results reproduced in a in an in- independently in another lab and it's it's not written here but the higher yield from the 2-methylanthraquinone has been published by two previous research groups . when you when we bleached this pulp without oxygen at D-zero stage and E-P and a D-one you can see that the soda-MAQ pulp bleached to approximately the same brightness as the kraft pulp it's this one point is significant you always see a slightly lower brightness and we see equal or higher tensile-tear for the AQ and MAQ pulps and others have seen it as well one of the er there used to be a complaint that you get a lower tear-strength for the soda-AQ pulps but we just haven't seen it and others have agreed with us that you it's at least equal to kraft , the performance problem . when you replace chlorine dioxide with oxygen when you do an oxygen delignification (xx) kappa number 10 and then you use less chlorine dioxide in the D-zero stage all of a sudden you have a 2.3 point brightness gap and that 2.3 point brightness gap was why i got into this soda-AQ process in the first place and er it's really a troublesome two and a half brightness point because we cannot we have tried all the simple way of getting rid of this brightness in- er brightness gap and we have been unsuccessful what you have is that when you use the without oxygen you use 2.2 per cent chlorine dioxide and pulp when you use oxygen you use 1.3 per cent chlorine dioxide and pulp er chlorine dioxide is a stronger one-electron oxidant than any species that is present generated during the oxygen delignification other than the only exception is the hydroxyl radical and you don't generate a lot of hydroxyl radical (using) oxygen and you don't want it either because it will er degrade the carbohydrates so you need the soda-MAQ pulp or the soda-AQ pulp need a higher dose of strong oxidants er so oxygen and peroxide don't do it you'll have to use chlorine dioxide or peracid or some str- some er strong oxidant er this is some result we have for er soda-MAQ pulp this one and this one and this is some result for a soda-AQ pulp so they are they are fairly similar one of the result we saw these pulps here are kraft and kraft AQ pulp and it's from our labs two other labs and two different mills so it's from five different sources these are kraft pulp and if you treat them the ex- under if you treat them exactly the same way in each bleaching stage what you see is that the light absorption coefficient which is linear with brightness which correlates linearly with brightness er after the final bleaching correlates quite well with with the post-oxygen kappa number and what you can see is that you get a darker pulp or a pulp with a higher light absorption coefficient after final bleaching before the AQ or or MAQ process , alright new results what i'll go through i'll talk about all of these these are some of the all of the issues we are trying to address er when you try to replace the kraft process er people want it to be they say equal to kraft but they actually mean better than kraft and that ain't easy to achieve you know the reason why we have been making kraft pulp for more than a 100 years is because it's a very efficient er process and basically what we want to do is to use the non-sulphur process so that we can make additional fuels and chemicals and er compete in other sectors but in order to get a pulp mill to to go that road you have to get you have to start with the pulp you know forget about the additional biomass you know let's you have to you want to convince them that they can make good pulp since they are actually pulp mills i'll talk about the synthesis of 2-methylanthraquinone is this thing commercially available then i'll talk about some of the colour problems in the early stages of bleaching and then i'll talk about lignin condensation which appears to be w- the root of the problem , er our route of making synthesising 2-methylanthraquinone is to replace benzine with toluene and i'll show you that reaction in a little while if you replace benzine with toluene you end up with the methyl group in the two-position right here er this reaction they are the largest AQ producer in china is using the friedel-craft reaction with (xx) nitrate and benzine catalysed by er aluminium chloride , er there is also some interest in studying 2-methylanthraquinone instead of anthraquinone because part of the problem with AQ it's derived from coal and er petroleum feedstock and the price of petroleum and the price of coal is going up so while (xx) nitrate was only 77 cents per kilo in january 2003 by march of this year it was up to a dollar 19 a kilo benzine gone from 40 cents per kilo to a dollar 13 per kilo while toluene has gone only from 36 to 70 cents toluene is historically cheaper than benzine because it's more abundant and actually about 50 per cent of the benzine in the world is actually made from toluene so if you can actually replace the er benzine with toluene there might be some economic benefit for a a producer who is using the friedel-craft reaction so we investigated this reaction er we couldn't find much data on on we have found it with benzine but not with toluene so we wanted to see how high a y- a yield yield of this compound we'll get and also how much 1-methylanthraquinone it's possible that the methyl group could end up here as well instead of here it would end up here as 1-methylanthraquinone and 1-methylanthraquinone is reported to be a less effective catalyst than 2-methylanthraquinone so we did the synthesis when we did the synthesis what we discover is that we got a 92 per cent yield of this intermediate here 92 per cent based on er (xx) nitrate as the limiting reactant and when we treated all we do to go from here to here er is treat it with concentrated sulphuric acid it's a very simple reaction we end up with 75 per cent yield of this compound in the pure in the pure form er let me go ahead and see if i have that slide somewhere here it's okay i need to go back yeah but the yield goes down to 75 per cent based on the starting material but the 17 per cent that we lose appear to be this intermediate it's the un- unconverted er benzil benzoyl benzoic acid intermediate and er we l- when we did it with the TLC this and this were the only two compounds we saw and when we the way we got the pure product is just by washing it with hot water and this thing with the carboxylic group wash washes out so in a commercial synthesis you could actually wash the crude-product the mixture of this and this with hot water and then vacuum dry your evaporate your water and get this product and recycle it back er to the start of the cyc- cyclisation stage the ring-closing stage so if you if you recycle the unconverted product you could get a theoretical yield of a 100 per cent for this stage of the reaction and then the yield of the overall reaction would be close to the 92 per cent that for the intermediate , so basically er w- you don't get any degradation the only product you get from this reaction is this product and er you get some unreacted material and all you'd have do is rec- keep on recycling it and the only thing that would leave is this product it's a very simple reaction and water is the only solvent er you use ex- excess toluene that you can recycle you can s- it's not that separ- it it's only toluene and water are the only two solvents you use here and it's not difficult to separate toluene from water so it's not a very complicated reaction this is the mass-spec of our purified er the 2MAQ that we synthesise and it's identical to the mass-spec of the one we purchased from aldridge chemical and this one is 95 per cent purity of 2MAQ so we assume that this is 95 per cent 2MAQ as well we don't form a lot of 1MAQ so the 2MAQ can be produced and as i said here it appears as if 2MAQ can be produced in high yield by the friedel-craft reaction and probably at a lower cost than AQ by the same reaction so i'm just trying to show that the 2-methylanthraquinone is not purely a theoretical chemical <P:06> alright topic two anthraquinone-related chromophores we were concerned that anthraquinone was forming complex with the pulp and the anthraquinones are yellow so we are you know we are the yellowness of the bleached pulp would be from anthraquinone in the pulp that wasn't bleached out in order to test that hypothesis we doubled the charge of 2MAQ from point one to to point two five but what we actually observed is that you get a higher brightness when you use the point two five per cent MAQ so it doesn't appear that you are forming any colour complex the colour complex with the pulp is a big problem because if that's the case you'd expect a bigger problem with the higher dose but we actually end up with a [brighter pulp] </BS1>
<S2> [were they cooked] using the same kappa number </S2>
<BS1> uh </BS1>
<S2> were they cooked in the same kappa number </S2>
<BS1> on the on the different (xx) one this one only [gave it] </BS1>
<S2> [so they are] </S2>
<BS1> mhm-hm </BS1>
<S2> er anthraquinone (xx) doesn't (xx) </S2>
<BS1> no er this gave a er this is a you don't need more than this this is close to the m- you get the maximum <S2> [okay] </S2> [effect] by the time you get to that dose [(xx)] </BS1>
<S3> [did] er did you er observe that the (xx) alkalinity (xx) </S3>
<BS1> no we didn't measure residual alkal- alkaline but i don't <S3> [okay] </S3> [think so] we just measured the NPH and it's still pretty pretty high alright chromoform formation during oxygen stage er one of the thing we observed quite a a- in er almost all cases is that the soda-AQ and MAQ pulps are approximately five points lower after the oxygen stage than a kraft pulp and that raised the question were we actually forming chromophores unusual chromophores in the oxygen stage so we investigate that er hydrogen peroxide delignified by a similar mechanism to oxygen however hydrogen peroxide is a superior brightener due to this intermediate which is used to brighten mechanical pulps . so what we did was the oxygen and we did oxygen plus peroxide and we get a s- er 1.7 unit lower kappa number for the peroxide inclusion and we make up that five point brightness gap however when we bleach the pulp we only end up with 1.1 points of brightness and so the peroxide does give some improvement but when you go back to this graph this is for the oxygen pulp when it's fully bleached and this is the peroxide plus oxygen it's lower than for the oxygen pulp but if you compare it to a kraft pulp with the same with kappa number 8.7 you s- you still end up with a higher </BS1>
<S4> could you (xx) is it s- so that chlorine dioxide is er dependent on the kappa number so chlorine dioxide [(xx)] </S4>
<BS1> [yeah yeah] yeah so what you get with a lower kappa number what you get with a we use the standard condition so this one the kappa number was about 15 or 15 per cent lower the kappa number of this pulp 8.7 compared to 10.4 so we use less chlorine dioxide in in the with this pulp but that's the standard we use we use a kappa factor of point two in all in all cases what what you can see from here is that the difference between a kappa number 10 and a kappa number nine after oxygen stage is quite significant you know you end up with a higher bleach brightness and you also use 10 per cent less chlorine dioxide in the (xx) stage so that post-oxygen kappa number is quite significant but you can see that the MAQ pulp is still darker than the than the kraft than a kraft pulp would be . alright the next topic is lignin condensation and this is one of the main condensation reaction or s- er one that is suspected and we actually made this intermediate by this exact reaction we actually made this intermediate with ethyl side-chain with an ethyl side-chain and an ethyl side-chain here but based on this reaction if you are having a er basically it's a condensation between two phenols so if this reaction is occurring you would expect the phenolic hydroxyl content of the residual lignin to increase and we er okay based on the condensation mechanism you would expect more phenolic hydroxyl in the residual lignin and when we measured the phenolic hydroxyl content by the periodate oxidation method what we found is that the MAQ pulp from the hardwood sugar maple had more phenolic hydroxyl group but they are not reactive to oxygen so we have phenolic hydroxyl groups that er aren't being oxidised away on the relatively harsh condition and this is an indication that these are condensed phenolic units because they are less reactive to oxygen and to most bleaching chemicals we also did it with pine er softwood we er we would expect more condensation because this condensation occur between guaiacyl units the syringyl units that have the methoxyl group at the C5 position wouldn't be wouldn't be involved in this condensation the C5 position has to be has to be free for this condensation reaction to occur so it it only occurs with guaiacyl units . so when we did it with pine we saw much higher phenolic hydroxyl group but again after the oxygen stage you still end up with a higher phenolic hydroxyl hydroxyl group er in the lignin , okay what we did was analyse the the lignins (xx) dissolve and (xx) dissolve the residual lignin with by permanganate oxidation and you can oxidise this thing with permanganate and you cleave this bond this bond and this bond to give you isohemipinic acid you oxidise this carbon here to a carboxylic acid and we did it with the model compound i told you we synthesised and we got a high yield of isohemipinic acid , and isohemipinic acid is this one here you you break the C5 carbon-carbon bond and oxidise it to a carboxylic acid after the permanganate oxidation you esterify all of the esters and you quantify these these products er we use permanganate oxidation because we fo- found it to give reliable results for this C5 con- this dimer the biphenyl dimer and for C5 condense structures and i'll show you the significance the beauty of this method most methods you are con- you are measuring condense structures as one but in this thing you can measure more than one condense structure so you can see if if you are getting the expected trends in two dimensions basically , so these are the eight products you get from hardwood one is the uncondensed guaiacyl and a condense is one with carbon-carbon bond and the ring other than the carbon-carbon bond in the side-chain so the un- the uncondensed structure as these three positions are free or there's no carbon-carbon bond other than this carbon-carbon bond and so you have the uncondensed guaiacyl uncondensed syringyl and then you get this from the C5 condense the C6 condense the dihoryl ether this this ether dihoryl ether is difficult to cleave and if both of these groups are methylated you do not cleave the the biphenyl bond , alright we did some work on native hardwood lignin er this was a poplar this was another poplar these are some hybrid poplars i'm working on and this was a maple birch co- cottonwood mixture and we were hoping to get the syringyl to guaiacyl ratio what we did we hydrolysed the lignin with an alkaline copper oxide treatment and that breaks off the lignin and generate a lot of phenolic hydroxyl groups so we get a high product yield after the permanganate oxidation er but what we found is that we get a relatively l- low amount of syringyl units in each case and that was because the copper oxide actually oxidised the syringyl units which are more reactive in oxidation but what we were glad to see was the consistency the method gave for the condense structures and we are interested in the isohemipinic acid from the C5 condense structure as well as the biphenyl structure and you can see that the method gave pretty good results also er if you this is the uncondense unit and we can measure the uncondense unit in a native lignin by nitrobenzine oxidation er the ratio of the condense to the uncondense is about 1.5 for the softwood and for the hardwood it's about 1.06 the hardwood would be two plus one half of seven you get seven is with the with the syringyl unit here all of these are from guaiacyl products so , when you do it here when you total up the guaiacyl products you have to take one half of this plus all of this it's about 50 per cent of this amount and the half of this the 2.8 is about six per cent of this amount and i'll tell you why that's significant later on , and i should be done in no longer than 10 minutes , alright what we did was made kraft and er soda-AQ pulp from the birch maple cottonwood mix i like to use a mixture of chips to be representative of you know all hardwoods and what you can see is that in the dissolve lignin you would expect the biphenyls to be extracted from the wood at a slower rate than the uncondensed structure and that has been shown a lot so you would expect a lower concentration of the biphenyls in the dissolve lignin and we did observe that that there was a decrease in the amount of biphenyl this is in the lignin that is dissolved in solution you would also expect based on the phenyl (xx) or the beta-five structures in the wood meal you would expect a a lower rate of extraction of those structures so you should expect a decrease from about 6.9 to 6.0 for the m- for the beta-five structures that are present in the native lignin but what you see is that you get an increase in the beta-five structure and this we assu- a- assign to condensation to the formation of of the diphenyl methane structure or the alpha-five structure by condensation so in the kraft black liquor we would say this goes from about six to eight as a result of condensation and then with this soda-AQ process it goes from about six to 10.4 so you get you get more condensation in the dissolved lignin from the soda-AQ process then we did it with the pulp the copper hydrolysed pulp and what you can see is that the biphenyl accumulates in the pulp so while you have only 4.4 per cent in the in the native lignin it goes up to about 13.5 per cent in kraft soda and soda-AQ AQ pulps and what you can see is that the the other C5 er from the beta-five and the alpha-five structures also accumulates in the lignin and you can see that er the difference here between this and these two is we assign to condensation so what it looks like is that you form about three diphenyl methane dimer in the soda-AQ process or at least three more than you form in kraft i suspect that you don't actually that this increase in the alpha-five in the isohemipinic acid is due to accumulation of beta-five in the residual lignin and not to condensation so i i don't think you have any condensation in the kraft process and i think you have about three dimers er formed in the soda-AQ process and those three dimers are six (millimoles) those th- those six per cent of condense structure in the lignin is what we think is responsible for the poorer bleachability . alright some areas that have worked er if you er my biggest funded programme is with the i'm investigating 22 different hybrid poplars for the US forest service and er what we see is that the pulping and bleaching of these poplars varied quite dramatically and we suspected that it has to do with the syringyl to guaiacyl ratio because the syringyl groups accelerate both pulping and oxidative bleaching so from the permanganate oxidation we discussed the total G-unit for the uncondensed guaiacyl unit was 1.5 to one and the total S-unit to uncondense unit is er is a factor of 1.06 so what we did was measure the uncondensed syringyl and the uncondensed guaiacyl by nitrobenzine oxidation this is a s- very simple reaction and and one that has been used for a long long time and when you do this reaction from hardwood the minimum yields we got was 40 (millimoles) per 100 C9 you get a very high yield of these four if you total these four products it comes to at least 40 per cent of the lignin and we have gotten it as high as 56 er per cent of the lignin so you can get the two s- the two s- syringaldehyde and syringic acid and vanillin and vanillic acid are the two syringyl products and when you multiply the syringyl to get the total the uncondensed plus condensed syringyl and the uncondensed plus condensed guaiacyl you get a syringyl to guaiacyl ratio and when you plot that ratio and you do kraft and soda-AQ pulp in under the same condition you see that your kappa number goes anywhere from 20 with a low syringyl to guaiacyl ratio down to 12.5 with a high syringyl to to guaiacyl ratio also when we did the soda the er the permanganate oxidation and the black liquor we got an S to G ratio of 1.2 for this sample this is the birch maple cottonwood mix and here we got 1.25 and for this cottonwood we got 1.6 by the permanganate and we got 1.5 here so the ratios we are getting er i- are is collaborated by the permanganate oxidation but it's the permanganate oxidation without copper oxide . one interesting approach we have found is to do this soda this is for soda-MAQ sulphide and what we do is add about one quarter as much sulphide as we had to the kraft process and this small amount of sulphide er gives you a kraft pulp and it gives you a higher yield from the MAQ but you only use er typically we had four per cent NA2O as sodium sulphide but if you had only one per cent here you get a a hybrid process that might be workable in this case you'd have to recover the sodium sulphide as H2S but you are dealing with a much smaller amount of H2S er to to recover you'd have to recover and recycle you'd have to recover this thing as H2S and dissolve it in caustic to regenerate the NA2S but the problem would be much more manageable if you are dealing with a er with a smaller amount if you are de- doing an absorption process it's a much simpler process if you want to recover 99.5 per cent by by absorption so we are s- tr- trying to not to use sulphur but it's possible it's a possibility , summary the soda-AQ and MAQ produces unbleached hardwood pulps that are nearly equivalent to kraft however their residual lignin appears to contain more condense structure and the pulps are more difficult to bleach than kraft er that's it er did i have the acknowledgements here good the financial support of the member companies of the empire state paper research institute er michigan michigan state eastern hardwood utilisation and andritz is deeply appreciated i think that's it and i'll try to answer any questions you may have </BS1>
<P:09>
<S2> thank you very much for a very interesting presentation </S2>
<BS1> [you're welcome] </BS1>
<S2> [i would have] a couple of questions erm this mill in tennessee <BS1>  yeah </BS1> erm the (xx) you used for that was that er maple and and w- what are the </S2>
<BS1> er mixed hardwoods <S2> yeah </S2> in the south er oak sycamore it's hardwood and you can classify the hardwoods as manageable <S2> mhm-hm </S2> er th- th- their their reactivity varies but you can you can pulp most hardwood by this process mhm-hm </BS1>
<S2> and er did you say that there were buildings in the US using soda-MAQ or [was there any] </S2>
<BS1> [no two] mills doing <S2> [okay] </S2> [gasification] they are both non-sulphur mills these are mills that make high-yield pulps for packaging so they use sodium mostly sodium carbonate to lower the yield to about 80 per cent so they remove about 10 per cent lignin about 10 per cent hemicellulose and when they get it at 80 per cent yield they refine the er the pulp and the- they blow it and refine it er about 170 degrees so it's a non-sulphur process but it's not a it's not a chemical-grade er pulp but both mills are non-sulphur so it's they just recover the sodium carbonate and send it back to to the to the pulping process and both of them at the present time just burn the fuel gas er they th- there's not er these mills don't have an alkaline recovery system you know the you the so they have an environmental problem so in this case they recover the sodium carbonate as a powder (xx) the gasifier and recycle it and they get some energy value as well </BS1>
<S4> who has built those er gasification (xx) </S4>
<BS1> it's a company called thermochemical incorporated in baltimore er thermochemical i'd say that thermochemical recovery in er er in baltimore TCI or TRI , is the name of the is the name of the company </BS1>
<P:05>
<S4> [(xx)] </S4>
<BS1> [actually] yeah i it's on one of my slides i can should in case you want to look it up in the internet end show <P:05> one of these early slides <P:05> i i think this one it's <S4> [okay] </S4> [TRI] thermochemical recovery incorporated , so er they started up one in ontario canada and they started up one in big island big island virginia it's a geor- georgia pacific mill and er i hope they start advertising their but they got they were approaching this percentage of hydrogen from day one actually someone one of their senior consultant they had a problem when they started this thing up and they said well suppose we have to shut this process down we are gonna have a reactor @full of hydrogen yeah so that@ <SS> @@ </SS> that was one of the problems they had at day one you know what if what happen when we shut this down you know we are gonna have this big digester of oxyge- of hydrogen and you know suppose we have a little leak and a little fire [@you get what i mean ba-doom@] </BS1>
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<S2> (xx) space programme </S2>
<BS1> @yeah right oh sorry well@ so that's that any more questions er </BS1>
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<S2> i think you could maybe just a a few words well if i don't know you were talking about at lunch er about this school ho- how big is the the is the erm college of environmental science and </S2>
<BS1> it's only 2,000 students we are a pri- we are part of the state university of new york which is the biggest university system in the world the state university of new york has about 400,000 students <SS> @@ </SS> spread over 64 campuses but we have about four specialised schools er that are too small to stand on their own so they are built we have t- they are built on the campuses of bigger university so we are under syracuse university campus and since they don't want any competition er they have us in a @corner of their campus@ <SS> [@@] </SS> [and they] they @you know@ we are in a constant tug of war with them so but but er we make the relationship work but we amongst the 2,000 students we have 10 faculties 10 separate faculties and we have the faculty of paper science and engineering er which in the good old days we used to have about a 100 undergraduate and about 40 graduate students per year er now we are down to about 50 undergraduates and er 20 to 25 graduate students er in the at the present time er but we have been around we are the oldest paper school in north america we opened in 1919 i think or in 19- er 20 and er i've actually trained a lot of older paper makers er all around the world including many from scandinavia er er we you know we used to train in our (heydays) but we do work in wood chemistry pulping and bleaching paper making paper physics er i think that's basically it we are now getting into the so-called biorefinery approach er we are we are pre-extracting the carbohydrates before the digester with the aim of making chemicals and fuels from those xylene instead of sending them to the digester where they they are extracted they consume alkaline being extracted so they are gonna be extract- er you know if you are putting in extra volume that goes into the liquor it's like a deliberate they're doing something negative deliberately so we are trying to remove the xylene and er do something with them er we have people in our environment people who are good with enzymatic processes that is we are removing the xylene without degradation hydrolysing them into xylose and then use xylose to make er polyhydroxial (xx) which is a polymer or plastic or biodegradable plastic and people have tried it before it's not a new process but the problem with it sometime it biodegrades too fast so we have an <SS> [@@] </SS> [we can't get consistent] we can't get consistently high er molecular weights as yet but we are we are working on it and we are also now in the US starting to ferment pentoxides to ethanol we are trying to do that but my approach is if you pre-extract the xylene er forward the extract to the brown stock wash it after pulping and just gasify the thing make hydrogen you know those two things that we know will work you know so so that's that that that's it , well thanks a lot everybody stayed awake <SS> @@ </SS> that's the good thing about a small group <SS> @@ </SS> @everybody stayed awake@ </BS1>
