Rules and Guidelines
Want to participate in the discussions? Please read our Community Rules and Guidelines. Need some help? Visit Support and Answers.

  • State Not Answered
  • Locked Locked
  • Replies 45 replies
  • Subscribers 10 subscribers
  • Views 1475 views
  • Users 0 members are here
Options
You may also be interested in
This discussion is locked.
You cannot post a reply to this discussion. If you have a question start a new discussion

Energy systems thinking a new design

Helios
Hi I would like to ask the community if we can set up a post for a new energy system I have been working on ,I think it works out more efficient and ecologically better , and its large scale thinking for energy systems , and now I need to check through my figures and need the views of IET thinkers for instance on combustion , post combustion chemistry , it unfolds into quite a complex system which I have been working on for 8 years , but enables us to get more energy from wastes and perhaps helps to move to biomaterials. I have an interest as environmental thinker and have designed the system to go through to government funding phases and pretty confident it works well in a number of questions around energy and environmental thinking .
  • 0
    Hi Maurice , I note a new coal plant is due to open in Germany this week, biomass itself isn't necessarily clean in emissions but is carbon neutral as a fuel , Drax is really interesting , next year it will stop burning coal and go 100% biomass and its hoping to fit CO2 scrubbers for a CO2 capture and store idea , but I just don't get this CO2 capture and store idea , I mean if you have to use more energy to capture the CO2 you will be making more CO2 to do this. at the moment Drax as a baseload plant is strategically important at 9% of uk electricity needs its done a  very good job , but as each new wind farm comes on line and combustion efficiency improves  , its design is becoming unsustainable, I mean if we used modern combustion designs plant we could up the efficiency conversion of fuel to KW , drax could burn the same amount of biomass but get 15-20% more electrical output , although 1 power plant supplying 12% of the uks electricity may be isn't where we want to go , Drax may be in entirely the wrong place now as demands are now mostly urban ones with much less heavy industry. It may be that we could save more energy , by moving power stations closer to demands and reducing line losses.  ,
  • 0
    RDF figure I have got is around 15000 kj/kg and around 1.2 m3 of O2 per kg of RDF(20% moist) , but it is a guide as its quite a mixture depending on how your waste sorting is  1,5 kg of CO2 per KG combusted.


    Ok lets do a combustion run well use a 500mw example needing 6,125,000,000 kj hr . 80%efficient boiler

    Biomass 16,000kj/kg around 383,000 kg hr req 383,000m3 if O2  giving 635,014 kg of CO2 and 243,000 kg of H20 

    RDF  at 15,000kj/kg around 408,000kg hr req 489,000m3 of O2 giving 612,000 kg of CO2 and 258,264 kg of H2O (20% moisture)

    CH4 at 39000kj/m3  around 157,000 m3 hr req 314,000 m3 of O2 giving 289,000 kg of CO2 and 236,756 kg of H20 

    Ethanol 23434 kj/li around 262,000 litres/hr req  323,832 of O2     giving 394,000 kg of CO2 and 242,612 kg of H2O

    Bio solids at 7000 kj/kg  around 875,000 kg and hr 1,050,000 m3 of O2 per hour giving 830,375 kg of CO2 and 617,750  Kg of water 


    every one happy at these ?
  • 0
    Ok then lets have a think about fuel availability , so if we can co fire at say 40% CH4 and 60% solid fuels (comprised of 20% Bio mass 20% Bio solids and 20% RDF ) as an approximation for a 500MW 80% boiler as follows.(values at NPT)


    CH4 62800m3 per hr using 125600m3 of O2 (154,000kg) giving 62800m3 of CO2 (34000kg) and 94577 kg of H2O

    Bio Mass at  76600kg hr using 76600m3 of O2 giving 127000kg of CO2 and 48488kg of H2O

    Bio solids at 175000kg/hr using 210000m3 of O2 giving 166000kg of CO2 and 123550 kg of H2O 

    RDF at 81600kg/hr using 97800 m3 of O2 giving 122400kg of CO2 and 51650 kg of H2O 


    giving a total o2 requirement of around 510000m3 hr (678800kg)

    giving a total CO2 of around 450000 kg (244000m3) 

    giving a total water of 318000kg (318m3 )


    In reality fuel availability may vary , bio solids is pretty regular (excuse the pun ) as should RDF with the right fuel processing systems throughout the country , Biomass is perhaps the more variable probably getting more during summer when construction industry is going strong , but more interesting availability would be if we use it as building material more and then in 50-100yrs we start to get more regular biomass coming through and as a carbon store biomass would be sequestering CO2 giving both a safe and useful carbon capture system over a long time span .The O2 use figure may be high but its the amount of non carbon atom that we make into oxides , mainly nitrogen and sulphur which are difficult to determine ,the High O2/CH4 combustion temperatures will greatly aid thermal decomposition enabling the furans and benzenes to be decomposed to simpler molicules.

    ta daa everyone still happy ??
  • 0
    ta daa everyone still happy ??


    I suspect that the number of people reading this who actually know enough to check your figures is very small.


  • 0
    Simon Barker:
    ta daa everyone still happy ??


    I suspect that the number of people reading this who actually know enough to check your figures is very small.




    And any that do probably aren't going to comment! We live in a commercial world (even academics live in a commercial world) where ideas are money and business survival. No-one wants to discuss ideas in public, because that's letting knowledge escape to competitors. So the way this needs to work is that anyone with a potentially new idea needs to identify key potential partners, get them interested so that they don't feel that they are wasting their time, and then both sides need to get NDAs set up to protect them (there's lots of literature around about this stuff now). 


    Which begs the question, how do you get potential partners interested? Theoretically one way is to "tease" on this forum, but actually a quick read through the posts here shows that the number of posters who are likely to be able to help is very small. A very common, and often quite successful, way is to present at conferences and seminars - let's face it, this is one of the main reasons why people present at these! (The other reason is simply to market their product or service.)


    And then there's the phenomenally hard way, but which can sometimes work, which is to directly approach companies in the field. You need a lot of resilience for this, because you will get knocked back a lot. I ran an R&D team for many years, and I was continuously being approached by individuals, companies from other fields, and university researchers all of whom had wonderful ideas that they knew were much better than our current offerings. Being a helpful and collaborative chap I spent many hours talking to such people in my early years in the role, and what I discovered time and again was that the reason they thought their solution was so good was because they hadn't really understood the problem. As I say, I really like having those conversations, and am always optimistic that something might come out of them, but even I got frustrated in the end and started avoiding them. Engineering managers and business leaders just haven't got the time. SO if you take that path you must have something really well thought through and ideally somewhat proven to take to the company, including costings, so that you can show it is really worth their time.



    Personally I'd love to have a forum where new ideas can be discussed openly, I believe (rightly or wrongly) that it would be better for society as a whole. But that's not the way society is set up. So for example on here I'll happily discuss audio circuit design (and in fact I do very actively on another group's forum) because these days that's a hobby and not the day job, but if anyone wants my opinion on a novel train detection system or level crossing system I'd have to direct them to my business address! And it will be the same for people working in the energy field.


    Hope that helps, good luck,


    Andy


  • 0
    Hi Andy thankyou for that , the journey of this idea has been similar to as you outline ,of course you have to speak with an NDA sort of thinking ,my favourite one was speaking to a guy with 3mn in renewable assets (city investor type) and he just didn't get it , he didn't think combustion efficiency could be improved, I have applied for at least 3 guest speaking slots at various energy conferences and even though they say its for Green technology they just don't give you the opportunity to show the efficiencies for collegiate examination. I even explained to the government science body but they didn't understand it either but didn't say the efficiencies were wrong . I suppose we shall see but looking at the climate patterns for last year and the pollution aspects governments will be asked to act differently , if that 2.5oC target is missed the climate outcomes will be very bad for business and then all those who have sat back and said/did nothing , will be in the dock.
  • 0
    Hi Ho Hi Ho its off to work we go and its Monday hope everyone had a good weekend , I think we now have a 500MW power station capable of burning a variety of low grade wastes , at 6,125,000,000 KJ/Hr and an 80% efficient boiler means that 1,225,000,000 KJHR is lost as so termed stack losses , which could be exiting the furnace at anything from 200-400oC .

    Each 1kg of water at 100oC makes 0,8m3 of water vapour , we have 318,000kg of water in our model so that's 254,400 m3h of water vapour however at around 300oC this would be double so 508,800m3 /hr as water vapour at 300oC same goes for the CO2 at 300oC of 488,000m3 , so perhaps a total gas/vapour of 996,800m3 hr  or 16,613m3/min or 278 m3 sec .


    But we still might have smoke/char uncombusted so If we combust again but this time using CH4 and O2 in a 90% efficient boiler , flame temperatures of 1800oC plus then we can pretty much break down (thermally) any organic chemistry molecule still present , into simpler molecules/oxides .A further third stage of combustion would ensure even the most difficult wastes could be thermally decomposed , I doubt we could use another 500MW modelling so lets use 250MW using around 50,000m3 of CH4 /hr and using 100,000m3 of O2 (plus any excess required) producing 50,000m3 of Co2 (100,000m3 at 300oC )and 75,000kg of water (60,000m3 of water vapour at 100oC , 120,000m3 at 300oC)


    So we now an exit exhaust at the third stage of 998,000 m3 plus a further 200,000 m3 of CO2 and 240,000m3 of H20 at 300oC giving around 1,440,000 m3 /hr , 24,000m3 min , 400m3 sec, at the third stage exit of exhaust ,containing the culmative 950,000m3 of water vapour at 300oC , will be carrying considerable heat in the water vapour , which can be recovered an reused .


    potentially then a theoretical 3 combustion stage 1000mw power plant making 440,000 m3 of CO2 (238,000kg) per hour (at NPT) and 440,000kg of H2O (at NPT), that is nearly half the CO2 output of the J.W Turk plant and 40% more electrical output. By using concurrent combustion , the stack loss of the previous stage is utilised , as well as getting the thermal decomposition to simpler molecules , and no NOX emissions and we can burn most of our organic problem wastes to simple molecules.
  • 0
    May be, but it is the IET ask the community blog , so someone can look through them , its rough thermal workings at the moment .

    but thanks
  • Former Community Member
    0 Former Community Member
    Lots of numbers way beyond my ability or concentration span, and probably most audiences.


    What people will be interested in is what is the additional cost of all the closed loop, recycling, more efficient combustion and energy recovery processes?


    If this all costs >100% more or 5-10% extra output, it is just a theoretical nicety and not practical or pragmatic. What is the extra overall cost v extra overall efficiency and reduced GHG output and GHG CCS benefit?
  • 0
    And it's even less worth it if the extra electricity used to run the extra plant is more than it generates.

Join us to get the best from IET EngX.

Joining EngX lets you personalise your experience so you stay up to date on the topics that interest you, plus you’ll be able to make connections who are looking to collaborate, exchange ideas and more.

Join us Not now

Community Rules & Guidelines