CaptainPanic

What process are you thinking of? Do you want to place wood pellets into a heating to distill the methanol and turpentines straight out of the wood? I know that these components are present (well, methanol isn't too abundant in wood, but if you distill at high enough temperature, it will form from wood). But if you plan on doing a pyrolysis step, then I fear that the selectivity towards methanol and the turpentines (a mixture) is rather poor. I'm curious to hear your opinion about it. Btw, processing pyrolysis oil further by cracking is is called gasification (It's the next step. Pyrolysis is from 400-600 deg C, gasifiers can run at 750 and up). One of the challenges with pyrolysis oil is its high reactivity (and low stability).

Contrary to popular newbie-belief, the introduction thread is read by people who visit the forum regularly. Welcome to all new people!

I advocate construction of a couple of dedicated dams for storage of lots of water, which should create a storage for electricity. Electricity storage is one of those common arguments against clean energy, and it is actually no argument, since the problem was solved 100 years ago. I also advocate that states nationalize energy companies. Those energy companies were privatized at the worst possible moment, just when the time had come for a transition to sustainable energy. As I wrote before, I fear that the market will not solve the problem by itself. Therefore I am happy to hear Americans, (the ultimate capitalists) and specifically Gore and also Obama state that they want to stimulate an energy independent America. It's brilliant. I hope they'll commit themselves and the country.

I am not sure that a pyrolysis oil flame can reach even 1100 deg C. It should be able to, I hope It really depends on the amount of water in the fuel. But you can probably imagine that if you have 40% water, and that all has to be heated, evaporated and heated even more... without it adding any heat (water obviously will not burn). It reduces the combustion temperature a lot. I have no time to really dig into it, unfortunately, because the topic is interesting. It would really be cool if you can have a car running on liquid wood Pyrolysis is simple, and the feedstock is very abundant. I had a quick look around on google and in literature that I have available close to me, but I couldn't find anything specific about combustion temperature of pyrolysis oil. Those turbines seem the right type of equipment though. It seems to me to be more robust than a normal combustion engine.

Indeed. You can build a lot of new companies, and in fact a whole new industry, if you'd spend the trillion dollars that the US government has now spent on bailing out companies. It's a shame that the world does not have the courage to reform quickly... And I always point at the 5 years that WWII has lasted to show that the world can reform really fast, if you want to. It was obviously not a good time in our history (no matter which side you were on - Allied, or Axis)... but it was a time where major changes were achieved in just a few years. And in a single decade that followed, entire countries and the whole continent of Europe were re-built. From that I conclude that it must be possible to achieve Al Gore's target. So, the main question is not: "Can we achieve it?" (Answer: "Yes we can")... but it's "How bad do we want it?"

We should send in the Space Yeast to make some Space Ethanol.

I really love economy, because it's absolutely NOT science. This thread shows it again: While physicists discuss the 100th decimal of the speed of light, and mathematicians calculate the millionth decimal of [math]\pi[/math], economists discuss whether NO tax, or 50% tax is best for the economy and government revenues. In other words: they're totally clueless. Economy is like religion. Whatever is believed by a majority is basically sort of perhaps true. And it can change in a matter of days.

The effect of NaOH is that the pH will change. Since I am not sure whether this is homework, I'll leave it up to you to figure out which way the pH is going (up or down). The exact effect depends on how much water there is... so, the size of the river, and the flowrate of the water... and of course the size of the truck. I wouldn't worry about decontaminating the river... because a river flows, it will clean itself. But a lake would need some treatment... I'll leave it to you to find out how to neutralize NaOH... and what will be the remaining pollution (you cannot clean it completely).

John Cuthber put you on the right track. You'll have to find experimental data (that means you need a book that gives you the numbers... and the people who wrote that book got it from experiments). Then with a list of points (different solubility at a different temperature) you can use a fit-program to make a line through it. The most simple, and (imho) one of the worst, programs is Excel. It has the "trendline" to fit the data.

I think that the challenge that Al gore has set can be reached. It would require a bit of a "war-economy" with forced investments. The market will not do this by itself, because the energy market, and its customers have interest in cheap and reliable energy today and tomorrow. After tomorrow is the far future. Obviously, a major investment will have a very long pay-back time. But the nice thing about investing in sustainable energy (especially wind and solar) is that you're only left with some maintenance after the initial investments. FYI, wind-power costs about 1 euro per watt (of installed peak power). That's maintenance included for a few years... but not for 30 years or so. I've once calculated for the Netherlands how expensive it would be to supply 100% of our total energy (not just electricity, but every Gigajoule that we need) by windpower alone (which is a rather stupid thing to do, but really easy to calculate). How many turbines we'd need, and the costs of that. It's both affordable and it can be built (there is enough space, and enough steel). For such a massive undertaking, we'd require an investment of about 5-10% of our gross national income... which is indeed massive, but for example equal to the USA's expenses on "Defense". I can post the calculation, but even though it is simple, it's still a long post.

Hmm. I thought that the soot particles simply wouldn't burn unless the temperature is high enough because they have a close to zero vapor pressure and are also not decomposing, and that this problem also occurs when sufficient oxygen is present. Pyrolysis oil burns at a much lower temperature due to the presence of lots of water. (Pyrolysis oil is really wet, with up to 40% water). Your explanation sounds pretty good, and I assume you're more an expert on the matter than me Thanks also for the additional explanation of the combustion (on the combustion time or residence time and presence of water). Sorry for not talking too much about the turbines in this post.

pm is picometer, or [math]10^{-12}[/math] meter. nm is nanometer, of [math]10^{-9}[/math] meter. parts per million is abbreviated as "ppm". It means 1/1000000, just like percent (%) means 1/100 and per mille (‰) is 1/1000.

Reaching emission standards are just a matter of: 1. Good combustion 2. Cleaning up the mess after you're done with step 1. And with pyrolysis oil, I also think that the combustion will generate quite a lot of particulate matter (aerosols, soot and such). The presence of water will mean that the combustion temperature is lower. This in turn can possibly mean that the combustion forms more soot. The soot can be cleaned with the same technology that is applied to modern diesel cars (a filter). A nice advantage however is the fact that plants (and therefore pyrolysis oil) contain very little sulfur.

I'll have to join YT's team: My goal hasn't changed for some time now (since I've discovered chemistry and physics): Give the world free energy (sustainable, clean, affordable (but probably more expensive than today)). In this goal it's rather irrelevant what I am or will become myself. But I seem to follow a logical path/career to achieve this: I've found help. What has changed? Nothing. Still going strong. Finished my masters, then found a job in the right business: sustainable energy

The acceleration lag can also be solved by adding a small flywheel to the vehicle. You'd only have the lag once, at the initial ignition moment. But many cars need a couple of seconds to come to life. Indeed, I totally agree that there are solutions... I'm curious if the turbines would be able to run on sustainable (and nasty) fuels such as pyrolysis oil which, if I'm allowed to exaggerate (a lot), contains all the chemicals that you can find in the organic chemistry section of the Handbook of Chem.&Phys.

Eehm, almost. When a gas is compressed, then we changed the pressure. But we're not dealing with compression, we're dealing with a change of temperature. If the temperature increases, and you have a rigid flask that cannot expand, the pressure will build, and the volume remains constant. If you heat something in a balloon that can expand, the volume will change and the pressure remains constant. In the 1st case, you use Cv, in the second, you use Cp. Because it's often dangerous, and not very practical to allow pressure to build because of heating, Cp is the most used. It's the value that you'll find in handbooks. Disclaimer: the following text does come from a Thermodynamics book (Smith & Van Ness) but also from wikipedia: Definition for Cp, Cv [math]C_V=\left(\frac{\partial U}{\partial T}\right)_V[/math] [math]C_P=\left(\frac{\partial H}{\partial T}\right)_P[/math] The subscript V and P mean "constant volume" and "constant pressure" respectively. These two formulas indicate that the Cv deals with the internal energy (U), and the Cp deals with the enthalpy (H). The enthalpy is the parameter used for heat balances in engineering.

Infinity probably means that there is no focus. A lens has a focal point, and if the object is at the same distance as that object, then it will be a sharp (focussed) picture. A lens that has the focal point at infinity will never completely focus. I think it means that in the "thin lens formula", the value of S1 is at infinity, meaning that the lines originating from a point on one side of the lens (picture side, S2 side) will never converge, or diverge, but in stead will run perfectly parallel.

That is why I initially proposed an over-pressure (created by water vapor) inside the greenhouse. I showed what pressure would be required at 5 deg C to have a normal equilibrium between liquid water and the water vapor at 5 deg C. But you're right that because of the really low pressure, it is not possible to have open systems like I proposed in the last line of my 2nd post in this thread. Conclusion: Greenhouses on Mars must be like big transparent balloons!

Cp is the value for the specific heat at constant pressure Cv is the value for the specific heat at constant volume A gas can be compressed, but a solid is (near) incompressible. If you decide to keep the pressure constant, you can just assume that the volume will also remain constant. Therefore, the two must be the same. Disclaimer - I did not get this from a thermodynamics book (which should be the right source). I just wrote it down because it seems logical to me. (i.e. I haven't done any research on it).

The problem challenge with most, if not all, turbines is the startup. As described in the article (which is interesting), the cars all had an "acceleration lag", because the compressor needs to build up speed (and pressure) before you can actually accelerate. In the newest versions of GM, this was 1 second. I also question the fuel efficiency, although I have no reason for that other than that US manufactured cars of the 60ies, 70ies and 80ies aren't famous for fuel efficiency.

I think... therefore there is life in the universe. I've never been to Mars, so I wouldn't know what's happening there. Seems rather dull for a lively place though.

First of all - thanks for the article. It's really interesting. I've enjoyed reading it. It probably contains more parameters for growing plants on Mars than we could come up with in this thread. Why would that be too low? 760 mmHg = 1 bar 6.5 mmHg = 0.0085 bar = 8.5 mbar. That is the vapor pressure of water at 5 deg C. You probably meant to say that, of course, the soil needs to be watered. Plants cannot get the water from the air. Plants (most at least) prefer liquid water. I'm just talking about the added vapor pressure that can be used to inflate the greenhouse, because in greenhouses the air is almost completely saturated with water... Hmm. Good point. We'd need a whole bunch of nutrients. We also need to remove a couple of other nutrients. Would moss be an option? Some of the mosses grow on bare rock. For those, perhaps merely removing the toxic components is enough? It could limit the amount of fertilzer needed. And they also grow at low temperatures. I would suggest that the ultimate goal of developing plants for Mars is that you can work in open greenhouses, like here on earth. Greenhouses that do have their own climate (temperature, humidity), but that are ventilated with outside CO2 (Martian air).

Snail asked: "can you please be a bit more specific". You are not more specific. You just repeated the same question. Try to make a post with more than 1 sentence. Explain what you want, why you want it, etc. Sorry if you think I am rude. It's my character to be direct, but it's all with the best intentions. RAJESHKUMAR, What is the level of school that you finished? What is your age?

Hello! Did you try to search on Google or Wikipedia? I think you should invest a little bit of time, before asking questions here. We are all volunteers who like to answer questions, but it's a little silly if somebody invests 15 minutes of time to explain something if you haven't even spent 1 minute to look it up. Sorry if you already tried to find it. Your question is so short that it suggests you didn't try yet.

Good morning! Over coffee, I came up with the following. I believe that Mars is quite a nice place for plants. The atmosphere is nearly pure CO2, which must sound like heaven for a plant if it had ears. The pressure is 750 Pa (7.5 mbar). That means that the CO2 pressure is a lot higher than on earth (where we have merely 35 Pa CO2 pressure). How difficult would it be to grow plants in the Martian atmosphere? I know that the temperature is too low. Water, if available at all, is solid. But those two points can be solved with a simple solution: a greenhouse. The point I'm trying to make is: a greenhouse could be really simple and low-tech. Just a plastic foil to create an insulation and raise the temperature to a little above zero Celsius. Also, the additional vapor pressure from water would be no problem (at 5 deg C, we are talking about 6.5 mmHg (or, 8.5 mbar). That overpressure is perfect for keeping the greenhouse inflated. The only high-tech piece of equipment you could need is a way to remove oxygen from the "air" inside the greenhouse. Venting it to the outside atmosphere would also cause the greenhouse to lose water. Any thoughts?