This is Engineer-Poet's Typepad Profile.
Join Typepad and start following Engineer-Poet's activity
Join Now!
Already a member? Sign In
Recent Activity
Something else that occurred to me while I was road-tripping is that the crankshaft throw is about 50% of that of a conventional engine. The up-down motion is amplified 2x by the lower link, but the side-to-side motion is not. This means less connecting-rod angle, less side force on the piston and less friction.
Certainly you can have efficiency and power at the same time. You use the turbocharger to get a 3:1 or greater compression ratio, use variable compression and VVT to achieve perhaps a net 15:1 CR with a 20:1 or greater expansion ratio, and run the turbocharger off the remaining expansion energy in the exhaust gases. It's quite possible to run with substantially lower exhaust back pressure than intake MP, so the piston engine operates partially as an expansion stage of a turbo air pump.
The most likely way to turn the eccentric shaft is a hydraulic piston supplied with engine oil.
I suspect that in the high-boost, high-flow conditions when low compression would be used, tumble might provide adequate turbulence.
At 375 W/l, a 20 kW unit would take up about 2 cubic feet. That fits neatly into most of today's engine compartments.
Fascinating papers indeed. I've long been frustrated by the failure of Ze-Gen to publish any data about their technology's performance. Something neither Buxbaum nor Ceres seems to have considered is the use of a high-temperature SOFC to do the auto-reforming of the fuel and full conversion of methane to syngas, and a Ceres SOFC at a much lower temperature to complete the conversion of CO to CO2.
Low temperatures leave unburned products, and carbon monoxide is extremely toxic. You'll need a catalytic step in an oxidizing atmosphere to make sure that's gone.
Its obvious that the weight and bulk of this is no good for passenger cars I saw no mention of weight or bulk in this item, care to link/quote? As for the supply of ethanol,there is plenty of it ATM, and plenty cheap. The EtOH we've got consumes a very large fraction of the US maize crop to make a small fraction of the LDV fuel supply (and effectively none of the heating, HDV or aircraft fuel). It is a farm-price support program, not an energy program. Last, the people around the world who are starving or have starved (think Arab Spring food riots) because of spiking maize prices want a word with you. Our roads will fall to pieces if Cars are getting 100 miles to gallon of ethanol. No problem, shift the local roads to property taxes and major roads to truck weight taxes.
Seriously, 5 kW isn't a powerplant for a highway vehicle. It's pretty good for a delivery truck that moves slowly and makes plenty of stops, though. The waste heat would keep a cabin warm in all but the coldest conditions. The real issue is the ethanol. Harvey is deluded if he thinks cellulosic ethanol is either cheap or readily available, even now. Cracking lignocellulose to fermentable sugars has never been easy and probably never will be. However, thermal cracking to small molecules which are liquid at room temperature is quite simple to do even on an industrial scale. You'd need a reformer of some type to convert pyrolysis oil to SOFC fuel gas, but the pyro oil can be made from almost anything on hand and requires no costly enzymes or other inputs, just heat.
I'm not finding anything for dearomitization. It looks like it's a difficult thing to do, even if you have a stream of hydrogen to do it with.
Benzene is carcinogenic and aromatics tend to promote soot formation IIUC, but if methane can be electrocatalytically converted to e.g. short-chain aliphatic hydrocarbons it would be a huge advance.
Yes, like they've always needed ways to convert food into vehicle fuel. </sarcasm> What would really improve matters is an SOFC which uses pyrolysis oil. It can be made from woody biomass and requires no complex processing.
Moving the vehicle with the electric motor requires a far bigger motor and battery than just starting the engine. This puts you way out of S/S cost territory.
Plug-in vehicles are currently about 0.2% of the US LDV fleet. A 44% availability rate of charging facilities at home or work means that the fleet can be multiplied roughly 100 times before we run into major difficulties. I can work with that.
Problem is that nearly nobody wants to buy the current plug-ins. Except you're obviously wrong. I can't afford a Tesla right now, but I have owned a Fusion Energi for 3 years. It has its issues (many involving Microsoft, damn Bill Gates to hell) but the car is great. I talked to a possible buyer a month or so ago. He's much like myself and, also finding Teslas unaffordable at the moment, looks likely to go Energi. The future is all-electric but in a battery-constrained world the path goes through hybrid and PHEV.
Ah, Harvey AT LAST admits that his solution is limited to Canada; not even the USA, let alone the rest of the world, has the required elements of geography to do the same. Actually, Harv, the USA used to have a program of keeping large grain reserves and holding cropland out of production to prevent prices from cratering when big crops came in. That got unpopular when the price went up too much once (sound familiar?) after which overproduction was the rule. Ethanol was the new sink for the surplus... and never mind what all the extra nitrate pollution, soil erosion and loss of wildlife habitat did to everything else. Now the USA turns enough maize into motor fuel to affect world prices. Meat producers were trying to get the ethanol mandate reduced or dropped when grain prices spiked again a few years ago, and the food riots which started the Arab Spring (which is now the Islamist Winter) were directly traceable to those same high grain prices.
Harvey thinksthe hydropower which suffices for the 8 million of Quebec can be scaled to the 350 million living north of Mexico, and"biofuels" which consume 40% of the US maize crop to make about 10% of its LDV fuel (and an even smaller fraction of the energy therein) will become a "fuel of choice", rather than a gap-filler. Harvey thinks this because he can't do arithmetic.
Must the farce of clean coal find its way into every energy program? I think Kemper is going to be the last nail in that particular coffin. Decades after the Wabash River Repowering Project, Southern Company can't manage to keep a coal gasification train running. Maybe this is due to too much affirmative action hiring, but regardless of the cause it won't prompt any follow-ups.
EP diesel will cost more than 2.5 USD. Current oil prices cannot support the development of new oil fields so the production will eventually fall as it already does in the US and then the price of diesel will go up to between 3 to 4 USD per gallon. Yeah, but when? The shale drillers have run well down their learning curve, so it'll be a while before their wells deplete enough to be unprofitable. EP diesel will cost more than 2.5 USD. Current oil prices cannot support the development of new oil fields so the production will eventually fall as it already does in the US and then the price of diesel will go up to between 3 to 4 USD per gallon. The relative economics don't change based on MPG, because the electric consumption goes up based on vehicle drag.
the EV car race (plugin or otherwise) will make a large demand for base loads at night... perhaps with all that cheap solar, make the night time the high point for electricity. Have you actually worked the numbers on solar? Absorbing Germany's peak PV generation would need something like 1/2 of a Chevy Volt per capita to buffer it. This begs the question, what would everyone do when PV takes a day off? Renewables need EVs and a smart grid to work well This is the backwards thinking which pervades talk about ruinables. The advocates demand that the grid, and the economy which depends on it, be re-engineered to serve unreliable energy sources. The grid exists to serve the economy, and if ruinables ever stop meriting the pejorative they need to serve the grid and not vice versa. Ruinables need EVs, but nobody asks if EVs need ruinables. If your EV is tied down to buffer wind and PV, it can't do its primary job of getting you around. Nuclear might be needed. Nuclear is absolutely required to meet even the completely inadequate emissions targets of the so-called "Clean Power Plan". There is growing recognition that it is the only scalable, dispatchable zero-emissions energy source we have. I'm with you on the overhead wire thing, I think it could work... but its just how to go about implementing it, like how do you bill for it?? Ever heard of Speedpass?
Cummings has already built a medium duty van with -90% carbon reduction as compared to the competition of diesel or gasoline. You don't give a citation, but I will bet dollars to donuts that the ethanol fraction of the fuel was assumed to be zero-carbon. EtOH made in the USA isn't remotely so, and can't come close so long as nitrate fertilizer and distillation still come from natural gas. Electric propulsion can be powered by emissions-free nuclear power, and the farmland freed from corn-growing duty could be returned to prairie or forest as a net carbon sink.
I was thinking of something more like continuous overhead power or charging-in-motion from overhead power in a dedicated lane of the road. Suppose you have some super-battery which can charge in 10 minutes (6C). The truck slows to 45 MPH for the charging lane, so 7.5 miles long. The truck is entirely powered by the overhead plus the battery is charged. Put one of these every 100 miles, so 92.5 miles of open road between chargers. If the truck speed limit is 70 MPH, it takes 85.7 minutes to go 100 miles. Cut that by 7.5% and add 10 minutes for the charging segment and you're up to 89.3 minutes, adding 3.5 minutes per 100 miles or about 24 minutes ($8 in labor) for 700 miles. This is faster than the tractor-swap and you don't need a second fleet of tractors to sit charging while the other is on the road. Wal-Mart has been pushing drag reductions to double the mileage of tractor-trailers to roughly 13 MPG. At 13 MPG, 140,000 BTU/gallon and 45% thermal efficiency, energy consumption at the transmission is about 5.1 MJ/mile or just under 1.5 kWh (allowing for losses). 700 miles at 13 MPG is 53.8 gallons; @$2.50/gallon (about today's price where I am) this is $134.60. Buying 1050 kWh at $0.10/kWh is $105, not a huge savings. At $0.15/kWh, the savings are negative. All these numbers change with anything like a carbon tax.
CE88: There is very little lithium in seawater compared to sodium, potassium and calcium.
It is roughly 11,000 amps. It's going to be interesting to watch this to see what kind of consequences fall out over time. The advocates of ruinables are all a-flutter over the potential tripping of a single 1.1 GW nuclear plant, but the impact of 11 times that much power being lost from a 12 GW HVDC line doesn't seem to get them excited since the source is supposed to be what they favor. We will see if and how it works, hmm?
I read the words of Henrik and DaveD and wonder if they're nuts. Fast EV charging demands large amounts of power at the beck and call of the driver. Who in their right mind thinks that wind or solar can have ANY significant role in this?! The only carbon-free sources of electric power which are there when called upon are water behind a dam and uranium in a reactor.