See below for interspersed responses. On Apr 24, 2015, at 5:35 AM, Mike Nickerson <m...@nickersonranch.com> wrote: > > let me ask the question more directly: > > Efficiency questions aside, it seems to me that converting the methane to H2 > has to have the same emissions at the plant that you would get at the > tailpipe when burning the methane in an ICE. The only thing that changes is > the location of the emissions. True? If it isn't true, why not? What am I > missing?
No, this wouldn't necessarily be true. Different emission control systems and different process. You need to compare NOx emissions from a reforming plant converting methane to combusting the same amount of methane in a car. I don't know much about reforming plants or their emissions. Of course, the numbers probably also change with an onsite reformer. > > Efficiency questions then make the hydrogen case less attractive since it > needs much more processing (cracking hydrogen and compressing to a very high > pressure). The only hope that fuel cells have to get back to even is the > relative efficiency of the fuel cell relative to the ICE. > L The latter certainly makes a difference. Not sure what you mean by back to even, but a fuel cell is twice or more efficient than a gasoline engine. This number is changing and varies by manufacturer. As to your earlier point, that seems to make sense. However, as an aside (an aside since you're comparing methane with that same methane being converted to hydrogen) you can't assume that hydrogen will all be created from methane. It just won't, and the percentages are dropping and will continue to do so. > > Mike > > >> On April 24, 2015 12:35:18 AM MDT, Mark Abramowitz via EV >> <ev@lists.evdl.org> wrote: >> Sure, that question has merit. I only answered his first question. >> >> But the emissions I was particularly referring to were combustion >> emissions at the tailpipe...not CO2 emissions, which certainly are of >> relevance. >> >> But when the ZEV standards were adopted, the driver was nonattainment >> criteria pollutants. >> Efficiency certainly has bearing on GHGs, cost and other things, but is >> not the be all, end all. Or the hobbyists on this list would be arguing >> incessantly about ...everything. >> >> Clearly, at the tailpipe, nat gas v. H2 is "some emission number I >> don't know off the top of my head" versus zero. I guess if you go want >> to go beyond that you might assume worse case (?) that the cars are in >> the SCAQMD and the H2 is all produced by steam reformation in-basin. I >> don't know what that number looks like, but I'll bet it's still a huge >> advantage to use H2. >> >> Sent from my iPhone >> >>>> On Apr 23, 2015, at 7:59 PM, Mike Nickerson <m...@nickersonranch.com> >>> wrote: >>> >>> I think Ben's question still has merit, though. If you start with >> methane and take it down two paths, what is the difference in emissions >> and efficiency? The first path is burning the methane in an ICE. The >> second path is converting the methane to hydrogen and using it in a >> fuel cell. It seems like the hydrogen conversion is still likely to >> create CO2. How does the hydrogen cycle reduce air pollution from >> using methane? >>> >>> Mike >>> >>> >>>> On April 23, 2015 7:28:17 PM MDT, Mark Abramowitz via EV >> <ev@lists.evdl.org> wrote: >>>> On Apr 23, 2015, at 3:57 PM, Ben Goren via EV <ev@lists.evdl.org> >>>> wrote: >>>>> >>>>> Um...why not just use that methane as is? I mean, we already do -- >>>> every vehicle with a "CNG" or "LNG" sticker on it is burning >> methane. >>>> >>>> To reduce air pollution. That's why CARB adopted the ZEV mandate. >>>> _______________________________________________ >>>> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub >>>> http://lists.evdl.org/listinfo.cgi/ev-evdl.org >>>> For EV drag racing discussion, please use NEDRA >>>> (http://groups.yahoo.com/group/NEDRA) >> _______________________________________________ >> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub >> http://lists.evdl.org/listinfo.cgi/ev-evdl.org >> For EV drag racing discussion, please use NEDRA >> (http://groups.yahoo.com/group/NEDRA) > > _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
