[Terrapreta] Using wasted energy from ICE exhaust to produce charcoal

[jim mason]

i too have thought much about this.  i think anyone who spends anytime
in gasification aimed at ic engines thinks about this.  i have yet to
build my design that recycles waste exhaust heat into the gasifier for
pyrolysis energy, but hope to very soon.

some numbers.

pyrolysis is 200c to 600c.

gas engine exhaust under power are usually 700-800c.  diesels are
usually about 100c lower.

about 1/3 of the fuel energy fed into the ic is being lost out the exhaust.

that is a lot of energy begging to be used to make more fuel for the
engine, and/or char for currently discussed purposes.

j

ps- more generally, i am very excited about this new list and the
active wondering already in progress on it.  it is great to see an
actual new and open question on the energy front, and people trying to
assemble numbers across specialities and disciplines to address it.
terra preta seems to me about the only new idea in the energy world
that was not already explored in the late 70s and early 80s, during
the last round of energy concerns.





On 2/13/07, Duane Pendergast <still.thinking at computare.org> wrote:
>
>
>
>
> Dear Colleagues,
>
> I've idly wondered about using the waste heat from the exhaust gases of an
> ICE to produce charcoal. This could be a basis to develop a system to
> convert agricultural wastes to charcoal on the spot. Some Google searching
> revealed a single paper. The abstract is below. Has anyone encountered more
> information on this?
>
> Duane Pendergast
>
> www.computare.org
>
> _____________________________________________
>
>
>
> Modelling a charcoal production system fired by the exhaust of a diesel
> engine
>
> Surendra B. Prasad
>
>  Physics Department, School of Pure and Applied Sciences, University of
> South Pacific, Suva, Fiji
>
>  Received 9 January 1995;  revised 6 November 1995.  Available online 22
> February 1999.
>
>
> Abstract
>
> A rural area power supply system (RAPSS) which produces charcoal as a
> by-product for use elsewhere through the gasification of biomass fuels is
> modelled. The power generation system utilizes a conventionally-fuelled
> engine-generator combination to produce electricity for local use. The
> energy needed for the gasification process is obtained from the exhaust
> gases from an internal combustion (IC) engine, which could be a petrol
> engine, a diesel engine or a gas engine. In this particular model, a diesel
> engine-generator system is specifically used. The charcoal production system
> being modelled is a small-scale system, producing between 20 and 60 kg of
> charcoal per hour, with the diesel engine running at its rated capacity. The
> special features and constraints which govern such a system operating in a
> rural environment of a developing country are addressed, followed by a study
> of the rate of charcoal production from a given system, using thermodynamic
> relationships. The key features of such a system include reliability,
> simplicity of operation, robustness, operation by local personnel and a
> level of technology appropriate to the location of the system.
>
> Author Keywords: Charcoal production; Biomass gasification; Pyrolysis;
> Exhaust energy; Biomass energy; Energy for rural areas; Charcoal reactor;
> Wood chips
>
> Available from,
>
>
>
> http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V2P-3VVTX3C-7&_user=10&_coverDate=10%2F31%2F1996&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=66695c0adeaedb7e1073b56155c80f2f
>
>
>
>
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>
>