Biogas Furnace is Tubelib-compatible version of standard furnace that
uses Biogas as fuel. All default furnace cooking recipes apply.
See gasfurnace.lua for details and differences.
Signed-off-by: Michal Cieslakiewicz <michal.cieslakiewicz@wp.pl>
Coal block output changed to 9 Biogas units.
Timer code optimized by using local recipe variable.
Signed-off-by: Michal Cieslakiewicz <michal.cieslakiewicz@wp.pl>