*3.2. Potential of Ethanol*

Figure 5 presents the long term ethanol (tonne) probabilities in three scenarios: (1) ethanol by thermo-chemical process without catalytic methane reformation, (2) ethanol by thermo-chemical process with catalytic methane reformation, and (3) ethanol by biochemical process. As it can be seen in Figure 5, long term ethanol production shows steadily increasing trends for all three scenarios. As expected, the mass of ethanol in the scenario (1) achieves the highest when comparing with the other two scenarios due to no catalytic methane was reformed in the conversion process. The low mass ratio in scenario (2) resulted in low tonnage of ethanol production.

**Figure 5.** Long term ethanol probabilities in Michigan.

### *3.3. Potential of Energy and Emission Savings*

According to [11], the commercial timber species within the Kinross supply region are categorized into five hardwood groups (Aspen, Maple, Oak, Upland Hardwoods, and Lowland Hardwoods) and three softwood groups (Pine, Upland Softwoods, and Lowland Softwoods). The Kinross supply region covers the Western Upper Peninsula (WUP, refer to Figure 1 for Michigan regions) in total, the Eastern Upper Peninsula (EUP) in part, and the Northern Lower Peninsula (NLP) in major part. As it can be seen from the Figure 1, the three regions (WUP, EUP, and NLP) are the main forest regions in Michigan. Thus, it is reasonable to take the timber species within the Kinross supply region as the timber species in Michigan. Since the HHV variation between species is usually smaller than the variations within one species [46], the average HHV (19.3 MJ/kg) collected for maple is used as the HHV for hardwood and the average HHV (20.9 MJ/kg) for pine as the HHV for softwood in this study. The results were illustrated in Figure 6. As expected, scenario 2 resulted in the most energy production due to the high mass and energy ratios.

**Figure 6.** Long term energy probabilities of ethanol from forest biomass in Michigan.

Based on the long term energy probabilities of ethanol as shown in Figure 6, the total GHG savings are calculated and the predication results are shown in Figure 7.

**Figure 7.** Long term emission savings probabilities of replacing gasoline with ethanol from forest biomass in Michigan.
