**3. Conclusions**

*Sustainable Alternative Syngas Fuel*

the separated MSW for the same reasons.

The impact of coal-to-MSW ratios is evident as already said. When adding coal, the water generation diminishes as the coal water content is much lower than the one in MSW and their concentrations in the syngas tend to be clearly lower for the case of

The water content of the syngas has an impact that should be considered in the options for its use. The water concentrations are so high that there could be possibilities of having water condensations on the gases if they reach the dew point

**16**

**Figure 13.**

**Figure 12.**

*Syngas H2O concentrations and specific generations.*

*Minimum cool wall temperatures to avoid water condensation.*

The theoretical model showed quite consistent results. It was possible to develop a way of estimating syngas characteristics for the gasification of MSW in co-gasification, within practical working ranges for the studied variables. This was done under two extreme conditions for the MSW: as generated in a town with high organic material content and after separation of 55% of the initial waste for recycling and organics treatment (e.g., by biological composting and digestion). The model allowed to find the working ranges for steam-to-MSW ratios (between 0 and 1.0); air-to-MSW (between 1.7 and 5), for co-gasification with coal; and cola-to-MSW ratios in the range of 0.0–0.5.

The gasification can generate electricity in all these ranges, with potentials that go from 0.5 to 2.2 kWh per kg of MSW. For the case of a plant processing 200 tons of MSW per day, the generation capacities would be between 4800 and 17,000 kW. These capacities are entirely within the electricity needs of a country like Colombia. They are between 0.28 and 0.90 kWh per person per day, for the current per capita MSW generated in the country. These figures are to be compared to the current daily electricity per capita use, which is 3.90.

From the practical point of view, it is important to use this as a conceptual basis for future work seeking indications on systems that could be feasible. This will help doing the correct steps. Engineering and design are very important components of the technology necessary to impulse WtE in a country. These systems require detailed studies and planning activities and it is advisable to do the projects considering all the engineering stages. There is always the temptation and the idea that the projects can be accelerated and put into place based on the experience and support of suppliers and makers. This by means of EPC developments, in such a way that engineering stages can be simplified or even avoided. This normally is a much costlier and rigid solution and does not contribute to developing local technology and prosperity. With regard to the solution of the problems, there is ample space to develop a region, as compared to relying only on externally provided solutions. MSW co-gasification with coal seems to be a possible alternative.
