Traditionally, biomass muse mainly overwrites bioenergy, i.e. the energetic use of biomass (hydrocarbons) and is committed to the success of the energy transition. In the following, therefore, some approaches on how methanol can contribute to the success of the energy transition.
Methanol can be used in all three energy sectors (electricity, heat and mobility). The greatest potential as an energy source is clearly in the area of mobility. Why is that? Firstly, due to the lack of market-ready alternatives. E-mobility and infrastructure are only slowly opening up to combustion technology (as of 2019: 99,8 percent of cars are combustion engines) and classic ones Biofuelswhich could be used directly still digest those Acceptance problems of the past decade (Biospit). The most promising alternatives for the turnaround in traffic towards renewable drive systems and fuels are only slowly coming onto the road. In contrast to the electricity sector, Germany and most of Europe have not seen any progress in reducing emissions in the transport sector for years. One of the upcoming articles will deal with the potential and hopes that the RED II (Renewable Energy Directive) will bring to improve the situation.
What is the basic problem of the energy transition in the transport sector? While electricity and heat are largely in demand in a fixed location (buildings), the mobility sector is mobile in name. Without a direct power connection or a battery, a material and low-CO2 energy source is required. Methanol is liquid, storable and transportable like gasoline or diesel. In contrast to the classics among fuels, methanol is not a complex mixture of many different components, but a simple and homogeneous compound. Apart from small changes to the technology, cars can be operated with alcohol (methanol, ethanol), esters (FAME) and ether (DME) or mixed with fossil fuels (gasoline, diesel) without any problems. Methanol has the advantage of a higher octane number than classic gasoline, which means that engines run more stable or less the Klopfer. In general, alcohols are among the fuels with the highest octane and therefore knock numbers, which means that a better compression ratio of methanol and air in the engine leads to more efficient combustion. As the M15, a 15 percent methanol-gasoline mixture can already be used in any gasoline engine without retrofitting. DME is made from methanol, is the simplest ether and can be used as a diesel substitute. The higher cetane number of DME compared to diesel makes it easier to ignite the fuel in the engine and achieve more complete combustion. And that without the addition of potentially harmful additives. Because of its advantages, DME is currently experiencing a boom as an alternative fuel in Asia (China, Korea, Japa).
Methanol also has a lower emission of nitrogen oxides, sulfur oxides and particulate matter than classic fuels. In the best case from a climate balance point of view, methanol is generated from CO2, green hydrogen and renewable electricity, which makes it CO2-neutral and forms a CO2 sink during storage.
As synthetic biofuels, biomethanol and bio-DME are exempt from the energy tax in Germany, which means that they cost 60 cents less per liter. Unfortunately, the following also applies to these alternative fuels: the greener they are, the lower their price competitiveness compared to fossil fuels. An increasing CO2 price In addition to advances in R&D, this will help to ensure that price differentials will continue to decrease over the next decade. Another disadvantage of methanol as a fuel is that the cold start is slightly slower than with petroleum-based fuels. In addition, the energy density or calorific value of methanol is lower than that of gasoline or diesel. On the other hand, methanol burns more completely, which leads to a roughly 25 percent shorter range of methanol vehicles. The advantages of methanol and its derivatives (DME) can outweigh this limitation and the evaluation is ultimately in the eye of the beholder / consumer. In the medium term, there are no alternatives to achieve a CO2-neutral transport turnaround, especially for long distances and heavy weights (trucks, shipping). E-mobility is no longer necessary because of the size of the batteries required for these heavy vehicles.
Apart from a slight loss in efficiency, hybrid cars offer the greatest flexibility for the driver. The increased use of flexible fuel vehicles (FFV) is therefore an elegant approach to support the transition from fossil to renewable and to accelerate the turnaround in traffic.
A comprehensive presentation of methanol in the transport sector can be found in the document “On the road with methanol”By Gregory P. Nowell (1994).