From fossil to green

In the year 2040 we will have to feed 9-10 billion people and to provide them with energy and materials. We want them to live according to the requirements of a developed society, and we do not want to pollute the earth or change the climate. The question addressed in this contribution is whether this scenario-sustainable technological growth-is technologically possible on a world wide basis. In 1996, more than 80% of the world's energy demands (350 EJ a(-1)) originated from fossil resources (mineral oil, coal and gas) and the same holds for organic raw materials. In view of the exhaustion of fossil resources and environmental considerations, our radical hypothesis has been that we will no longer use fossil organic resources from, let's say, 2040 onwards. Our natural resources are the sun, CO2 in the atmosphere and land and water on the earth. It will be shown that these natural resources and the appropriate conversion technologies will enable us to move from the present fossil resources based economy to a plant-based economy as far as organic raw materials are concerned. The sun will be the major source of energy. The limiting factors in such a scenario are: 1 the amount of agricultural land available; 2 the ability of the world community to overcome the socio-economic and political problems in realising the scenario as formulated in the first paragraph of this abstract. It will be illustrated which technologies need to be developed further and fine-tuned in the coming decades. Examples will be given how present-day bulk organic chemicals and materials can be approached from biomass. Methanol is expected to develop as a key chemical (and hydrogen-carrier). Moreover, one may consider a partial substitution of materials of today by "green" materials, that are directly or in a few reaction steps available from biomass, such as starch and polylactate, respectively. One thing is certain: the plant will be the 'plant' of the future!