Potential for fuel production from crops

Abstract

Studies conducted during the last few years show that the various ecological conditions in Romania determine different pathways of energetic phytomass production and transformation into fuel. There are approximately 22 million ha of land covered by terrestrial vegetation of which 10 million is arable land and one-fifth of this is of poor productivity. Waters (lakes, ponds, rivers) cover approximately 0.7 million ha. The technologies used for the production of energetic phytomass from various agricultural, forest and aquatic species tend to yield 20–25 t of dry matter for the terrestrial forms and 20–40 t of dry matter for the aquatic ones ( Pistia, Eichhornia, etc.); this represents a mean annual output of 2000–2500 l of ethanol per ha. The investigations performed so far suggest the main phytomass sources to be explored for obtaining the various forms of energy; e.g., for agricultural lands having a high fertility, the following species were shown to be important from an energy point of view: sugar beet (roots), sweet sorghum at the milk-dough stage, kernel maize, Jerusalem artichoke (tubers and green above-ground parts), potatoes (tubers), and oil rape. Some laticiferous plants are also being studied. On fertile soils in the southern irrigated areas, high yields of energetic phytomass were obtained in stubble crops with maize, sorghum × Sudan grass and grain sorghum. Special attention is paid to the utilization of the pulp which remains after sweet juice extraction from plants for alcohol fermentation. This pulp may be used as fresh forage or may be ensiled. Investigations are being conducted with a view to improving the fertility of poorly productive soils, which cannot be used for agricultural purposes at the present time. Species with a rapid growth, such as poplar, willow and osier are being grown on river meadows and in the Danube Delta. Studies aimed at the energy utilization of wood and plant wastes remaining after harvest (straw, cobs, stalks, branches) are also being conducted.