As part of its current assessment of the modalities of a long-term national transition to sustainable energy systems, the Netherlands Environmental Assessment Agency asked CE Delft to conduct an in-depth evaluation of the system option ‘Green Feedstocks’. For this purpose a literature study was carried out and interviews held with six people working ‘in the field’. The study provides insight into the approximate production costs and environmental burden associated with ‘biofeedstocks’, and compares these with the production costs and burden of competing, conventional petrochemical alternatives.
Based on current data, we conclude there are already plenty of technologies available and that in terms of technical feasibility a significant or even very substantial share of today’s chemical feedstocks could in principle be produced from biomass. The two main impediments to market introduction are cost price and unfamiliarity with the product on the part of potential customers. With cost prices sometimes 2 – 3 times higher than those of the conventional petrochemicals being replaced, these alternatives are often only implemented if the petrochemical in question has been banned because of its in-use environmental impact (lubricants, solvents, inks, paints) or in cases where an end-user is keen to promote a ‘green’ image (bioplastics). We found only a limited number of examples of biomass-based production being cheaper than production based on petrochemical feedstocks (ethanol, 1,3-propanediol).
The main advantages of biofeedstocks, in terms of the life-cycle environmental impact, are the lower toxicity of a range of products during usage (lubricants, solvents, inks, paints).
In many cases the environmental burden per unit product, in the form of greenhouse gas emissions, is only lower because a petrochemical feedstock has been substituted – and its fossil energy and carbon content therefore saved. However, biofeedstock production processes are often less energy-efficient than their petrochemical counterparts. One possible exception here is production of chemicals with a nitrogen atom.
Another issue is that cultivation of oilseed rape and other protein crops involves significant greenhouse gas emissions because of the need for substantial inputs of nitrogen fertiliser. Most oil and carbohydrate crops are perennials and do not have this drawback.
A third issue when it comes to using dedicated biofeedstock crops is that land requirements may have a major environmental impact if it is unspoilt nature that is being converted to cropland. It is therefore recommended to make maximum use of biomass waste streams, or otherwise crops with an as high as possible per-hectare yield of useful crop constituents (sugarcane, sugarbeet, palm oil).
What we also see in Europe is that the subsidies on using biomass for power generation and vehicle fuels have created an uneven playing field, with less priority being given to development of biofeedstocks and the cost of the raw materials for today’s biofeedstocks continually rising because of the massive market demand for these materials for subsidised application in the former two areas.
Given the above, our recommendations are as follows: