Reduced Local Emissions and Long-term Carbon Storage through Pyrolysis of Agricultural Waste and Application of Pyrolysis Char for Soil Improvement. (July 2017)

• Record Type: Journal Article
• Authors: Pröll, Tobias; Afif, Rafat Al; Schaffer, Sebastian; Pfeifer, Christoph
• Is Part Of: Energy procedia. Volume 114(2017)
• Page Start: 6057
• Page End: 6066
• Publication Date: 2017-07
• Subjects: Biomass -- Pyrolysis -- Biochar -- Soil -- Carbon storage -- Cotton; Power resources -- Congresses; Power resources -- Periodicals; Power resources; Conference proceedings; Periodicals; 333.7905
• DOI: 10.1016/j.egypro.2017.03.1742
• Languages: English
• ISSNs: 1876-6102

Abstract

Abstract: The direct storage of biologically stable pyrolysis char in soils is discussed as a low-tech below zero emission technology option with positive side-effects. A rotary kiln pyrolysis process, which has already been successfully applied at industrial scale before, is selected as the reference technology. Cotton stalks are considered as feed for the pyrolysis plant, representing a typical agricultural by-product with short rotation times. The plant efficiency is calculated for the case that the thermal energy that runs the pyrolysis process is provided by combustion of a part of the pyrolysis gas, while pyrolysis oil is provided as a product. The remaining pyrolysis gas powers a gas engine-based combined heat and power (CHP) island. 100% of fuel power fed with the biomass are distributed as follows (based on the lower heating value): 52% stay in the biochar, 13% in the pyrolysis oil, 10% are converted to electric power in the CHP plant, and, finally 15% are available as heat at a temperature span between forward and back flow of 100 °C/70 °C and may be used on-site for drying of agricultural products and pyrolysis feedstock. A rough comparison of the proposed process to biomass power generation substituting coal-fired power generation shows that the net effects on the carbon balance are comparable, but additional carbon-neutral energy streams are generated in the pyrolysis case.