Title: Biorefineries in the Siena Province (BISP)

Type: research project

Funding program: Reserach fellowship funded by the Province of Siena

Timeframe: 2010-2011

 

Objective.

This study presents a possible implementation of a second generation bioethanol production chain within the Province of Siena (Tuscany, Italy) by means of a biorefinery, and its consequences for the regional GHG balance in order to meet the European requirements for partial substitution of 10% bioethanol for gasoline by 2020. According to the GHG inventory of the Province of Siena, the transport sector represents the main contributor to the overall GHG emissions within the Province. A biorefinery project is hypothesized, fed by residual straw (from the local production of wheat, barley and oat) and residual geothermal heat (from local geothermal power plant) in order to produce bioethanol. The target of the production plant was about 8,200 tons/year of bioethanol, representing the amount needed to replace 10% of the gasoline consumed in 2008 in the Province of Siena.

About 37% of the territory of the Province of Siena is dedicated to agriculture. Firstly, the potential amount of residual biomass (straw from the foremost crop cultivations of the territory of the Province of Siena) is evaluated that could be converted into bioethanol. Then, the possible implementation of an integrated biorefinery within the territory of the Province of Siena is investigated by means of LCA analysis, including the total CO2eq released along the production chain of the bioethanol. Finally, the consequences of that production process, combined with the partial substitution of gasoline with bioethanol in the GHG balance of the Province of Siena, are evaluated. The results of the Life Cycle Assessment (LCA) of the entire production chain have been included within the GHG balance of the Province of Siena in order to assess the effect of this substitution. The emissions derived from the production chain have been added to the current gross CO2eq emissions, and the CO2eq avoided, thanks to the substitution of bioethanol, has been subtracted. Finally a roughly estimation of the payback period has been carried out.

Ecodynamics group and Environmental and Energy Agency of the Province of Siena (APEA) worked together for the development of the project.

 

Outcomes.

The main results of this paper are:

  1. the territory of the Province of Siena produces enough straw to implement the bioethanol production chain (38,000 tons/year of ethanol out of 147,000 tons/year of straw);
  2. the emissions deriving from the entire bioethanol production chain are about 601.51 kg CO2eq per ton of bioethanol produced (about 4,932 tons of CO2eq are the emissions associated to the production of 8,200 tons of bioethanol);
  3. the use of the produced bioethanol in Siena’s transport sector could bring about a reduction of 15,393 tons of CO2eq in emissions, equal to 6% of the net CO2eq emissions.
  4. The payback period for the biorefinery, have been estimated in 15-16 years if 30% of the investment could be covered by national or European incentives.

 fig1-bacino
Location of the hypothetical biorefinery and the municipalities that could be involved in the production chain (colored in grey).

fig2-diagramma
Flow diagram of the bioethanol production chain in the Province of Siena.

 

 

References.

- Patrizi et al; 2013: Environmental feasibility of partial substitution of gasoline with ethanol in the Province of Siena (Italy). Journal of Cleaner Production, 47, 388-395.

- Patrizi et al., 2015. Evaluation of the emergy investment needed for bioethanol production in a biorefinery using residual resources and energy. Journal of Cleaner Production, 96: 549-556.

 

Keywords: Biofuels, Biorefinery, Straw, Greenhouse gas emissions (GHG), Life Cycle Assessment (LCA), Geothermal heat

Methods: Life Cyclce Assessment, Emergy Evaluation

Principal Investigator @EG: Nicoletta Patrizi PhD