The UK government is looking into the opportunity of investing

1 Design and Professional Skills II (CENG201P) Coursework 2 – Sustainability To be submitted via Moodle by 9:00 am, February 14th Life Cycle Assessment of biodiesel production using different feedstocks The UK government is looking into the opportunity of investing in the biofuel sector for use in transportation. The Government has identified two alternate scenarios for the production of biodiesel using different feedstocks, and is interested in determining which is the best environmental option as well as the “hot-spots” in the life cycle of each production process. One scenario envisages importing soybean-based biodiesel from Brasil; whilst the other involves in-house production of biodiesel from microalgae. A brief description of the product systems is provided below. A simplified inventory for the two systems is included in a separate excel spreadsheet. It must be noted that because both systems have yet to be implemented for commercial production, the inventory refers to data obtained during laboratory and pilot scale development. Soybean-based biodiesel Soybeans are cultivated in a generic location in Brasil; this step requires fertilisers and herbicides to be applied on the field, and diesel to be consumed by agricultural machines. The soybeans are then harvested and soybean oil is extracted using a hexane solvent wash. Besides soybean oil, the extraction process also produces soybean meal, which is to be considered a by-product. The soybean oil contains some impurities, and is thus treated with sodium hydroxide in a refining process. Finally, the last step involves transesterification of the refined vegetable oil, where triglycerides react with methanol in the presence of sodium methoxide as catalyst, and hydrochloric acid to produce methyl ester, also known as biodiesel, and glycerine as by-product. This is sold in the market and is assumed to displace an equivalent amount of glycerine produced from an alternative production process that uses epichlorohydrin as feed. The produced biodiesel is then transported to a shipping port by rail and to UK by sea freight. It is assumed that the cultivation, milling, extraction and transesterification processes occur at the same site, and that energy and heat are supplied by an on-site Combined Heat and Power (CHP) plant. Inventory data are included in a separate excel spreadsheet. Microalgae-based biodiesel This scenario considers the cultivation of microalgae Chlorella Vulgaris in raceway, open ponds with freshwater, agitated by means of a paddlewheel. Cultivation requires fertiliser and carbon dioxide, which the microalgae absorb for photosynthesis and transform into biomass. Pond water containing microalgae is then pumped, filtrated, and dried to obtain a dry mass which is then sent to the extraction phase. Here, vegetable oil is extracted using a hexane solvent, producing Lipid-Extracted Algae (LEA) as by-product. Similar to the soybean scenario, the vegetable oil is transesterified with methanol in presence of sodium methoxide as a catalyst and hydrochloric acid, to obtain methyl ester, and glycerine as by-product, which is assumed to displace an equivalent amount of glycerine produced from an alternative production process that uses epichlorohydrin as feed (same as soybean scenario). Energy and heat are provided by the UK grid mix. Inventory data are included in a separate excel spreadsheet.2 Deliverables This study is to be performed in pairs of 2 students (team allocations can be found on Moodle) with sections a-c.i) done individually, one for each system, and the remaining sections done together. The report should outline the individual sections first, the soy-bean based scenario followed by the micro-algae based scenario, and then the group section. The assessment will be based on individual marks for sections a-c.i. and a group mark for the remaining sections. INDIVIDUAL SECTIONS: a. Scope of the study: i. Draw a simplified block flow diagram of the product system, soy-bean based or micro-algae based, including energy and material flows entering and leaving each block. ii. In preparation for a comparative analysis, define a functional unit of the system and draw a system boundary for the product system. [10] b. Life Cycle Impact Assessment: i. Calculate the amount of primary resources used and the amount of emissions released by your process per functional unit. ii. Calculate the impact per functional unit of the product system in terms of Global Warming Potential (GWP), Acidification Potential (AP) and Abiotic Depletion (AD). (All relevant impact factors are included at the end of the brief.) [20] (For the Impact Assessment phase the main report must include only the following: ï‚· Impacts (GWP, AP and AD) of each main aggregated life cycle step; ï‚· Total impacts (GWP, AP and AD) of each product systems; ï‚· An example of calculations of each deliverable (e.g. emission of CO2 and GWP). All calculations, including consumption of primary resources and amount of emissions of each step, have to be submitted in a separate document.) c. Life Cycle Interpretation: i. Perform a contribution analysis on the system showing the relative contribution of each step in the life cycle to the total impact, and comment on the hot-spots. (max 1/3 of a page) [10]3 GROUP SECTIONS: ii. Perform a comparative analysis of the two systems, using the impact of fossil fuelbased diesel production as reference benchmarks. iii. Comment and give recommendations based on the obtained results (max 1/3 of a page). [15] d. The LCA study currently looks exclusively at the production of biodiesel, i.e. cradle-to-gate. What other processes/stages would you consider to extend the boundaries to cradle-tograve? And how could they be important? (max 1/3 of a page). [15] e. Identify at least one other impact category that may be of particular interest for the investigated system products, and justify your choice. (max 1/3 of a page) [15] f. Sustainability is a broad concept encompassing three main areas: environment, economy and society. Assuming the UK Government decides to invest into either of the two scenarios, i.e. soybean-based biodiesel imported from Brazil or in-house produced microalgae-based biodiesel, how would such decision affect the other aspects of sustainability (economic and social)? (max 1/3 of a page) [15] ———— [100]

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