Integration in a depot‐based decentralized biorefinery system: Corn stover‐based cellulosic biofuel

Abstract

The current or “conventional” paradigm for producing process energy in a biorefinery processing cellulosic biomass is on‐site energy recovery through combustion of residual solids and biogas generated by the process. Excess electricity is then exported, resulting in large greenhouse gas (GHG) credits. However, this approach will cause lifecycle GHG emissions of biofuels to increase as more renewable energy sources (wind, solar, etc.) participate in grid‐electricity generation, and the GHG credits from displacing fossil fuel decrease. To overcome this drawback, a decentralized (depot‐based) biorefinery can be integrated with a coal‐fired power plant near a large urban area. In an integrated, decentralized, depot‐based biorefinery (IDB), the residual solids are co‐fired with coal either in the adjacent power plant or in coal‐fired boilers elsewhere to displace coal. An IDB system does not rely on indirect GHG credits through grid‐electricity displacement. In an IDB system, biogas from the wastewater treatment facility is also upgraded to biomethane and used as a transportation biofuel. The GHG savings per unit of cropland in the IDB systems (2.7–2.9 MgCO2/ha) are 1.5–1.6 fold greater than those in a conventional centralized system (1.7–1.8 MgCO2/ha). Importantly, the biofuel selling price in the IDBs is lower by 28–30 cents per gasoline‐equivalent liter than in the conventional centralized system. Furthermore, the total capital investment per annual biofuel volume in the IDB is much lower (by ~80%) than that in the conventional centralized system. Therefore, utilization of biomethane and residual solids in the IDB systems leads to much lower biofuel selling prices and significantly greater GHG savings per unit of cropland participating in the biorefinery system compared to the conventional centralized biorefineries.

Effects of Extractive Ammonia Pretreatment on the Ultrastructure and Glycan Composition of Corn Stover

“…Interest in this field has been increased markedly in the past two decades due to high fluctuation of petroleum prices and climate change concerns (Sarks et al, 2017). Overcoming biomass recalcitrance is a key factor for reducing the price of lignocellulosic-based fuels and chemicals so that they become more competitive with petroleum products (Himmel et al, 2007;da Costa Sousa et al, 2009;Kumar and Sani, 2018;Kim et al, 2019). Various physical, chemical, physicochemical, and biological pretreatment methods have been tested on different biomasses in order to improve enzymatic hydrolysis yields, with varying degrees of success.…”

Dynamic life-cycle carbon analysis for fast pyrolysis biofuel produced from pine residues: implications of carbon temporal effects

“…If the CHP plant generated any surplus electricity, it was assumed to be sold to the grid [33]. System expansion was used for this co-product electricity as a method recommended by ISO Standard 14044 to avoid allocation, this method also has been used in similar biorefineries [113][114][115]. The surplus electricity is assumed to displace U.S. average electricity mix [57].…”

Deciphering the initial products of coal during methanogenic bioconversion: Based on an untargeted metabolomics approach

“…Burning of coal as a fossil fuel has caused detrimental effects on the environment while utilization of clean energy biomethane leads to significantly great greenhouse gas credits savings (Kim et al, 2019). The generation of biomethane from the microbial conversion of coal in situ has spurred interests to explore new ways of using coal cleanly (Strąpoć et al, 2008(Strąpoć et al, , 2011.…”