Current Challenges in Commercially Producing Biofuels from Lignocellulosic Biomass

Abstract

Biofuels that are produced from biobased materials are a good alternative to petroleum based fuels. They offer several benefits to society and the environment. Producing second generation biofuels is even more challenging than producing first generation biofuels due the complexity of the biomass and issues related to producing, harvesting, and transporting less dense biomass to centralized biorefineries. In addition to this logistic challenge, other challenges with respect to processing steps in converting biomass to liquid transportation fuel like pretreatment, hydrolysis, microbial fermentation, and fuel separation still exist and are discussed in this review. The possible coproducts that could be produced in the biorefinery and their importance to reduce the processing cost of biofuel are discussed. About $1 billion was spent in the year 2012 by the government agencies in US to meet the mandate to replace 30% existing liquid transportation fuels by 2022 which is 36 billion gallons/year. Other countries in the world have set their own targets to replace petroleum fuel by biofuels. Because of the challenges listed in this review and lack of government policies to create the demand for biofuels, it may take more time for the lignocellulosic biofuels to hit the market place than previously projected.

Second-generation bioethanol from industrial wood waste of South American species

“…Temperature and LSR mainly govern the thermal energy consumption in chemical pretreatments, so the reduction of these parameters is critical for the increase of their energy efficiency (Balan, 2014;Kang et al, 2014). The pretreatments with IL are carried out at temperatures below 100°C but require LSR of 10 to 20 (Tian et al, 2016).…”

“…The performance of different pretreatments at varied LSR was studied in several works (Saska and Ozer, 1995 The production of multiple products is key to have competitive production cost against the first-generation biofuels and that depends on the pretreatment processes. Several high-value products can be produced through the secondgeneration biorefineries to reduce the overall processing cost of biofuels (Stephen et al, 2012;Balan, 2014). Lignin is an aromatic polymer usually used in the pulp and paper industry to generate energy (heat and power).…”

“…The United States has set forth plans to produce 60 billion L of second-generation biofuel, i.e., about 20% of its liquid transportation fuel, by the year 2022. These biofuel policies have driven the second-generation biofuel development (Eisentraut, 2010;Balan, 2014). North America, especially the United States, has been an outstanding leader in cellulosic ethanol production (Griffin et al, 2016).…”

Construction of recombinant Yarrowia lipolytica and its application in bio-transformation of lignocellulose

“…1 There are about 180 billion tons of biomass both above ground and in the soil, and an additional 40 million tons in the oceans. 2 These resources are widely used in stockbreeding, energy, biomaterials, chemicals, and other fields.…”

Yarrowia lipolytica as an Oleaginous Cell Factory Platform for Production of Fatty Acid-Based Biofuel and Bioproducts

“…Recently, the microbial production of oil and oil-based bioproducts from renewable sources such as lignocellulosic biomass has received attention because they are abundant and low cost. However, the economically feasible production of cellulosic lipid has been hampered by the lack of systematic management for food waste, agro-, forest-, industrial process-, and microbial biomass residues; the lack of highly dedicated technologies; inadequate cultivation of energy crops in marginal lands; the shortage of highly engineered microbial strains for industrial application; the inadequate expansion of valuable co-product; potential environmental consequences (Yousuf, 2012;Chung, 2013;Balan, 2014). However, some of these issues can be addressed by systematically cultivating high-yielding crops, applying tailored technologies and genetically engineering plant and inhibitor-tolerant microbial strains (Pu et al, 2011).…”